1 /* -*- mode: C; c-file-style: "gnu" -*- */ 2 /* dbus-connection.c DBusConnection object 3 * 4 * Copyright (C) 2002-2006 Red Hat Inc. 5 * 6 * Licensed under the Academic Free License version 2.1 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23 24 #include <config.h> 25 #include "dbus-shared.h" 26 #include "dbus-connection.h" 27 #include "dbus-list.h" 28 #include "dbus-timeout.h" 29 #include "dbus-transport.h" 30 #include "dbus-watch.h" 31 #include "dbus-connection-internal.h" 32 #include "dbus-pending-call-internal.h" 33 #include "dbus-list.h" 34 #include "dbus-hash.h" 35 #include "dbus-message-internal.h" 36 #include "dbus-threads.h" 37 #include "dbus-protocol.h" 38 #include "dbus-dataslot.h" 39 #include "dbus-string.h" 40 #include "dbus-pending-call.h" 41 #include "dbus-object-tree.h" 42 #include "dbus-threads-internal.h" 43 #include "dbus-bus.h" 44 45 #ifdef DBUS_DISABLE_CHECKS 46 #define TOOK_LOCK_CHECK(connection) 47 #define RELEASING_LOCK_CHECK(connection) 48 #define HAVE_LOCK_CHECK(connection) 49 #else 50 #define TOOK_LOCK_CHECK(connection) do { \ 51 _dbus_assert (!(connection)->have_connection_lock); \ 52 (connection)->have_connection_lock = TRUE; \ 53 } while (0) 54 #define RELEASING_LOCK_CHECK(connection) do { \ 55 _dbus_assert ((connection)->have_connection_lock); \ 56 (connection)->have_connection_lock = FALSE; \ 57 } while (0) 58 #define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock) 59 /* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */ 60 #endif 61 62 #define TRACE_LOCKS 0 63 64 #define CONNECTION_LOCK(connection) do { \ 65 if (TRACE_LOCKS) { _dbus_verbose (" LOCK: %s\n", _DBUS_FUNCTION_NAME); } \ 66 _dbus_mutex_lock ((connection)->mutex); \ 67 TOOK_LOCK_CHECK (connection); \ 68 } while (0) 69 70 #define CONNECTION_UNLOCK(connection) do { \ 71 if (TRACE_LOCKS) { _dbus_verbose (" UNLOCK: %s\n", _DBUS_FUNCTION_NAME); } \ 72 RELEASING_LOCK_CHECK (connection); \ 73 _dbus_mutex_unlock ((connection)->mutex); \ 74 } while (0) 75 76 #define DISPATCH_STATUS_NAME(s) \ 77 ((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \ 78 (s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \ 79 (s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \ 80 "???") 81 82 /** 83 * @defgroup DBusConnection DBusConnection 84 * @ingroup DBus 85 * @brief Connection to another application 86 * 87 * A DBusConnection represents a connection to another 88 * application. Messages can be sent and received via this connection. 89 * The other application may be a message bus; for convenience, the 90 * function dbus_bus_get() is provided to automatically open a 91 * connection to the well-known message buses. 92 * 93 * In brief a DBusConnection is a message queue associated with some 94 * message transport mechanism such as a socket. The connection 95 * maintains a queue of incoming messages and a queue of outgoing 96 * messages. 97 * 98 * Several functions use the following terms: 99 * <ul> 100 * <li><b>read</b> means to fill the incoming message queue by reading from the socket</li> 101 * <li><b>write</b> means to drain the outgoing queue by writing to the socket</li> 102 * <li><b>dispatch</b> means to drain the incoming queue by invoking application-provided message handlers</li> 103 * </ul> 104 * 105 * The function dbus_connection_read_write_dispatch() for example does all 106 * three of these things, offering a simple alternative to a main loop. 107 * 108 * In an application with a main loop, the read/write/dispatch 109 * operations are usually separate. 110 * 111 * The connection provides #DBusWatch and #DBusTimeout objects to 112 * the main loop. These are used to know when reading, writing, or 113 * dispatching should be performed. 114 * 115 * Incoming messages are processed 116 * by calling dbus_connection_dispatch(). dbus_connection_dispatch() 117 * runs any handlers registered for the topmost message in the message 118 * queue, then discards the message, then returns. 119 * 120 * dbus_connection_get_dispatch_status() indicates whether 121 * messages are currently in the queue that need dispatching. 122 * dbus_connection_set_dispatch_status_function() allows 123 * you to set a function to be used to monitor the dispatch status. 124 * 125 * If you're using GLib or Qt add-on libraries for D-Bus, there are 126 * special convenience APIs in those libraries that hide 127 * all the details of dispatch and watch/timeout monitoring. 128 * For example, dbus_connection_setup_with_g_main(). 129 * 130 * If you aren't using these add-on libraries, but want to process 131 * messages asynchronously, you must manually call 132 * dbus_connection_set_dispatch_status_function(), 133 * dbus_connection_set_watch_functions(), 134 * dbus_connection_set_timeout_functions() providing appropriate 135 * functions to integrate the connection with your application's main 136 * loop. This can be tricky to get right; main loops are not simple. 137 * 138 * If you don't need to be asynchronous, you can ignore #DBusWatch, 139 * #DBusTimeout, and dbus_connection_dispatch(). Instead, 140 * dbus_connection_read_write_dispatch() can be used. 141 * 142 * Or, in <em>very</em> simple applications, 143 * dbus_connection_pop_message() may be all you need, allowing you to 144 * avoid setting up any handler functions (see 145 * dbus_connection_add_filter(), 146 * dbus_connection_register_object_path() for more on handlers). 147 * 148 * When you use dbus_connection_send() or one of its variants to send 149 * a message, the message is added to the outgoing queue. It's 150 * actually written to the network later; either in 151 * dbus_watch_handle() invoked by your main loop, or in 152 * dbus_connection_flush() which blocks until it can write out the 153 * entire outgoing queue. The GLib/Qt add-on libraries again 154 * handle the details here for you by setting up watch functions. 155 * 156 * When a connection is disconnected, you are guaranteed to get a 157 * signal "Disconnected" from the interface 158 * #DBUS_INTERFACE_LOCAL, path 159 * #DBUS_PATH_LOCAL. 160 * 161 * You may not drop the last reference to a #DBusConnection 162 * until that connection has been disconnected. 163 * 164 * You may dispatch the unprocessed incoming message queue even if the 165 * connection is disconnected. However, "Disconnected" will always be 166 * the last message in the queue (obviously no messages are received 167 * after disconnection). 168 * 169 * After calling dbus_threads_init(), #DBusConnection has thread 170 * locks and drops them when invoking user callbacks, so in general is 171 * transparently threadsafe. However, #DBusMessage does NOT have 172 * thread locks; you must not send the same message to multiple 173 * #DBusConnection if those connections will be used from different threads, 174 * for example. 175 * 176 * Also, if you dispatch or pop messages from multiple threads, it 177 * may work in the sense that it won't crash, but it's tough to imagine 178 * sane results; it will be completely unpredictable which messages 179 * go to which threads. 180 * 181 * It's recommended to dispatch from a single thread. 182 * 183 * The most useful function to call from multiple threads at once 184 * is dbus_connection_send_with_reply_and_block(). That is, 185 * multiple threads can make method calls at the same time. 186 * 187 * If you aren't using threads, you can use a main loop and 188 * dbus_pending_call_set_notify() to achieve a similar result. 189 */ 190 191 /** 192 * @defgroup DBusConnectionInternals DBusConnection implementation details 193 * @ingroup DBusInternals 194 * @brief Implementation details of DBusConnection 195 * 196 * @{ 197 */ 198 199 /** 200 * Internal struct representing a message filter function 201 */ 202 typedef struct DBusMessageFilter DBusMessageFilter; 203 204 /** 205 * Internal struct representing a message filter function 206 */ 207 struct DBusMessageFilter 208 { 209 DBusAtomic refcount; /**< Reference count */ 210 DBusHandleMessageFunction function; /**< Function to call to filter */ 211 void *user_data; /**< User data for the function */ 212 DBusFreeFunction free_user_data_function; /**< Function to free the user data */ 213 }; 214 215 216 /** 217 * Internals of DBusPreallocatedSend 218 */ 219 struct DBusPreallocatedSend 220 { 221 DBusConnection *connection; /**< Connection we'd send the message to */ 222 DBusList *queue_link; /**< Preallocated link in the queue */ 223 DBusList *counter_link; /**< Preallocated link in the resource counter */ 224 }; 225 226 static dbus_bool_t _dbus_modify_sigpipe = TRUE; 227 228 /** 229 * Implementation details of DBusConnection. All fields are private. 230 */ 231 struct DBusConnection 232 { 233 DBusAtomic refcount; /**< Reference count. */ 234 235 DBusMutex *mutex; /**< Lock on the entire DBusConnection */ 236 237 DBusMutex *dispatch_mutex; /**< Protects dispatch_acquired */ 238 DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */ 239 DBusMutex *io_path_mutex; /**< Protects io_path_acquired */ 240 DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */ 241 242 DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */ 243 DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */ 244 245 DBusMessage *message_borrowed; /**< Filled in if the first incoming message has been borrowed; 246 * dispatch_acquired will be set by the borrower 247 */ 248 249 int n_outgoing; /**< Length of outgoing queue. */ 250 int n_incoming; /**< Length of incoming queue. */ 251 252 DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */ 253 254 DBusTransport *transport; /**< Object that sends/receives messages over network. */ 255 DBusWatchList *watches; /**< Stores active watches. */ 256 DBusTimeoutList *timeouts; /**< Stores active timeouts. */ 257 258 DBusList *filter_list; /**< List of filters. */ 259 260 DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */ 261 262 DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */ 263 264 dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */ 265 DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */ 266 267 DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */ 268 void *wakeup_main_data; /**< Application data for wakeup_main_function */ 269 DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */ 270 271 DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */ 272 void *dispatch_status_data; /**< Application data for dispatch_status_function */ 273 DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */ 274 275 DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */ 276 277 DBusList *link_cache; /**< A cache of linked list links to prevent contention 278 * for the global linked list mempool lock 279 */ 280 DBusObjectTree *objects; /**< Object path handlers registered with this connection */ 281 282 char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */ 283 284 /* These two MUST be bools and not bitfields, because they are protected by a separate lock 285 * from connection->mutex and all bitfields in a word have to be read/written together. 286 * So you can't have a different lock for different bitfields in the same word. 287 */ 288 dbus_bool_t dispatch_acquired; /**< Someone has dispatch path (can drain incoming queue) */ 289 dbus_bool_t io_path_acquired; /**< Someone has transport io path (can use the transport to read/write messages) */ 290 291 unsigned int shareable : 1; /**< #TRUE if libdbus owns a reference to the connection and can return it from dbus_connection_open() more than once */ 292 293 unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */ 294 295 unsigned int route_peer_messages : 1; /**< If #TRUE, if org.freedesktop.DBus.Peer messages have a bus name, don't handle them automatically */ 296 297 unsigned int disconnected_message_arrived : 1; /**< We popped or are dispatching the disconnected message. 298 * if the disconnect_message_link is NULL then we queued it, but 299 * this flag is whether it got to the head of the queue. 300 */ 301 unsigned int disconnected_message_processed : 1; /**< We did our default handling of the disconnected message, 302 * such as closing the connection. 303 */ 304 305 #ifndef DBUS_DISABLE_CHECKS 306 unsigned int have_connection_lock : 1; /**< Used to check locking */ 307 #endif 308 309 #ifndef DBUS_DISABLE_CHECKS 310 int generation; /**< _dbus_current_generation that should correspond to this connection */ 311 #endif 312 }; 313 314 static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection); 315 static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, 316 DBusDispatchStatus new_status); 317 static void _dbus_connection_last_unref (DBusConnection *connection); 318 static void _dbus_connection_acquire_dispatch (DBusConnection *connection); 319 static void _dbus_connection_release_dispatch (DBusConnection *connection); 320 static DBusDispatchStatus _dbus_connection_flush_unlocked (DBusConnection *connection); 321 static void _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection); 322 static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection); 323 static dbus_bool_t _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection, 324 dbus_uint32_t client_serial); 325 326 static DBusMessageFilter * 327 _dbus_message_filter_ref (DBusMessageFilter *filter) 328 { 329 _dbus_assert (filter->refcount.value > 0); 330 _dbus_atomic_inc (&filter->refcount); 331 332 return filter; 333 } 334 335 static void 336 _dbus_message_filter_unref (DBusMessageFilter *filter) 337 { 338 _dbus_assert (filter->refcount.value > 0); 339 340 if (_dbus_atomic_dec (&filter->refcount) == 1) 341 { 342 if (filter->free_user_data_function) 343 (* filter->free_user_data_function) (filter->user_data); 344 345 dbus_free (filter); 346 } 347 } 348 349 /** 350 * Acquires the connection lock. 351 * 352 * @param connection the connection. 353 */ 354 void 355 _dbus_connection_lock (DBusConnection *connection) 356 { 357 CONNECTION_LOCK (connection); 358 } 359 360 /** 361 * Releases the connection lock. 362 * 363 * @param connection the connection. 364 */ 365 void 366 _dbus_connection_unlock (DBusConnection *connection) 367 { 368 CONNECTION_UNLOCK (connection); 369 } 370 371 /** 372 * Wakes up the main loop if it is sleeping 373 * Needed if we're e.g. queueing outgoing messages 374 * on a thread while the mainloop sleeps. 375 * 376 * @param connection the connection. 377 */ 378 static void 379 _dbus_connection_wakeup_mainloop (DBusConnection *connection) 380 { 381 if (connection->wakeup_main_function) 382 (*connection->wakeup_main_function) (connection->wakeup_main_data); 383 } 384 385 #ifdef DBUS_BUILD_TESTS 386 /* For now this function isn't used */ 387 /** 388 * Adds a message to the incoming message queue, returning #FALSE 389 * if there's insufficient memory to queue the message. 390 * Does not take over refcount of the message. 391 * 392 * @param connection the connection. 393 * @param message the message to queue. 394 * @returns #TRUE on success. 395 */ 396 dbus_bool_t 397 _dbus_connection_queue_received_message (DBusConnection *connection, 398 DBusMessage *message) 399 { 400 DBusList *link; 401 402 link = _dbus_list_alloc_link (message); 403 if (link == NULL) 404 return FALSE; 405 406 dbus_message_ref (message); 407 _dbus_connection_queue_received_message_link (connection, link); 408 409 return TRUE; 410 } 411 412 /** 413 * Gets the locks so we can examine them 414 * 415 * @param connection the connection. 416 * @param mutex_loc return for the location of the main mutex pointer 417 * @param dispatch_mutex_loc return location of the dispatch mutex pointer 418 * @param io_path_mutex_loc return location of the io_path mutex pointer 419 * @param dispatch_cond_loc return location of the dispatch conditional 420 * variable pointer 421 * @param io_path_cond_loc return location of the io_path conditional 422 * variable pointer 423 */ 424 void 425 _dbus_connection_test_get_locks (DBusConnection *connection, 426 DBusMutex **mutex_loc, 427 DBusMutex **dispatch_mutex_loc, 428 DBusMutex **io_path_mutex_loc, 429 DBusCondVar **dispatch_cond_loc, 430 DBusCondVar **io_path_cond_loc) 431 { 432 *mutex_loc = connection->mutex; 433 *dispatch_mutex_loc = connection->dispatch_mutex; 434 *io_path_mutex_loc = connection->io_path_mutex; 435 *dispatch_cond_loc = connection->dispatch_cond; 436 *io_path_cond_loc = connection->io_path_cond; 437 } 438 #endif 439 440 /** 441 * Adds a message-containing list link to the incoming message queue, 442 * taking ownership of the link and the message's current refcount. 443 * Cannot fail due to lack of memory. 444 * 445 * @param connection the connection. 446 * @param link the message link to queue. 447 */ 448 void 449 _dbus_connection_queue_received_message_link (DBusConnection *connection, 450 DBusList *link) 451 { 452 DBusPendingCall *pending; 453 dbus_int32_t reply_serial; 454 DBusMessage *message; 455 456 _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport)); 457 458 _dbus_list_append_link (&connection->incoming_messages, 459 link); 460 message = link->data; 461 462 /* If this is a reply we're waiting on, remove timeout for it */ 463 reply_serial = dbus_message_get_reply_serial (message); 464 if (reply_serial != -1) 465 { 466 pending = _dbus_hash_table_lookup_int (connection->pending_replies, 467 reply_serial); 468 if (pending != NULL) 469 { 470 if (_dbus_pending_call_is_timeout_added_unlocked (pending)) 471 _dbus_connection_remove_timeout_unlocked (connection, 472 _dbus_pending_call_get_timeout_unlocked (pending)); 473 474 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); 475 } 476 } 477 478 479 480 connection->n_incoming += 1; 481 482 _dbus_connection_wakeup_mainloop (connection); 483 484 _dbus_verbose ("Message %p (%d %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n", 485 message, 486 dbus_message_get_type (message), 487 dbus_message_get_path (message) ? 488 dbus_message_get_path (message) : 489 "no path", 490 dbus_message_get_interface (message) ? 491 dbus_message_get_interface (message) : 492 "no interface", 493 dbus_message_get_member (message) ? 494 dbus_message_get_member (message) : 495 "no member", 496 dbus_message_get_signature (message), 497 dbus_message_get_reply_serial (message), 498 connection, 499 connection->n_incoming);} 500 501 /** 502 * Adds a link + message to the incoming message queue. 503 * Can't fail. Takes ownership of both link and message. 504 * 505 * @param connection the connection. 506 * @param link the list node and message to queue. 507 * 508 */ 509 void 510 _dbus_connection_queue_synthesized_message_link (DBusConnection *connection, 511 DBusList *link) 512 { 513 HAVE_LOCK_CHECK (connection); 514 515 _dbus_list_append_link (&connection->incoming_messages, link); 516 517 connection->n_incoming += 1; 518 519 _dbus_connection_wakeup_mainloop (connection); 520 521 _dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n", 522 link->data, connection, connection->n_incoming); 523 } 524 525 526 /** 527 * Checks whether there are messages in the outgoing message queue. 528 * Called with connection lock held. 529 * 530 * @param connection the connection. 531 * @returns #TRUE if the outgoing queue is non-empty. 532 */ 533 dbus_bool_t 534 _dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection) 535 { 536 HAVE_LOCK_CHECK (connection); 537 return connection->outgoing_messages != NULL; 538 } 539 540 /** 541 * Checks whether there are messages in the outgoing message queue. 542 * Use dbus_connection_flush() to block until all outgoing 543 * messages have been written to the underlying transport 544 * (such as a socket). 545 * 546 * @param connection the connection. 547 * @returns #TRUE if the outgoing queue is non-empty. 548 */ 549 dbus_bool_t 550 dbus_connection_has_messages_to_send (DBusConnection *connection) 551 { 552 dbus_bool_t v; 553 554 _dbus_return_val_if_fail (connection != NULL, FALSE); 555 556 CONNECTION_LOCK (connection); 557 v = _dbus_connection_has_messages_to_send_unlocked (connection); 558 CONNECTION_UNLOCK (connection); 559 560 return v; 561 } 562 563 /** 564 * Gets the next outgoing message. The message remains in the 565 * queue, and the caller does not own a reference to it. 566 * 567 * @param connection the connection. 568 * @returns the message to be sent. 569 */ 570 DBusMessage* 571 _dbus_connection_get_message_to_send (DBusConnection *connection) 572 { 573 HAVE_LOCK_CHECK (connection); 574 575 return _dbus_list_get_last (&connection->outgoing_messages); 576 } 577 578 /** 579 * Notifies the connection that a message has been sent, so the 580 * message can be removed from the outgoing queue. 581 * Called with the connection lock held. 582 * 583 * @param connection the connection. 584 * @param message the message that was sent. 585 */ 586 void 587 _dbus_connection_message_sent (DBusConnection *connection, 588 DBusMessage *message) 589 { 590 DBusList *link; 591 592 HAVE_LOCK_CHECK (connection); 593 594 /* This can be called before we even complete authentication, since 595 * it's called on disconnect to clean up the outgoing queue. 596 * It's also called as we successfully send each message. 597 */ 598 599 link = _dbus_list_get_last_link (&connection->outgoing_messages); 600 _dbus_assert (link != NULL); 601 _dbus_assert (link->data == message); 602 603 /* Save this link in the link cache */ 604 _dbus_list_unlink (&connection->outgoing_messages, 605 link); 606 _dbus_list_prepend_link (&connection->link_cache, link); 607 608 connection->n_outgoing -= 1; 609 610 _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from outgoing queue %p, %d left to send\n", 611 message, 612 dbus_message_get_type (message), 613 dbus_message_get_path (message) ? 614 dbus_message_get_path (message) : 615 "no path", 616 dbus_message_get_interface (message) ? 617 dbus_message_get_interface (message) : 618 "no interface", 619 dbus_message_get_member (message) ? 620 dbus_message_get_member (message) : 621 "no member", 622 dbus_message_get_signature (message), 623 connection, connection->n_outgoing); 624 625 /* Save this link in the link cache also */ 626 _dbus_message_remove_size_counter (message, connection->outgoing_counter, 627 &link); 628 _dbus_list_prepend_link (&connection->link_cache, link); 629 630 dbus_message_unref (message); 631 } 632 633 /** Function to be called in protected_change_watch() with refcount held */ 634 typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list, 635 DBusWatch *watch); 636 /** Function to be called in protected_change_watch() with refcount held */ 637 typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list, 638 DBusWatch *watch); 639 /** Function to be called in protected_change_watch() with refcount held */ 640 typedef void (* DBusWatchToggleFunction) (DBusWatchList *list, 641 DBusWatch *watch, 642 dbus_bool_t enabled); 643 644 static dbus_bool_t 645 protected_change_watch (DBusConnection *connection, 646 DBusWatch *watch, 647 DBusWatchAddFunction add_function, 648 DBusWatchRemoveFunction remove_function, 649 DBusWatchToggleFunction toggle_function, 650 dbus_bool_t enabled) 651 { 652 DBusWatchList *watches; 653 dbus_bool_t retval; 654 655 HAVE_LOCK_CHECK (connection); 656 657 /* This isn't really safe or reasonable; a better pattern is the "do everything, then 658 * drop lock and call out" one; but it has to be propagated up through all callers 659 */ 660 661 watches = connection->watches; 662 if (watches) 663 { 664 connection->watches = NULL; 665 _dbus_connection_ref_unlocked (connection); 666 CONNECTION_UNLOCK (connection); 667 668 if (add_function) 669 retval = (* add_function) (watches, watch); 670 else if (remove_function) 671 { 672 retval = TRUE; 673 (* remove_function) (watches, watch); 674 } 675 else 676 { 677 retval = TRUE; 678 (* toggle_function) (watches, watch, enabled); 679 } 680 681 CONNECTION_LOCK (connection); 682 connection->watches = watches; 683 _dbus_connection_unref_unlocked (connection); 684 685 return retval; 686 } 687 else 688 return FALSE; 689 } 690 691 692 /** 693 * Adds a watch using the connection's DBusAddWatchFunction if 694 * available. Otherwise records the watch to be added when said 695 * function is available. Also re-adds the watch if the 696 * DBusAddWatchFunction changes. May fail due to lack of memory. 697 * Connection lock should be held when calling this. 698 * 699 * @param connection the connection. 700 * @param watch the watch to add. 701 * @returns #TRUE on success. 702 */ 703 dbus_bool_t 704 _dbus_connection_add_watch_unlocked (DBusConnection *connection, 705 DBusWatch *watch) 706 { 707 return protected_change_watch (connection, watch, 708 _dbus_watch_list_add_watch, 709 NULL, NULL, FALSE); 710 } 711 712 /** 713 * Removes a watch using the connection's DBusRemoveWatchFunction 714 * if available. It's an error to call this function on a watch 715 * that was not previously added. 716 * Connection lock should be held when calling this. 717 * 718 * @param connection the connection. 719 * @param watch the watch to remove. 720 */ 721 void 722 _dbus_connection_remove_watch_unlocked (DBusConnection *connection, 723 DBusWatch *watch) 724 { 725 protected_change_watch (connection, watch, 726 NULL, 727 _dbus_watch_list_remove_watch, 728 NULL, FALSE); 729 } 730 731 /** 732 * Toggles a watch and notifies app via connection's 733 * DBusWatchToggledFunction if available. It's an error to call this 734 * function on a watch that was not previously added. 735 * Connection lock should be held when calling this. 736 * 737 * @param connection the connection. 738 * @param watch the watch to toggle. 739 * @param enabled whether to enable or disable 740 */ 741 void 742 _dbus_connection_toggle_watch_unlocked (DBusConnection *connection, 743 DBusWatch *watch, 744 dbus_bool_t enabled) 745 { 746 _dbus_assert (watch != NULL); 747 748 protected_change_watch (connection, watch, 749 NULL, NULL, 750 _dbus_watch_list_toggle_watch, 751 enabled); 752 } 753 754 /** Function to be called in protected_change_timeout() with refcount held */ 755 typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list, 756 DBusTimeout *timeout); 757 /** Function to be called in protected_change_timeout() with refcount held */ 758 typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list, 759 DBusTimeout *timeout); 760 /** Function to be called in protected_change_timeout() with refcount held */ 761 typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list, 762 DBusTimeout *timeout, 763 dbus_bool_t enabled); 764 765 static dbus_bool_t 766 protected_change_timeout (DBusConnection *connection, 767 DBusTimeout *timeout, 768 DBusTimeoutAddFunction add_function, 769 DBusTimeoutRemoveFunction remove_function, 770 DBusTimeoutToggleFunction toggle_function, 771 dbus_bool_t enabled) 772 { 773 DBusTimeoutList *timeouts; 774 dbus_bool_t retval; 775 776 HAVE_LOCK_CHECK (connection); 777 778 /* This isn't really safe or reasonable; a better pattern is the "do everything, then 779 * drop lock and call out" one; but it has to be propagated up through all callers 780 */ 781 782 timeouts = connection->timeouts; 783 if (timeouts) 784 { 785 connection->timeouts = NULL; 786 _dbus_connection_ref_unlocked (connection); 787 CONNECTION_UNLOCK (connection); 788 789 if (add_function) 790 retval = (* add_function) (timeouts, timeout); 791 else if (remove_function) 792 { 793 retval = TRUE; 794 (* remove_function) (timeouts, timeout); 795 } 796 else 797 { 798 retval = TRUE; 799 (* toggle_function) (timeouts, timeout, enabled); 800 } 801 802 CONNECTION_LOCK (connection); 803 connection->timeouts = timeouts; 804 _dbus_connection_unref_unlocked (connection); 805 806 return retval; 807 } 808 else 809 return FALSE; 810 } 811 812 /** 813 * Adds a timeout using the connection's DBusAddTimeoutFunction if 814 * available. Otherwise records the timeout to be added when said 815 * function is available. Also re-adds the timeout if the 816 * DBusAddTimeoutFunction changes. May fail due to lack of memory. 817 * The timeout will fire repeatedly until removed. 818 * Connection lock should be held when calling this. 819 * 820 * @param connection the connection. 821 * @param timeout the timeout to add. 822 * @returns #TRUE on success. 823 */ 824 dbus_bool_t 825 _dbus_connection_add_timeout_unlocked (DBusConnection *connection, 826 DBusTimeout *timeout) 827 { 828 return protected_change_timeout (connection, timeout, 829 _dbus_timeout_list_add_timeout, 830 NULL, NULL, FALSE); 831 } 832 833 /** 834 * Removes a timeout using the connection's DBusRemoveTimeoutFunction 835 * if available. It's an error to call this function on a timeout 836 * that was not previously added. 837 * Connection lock should be held when calling this. 838 * 839 * @param connection the connection. 840 * @param timeout the timeout to remove. 841 */ 842 void 843 _dbus_connection_remove_timeout_unlocked (DBusConnection *connection, 844 DBusTimeout *timeout) 845 { 846 protected_change_timeout (connection, timeout, 847 NULL, 848 _dbus_timeout_list_remove_timeout, 849 NULL, FALSE); 850 } 851 852 /** 853 * Toggles a timeout and notifies app via connection's 854 * DBusTimeoutToggledFunction if available. It's an error to call this 855 * function on a timeout that was not previously added. 856 * Connection lock should be held when calling this. 857 * 858 * @param connection the connection. 859 * @param timeout the timeout to toggle. 860 * @param enabled whether to enable or disable 861 */ 862 void 863 _dbus_connection_toggle_timeout_unlocked (DBusConnection *connection, 864 DBusTimeout *timeout, 865 dbus_bool_t enabled) 866 { 867 protected_change_timeout (connection, timeout, 868 NULL, NULL, 869 _dbus_timeout_list_toggle_timeout, 870 enabled); 871 } 872 873 static dbus_bool_t 874 _dbus_connection_attach_pending_call_unlocked (DBusConnection *connection, 875 DBusPendingCall *pending) 876 { 877 dbus_uint32_t reply_serial; 878 DBusTimeout *timeout; 879 880 HAVE_LOCK_CHECK (connection); 881 882 reply_serial = _dbus_pending_call_get_reply_serial_unlocked (pending); 883 884 _dbus_assert (reply_serial != 0); 885 886 timeout = _dbus_pending_call_get_timeout_unlocked (pending); 887 888 if (!_dbus_connection_add_timeout_unlocked (connection, timeout)) 889 return FALSE; 890 891 if (!_dbus_hash_table_insert_int (connection->pending_replies, 892 reply_serial, 893 pending)) 894 { 895 _dbus_connection_remove_timeout_unlocked (connection, timeout); 896 897 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); 898 HAVE_LOCK_CHECK (connection); 899 return FALSE; 900 } 901 902 _dbus_pending_call_set_timeout_added_unlocked (pending, TRUE); 903 904 _dbus_pending_call_ref_unlocked (pending); 905 906 HAVE_LOCK_CHECK (connection); 907 908 return TRUE; 909 } 910 911 static void 912 free_pending_call_on_hash_removal (void *data) 913 { 914 DBusPendingCall *pending; 915 DBusConnection *connection; 916 917 if (data == NULL) 918 return; 919 920 pending = data; 921 922 connection = _dbus_pending_call_get_connection_unlocked (pending); 923 924 HAVE_LOCK_CHECK (connection); 925 926 if (_dbus_pending_call_is_timeout_added_unlocked (pending)) 927 { 928 _dbus_connection_remove_timeout_unlocked (connection, 929 _dbus_pending_call_get_timeout_unlocked (pending)); 930 931 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); 932 } 933 934 /* FIXME 1.0? this is sort of dangerous and undesirable to drop the lock 935 * here, but the pending call finalizer could in principle call out to 936 * application code so we pretty much have to... some larger code reorg 937 * might be needed. 938 */ 939 _dbus_connection_ref_unlocked (connection); 940 _dbus_pending_call_unref_and_unlock (pending); 941 CONNECTION_LOCK (connection); 942 _dbus_connection_unref_unlocked (connection); 943 } 944 945 static void 946 _dbus_connection_detach_pending_call_unlocked (DBusConnection *connection, 947 DBusPendingCall *pending) 948 { 949 /* This ends up unlocking to call the pending call finalizer, which is unexpected to 950 * say the least. 951 */ 952 _dbus_hash_table_remove_int (connection->pending_replies, 953 _dbus_pending_call_get_reply_serial_unlocked (pending)); 954 } 955 956 static void 957 _dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection, 958 DBusPendingCall *pending) 959 { 960 /* The idea here is to avoid finalizing the pending call 961 * with the lock held, since there's a destroy notifier 962 * in pending call that goes out to application code. 963 * 964 * There's an extra unlock inside the hash table 965 * "free pending call" function FIXME... 966 */ 967 _dbus_pending_call_ref_unlocked (pending); 968 _dbus_hash_table_remove_int (connection->pending_replies, 969 _dbus_pending_call_get_reply_serial_unlocked (pending)); 970 _dbus_pending_call_unref_and_unlock (pending); 971 } 972 973 /** 974 * Removes a pending call from the connection, such that 975 * the pending reply will be ignored. May drop the last 976 * reference to the pending call. 977 * 978 * @param connection the connection 979 * @param pending the pending call 980 */ 981 void 982 _dbus_connection_remove_pending_call (DBusConnection *connection, 983 DBusPendingCall *pending) 984 { 985 CONNECTION_LOCK (connection); 986 _dbus_connection_detach_pending_call_and_unlock (connection, pending); 987 } 988 989 /** 990 * Acquire the transporter I/O path. This must be done before 991 * doing any I/O in the transporter. May sleep and drop the 992 * IO path mutex while waiting for the I/O path. 993 * 994 * @param connection the connection. 995 * @param timeout_milliseconds maximum blocking time, or -1 for no limit. 996 * @returns TRUE if the I/O path was acquired. 997 */ 998 static dbus_bool_t 999 _dbus_connection_acquire_io_path (DBusConnection *connection, 1000 int timeout_milliseconds) 1001 { 1002 dbus_bool_t we_acquired; 1003 1004 HAVE_LOCK_CHECK (connection); 1005 1006 /* We don't want the connection to vanish */ 1007 _dbus_connection_ref_unlocked (connection); 1008 1009 /* We will only touch io_path_acquired which is protected by our mutex */ 1010 CONNECTION_UNLOCK (connection); 1011 1012 _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME); 1013 _dbus_mutex_lock (connection->io_path_mutex); 1014 1015 _dbus_verbose ("%s start connection->io_path_acquired = %d timeout = %d\n", 1016 _DBUS_FUNCTION_NAME, connection->io_path_acquired, timeout_milliseconds); 1017 1018 we_acquired = FALSE; 1019 1020 if (connection->io_path_acquired) 1021 { 1022 if (timeout_milliseconds != -1) 1023 { 1024 _dbus_verbose ("%s waiting %d for IO path to be acquirable\n", 1025 _DBUS_FUNCTION_NAME, timeout_milliseconds); 1026 1027 if (!_dbus_condvar_wait_timeout (connection->io_path_cond, 1028 connection->io_path_mutex, 1029 timeout_milliseconds)) 1030 { 1031 /* We timed out before anyone signaled. */ 1032 /* (writing the loop to handle the !timedout case by 1033 * waiting longer if needed is a pain since dbus 1034 * wraps pthread_cond_timedwait to take a relative 1035 * time instead of absolute, something kind of stupid 1036 * on our part. for now it doesn't matter, we will just 1037 * end up back here eventually.) 1038 */ 1039 } 1040 } 1041 else 1042 { 1043 while (connection->io_path_acquired) 1044 { 1045 _dbus_verbose ("%s waiting for IO path to be acquirable\n", _DBUS_FUNCTION_NAME); 1046 _dbus_condvar_wait (connection->io_path_cond, 1047 connection->io_path_mutex); 1048 } 1049 } 1050 } 1051 1052 if (!connection->io_path_acquired) 1053 { 1054 we_acquired = TRUE; 1055 connection->io_path_acquired = TRUE; 1056 } 1057 1058 _dbus_verbose ("%s end connection->io_path_acquired = %d we_acquired = %d\n", 1059 _DBUS_FUNCTION_NAME, connection->io_path_acquired, we_acquired); 1060 1061 _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME); 1062 _dbus_mutex_unlock (connection->io_path_mutex); 1063 1064 CONNECTION_LOCK (connection); 1065 1066 HAVE_LOCK_CHECK (connection); 1067 1068 _dbus_connection_unref_unlocked (connection); 1069 1070 return we_acquired; 1071 } 1072 1073 /** 1074 * Release the I/O path when you're done with it. Only call 1075 * after you've acquired the I/O. Wakes up at most one thread 1076 * currently waiting to acquire the I/O path. 1077 * 1078 * @param connection the connection. 1079 */ 1080 static void 1081 _dbus_connection_release_io_path (DBusConnection *connection) 1082 { 1083 HAVE_LOCK_CHECK (connection); 1084 1085 _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME); 1086 _dbus_mutex_lock (connection->io_path_mutex); 1087 1088 _dbus_assert (connection->io_path_acquired); 1089 1090 _dbus_verbose ("%s start connection->io_path_acquired = %d\n", 1091 _DBUS_FUNCTION_NAME, connection->io_path_acquired); 1092 1093 connection->io_path_acquired = FALSE; 1094 _dbus_condvar_wake_one (connection->io_path_cond); 1095 1096 _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME); 1097 _dbus_mutex_unlock (connection->io_path_mutex); 1098 } 1099 1100 /** 1101 * Queues incoming messages and sends outgoing messages for this 1102 * connection, optionally blocking in the process. Each call to 1103 * _dbus_connection_do_iteration_unlocked() will call select() or poll() one 1104 * time and then read or write data if possible. 1105 * 1106 * The purpose of this function is to be able to flush outgoing 1107 * messages or queue up incoming messages without returning 1108 * control to the application and causing reentrancy weirdness. 1109 * 1110 * The flags parameter allows you to specify whether to 1111 * read incoming messages, write outgoing messages, or both, 1112 * and whether to block if no immediate action is possible. 1113 * 1114 * The timeout_milliseconds parameter does nothing unless the 1115 * iteration is blocking. 1116 * 1117 * If there are no outgoing messages and DBUS_ITERATION_DO_READING 1118 * wasn't specified, then it's impossible to block, even if 1119 * you specify DBUS_ITERATION_BLOCK; in that case the function 1120 * returns immediately. 1121 * 1122 * If pending is not NULL then a check is made if the pending call 1123 * is completed after the io path has been required. If the call 1124 * has been completed nothing is done. This must be done since 1125 * the _dbus_connection_acquire_io_path releases the connection 1126 * lock for a while. 1127 * 1128 * Called with connection lock held. 1129 * 1130 * @param connection the connection. 1131 * @param pending the pending call that should be checked or NULL 1132 * @param flags iteration flags. 1133 * @param timeout_milliseconds maximum blocking time, or -1 for no limit. 1134 */ 1135 void 1136 _dbus_connection_do_iteration_unlocked (DBusConnection *connection, 1137 DBusPendingCall *pending, 1138 unsigned int flags, 1139 int timeout_milliseconds) 1140 { 1141 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); 1142 1143 HAVE_LOCK_CHECK (connection); 1144 1145 if (connection->n_outgoing == 0) 1146 flags &= ~DBUS_ITERATION_DO_WRITING; 1147 1148 if (_dbus_connection_acquire_io_path (connection, 1149 (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0)) 1150 { 1151 HAVE_LOCK_CHECK (connection); 1152 1153 if ( (pending != NULL) && _dbus_pending_call_get_completed_unlocked(pending)) 1154 { 1155 _dbus_verbose ("pending call completed while acquiring I/O path"); 1156 } 1157 else if ( (pending != NULL) && 1158 _dbus_connection_peek_for_reply_unlocked (connection, 1159 _dbus_pending_call_get_reply_serial_unlocked (pending))) 1160 { 1161 _dbus_verbose ("pending call completed while acquiring I/O path (reply found in queue)"); 1162 } 1163 else 1164 { 1165 _dbus_transport_do_iteration (connection->transport, 1166 flags, timeout_milliseconds); 1167 } 1168 1169 _dbus_connection_release_io_path (connection); 1170 } 1171 1172 HAVE_LOCK_CHECK (connection); 1173 1174 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); 1175 } 1176 1177 /** 1178 * Creates a new connection for the given transport. A transport 1179 * represents a message stream that uses some concrete mechanism, such 1180 * as UNIX domain sockets. May return #NULL if insufficient 1181 * memory exists to create the connection. 1182 * 1183 * @param transport the transport. 1184 * @returns the new connection, or #NULL on failure. 1185 */ 1186 DBusConnection* 1187 _dbus_connection_new_for_transport (DBusTransport *transport) 1188 { 1189 DBusConnection *connection; 1190 DBusWatchList *watch_list; 1191 DBusTimeoutList *timeout_list; 1192 DBusHashTable *pending_replies; 1193 DBusList *disconnect_link; 1194 DBusMessage *disconnect_message; 1195 DBusCounter *outgoing_counter; 1196 DBusObjectTree *objects; 1197 1198 watch_list = NULL; 1199 connection = NULL; 1200 pending_replies = NULL; 1201 timeout_list = NULL; 1202 disconnect_link = NULL; 1203 disconnect_message = NULL; 1204 outgoing_counter = NULL; 1205 objects = NULL; 1206 1207 watch_list = _dbus_watch_list_new (); 1208 if (watch_list == NULL) 1209 goto error; 1210 1211 timeout_list = _dbus_timeout_list_new (); 1212 if (timeout_list == NULL) 1213 goto error; 1214 1215 pending_replies = 1216 _dbus_hash_table_new (DBUS_HASH_INT, 1217 NULL, 1218 (DBusFreeFunction)free_pending_call_on_hash_removal); 1219 if (pending_replies == NULL) 1220 goto error; 1221 1222 connection = dbus_new0 (DBusConnection, 1); 1223 if (connection == NULL) 1224 goto error; 1225 1226 _dbus_mutex_new_at_location (&connection->mutex); 1227 if (connection->mutex == NULL) 1228 goto error; 1229 1230 _dbus_mutex_new_at_location (&connection->io_path_mutex); 1231 if (connection->io_path_mutex == NULL) 1232 goto error; 1233 1234 _dbus_mutex_new_at_location (&connection->dispatch_mutex); 1235 if (connection->dispatch_mutex == NULL) 1236 goto error; 1237 1238 _dbus_condvar_new_at_location (&connection->dispatch_cond); 1239 if (connection->dispatch_cond == NULL) 1240 goto error; 1241 1242 _dbus_condvar_new_at_location (&connection->io_path_cond); 1243 if (connection->io_path_cond == NULL) 1244 goto error; 1245 1246 disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL, 1247 DBUS_INTERFACE_LOCAL, 1248 "Disconnected"); 1249 1250 if (disconnect_message == NULL) 1251 goto error; 1252 1253 disconnect_link = _dbus_list_alloc_link (disconnect_message); 1254 if (disconnect_link == NULL) 1255 goto error; 1256 1257 outgoing_counter = _dbus_counter_new (); 1258 if (outgoing_counter == NULL) 1259 goto error; 1260 1261 objects = _dbus_object_tree_new (connection); 1262 if (objects == NULL) 1263 goto error; 1264 1265 if (_dbus_modify_sigpipe) 1266 _dbus_disable_sigpipe (); 1267 1268 connection->refcount.value = 1; 1269 connection->transport = transport; 1270 connection->watches = watch_list; 1271 connection->timeouts = timeout_list; 1272 connection->pending_replies = pending_replies; 1273 connection->outgoing_counter = outgoing_counter; 1274 connection->filter_list = NULL; 1275 connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */ 1276 connection->objects = objects; 1277 connection->exit_on_disconnect = FALSE; 1278 connection->shareable = FALSE; 1279 connection->route_peer_messages = FALSE; 1280 connection->disconnected_message_arrived = FALSE; 1281 connection->disconnected_message_processed = FALSE; 1282 1283 #ifndef DBUS_DISABLE_CHECKS 1284 connection->generation = _dbus_current_generation; 1285 #endif 1286 1287 _dbus_data_slot_list_init (&connection->slot_list); 1288 1289 connection->client_serial = 1; 1290 1291 connection->disconnect_message_link = disconnect_link; 1292 1293 CONNECTION_LOCK (connection); 1294 1295 if (!_dbus_transport_set_connection (transport, connection)) 1296 { 1297 CONNECTION_UNLOCK (connection); 1298 1299 goto error; 1300 } 1301 1302 _dbus_transport_ref (transport); 1303 1304 CONNECTION_UNLOCK (connection); 1305 1306 return connection; 1307 1308 error: 1309 if (disconnect_message != NULL) 1310 dbus_message_unref (disconnect_message); 1311 1312 if (disconnect_link != NULL) 1313 _dbus_list_free_link (disconnect_link); 1314 1315 if (connection != NULL) 1316 { 1317 _dbus_condvar_free_at_location (&connection->io_path_cond); 1318 _dbus_condvar_free_at_location (&connection->dispatch_cond); 1319 _dbus_mutex_free_at_location (&connection->mutex); 1320 _dbus_mutex_free_at_location (&connection->io_path_mutex); 1321 _dbus_mutex_free_at_location (&connection->dispatch_mutex); 1322 dbus_free (connection); 1323 } 1324 if (pending_replies) 1325 _dbus_hash_table_unref (pending_replies); 1326 1327 if (watch_list) 1328 _dbus_watch_list_free (watch_list); 1329 1330 if (timeout_list) 1331 _dbus_timeout_list_free (timeout_list); 1332 1333 if (outgoing_counter) 1334 _dbus_counter_unref (outgoing_counter); 1335 1336 if (objects) 1337 _dbus_object_tree_unref (objects); 1338 1339 return NULL; 1340 } 1341 1342 /** 1343 * Increments the reference count of a DBusConnection. 1344 * Requires that the caller already holds the connection lock. 1345 * 1346 * @param connection the connection. 1347 * @returns the connection. 1348 */ 1349 DBusConnection * 1350 _dbus_connection_ref_unlocked (DBusConnection *connection) 1351 { 1352 _dbus_assert (connection != NULL); 1353 _dbus_assert (connection->generation == _dbus_current_generation); 1354 1355 HAVE_LOCK_CHECK (connection); 1356 1357 #ifdef DBUS_HAVE_ATOMIC_INT 1358 _dbus_atomic_inc (&connection->refcount); 1359 #else 1360 _dbus_assert (connection->refcount.value > 0); 1361 connection->refcount.value += 1; 1362 #endif 1363 1364 return connection; 1365 } 1366 1367 /** 1368 * Decrements the reference count of a DBusConnection. 1369 * Requires that the caller already holds the connection lock. 1370 * 1371 * @param connection the connection. 1372 */ 1373 void 1374 _dbus_connection_unref_unlocked (DBusConnection *connection) 1375 { 1376 dbus_bool_t last_unref; 1377 1378 HAVE_LOCK_CHECK (connection); 1379 1380 _dbus_assert (connection != NULL); 1381 1382 /* The connection lock is better than the global 1383 * lock in the atomic increment fallback 1384 */ 1385 1386 #ifdef DBUS_HAVE_ATOMIC_INT 1387 last_unref = (_dbus_atomic_dec (&connection->refcount) == 1); 1388 #else 1389 _dbus_assert (connection->refcount.value > 0); 1390 1391 connection->refcount.value -= 1; 1392 last_unref = (connection->refcount.value == 0); 1393 #if 0 1394 printf ("unref_unlocked() connection %p count = %d\n", connection, connection->refcount.value); 1395 #endif 1396 #endif 1397 1398 if (last_unref) 1399 _dbus_connection_last_unref (connection); 1400 } 1401 1402 static dbus_uint32_t 1403 _dbus_connection_get_next_client_serial (DBusConnection *connection) 1404 { 1405 int serial; 1406 1407 serial = connection->client_serial++; 1408 1409 if (connection->client_serial < 0) 1410 connection->client_serial = 1; 1411 1412 return serial; 1413 } 1414 1415 /** 1416 * A callback for use with dbus_watch_new() to create a DBusWatch. 1417 * 1418 * @todo This is basically a hack - we could delete _dbus_transport_handle_watch() 1419 * and the virtual handle_watch in DBusTransport if we got rid of it. 1420 * The reason this is some work is threading, see the _dbus_connection_handle_watch() 1421 * implementation. 1422 * 1423 * @param watch the watch. 1424 * @param condition the current condition of the file descriptors being watched. 1425 * @param data must be a pointer to a #DBusConnection 1426 * @returns #FALSE if the IO condition may not have been fully handled due to lack of memory 1427 */ 1428 dbus_bool_t 1429 _dbus_connection_handle_watch (DBusWatch *watch, 1430 unsigned int condition, 1431 void *data) 1432 { 1433 DBusConnection *connection; 1434 dbus_bool_t retval; 1435 DBusDispatchStatus status; 1436 1437 connection = data; 1438 1439 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); 1440 1441 CONNECTION_LOCK (connection); 1442 _dbus_connection_acquire_io_path (connection, -1); 1443 HAVE_LOCK_CHECK (connection); 1444 retval = _dbus_transport_handle_watch (connection->transport, 1445 watch, condition); 1446 1447 _dbus_connection_release_io_path (connection); 1448 1449 HAVE_LOCK_CHECK (connection); 1450 1451 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); 1452 1453 status = _dbus_connection_get_dispatch_status_unlocked (connection); 1454 1455 /* this calls out to user code */ 1456 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 1457 1458 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); 1459 1460 return retval; 1461 } 1462 1463 _DBUS_DEFINE_GLOBAL_LOCK (shared_connections); 1464 static DBusHashTable *shared_connections = NULL; 1465 1466 static void 1467 shared_connections_shutdown (void *data) 1468 { 1469 int n_entries; 1470 1471 _DBUS_LOCK (shared_connections); 1472 1473 /* This is a little bit unpleasant... better ideas? */ 1474 while ((n_entries = _dbus_hash_table_get_n_entries (shared_connections)) > 0) 1475 { 1476 DBusConnection *connection; 1477 DBusMessage *message; 1478 DBusHashIter iter; 1479 1480 _dbus_hash_iter_init (shared_connections, &iter); 1481 _dbus_hash_iter_next (&iter); 1482 1483 connection = _dbus_hash_iter_get_value (&iter); 1484 1485 _DBUS_UNLOCK (shared_connections); 1486 1487 dbus_connection_ref (connection); 1488 _dbus_connection_close_possibly_shared (connection); 1489 1490 /* Churn through to the Disconnected message */ 1491 while ((message = dbus_connection_pop_message (connection))) 1492 { 1493 dbus_message_unref (message); 1494 } 1495 dbus_connection_unref (connection); 1496 1497 _DBUS_LOCK (shared_connections); 1498 1499 /* The connection should now be dead and not in our hash ... */ 1500 _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) < n_entries); 1501 } 1502 1503 _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0); 1504 1505 _dbus_hash_table_unref (shared_connections); 1506 shared_connections = NULL; 1507 1508 _DBUS_UNLOCK (shared_connections); 1509 } 1510 1511 static dbus_bool_t 1512 connection_lookup_shared (DBusAddressEntry *entry, 1513 DBusConnection **result) 1514 { 1515 _dbus_verbose ("checking for existing connection\n"); 1516 1517 *result = NULL; 1518 1519 _DBUS_LOCK (shared_connections); 1520 1521 if (shared_connections == NULL) 1522 { 1523 _dbus_verbose ("creating shared_connections hash table\n"); 1524 1525 shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING, 1526 dbus_free, 1527 NULL); 1528 if (shared_connections == NULL) 1529 { 1530 _DBUS_UNLOCK (shared_connections); 1531 return FALSE; 1532 } 1533 1534 if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL)) 1535 { 1536 _dbus_hash_table_unref (shared_connections); 1537 shared_connections = NULL; 1538 _DBUS_UNLOCK (shared_connections); 1539 return FALSE; 1540 } 1541 1542 _dbus_verbose (" successfully created shared_connections\n"); 1543 1544 _DBUS_UNLOCK (shared_connections); 1545 return TRUE; /* no point looking up in the hash we just made */ 1546 } 1547 else 1548 { 1549 const char *guid; 1550 1551 guid = dbus_address_entry_get_value (entry, "guid"); 1552 1553 if (guid != NULL) 1554 { 1555 DBusConnection *connection; 1556 1557 connection = _dbus_hash_table_lookup_string (shared_connections, 1558 guid); 1559 1560 if (connection) 1561 { 1562 /* The DBusConnection can't be finalized without taking 1563 * the shared_connections lock to remove it from the 1564 * hash. So it's safe to ref the connection here. 1565 * However, it may be disconnected if the Disconnected 1566 * message hasn't been processed yet, in which case we 1567 * want to pretend it isn't in the hash and avoid 1568 * returning it. 1569 * 1570 * The idea is to avoid ever returning a disconnected connection 1571 * from dbus_connection_open(). We could just synchronously 1572 * drop our shared ref to the connection on connection disconnect, 1573 * and then assert here that the connection is connected, but 1574 * that causes reentrancy headaches. 1575 */ 1576 CONNECTION_LOCK (connection); 1577 if (_dbus_connection_get_is_connected_unlocked (connection)) 1578 { 1579 _dbus_connection_ref_unlocked (connection); 1580 *result = connection; 1581 _dbus_verbose ("looked up existing connection to server guid %s\n", 1582 guid); 1583 } 1584 else 1585 { 1586 _dbus_verbose ("looked up existing connection to server guid %s but it was disconnected so ignoring it\n", 1587 guid); 1588 } 1589 CONNECTION_UNLOCK (connection); 1590 } 1591 } 1592 1593 _DBUS_UNLOCK (shared_connections); 1594 return TRUE; 1595 } 1596 } 1597 1598 static dbus_bool_t 1599 connection_record_shared_unlocked (DBusConnection *connection, 1600 const char *guid) 1601 { 1602 char *guid_key; 1603 char *guid_in_connection; 1604 1605 HAVE_LOCK_CHECK (connection); 1606 _dbus_assert (connection->server_guid == NULL); 1607 _dbus_assert (connection->shareable); 1608 1609 /* get a hard ref on this connection, even if 1610 * we won't in fact store it in the hash, we still 1611 * need to hold a ref on it until it's disconnected. 1612 */ 1613 _dbus_connection_ref_unlocked (connection); 1614 1615 if (guid == NULL) 1616 return TRUE; /* don't store in the hash */ 1617 1618 /* A separate copy of the key is required in the hash table, because 1619 * we don't have a lock on the connection when we are doing a hash 1620 * lookup. 1621 */ 1622 1623 guid_key = _dbus_strdup (guid); 1624 if (guid_key == NULL) 1625 return FALSE; 1626 1627 guid_in_connection = _dbus_strdup (guid); 1628 if (guid_in_connection == NULL) 1629 { 1630 dbus_free (guid_key); 1631 return FALSE; 1632 } 1633 1634 _DBUS_LOCK (shared_connections); 1635 _dbus_assert (shared_connections != NULL); 1636 1637 if (!_dbus_hash_table_insert_string (shared_connections, 1638 guid_key, connection)) 1639 { 1640 dbus_free (guid_key); 1641 dbus_free (guid_in_connection); 1642 _DBUS_UNLOCK (shared_connections); 1643 return FALSE; 1644 } 1645 1646 connection->server_guid = guid_in_connection; 1647 1648 _dbus_verbose ("stored connection to %s to be shared\n", 1649 connection->server_guid); 1650 1651 _DBUS_UNLOCK (shared_connections); 1652 1653 _dbus_assert (connection->server_guid != NULL); 1654 1655 return TRUE; 1656 } 1657 1658 static void 1659 connection_forget_shared_unlocked (DBusConnection *connection) 1660 { 1661 HAVE_LOCK_CHECK (connection); 1662 1663 if (!connection->shareable) 1664 return; 1665 1666 if (connection->server_guid != NULL) 1667 { 1668 _dbus_verbose ("dropping connection to %s out of the shared table\n", 1669 connection->server_guid); 1670 1671 _DBUS_LOCK (shared_connections); 1672 1673 if (!_dbus_hash_table_remove_string (shared_connections, 1674 connection->server_guid)) 1675 _dbus_assert_not_reached ("connection was not in the shared table"); 1676 1677 dbus_free (connection->server_guid); 1678 connection->server_guid = NULL; 1679 _DBUS_UNLOCK (shared_connections); 1680 } 1681 1682 /* remove our reference held on all shareable connections */ 1683 _dbus_connection_unref_unlocked (connection); 1684 } 1685 1686 static DBusConnection* 1687 connection_try_from_address_entry (DBusAddressEntry *entry, 1688 DBusError *error) 1689 { 1690 DBusTransport *transport; 1691 DBusConnection *connection; 1692 1693 transport = _dbus_transport_open (entry, error); 1694 1695 if (transport == NULL) 1696 { 1697 _DBUS_ASSERT_ERROR_IS_SET (error); 1698 return NULL; 1699 } 1700 1701 connection = _dbus_connection_new_for_transport (transport); 1702 1703 _dbus_transport_unref (transport); 1704 1705 if (connection == NULL) 1706 { 1707 _DBUS_SET_OOM (error); 1708 return NULL; 1709 } 1710 1711 #ifndef DBUS_DISABLE_CHECKS 1712 _dbus_assert (!connection->have_connection_lock); 1713 #endif 1714 return connection; 1715 } 1716 1717 /* 1718 * If the shared parameter is true, then any existing connection will 1719 * be used (and if a new connection is created, it will be available 1720 * for use by others). If the shared parameter is false, a new 1721 * connection will always be created, and the new connection will 1722 * never be returned to other callers. 1723 * 1724 * @param address the address 1725 * @param shared whether the connection is shared or private 1726 * @param error error return 1727 * @returns the connection or #NULL on error 1728 */ 1729 static DBusConnection* 1730 _dbus_connection_open_internal (const char *address, 1731 dbus_bool_t shared, 1732 DBusError *error) 1733 { 1734 DBusConnection *connection; 1735 DBusAddressEntry **entries; 1736 DBusError tmp_error; 1737 DBusError first_error; 1738 int len, i; 1739 1740 _DBUS_ASSERT_ERROR_IS_CLEAR (error); 1741 1742 _dbus_verbose ("opening %s connection to: %s\n", 1743 shared ? "shared" : "private", address); 1744 1745 if (!dbus_parse_address (address, &entries, &len, error)) 1746 return NULL; 1747 1748 _DBUS_ASSERT_ERROR_IS_CLEAR (error); 1749 1750 connection = NULL; 1751 1752 dbus_error_init (&tmp_error); 1753 dbus_error_init (&first_error); 1754 for (i = 0; i < len; i++) 1755 { 1756 if (shared) 1757 { 1758 if (!connection_lookup_shared (entries[i], &connection)) 1759 _DBUS_SET_OOM (&tmp_error); 1760 } 1761 1762 if (connection == NULL) 1763 { 1764 connection = connection_try_from_address_entry (entries[i], 1765 &tmp_error); 1766 1767 if (connection != NULL && shared) 1768 { 1769 const char *guid; 1770 1771 connection->shareable = TRUE; 1772 1773 /* guid may be NULL */ 1774 guid = dbus_address_entry_get_value (entries[i], "guid"); 1775 1776 CONNECTION_LOCK (connection); 1777 1778 if (!connection_record_shared_unlocked (connection, guid)) 1779 { 1780 _DBUS_SET_OOM (&tmp_error); 1781 _dbus_connection_close_possibly_shared_and_unlock (connection); 1782 dbus_connection_unref (connection); 1783 connection = NULL; 1784 } 1785 else 1786 CONNECTION_UNLOCK (connection); 1787 } 1788 } 1789 1790 if (connection) 1791 break; 1792 1793 _DBUS_ASSERT_ERROR_IS_SET (&tmp_error); 1794 1795 if (i == 0) 1796 dbus_move_error (&tmp_error, &first_error); 1797 else 1798 dbus_error_free (&tmp_error); 1799 } 1800 1801 _DBUS_ASSERT_ERROR_IS_CLEAR (error); 1802 _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error); 1803 1804 if (connection == NULL) 1805 { 1806 _DBUS_ASSERT_ERROR_IS_SET (&first_error); 1807 dbus_move_error (&first_error, error); 1808 } 1809 else 1810 dbus_error_free (&first_error); 1811 1812 dbus_address_entries_free (entries); 1813 return connection; 1814 } 1815 1816 /** 1817 * Closes a shared OR private connection, while dbus_connection_close() can 1818 * only be used on private connections. Should only be called by the 1819 * dbus code that owns the connection - an owner must be known, 1820 * the open/close state is like malloc/free, not like ref/unref. 1821 * 1822 * @param connection the connection 1823 */ 1824 void 1825 _dbus_connection_close_possibly_shared (DBusConnection *connection) 1826 { 1827 _dbus_assert (connection != NULL); 1828 _dbus_assert (connection->generation == _dbus_current_generation); 1829 1830 CONNECTION_LOCK (connection); 1831 _dbus_connection_close_possibly_shared_and_unlock (connection); 1832 } 1833 1834 static DBusPreallocatedSend* 1835 _dbus_connection_preallocate_send_unlocked (DBusConnection *connection) 1836 { 1837 DBusPreallocatedSend *preallocated; 1838 1839 HAVE_LOCK_CHECK (connection); 1840 1841 _dbus_assert (connection != NULL); 1842 1843 preallocated = dbus_new (DBusPreallocatedSend, 1); 1844 if (preallocated == NULL) 1845 return NULL; 1846 1847 if (connection->link_cache != NULL) 1848 { 1849 preallocated->queue_link = 1850 _dbus_list_pop_first_link (&connection->link_cache); 1851 preallocated->queue_link->data = NULL; 1852 } 1853 else 1854 { 1855 preallocated->queue_link = _dbus_list_alloc_link (NULL); 1856 if (preallocated->queue_link == NULL) 1857 goto failed_0; 1858 } 1859 1860 if (connection->link_cache != NULL) 1861 { 1862 preallocated->counter_link = 1863 _dbus_list_pop_first_link (&connection->link_cache); 1864 preallocated->counter_link->data = connection->outgoing_counter; 1865 } 1866 else 1867 { 1868 preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter); 1869 if (preallocated->counter_link == NULL) 1870 goto failed_1; 1871 } 1872 1873 _dbus_counter_ref (preallocated->counter_link->data); 1874 1875 preallocated->connection = connection; 1876 1877 return preallocated; 1878 1879 failed_1: 1880 _dbus_list_free_link (preallocated->queue_link); 1881 failed_0: 1882 dbus_free (preallocated); 1883 1884 return NULL; 1885 } 1886 1887 /* Called with lock held, does not update dispatch status */ 1888 static void 1889 _dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection, 1890 DBusPreallocatedSend *preallocated, 1891 DBusMessage *message, 1892 dbus_uint32_t *client_serial) 1893 { 1894 dbus_uint32_t serial; 1895 const char *sig; 1896 1897 preallocated->queue_link->data = message; 1898 _dbus_list_prepend_link (&connection->outgoing_messages, 1899 preallocated->queue_link); 1900 1901 _dbus_message_add_size_counter_link (message, 1902 preallocated->counter_link); 1903 1904 dbus_free (preallocated); 1905 preallocated = NULL; 1906 1907 dbus_message_ref (message); 1908 1909 connection->n_outgoing += 1; 1910 1911 sig = dbus_message_get_signature (message); 1912 1913 _dbus_verbose ("Message %p (%d %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n", 1914 message, 1915 dbus_message_get_type (message), 1916 dbus_message_get_path (message) ? 1917 dbus_message_get_path (message) : 1918 "no path", 1919 dbus_message_get_interface (message) ? 1920 dbus_message_get_interface (message) : 1921 "no interface", 1922 dbus_message_get_member (message) ? 1923 dbus_message_get_member (message) : 1924 "no member", 1925 sig, 1926 dbus_message_get_destination (message) ? 1927 dbus_message_get_destination (message) : 1928 "null", 1929 connection, 1930 connection->n_outgoing); 1931 1932 if (dbus_message_get_serial (message) == 0) 1933 { 1934 serial = _dbus_connection_get_next_client_serial (connection); 1935 _dbus_message_set_serial (message, serial); 1936 if (client_serial) 1937 *client_serial = serial; 1938 } 1939 else 1940 { 1941 if (client_serial) 1942 *client_serial = dbus_message_get_serial (message); 1943 } 1944 1945 _dbus_verbose ("Message %p serial is %u\n", 1946 message, dbus_message_get_serial (message)); 1947 1948 _dbus_message_lock (message); 1949 1950 /* Now we need to run an iteration to hopefully just write the messages 1951 * out immediately, and otherwise get them queued up 1952 */ 1953 _dbus_connection_do_iteration_unlocked (connection, 1954 NULL, 1955 DBUS_ITERATION_DO_WRITING, 1956 -1); 1957 1958 /* If stuff is still queued up, be sure we wake up the main loop */ 1959 if (connection->n_outgoing > 0) 1960 _dbus_connection_wakeup_mainloop (connection); 1961 } 1962 1963 static void 1964 _dbus_connection_send_preallocated_and_unlock (DBusConnection *connection, 1965 DBusPreallocatedSend *preallocated, 1966 DBusMessage *message, 1967 dbus_uint32_t *client_serial) 1968 { 1969 DBusDispatchStatus status; 1970 1971 HAVE_LOCK_CHECK (connection); 1972 1973 _dbus_connection_send_preallocated_unlocked_no_update (connection, 1974 preallocated, 1975 message, client_serial); 1976 1977 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); 1978 status = _dbus_connection_get_dispatch_status_unlocked (connection); 1979 1980 /* this calls out to user code */ 1981 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 1982 } 1983 1984 /** 1985 * Like dbus_connection_send(), but assumes the connection 1986 * is already locked on function entry, and unlocks before returning. 1987 * 1988 * @param connection the connection 1989 * @param message the message to send 1990 * @param client_serial return location for client serial of sent message 1991 * @returns #FALSE on out-of-memory 1992 */ 1993 dbus_bool_t 1994 _dbus_connection_send_and_unlock (DBusConnection *connection, 1995 DBusMessage *message, 1996 dbus_uint32_t *client_serial) 1997 { 1998 DBusPreallocatedSend *preallocated; 1999 2000 _dbus_assert (connection != NULL); 2001 _dbus_assert (message != NULL); 2002 2003 preallocated = _dbus_connection_preallocate_send_unlocked (connection); 2004 if (preallocated == NULL) 2005 { 2006 CONNECTION_UNLOCK (connection); 2007 return FALSE; 2008 } 2009 2010 _dbus_connection_send_preallocated_and_unlock (connection, 2011 preallocated, 2012 message, 2013 client_serial); 2014 return TRUE; 2015 } 2016 2017 /** 2018 * Used internally to handle the semantics of dbus_server_set_new_connection_function(). 2019 * If the new connection function does not ref the connection, we want to close it. 2020 * 2021 * A bit of a hack, probably the new connection function should have returned a value 2022 * for whether to close, or should have had to close the connection itself if it 2023 * didn't want it. 2024 * 2025 * But, this works OK as long as the new connection function doesn't do anything 2026 * crazy like keep the connection around without ref'ing it. 2027 * 2028 * We have to lock the connection across refcount check and close in case 2029 * the new connection function spawns a thread that closes and unrefs. 2030 * In that case, if the app thread 2031 * closes and unrefs first, we'll harmlessly close again; if the app thread 2032 * still has the ref, we'll close and then the app will close harmlessly. 2033 * If the app unrefs without closing, the app is broken since if the 2034 * app refs from the new connection function it is supposed to also close. 2035 * 2036 * If we didn't atomically check the refcount and close with the lock held 2037 * though, we could screw this up. 2038 * 2039 * @param connection the connection 2040 */ 2041 void 2042 _dbus_connection_close_if_only_one_ref (DBusConnection *connection) 2043 { 2044 CONNECTION_LOCK (connection); 2045 2046 _dbus_assert (connection->refcount.value > 0); 2047 2048 if (connection->refcount.value == 1) 2049 _dbus_connection_close_possibly_shared_and_unlock (connection); 2050 else 2051 CONNECTION_UNLOCK (connection); 2052 } 2053 2054 2055 /** 2056 * When a function that blocks has been called with a timeout, and we 2057 * run out of memory, the time to wait for memory is based on the 2058 * timeout. If the caller was willing to block a long time we wait a 2059 * relatively long time for memory, if they were only willing to block 2060 * briefly then we retry for memory at a rapid rate. 2061 * 2062 * @timeout_milliseconds the timeout requested for blocking 2063 */ 2064 static void 2065 _dbus_memory_pause_based_on_timeout (int timeout_milliseconds) 2066 { 2067 if (timeout_milliseconds == -1) 2068 _dbus_sleep_milliseconds (1000); 2069 else if (timeout_milliseconds < 100) 2070 ; /* just busy loop */ 2071 else if (timeout_milliseconds <= 1000) 2072 _dbus_sleep_milliseconds (timeout_milliseconds / 3); 2073 else 2074 _dbus_sleep_milliseconds (1000); 2075 } 2076 2077 static DBusMessage * 2078 generate_local_error_message (dbus_uint32_t serial, 2079 char *error_name, 2080 char *error_msg) 2081 { 2082 DBusMessage *message; 2083 message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR); 2084 if (!message) 2085 goto out; 2086 2087 if (!dbus_message_set_error_name (message, error_name)) 2088 { 2089 dbus_message_unref (message); 2090 message = NULL; 2091 goto out; 2092 } 2093 2094 dbus_message_set_no_reply (message, TRUE); 2095 2096 if (!dbus_message_set_reply_serial (message, 2097 serial)) 2098 { 2099 dbus_message_unref (message); 2100 message = NULL; 2101 goto out; 2102 } 2103 2104 if (error_msg != NULL) 2105 { 2106 DBusMessageIter iter; 2107 2108 dbus_message_iter_init_append (message, &iter); 2109 if (!dbus_message_iter_append_basic (&iter, 2110 DBUS_TYPE_STRING, 2111 &error_msg)) 2112 { 2113 dbus_message_unref (message); 2114 message = NULL; 2115 goto out; 2116 } 2117 } 2118 2119 out: 2120 return message; 2121 } 2122 2123 /* 2124 * Peek the incoming queue to see if we got reply for a specific serial 2125 */ 2126 static dbus_bool_t 2127 _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection, 2128 dbus_uint32_t client_serial) 2129 { 2130 DBusList *link; 2131 HAVE_LOCK_CHECK (connection); 2132 2133 link = _dbus_list_get_first_link (&connection->incoming_messages); 2134 2135 while (link != NULL) 2136 { 2137 DBusMessage *reply = link->data; 2138 2139 if (dbus_message_get_reply_serial (reply) == client_serial) 2140 { 2141 _dbus_verbose ("%s reply to %d found in queue\n", _DBUS_FUNCTION_NAME, client_serial); 2142 return TRUE; 2143 } 2144 link = _dbus_list_get_next_link (&connection->incoming_messages, link); 2145 } 2146 2147 return FALSE; 2148 } 2149 2150 /* This is slightly strange since we can pop a message here without 2151 * the dispatch lock. 2152 */ 2153 static DBusMessage* 2154 check_for_reply_unlocked (DBusConnection *connection, 2155 dbus_uint32_t client_serial) 2156 { 2157 DBusList *link; 2158 2159 HAVE_LOCK_CHECK (connection); 2160 2161 link = _dbus_list_get_first_link (&connection->incoming_messages); 2162 2163 while (link != NULL) 2164 { 2165 DBusMessage *reply = link->data; 2166 2167 if (dbus_message_get_reply_serial (reply) == client_serial) 2168 { 2169 _dbus_list_remove_link (&connection->incoming_messages, link); 2170 connection->n_incoming -= 1; 2171 return reply; 2172 } 2173 link = _dbus_list_get_next_link (&connection->incoming_messages, link); 2174 } 2175 2176 return NULL; 2177 } 2178 2179 static void 2180 connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection) 2181 { 2182 /* We can't iterate over the hash in the normal way since we'll be 2183 * dropping the lock for each item. So we restart the 2184 * iter each time as we drain the hash table. 2185 */ 2186 2187 while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0) 2188 { 2189 DBusPendingCall *pending; 2190 DBusHashIter iter; 2191 2192 _dbus_hash_iter_init (connection->pending_replies, &iter); 2193 _dbus_hash_iter_next (&iter); 2194 2195 pending = _dbus_hash_iter_get_value (&iter); 2196 _dbus_pending_call_ref_unlocked (pending); 2197 2198 _dbus_pending_call_queue_timeout_error_unlocked (pending, 2199 connection); 2200 _dbus_connection_remove_timeout_unlocked (connection, 2201 _dbus_pending_call_get_timeout_unlocked (pending)); 2202 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); 2203 _dbus_hash_iter_remove_entry (&iter); 2204 2205 _dbus_pending_call_unref_and_unlock (pending); 2206 CONNECTION_LOCK (connection); 2207 } 2208 HAVE_LOCK_CHECK (connection); 2209 } 2210 2211 static void 2212 complete_pending_call_and_unlock (DBusConnection *connection, 2213 DBusPendingCall *pending, 2214 DBusMessage *message) 2215 { 2216 _dbus_pending_call_set_reply_unlocked (pending, message); 2217 _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */ 2218 _dbus_connection_detach_pending_call_and_unlock (connection, pending); 2219 2220 /* Must be called unlocked since it invokes app callback */ 2221 _dbus_pending_call_complete (pending); 2222 dbus_pending_call_unref (pending); 2223 } 2224 2225 static dbus_bool_t 2226 check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection, 2227 DBusPendingCall *pending) 2228 { 2229 DBusMessage *reply; 2230 DBusDispatchStatus status; 2231 2232 reply = check_for_reply_unlocked (connection, 2233 _dbus_pending_call_get_reply_serial_unlocked (pending)); 2234 if (reply != NULL) 2235 { 2236 _dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME); 2237 2238 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n"); 2239 2240 complete_pending_call_and_unlock (connection, pending, reply); 2241 dbus_message_unref (reply); 2242 2243 CONNECTION_LOCK (connection); 2244 status = _dbus_connection_get_dispatch_status_unlocked (connection); 2245 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 2246 dbus_pending_call_unref (pending); 2247 2248 return TRUE; 2249 } 2250 2251 return FALSE; 2252 } 2253 2254 /** 2255 * Blocks until a pending call times out or gets a reply. 2256 * 2257 * Does not re-enter the main loop or run filter/path-registered 2258 * callbacks. The reply to the message will not be seen by 2259 * filter callbacks. 2260 * 2261 * Returns immediately if pending call already got a reply. 2262 * 2263 * @todo could use performance improvements (it keeps scanning 2264 * the whole message queue for example) 2265 * 2266 * @param pending the pending call we block for a reply on 2267 */ 2268 void 2269 _dbus_connection_block_pending_call (DBusPendingCall *pending) 2270 { 2271 long start_tv_sec, start_tv_usec; 2272 long end_tv_sec, end_tv_usec; 2273 long tv_sec, tv_usec; 2274 DBusDispatchStatus status; 2275 DBusConnection *connection; 2276 dbus_uint32_t client_serial; 2277 int timeout_milliseconds; 2278 2279 _dbus_assert (pending != NULL); 2280 2281 if (dbus_pending_call_get_completed (pending)) 2282 return; 2283 2284 dbus_pending_call_ref (pending); /* necessary because the call could be canceled */ 2285 2286 connection = _dbus_pending_call_get_connection_and_lock (pending); 2287 2288 /* Flush message queue - note, can affect dispatch status */ 2289 _dbus_connection_flush_unlocked (connection); 2290 2291 client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending); 2292 2293 /* note that timeout_milliseconds is limited to a smallish value 2294 * in _dbus_pending_call_new() so overflows aren't possible 2295 * below 2296 */ 2297 timeout_milliseconds = dbus_timeout_get_interval (_dbus_pending_call_get_timeout_unlocked (pending)); 2298 2299 _dbus_get_current_time (&start_tv_sec, &start_tv_usec); 2300 end_tv_sec = start_tv_sec + timeout_milliseconds / 1000; 2301 end_tv_usec = start_tv_usec + (timeout_milliseconds % 1000) * 1000; 2302 end_tv_sec += end_tv_usec / _DBUS_USEC_PER_SECOND; 2303 end_tv_usec = end_tv_usec % _DBUS_USEC_PER_SECOND; 2304 2305 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec to %ld sec %ld usec\n", 2306 timeout_milliseconds, 2307 client_serial, 2308 start_tv_sec, start_tv_usec, 2309 end_tv_sec, end_tv_usec); 2310 2311 /* check to see if we already got the data off the socket */ 2312 /* from another blocked pending call */ 2313 if (check_for_reply_and_update_dispatch_unlocked (connection, pending)) 2314 return; 2315 2316 /* Now we wait... */ 2317 /* always block at least once as we know we don't have the reply yet */ 2318 _dbus_connection_do_iteration_unlocked (connection, 2319 pending, 2320 DBUS_ITERATION_DO_READING | 2321 DBUS_ITERATION_BLOCK, 2322 timeout_milliseconds); 2323 2324 recheck_status: 2325 2326 _dbus_verbose ("%s top of recheck\n", _DBUS_FUNCTION_NAME); 2327 2328 HAVE_LOCK_CHECK (connection); 2329 2330 /* queue messages and get status */ 2331 2332 status = _dbus_connection_get_dispatch_status_unlocked (connection); 2333 2334 /* the get_completed() is in case a dispatch() while we were blocking 2335 * got the reply instead of us. 2336 */ 2337 if (_dbus_pending_call_get_completed_unlocked (pending)) 2338 { 2339 _dbus_verbose ("Pending call completed by dispatch in %s\n", _DBUS_FUNCTION_NAME); 2340 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 2341 dbus_pending_call_unref (pending); 2342 return; 2343 } 2344 2345 if (status == DBUS_DISPATCH_DATA_REMAINS) { 2346 if (check_for_reply_and_update_dispatch_unlocked (connection, pending)) 2347 return; 2348 } 2349 2350 _dbus_get_current_time (&tv_sec, &tv_usec); 2351 2352 if (!_dbus_connection_get_is_connected_unlocked (connection)) 2353 { 2354 DBusMessage *error_msg; 2355 2356 error_msg = generate_local_error_message (client_serial, 2357 DBUS_ERROR_DISCONNECTED, 2358 "Connection was disconnected before a reply was received"); 2359 2360 /* on OOM error_msg is set to NULL */ 2361 complete_pending_call_and_unlock (connection, pending, error_msg); 2362 dbus_pending_call_unref (pending); 2363 return; 2364 } 2365 else if (tv_sec < start_tv_sec) 2366 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n"); 2367 else if (connection->disconnect_message_link == NULL) 2368 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n"); 2369 else if (tv_sec < end_tv_sec || 2370 (tv_sec == end_tv_sec && tv_usec < end_tv_usec)) 2371 { 2372 timeout_milliseconds = (end_tv_sec - tv_sec) * 1000 + 2373 (end_tv_usec - tv_usec) / 1000; 2374 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds); 2375 _dbus_assert (timeout_milliseconds >= 0); 2376 2377 if (status == DBUS_DISPATCH_NEED_MEMORY) 2378 { 2379 /* Try sleeping a bit, as we aren't sure we need to block for reading, 2380 * we may already have a reply in the buffer and just can't process 2381 * it. 2382 */ 2383 _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n"); 2384 2385 _dbus_memory_pause_based_on_timeout (timeout_milliseconds); 2386 } 2387 else 2388 { 2389 /* block again, we don't have the reply buffered yet. */ 2390 _dbus_connection_do_iteration_unlocked (connection, 2391 pending, 2392 DBUS_ITERATION_DO_READING | 2393 DBUS_ITERATION_BLOCK, 2394 timeout_milliseconds); 2395 } 2396 2397 goto recheck_status; 2398 } 2399 2400 _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %ld milliseconds and got no reply\n", 2401 (tv_sec - start_tv_sec) * 1000 + (tv_usec - start_tv_usec) / 1000); 2402 2403 _dbus_assert (!_dbus_pending_call_get_completed_unlocked (pending)); 2404 2405 /* unlock and call user code */ 2406 complete_pending_call_and_unlock (connection, pending, NULL); 2407 2408 /* update user code on dispatch status */ 2409 CONNECTION_LOCK (connection); 2410 status = _dbus_connection_get_dispatch_status_unlocked (connection); 2411 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 2412 dbus_pending_call_unref (pending); 2413 } 2414 2415 /** @} */ 2416 2417 /** 2418 * @addtogroup DBusConnection 2419 * 2420 * @{ 2421 */ 2422 2423 /** 2424 * Gets a connection to a remote address. If a connection to the given 2425 * address already exists, returns the existing connection with its 2426 * reference count incremented. Otherwise, returns a new connection 2427 * and saves the new connection for possible re-use if a future call 2428 * to dbus_connection_open() asks to connect to the same server. 2429 * 2430 * Use dbus_connection_open_private() to get a dedicated connection 2431 * not shared with other callers of dbus_connection_open(). 2432 * 2433 * If the open fails, the function returns #NULL, and provides a 2434 * reason for the failure in the error parameter. Pass #NULL for the 2435 * error parameter if you aren't interested in the reason for 2436 * failure. 2437 * 2438 * Because this connection is shared, no user of the connection 2439 * may call dbus_connection_close(). However, when you are done with the 2440 * connection you should call dbus_connection_unref(). 2441 * 2442 * @note Prefer dbus_connection_open() to dbus_connection_open_private() 2443 * unless you have good reason; connections are expensive enough 2444 * that it's wasteful to create lots of connections to the same 2445 * server. 2446 * 2447 * @param address the address. 2448 * @param error address where an error can be returned. 2449 * @returns new connection, or #NULL on failure. 2450 */ 2451 DBusConnection* 2452 dbus_connection_open (const char *address, 2453 DBusError *error) 2454 { 2455 DBusConnection *connection; 2456 2457 _dbus_return_val_if_fail (address != NULL, NULL); 2458 _dbus_return_val_if_error_is_set (error, NULL); 2459 2460 connection = _dbus_connection_open_internal (address, 2461 TRUE, 2462 error); 2463 2464 return connection; 2465 } 2466 2467 /** 2468 * Opens a new, dedicated connection to a remote address. Unlike 2469 * dbus_connection_open(), always creates a new connection. 2470 * This connection will not be saved or recycled by libdbus. 2471 * 2472 * If the open fails, the function returns #NULL, and provides a 2473 * reason for the failure in the error parameter. Pass #NULL for the 2474 * error parameter if you aren't interested in the reason for 2475 * failure. 2476 * 2477 * When you are done with this connection, you must 2478 * dbus_connection_close() to disconnect it, 2479 * and dbus_connection_unref() to free the connection object. 2480 * 2481 * (The dbus_connection_close() can be skipped if the 2482 * connection is already known to be disconnected, for example 2483 * if you are inside a handler for the Disconnected signal.) 2484 * 2485 * @note Prefer dbus_connection_open() to dbus_connection_open_private() 2486 * unless you have good reason; connections are expensive enough 2487 * that it's wasteful to create lots of connections to the same 2488 * server. 2489 * 2490 * @param address the address. 2491 * @param error address where an error can be returned. 2492 * @returns new connection, or #NULL on failure. 2493 */ 2494 DBusConnection* 2495 dbus_connection_open_private (const char *address, 2496 DBusError *error) 2497 { 2498 DBusConnection *connection; 2499 2500 _dbus_return_val_if_fail (address != NULL, NULL); 2501 _dbus_return_val_if_error_is_set (error, NULL); 2502 2503 connection = _dbus_connection_open_internal (address, 2504 FALSE, 2505 error); 2506 2507 return connection; 2508 } 2509 2510 /** 2511 * Increments the reference count of a DBusConnection. 2512 * 2513 * @param connection the connection. 2514 * @returns the connection. 2515 */ 2516 DBusConnection * 2517 dbus_connection_ref (DBusConnection *connection) 2518 { 2519 _dbus_return_val_if_fail (connection != NULL, NULL); 2520 _dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL); 2521 2522 /* The connection lock is better than the global 2523 * lock in the atomic increment fallback 2524 */ 2525 2526 #ifdef DBUS_HAVE_ATOMIC_INT 2527 _dbus_atomic_inc (&connection->refcount); 2528 #else 2529 CONNECTION_LOCK (connection); 2530 _dbus_assert (connection->refcount.value > 0); 2531 2532 connection->refcount.value += 1; 2533 CONNECTION_UNLOCK (connection); 2534 #endif 2535 2536 return connection; 2537 } 2538 2539 static void 2540 free_outgoing_message (void *element, 2541 void *data) 2542 { 2543 DBusMessage *message = element; 2544 DBusConnection *connection = data; 2545 2546 _dbus_message_remove_size_counter (message, 2547 connection->outgoing_counter, 2548 NULL); 2549 dbus_message_unref (message); 2550 } 2551 2552 /* This is run without the mutex held, but after the last reference 2553 * to the connection has been dropped we should have no thread-related 2554 * problems 2555 */ 2556 static void 2557 _dbus_connection_last_unref (DBusConnection *connection) 2558 { 2559 DBusList *link; 2560 2561 _dbus_verbose ("Finalizing connection %p\n", connection); 2562 2563 _dbus_assert (connection->refcount.value == 0); 2564 2565 /* You have to disconnect the connection before unref:ing it. Otherwise 2566 * you won't get the disconnected message. 2567 */ 2568 _dbus_assert (!_dbus_transport_get_is_connected (connection->transport)); 2569 _dbus_assert (connection->server_guid == NULL); 2570 2571 /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */ 2572 _dbus_object_tree_free_all_unlocked (connection->objects); 2573 2574 dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL); 2575 dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL); 2576 dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL); 2577 2578 _dbus_watch_list_free (connection->watches); 2579 connection->watches = NULL; 2580 2581 _dbus_timeout_list_free (connection->timeouts); 2582 connection->timeouts = NULL; 2583 2584 _dbus_data_slot_list_free (&connection->slot_list); 2585 2586 link = _dbus_list_get_first_link (&connection->filter_list); 2587 while (link != NULL) 2588 { 2589 DBusMessageFilter *filter = link->data; 2590 DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link); 2591 2592 filter->function = NULL; 2593 _dbus_message_filter_unref (filter); /* calls app callback */ 2594 link->data = NULL; 2595 2596 link = next; 2597 } 2598 _dbus_list_clear (&connection->filter_list); 2599 2600 /* ---- Done with stuff that invokes application callbacks */ 2601 2602 _dbus_object_tree_unref (connection->objects); 2603 2604 _dbus_hash_table_unref (connection->pending_replies); 2605 connection->pending_replies = NULL; 2606 2607 _dbus_list_clear (&connection->filter_list); 2608 2609 _dbus_list_foreach (&connection->outgoing_messages, 2610 free_outgoing_message, 2611 connection); 2612 _dbus_list_clear (&connection->outgoing_messages); 2613 2614 _dbus_list_foreach (&connection->incoming_messages, 2615 (DBusForeachFunction) dbus_message_unref, 2616 NULL); 2617 _dbus_list_clear (&connection->incoming_messages); 2618 2619 _dbus_counter_unref (connection->outgoing_counter); 2620 2621 _dbus_transport_unref (connection->transport); 2622 2623 if (connection->disconnect_message_link) 2624 { 2625 DBusMessage *message = connection->disconnect_message_link->data; 2626 dbus_message_unref (message); 2627 _dbus_list_free_link (connection->disconnect_message_link); 2628 } 2629 2630 _dbus_list_clear (&connection->link_cache); 2631 2632 _dbus_condvar_free_at_location (&connection->dispatch_cond); 2633 _dbus_condvar_free_at_location (&connection->io_path_cond); 2634 2635 _dbus_mutex_free_at_location (&connection->io_path_mutex); 2636 _dbus_mutex_free_at_location (&connection->dispatch_mutex); 2637 2638 _dbus_mutex_free_at_location (&connection->mutex); 2639 2640 dbus_free (connection); 2641 } 2642 2643 /** 2644 * Decrements the reference count of a DBusConnection, and finalizes 2645 * it if the count reaches zero. 2646 * 2647 * Note: it is a bug to drop the last reference to a connection that 2648 * is still connected. 2649 * 2650 * For shared connections, libdbus will own a reference 2651 * as long as the connection is connected, so you can know that either 2652 * you don't have the last reference, or it's OK to drop the last reference. 2653 * Most connections are shared. dbus_connection_open() and dbus_bus_get() 2654 * return shared connections. 2655 * 2656 * For private connections, the creator of the connection must arrange for 2657 * dbus_connection_close() to be called prior to dropping the last reference. 2658 * Private connections come from dbus_connection_open_private() or dbus_bus_get_private(). 2659 * 2660 * @param connection the connection. 2661 */ 2662 void 2663 dbus_connection_unref (DBusConnection *connection) 2664 { 2665 dbus_bool_t last_unref; 2666 2667 _dbus_return_if_fail (connection != NULL); 2668 _dbus_return_if_fail (connection->generation == _dbus_current_generation); 2669 2670 /* The connection lock is better than the global 2671 * lock in the atomic increment fallback 2672 */ 2673 2674 #ifdef DBUS_HAVE_ATOMIC_INT 2675 last_unref = (_dbus_atomic_dec (&connection->refcount) == 1); 2676 #else 2677 CONNECTION_LOCK (connection); 2678 2679 _dbus_assert (connection->refcount.value > 0); 2680 2681 connection->refcount.value -= 1; 2682 last_unref = (connection->refcount.value == 0); 2683 2684 #if 0 2685 printf ("unref() connection %p count = %d\n", connection, connection->refcount.value); 2686 #endif 2687 2688 CONNECTION_UNLOCK (connection); 2689 #endif 2690 2691 if (last_unref) 2692 { 2693 #ifndef DBUS_DISABLE_CHECKS 2694 if (_dbus_transport_get_is_connected (connection->transport)) 2695 { 2696 _dbus_warn_check_failed ("The last reference on a connection was dropped without closing the connection. This is a bug in an application. See dbus_connection_unref() documentation for details.\n%s", 2697 connection->shareable ? 2698 "Most likely, the application called unref() too many times and removed a reference belonging to libdbus, since this is a shared connection.\n" : 2699 "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.\n"); 2700 return; 2701 } 2702 #endif 2703 _dbus_connection_last_unref (connection); 2704 } 2705 } 2706 2707 /* 2708 * Note that the transport can disconnect itself (other end drops us) 2709 * and in that case this function never runs. So this function must 2710 * not do anything more than disconnect the transport and update the 2711 * dispatch status. 2712 * 2713 * If the transport self-disconnects, then we assume someone will 2714 * dispatch the connection to cause the dispatch status update. 2715 */ 2716 static void 2717 _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection) 2718 { 2719 DBusDispatchStatus status; 2720 2721 HAVE_LOCK_CHECK (connection); 2722 2723 _dbus_verbose ("Disconnecting %p\n", connection); 2724 2725 /* We need to ref because update_dispatch_status_and_unlock will unref 2726 * the connection if it was shared and libdbus was the only remaining 2727 * refcount holder. 2728 */ 2729 _dbus_connection_ref_unlocked (connection); 2730 2731 _dbus_transport_disconnect (connection->transport); 2732 2733 /* This has the side effect of queuing the disconnect message link 2734 * (unless we don't have enough memory, possibly, so don't assert it). 2735 * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open 2736 * should never again return the newly-disconnected connection. 2737 * 2738 * However, we only unref the shared connection and exit_on_disconnect when 2739 * the disconnect message reaches the head of the message queue, 2740 * NOT when it's first queued. 2741 */ 2742 status = _dbus_connection_get_dispatch_status_unlocked (connection); 2743 2744 /* This calls out to user code */ 2745 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 2746 2747 /* Could also call out to user code */ 2748 dbus_connection_unref (connection); 2749 } 2750 2751 /** 2752 * Closes a private connection, so no further data can be sent or received. 2753 * This disconnects the transport (such as a socket) underlying the 2754 * connection. 2755 * 2756 * Attempts to send messages after closing a connection are safe, but will result in 2757 * error replies generated locally in libdbus. 2758 * 2759 * This function does not affect the connection's reference count. It's 2760 * safe to close a connection more than once; all calls after the 2761 * first do nothing. It's impossible to "reopen" a connection, a 2762 * new connection must be created. This function may result in a call 2763 * to the DBusDispatchStatusFunction set with 2764 * dbus_connection_set_dispatch_status_function(), as the disconnect 2765 * message it generates needs to be dispatched. 2766 * 2767 * If a connection is dropped by the remote application, it will 2768 * close itself. 2769 * 2770 * You must close a connection prior to releasing the last reference to 2771 * the connection. If you dbus_connection_unref() for the last time 2772 * without closing the connection, the results are undefined; it 2773 * is a bug in your program and libdbus will try to print a warning. 2774 * 2775 * You may not close a shared connection. Connections created with 2776 * dbus_connection_open() or dbus_bus_get() are shared. 2777 * These connections are owned by libdbus, and applications should 2778 * only unref them, never close them. Applications can know it is 2779 * safe to unref these connections because libdbus will be holding a 2780 * reference as long as the connection is open. Thus, either the 2781 * connection is closed and it is OK to drop the last reference, 2782 * or the connection is open and the app knows it does not have the 2783 * last reference. 2784 * 2785 * Connections created with dbus_connection_open_private() or 2786 * dbus_bus_get_private() are not kept track of or referenced by 2787 * libdbus. The creator of these connections is responsible for 2788 * calling dbus_connection_close() prior to releasing the last 2789 * reference, if the connection is not already disconnected. 2790 * 2791 * @param connection the private (unshared) connection to close 2792 */ 2793 void 2794 dbus_connection_close (DBusConnection *connection) 2795 { 2796 _dbus_return_if_fail (connection != NULL); 2797 _dbus_return_if_fail (connection->generation == _dbus_current_generation); 2798 2799 CONNECTION_LOCK (connection); 2800 2801 #ifndef DBUS_DISABLE_CHECKS 2802 if (connection->shareable) 2803 { 2804 CONNECTION_UNLOCK (connection); 2805 2806 _dbus_warn_check_failed ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.\n"); 2807 return; 2808 } 2809 #endif 2810 2811 _dbus_connection_close_possibly_shared_and_unlock (connection); 2812 } 2813 2814 static dbus_bool_t 2815 _dbus_connection_get_is_connected_unlocked (DBusConnection *connection) 2816 { 2817 HAVE_LOCK_CHECK (connection); 2818 return _dbus_transport_get_is_connected (connection->transport); 2819 } 2820 2821 /** 2822 * Gets whether the connection is currently open. A connection may 2823 * become disconnected when the remote application closes its end, or 2824 * exits; a connection may also be disconnected with 2825 * dbus_connection_close(). 2826 * 2827 * There are not separate states for "closed" and "disconnected," the two 2828 * terms are synonymous. This function should really be called 2829 * get_is_open() but for historical reasons is not. 2830 * 2831 * @param connection the connection. 2832 * @returns #TRUE if the connection is still alive. 2833 */ 2834 dbus_bool_t 2835 dbus_connection_get_is_connected (DBusConnection *connection) 2836 { 2837 dbus_bool_t res; 2838 2839 _dbus_return_val_if_fail (connection != NULL, FALSE); 2840 2841 CONNECTION_LOCK (connection); 2842 res = _dbus_connection_get_is_connected_unlocked (connection); 2843 CONNECTION_UNLOCK (connection); 2844 2845 return res; 2846 } 2847 2848 /** 2849 * Gets whether the connection was authenticated. (Note that 2850 * if the connection was authenticated then disconnected, 2851 * this function still returns #TRUE) 2852 * 2853 * @param connection the connection 2854 * @returns #TRUE if the connection was ever authenticated 2855 */ 2856 dbus_bool_t 2857 dbus_connection_get_is_authenticated (DBusConnection *connection) 2858 { 2859 dbus_bool_t res; 2860 2861 _dbus_return_val_if_fail (connection != NULL, FALSE); 2862 2863 CONNECTION_LOCK (connection); 2864 res = _dbus_transport_get_is_authenticated (connection->transport); 2865 CONNECTION_UNLOCK (connection); 2866 2867 return res; 2868 } 2869 2870 /** 2871 * Set whether _exit() should be called when the connection receives a 2872 * disconnect signal. The call to _exit() comes after any handlers for 2873 * the disconnect signal run; handlers can cancel the exit by calling 2874 * this function. 2875 * 2876 * By default, exit_on_disconnect is #FALSE; but for message bus 2877 * connections returned from dbus_bus_get() it will be toggled on 2878 * by default. 2879 * 2880 * @param connection the connection 2881 * @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal 2882 */ 2883 void 2884 dbus_connection_set_exit_on_disconnect (DBusConnection *connection, 2885 dbus_bool_t exit_on_disconnect) 2886 { 2887 _dbus_return_if_fail (connection != NULL); 2888 2889 CONNECTION_LOCK (connection); 2890 connection->exit_on_disconnect = exit_on_disconnect != FALSE; 2891 CONNECTION_UNLOCK (connection); 2892 } 2893 2894 /** 2895 * Preallocates resources needed to send a message, allowing the message 2896 * to be sent without the possibility of memory allocation failure. 2897 * Allows apps to create a future guarantee that they can send 2898 * a message regardless of memory shortages. 2899 * 2900 * @param connection the connection we're preallocating for. 2901 * @returns the preallocated resources, or #NULL 2902 */ 2903 DBusPreallocatedSend* 2904 dbus_connection_preallocate_send (DBusConnection *connection) 2905 { 2906 DBusPreallocatedSend *preallocated; 2907 2908 _dbus_return_val_if_fail (connection != NULL, NULL); 2909 2910 CONNECTION_LOCK (connection); 2911 2912 preallocated = 2913 _dbus_connection_preallocate_send_unlocked (connection); 2914 2915 CONNECTION_UNLOCK (connection); 2916 2917 return preallocated; 2918 } 2919 2920 /** 2921 * Frees preallocated message-sending resources from 2922 * dbus_connection_preallocate_send(). Should only 2923 * be called if the preallocated resources are not used 2924 * to send a message. 2925 * 2926 * @param connection the connection 2927 * @param preallocated the resources 2928 */ 2929 void 2930 dbus_connection_free_preallocated_send (DBusConnection *connection, 2931 DBusPreallocatedSend *preallocated) 2932 { 2933 _dbus_return_if_fail (connection != NULL); 2934 _dbus_return_if_fail (preallocated != NULL); 2935 _dbus_return_if_fail (connection == preallocated->connection); 2936 2937 _dbus_list_free_link (preallocated->queue_link); 2938 _dbus_counter_unref (preallocated->counter_link->data); 2939 _dbus_list_free_link (preallocated->counter_link); 2940 dbus_free (preallocated); 2941 } 2942 2943 /** 2944 * Sends a message using preallocated resources. This function cannot fail. 2945 * It works identically to dbus_connection_send() in other respects. 2946 * Preallocated resources comes from dbus_connection_preallocate_send(). 2947 * This function "consumes" the preallocated resources, they need not 2948 * be freed separately. 2949 * 2950 * @param connection the connection 2951 * @param preallocated the preallocated resources 2952 * @param message the message to send 2953 * @param client_serial return location for client serial assigned to the message 2954 */ 2955 void 2956 dbus_connection_send_preallocated (DBusConnection *connection, 2957 DBusPreallocatedSend *preallocated, 2958 DBusMessage *message, 2959 dbus_uint32_t *client_serial) 2960 { 2961 _dbus_return_if_fail (connection != NULL); 2962 _dbus_return_if_fail (preallocated != NULL); 2963 _dbus_return_if_fail (message != NULL); 2964 _dbus_return_if_fail (preallocated->connection == connection); 2965 _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL || 2966 dbus_message_get_member (message) != NULL); 2967 _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL || 2968 (dbus_message_get_interface (message) != NULL && 2969 dbus_message_get_member (message) != NULL)); 2970 2971 CONNECTION_LOCK (connection); 2972 _dbus_connection_send_preallocated_and_unlock (connection, 2973 preallocated, 2974 message, client_serial); 2975 } 2976 2977 static dbus_bool_t 2978 _dbus_connection_send_unlocked_no_update (DBusConnection *connection, 2979 DBusMessage *message, 2980 dbus_uint32_t *client_serial) 2981 { 2982 DBusPreallocatedSend *preallocated; 2983 2984 _dbus_assert (connection != NULL); 2985 _dbus_assert (message != NULL); 2986 2987 preallocated = _dbus_connection_preallocate_send_unlocked (connection); 2988 if (preallocated == NULL) 2989 return FALSE; 2990 2991 _dbus_connection_send_preallocated_unlocked_no_update (connection, 2992 preallocated, 2993 message, 2994 client_serial); 2995 return TRUE; 2996 } 2997 2998 /** 2999 * Adds a message to the outgoing message queue. Does not block to 3000 * write the message to the network; that happens asynchronously. To 3001 * force the message to be written, call dbus_connection_flush(). 3002 * Because this only queues the message, the only reason it can 3003 * fail is lack of memory. Even if the connection is disconnected, 3004 * no error will be returned. 3005 * 3006 * If the function fails due to lack of memory, it returns #FALSE. 3007 * The function will never fail for other reasons; even if the 3008 * connection is disconnected, you can queue an outgoing message, 3009 * though obviously it won't be sent. 3010 * 3011 * The message serial is used by the remote application to send a 3012 * reply; see dbus_message_get_serial() or the D-Bus specification. 3013 * 3014 * @param connection the connection. 3015 * @param message the message to write. 3016 * @param serial return location for message serial, or #NULL if you don't care 3017 * @returns #TRUE on success. 3018 */ 3019 dbus_bool_t 3020 dbus_connection_send (DBusConnection *connection, 3021 DBusMessage *message, 3022 dbus_uint32_t *serial) 3023 { 3024 _dbus_return_val_if_fail (connection != NULL, FALSE); 3025 _dbus_return_val_if_fail (message != NULL, FALSE); 3026 3027 CONNECTION_LOCK (connection); 3028 3029 return _dbus_connection_send_and_unlock (connection, 3030 message, 3031 serial); 3032 } 3033 3034 static dbus_bool_t 3035 reply_handler_timeout (void *data) 3036 { 3037 DBusConnection *connection; 3038 DBusDispatchStatus status; 3039 DBusPendingCall *pending = data; 3040 3041 connection = _dbus_pending_call_get_connection_and_lock (pending); 3042 3043 _dbus_pending_call_queue_timeout_error_unlocked (pending, 3044 connection); 3045 _dbus_connection_remove_timeout_unlocked (connection, 3046 _dbus_pending_call_get_timeout_unlocked (pending)); 3047 _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); 3048 3049 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); 3050 status = _dbus_connection_get_dispatch_status_unlocked (connection); 3051 3052 /* Unlocks, and calls out to user code */ 3053 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 3054 3055 return TRUE; 3056 } 3057 3058 /** 3059 * Queues a message to send, as with dbus_connection_send(), 3060 * but also returns a #DBusPendingCall used to receive a reply to the 3061 * message. If no reply is received in the given timeout_milliseconds, 3062 * this function expires the pending reply and generates a synthetic 3063 * error reply (generated in-process, not by the remote application) 3064 * indicating that a timeout occurred. 3065 * 3066 * A #DBusPendingCall will see a reply message before any filters or 3067 * registered object path handlers. See dbus_connection_dispatch() for 3068 * details on when handlers are run. 3069 * 3070 * A #DBusPendingCall will always see exactly one reply message, 3071 * unless it's cancelled with dbus_pending_call_cancel(). 3072 * 3073 * If #NULL is passed for the pending_return, the #DBusPendingCall 3074 * will still be generated internally, and used to track 3075 * the message reply timeout. This means a timeout error will 3076 * occur if no reply arrives, unlike with dbus_connection_send(). 3077 * 3078 * If -1 is passed for the timeout, a sane default timeout is used. -1 3079 * is typically the best value for the timeout for this reason, unless 3080 * you want a very short or very long timeout. There is no way to 3081 * avoid a timeout entirely, other than passing INT_MAX for the 3082 * timeout to mean "very long timeout." libdbus clamps an INT_MAX 3083 * timeout down to a few hours timeout though. 3084 * 3085 * @warning if the connection is disconnected, the #DBusPendingCall 3086 * will be set to #NULL, so be careful with this. 3087 * 3088 * @param connection the connection 3089 * @param message the message to send 3090 * @param pending_return return location for a #DBusPendingCall object, or #NULL if connection is disconnected 3091 * @param timeout_milliseconds timeout in milliseconds or -1 for default 3092 * @returns #FALSE if no memory, #TRUE otherwise. 3093 * 3094 */ 3095 dbus_bool_t 3096 dbus_connection_send_with_reply (DBusConnection *connection, 3097 DBusMessage *message, 3098 DBusPendingCall **pending_return, 3099 int timeout_milliseconds) 3100 { 3101 DBusPendingCall *pending; 3102 dbus_int32_t serial = -1; 3103 DBusDispatchStatus status; 3104 3105 _dbus_return_val_if_fail (connection != NULL, FALSE); 3106 _dbus_return_val_if_fail (message != NULL, FALSE); 3107 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); 3108 3109 if (pending_return) 3110 *pending_return = NULL; 3111 3112 CONNECTION_LOCK (connection); 3113 3114 if (!_dbus_connection_get_is_connected_unlocked (connection)) 3115 { 3116 CONNECTION_UNLOCK (connection); 3117 3118 *pending_return = NULL; 3119 3120 return TRUE; 3121 } 3122 3123 pending = _dbus_pending_call_new_unlocked (connection, 3124 timeout_milliseconds, 3125 reply_handler_timeout); 3126 3127 if (pending == NULL) 3128 { 3129 CONNECTION_UNLOCK (connection); 3130 return FALSE; 3131 } 3132 3133 /* Assign a serial to the message */ 3134 serial = dbus_message_get_serial (message); 3135 if (serial == 0) 3136 { 3137 serial = _dbus_connection_get_next_client_serial (connection); 3138 _dbus_message_set_serial (message, serial); 3139 } 3140 3141 if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial)) 3142 goto error; 3143 3144 /* Insert the serial in the pending replies hash; 3145 * hash takes a refcount on DBusPendingCall. 3146 * Also, add the timeout. 3147 */ 3148 if (!_dbus_connection_attach_pending_call_unlocked (connection, 3149 pending)) 3150 goto error; 3151 3152 if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL)) 3153 { 3154 _dbus_connection_detach_pending_call_and_unlock (connection, 3155 pending); 3156 goto error_unlocked; 3157 } 3158 3159 if (pending_return) 3160 *pending_return = pending; /* hand off refcount */ 3161 else 3162 { 3163 _dbus_connection_detach_pending_call_unlocked (connection, pending); 3164 /* we still have a ref to the pending call in this case, we unref 3165 * after unlocking, below 3166 */ 3167 } 3168 3169 status = _dbus_connection_get_dispatch_status_unlocked (connection); 3170 3171 /* this calls out to user code */ 3172 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 3173 3174 if (pending_return == NULL) 3175 dbus_pending_call_unref (pending); 3176 3177 return TRUE; 3178 3179 error: 3180 CONNECTION_UNLOCK (connection); 3181 error_unlocked: 3182 dbus_pending_call_unref (pending); 3183 return FALSE; 3184 } 3185 3186 /** 3187 * Sends a message and blocks a certain time period while waiting for 3188 * a reply. This function does not reenter the main loop, 3189 * i.e. messages other than the reply are queued up but not 3190 * processed. This function is used to invoke method calls on a 3191 * remote object. 3192 * 3193 * If a normal reply is received, it is returned, and removed from the 3194 * incoming message queue. If it is not received, #NULL is returned 3195 * and the error is set to #DBUS_ERROR_NO_REPLY. If an error reply is 3196 * received, it is converted to a #DBusError and returned as an error, 3197 * then the reply message is deleted and #NULL is returned. If 3198 * something else goes wrong, result is set to whatever is 3199 * appropriate, such as #DBUS_ERROR_NO_MEMORY or 3200 * #DBUS_ERROR_DISCONNECTED. 3201 * 3202 * @warning While this function blocks the calling thread will not be 3203 * processing the incoming message queue. This means you can end up 3204 * deadlocked if the application you're talking to needs you to reply 3205 * to a method. To solve this, either avoid the situation, block in a 3206 * separate thread from the main connection-dispatching thread, or use 3207 * dbus_pending_call_set_notify() to avoid blocking. 3208 * 3209 * @param connection the connection 3210 * @param message the message to send 3211 * @param timeout_milliseconds timeout in milliseconds or -1 for default 3212 * @param error return location for error message 3213 * @returns the message that is the reply or #NULL with an error code if the 3214 * function fails. 3215 */ 3216 DBusMessage* 3217 dbus_connection_send_with_reply_and_block (DBusConnection *connection, 3218 DBusMessage *message, 3219 int timeout_milliseconds, 3220 DBusError *error) 3221 { 3222 DBusMessage *reply; 3223 DBusPendingCall *pending; 3224 3225 _dbus_return_val_if_fail (connection != NULL, NULL); 3226 _dbus_return_val_if_fail (message != NULL, NULL); 3227 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL); 3228 _dbus_return_val_if_error_is_set (error, NULL); 3229 3230 if (!dbus_connection_send_with_reply (connection, message, 3231 &pending, timeout_milliseconds)) 3232 { 3233 _DBUS_SET_OOM (error); 3234 return NULL; 3235 } 3236 3237 if (pending == NULL) 3238 { 3239 dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed"); 3240 return NULL; 3241 } 3242 3243 dbus_pending_call_block (pending); 3244 3245 reply = dbus_pending_call_steal_reply (pending); 3246 dbus_pending_call_unref (pending); 3247 3248 /* call_complete_and_unlock() called from pending_call_block() should 3249 * always fill this in. 3250 */ 3251 _dbus_assert (reply != NULL); 3252 3253 if (dbus_set_error_from_message (error, reply)) 3254 { 3255 dbus_message_unref (reply); 3256 return NULL; 3257 } 3258 else 3259 return reply; 3260 } 3261 3262 /** 3263 * Blocks until the outgoing message queue is empty. 3264 * Assumes connection lock already held. 3265 * 3266 * If you call this, you MUST call update_dispatch_status afterword... 3267 * 3268 * @param connection the connection. 3269 */ 3270 DBusDispatchStatus 3271 _dbus_connection_flush_unlocked (DBusConnection *connection) 3272 { 3273 /* We have to specify DBUS_ITERATION_DO_READING here because 3274 * otherwise we could have two apps deadlock if they are both doing 3275 * a flush(), and the kernel buffers fill up. This could change the 3276 * dispatch status. 3277 */ 3278 DBusDispatchStatus status; 3279 3280 HAVE_LOCK_CHECK (connection); 3281 3282 while (connection->n_outgoing > 0 && 3283 _dbus_connection_get_is_connected_unlocked (connection)) 3284 { 3285 _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME); 3286 HAVE_LOCK_CHECK (connection); 3287 _dbus_connection_do_iteration_unlocked (connection, 3288 NULL, 3289 DBUS_ITERATION_DO_READING | 3290 DBUS_ITERATION_DO_WRITING | 3291 DBUS_ITERATION_BLOCK, 3292 -1); 3293 } 3294 3295 HAVE_LOCK_CHECK (connection); 3296 _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); 3297 status = _dbus_connection_get_dispatch_status_unlocked (connection); 3298 3299 HAVE_LOCK_CHECK (connection); 3300 return status; 3301 } 3302 3303 /** 3304 * Blocks until the outgoing message queue is empty. 3305 * 3306 * @param connection the connection. 3307 */ 3308 void 3309 dbus_connection_flush (DBusConnection *connection) 3310 { 3311 /* We have to specify DBUS_ITERATION_DO_READING here because 3312 * otherwise we could have two apps deadlock if they are both doing 3313 * a flush(), and the kernel buffers fill up. This could change the 3314 * dispatch status. 3315 */ 3316 DBusDispatchStatus status; 3317 3318 _dbus_return_if_fail (connection != NULL); 3319 3320 CONNECTION_LOCK (connection); 3321 3322 status = _dbus_connection_flush_unlocked (connection); 3323 3324 HAVE_LOCK_CHECK (connection); 3325 /* Unlocks and calls out to user code */ 3326 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 3327 3328 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); 3329 } 3330 3331 /** 3332 * This function implements dbus_connection_read_write_dispatch() and 3333 * dbus_connection_read_write() (they pass a different value for the 3334 * dispatch parameter). 3335 * 3336 * @param connection the connection 3337 * @param timeout_milliseconds max time to block or -1 for infinite 3338 * @param dispatch dispatch new messages or leave them on the incoming queue 3339 * @returns #TRUE if the disconnect message has not been processed 3340 */ 3341 static dbus_bool_t 3342 _dbus_connection_read_write_dispatch (DBusConnection *connection, 3343 int timeout_milliseconds, 3344 dbus_bool_t dispatch) 3345 { 3346 DBusDispatchStatus dstatus; 3347 dbus_bool_t no_progress_possible; 3348 3349 dstatus = dbus_connection_get_dispatch_status (connection); 3350 3351 if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS) 3352 { 3353 _dbus_verbose ("doing dispatch in %s\n", _DBUS_FUNCTION_NAME); 3354 dbus_connection_dispatch (connection); 3355 CONNECTION_LOCK (connection); 3356 } 3357 else if (dstatus == DBUS_DISPATCH_NEED_MEMORY) 3358 { 3359 _dbus_verbose ("pausing for memory in %s\n", _DBUS_FUNCTION_NAME); 3360 _dbus_memory_pause_based_on_timeout (timeout_milliseconds); 3361 CONNECTION_LOCK (connection); 3362 } 3363 else 3364 { 3365 CONNECTION_LOCK (connection); 3366 if (_dbus_connection_get_is_connected_unlocked (connection)) 3367 { 3368 _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME); 3369 _dbus_connection_do_iteration_unlocked (connection, 3370 NULL, 3371 DBUS_ITERATION_DO_READING | 3372 DBUS_ITERATION_DO_WRITING | 3373 DBUS_ITERATION_BLOCK, 3374 timeout_milliseconds); 3375 } 3376 } 3377 3378 HAVE_LOCK_CHECK (connection); 3379 /* If we can dispatch, we can make progress until the Disconnected message 3380 * has been processed; if we can only read/write, we can make progress 3381 * as long as the transport is open. 3382 */ 3383 if (dispatch) 3384 no_progress_possible = connection->n_incoming == 0 && 3385 connection->disconnect_message_link == NULL; 3386 else 3387 no_progress_possible = _dbus_connection_get_is_connected_unlocked (connection); 3388 CONNECTION_UNLOCK (connection); 3389 return !no_progress_possible; /* TRUE if we can make more progress */ 3390 } 3391 3392 3393 /** 3394 * This function is intended for use with applications that don't want 3395 * to write a main loop and deal with #DBusWatch and #DBusTimeout. An 3396 * example usage would be: 3397 * 3398 * @code 3399 * while (dbus_connection_read_write_dispatch (connection, -1)) 3400 * ; // empty loop body 3401 * @endcode 3402 * 3403 * In this usage you would normally have set up a filter function to look 3404 * at each message as it is dispatched. The loop terminates when the last 3405 * message from the connection (the disconnected signal) is processed. 3406 * 3407 * If there are messages to dispatch, this function will 3408 * dbus_connection_dispatch() once, and return. If there are no 3409 * messages to dispatch, this function will block until it can read or 3410 * write, then read or write, then return. 3411 * 3412 * The way to think of this function is that it either makes some sort 3413 * of progress, or it blocks. Note that, while it is blocked on I/O, it 3414 * cannot be interrupted (even by other threads), which makes this function 3415 * unsuitable for applications that do more than just react to received 3416 * messages. 3417 * 3418 * The return value indicates whether the disconnect message has been 3419 * processed, NOT whether the connection is connected. This is 3420 * important because even after disconnecting, you want to process any 3421 * messages you received prior to the disconnect. 3422 * 3423 * @param connection the connection 3424 * @param timeout_milliseconds max time to block or -1 for infinite 3425 * @returns #TRUE if the disconnect message has not been processed 3426 */ 3427 dbus_bool_t 3428 dbus_connection_read_write_dispatch (DBusConnection *connection, 3429 int timeout_milliseconds) 3430 { 3431 _dbus_return_val_if_fail (connection != NULL, FALSE); 3432 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); 3433 return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, TRUE); 3434 } 3435 3436 3437 /** 3438 * This function is intended for use with applications that want to 3439 * dispatch all the events in the incoming/outgoing queue before returning. 3440 * The function just calls dbus_connection_read_write_dispatch till 3441 * the incoming queue is empty. 3442 * 3443 * @param connection the connection 3444 * @param timeout_milliseconds max time to block or -1 for infinite 3445 * @returns #TRUE if the disconnect message has not been processed 3446 */ 3447 dbus_bool_t 3448 dbus_connection_read_write_dispatch_greedy (DBusConnection *connection, 3449 int timeout_milliseconds) 3450 { 3451 dbus_bool_t ret, progress_possible; 3452 int pre_incoming, pre_outgoing; 3453 do 3454 { 3455 pre_incoming = connection->n_incoming; 3456 pre_outgoing = connection->n_outgoing; 3457 ret = dbus_connection_read_write_dispatch(connection, timeout_milliseconds); 3458 /* No need to take a lock here. If another 'reader' thread has read the packet, 3459 * dbus_connection_read_write_dispatch will just return. If a writer 3460 * writes a packet between the call and the check, it will get processed 3461 * in the next call to the function. 3462 */ 3463 if ((pre_incoming != connection->n_incoming || 3464 pre_outgoing != connection->n_outgoing) && 3465 (connection->n_incoming > 0 || 3466 connection->n_outgoing > 0)) { 3467 progress_possible = TRUE; 3468 } else { 3469 progress_possible = FALSE; 3470 } 3471 } while (ret == TRUE && progress_possible); 3472 return ret; 3473 } 3474 3475 3476 /** 3477 * This function is intended for use with applications that don't want to 3478 * write a main loop and deal with #DBusWatch and #DBusTimeout. See also 3479 * dbus_connection_read_write_dispatch(). 3480 * 3481 * As long as the connection is open, this function will block until it can 3482 * read or write, then read or write, then return #TRUE. 3483 * 3484 * If the connection is closed, the function returns #FALSE. 3485 * 3486 * The return value indicates whether reading or writing is still 3487 * possible, i.e. whether the connection is connected. 3488 * 3489 * Note that even after disconnection, messages may remain in the 3490 * incoming queue that need to be 3491 * processed. dbus_connection_read_write_dispatch() dispatches 3492 * incoming messages for you; with dbus_connection_read_write() you 3493 * have to arrange to drain the incoming queue yourself. 3494 * 3495 * @param connection the connection 3496 * @param timeout_milliseconds max time to block or -1 for infinite 3497 * @returns #TRUE if still connected 3498 */ 3499 dbus_bool_t 3500 dbus_connection_read_write (DBusConnection *connection, 3501 int timeout_milliseconds) 3502 { 3503 _dbus_return_val_if_fail (connection != NULL, FALSE); 3504 _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); 3505 return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE); 3506 } 3507 3508 /* We need to call this anytime we pop the head of the queue, and then 3509 * update_dispatch_status_and_unlock needs to be called afterward 3510 * which will "process" the disconnected message and set 3511 * disconnected_message_processed. 3512 */ 3513 static void 3514 check_disconnected_message_arrived_unlocked (DBusConnection *connection, 3515 DBusMessage *head_of_queue) 3516 { 3517 HAVE_LOCK_CHECK (connection); 3518 3519 /* checking that the link is NULL is an optimization to avoid the is_signal call */ 3520 if (connection->disconnect_message_link == NULL && 3521 dbus_message_is_signal (head_of_queue, 3522 DBUS_INTERFACE_LOCAL, 3523 "Disconnected")) 3524 { 3525 connection->disconnected_message_arrived = TRUE; 3526 } 3527 } 3528 3529 /** 3530 * Returns the first-received message from the incoming message queue, 3531 * leaving it in the queue. If the queue is empty, returns #NULL. 3532 * 3533 * The caller does not own a reference to the returned message, and 3534 * must either return it using dbus_connection_return_message() or 3535 * keep it after calling dbus_connection_steal_borrowed_message(). No 3536 * one can get at the message while its borrowed, so return it as 3537 * quickly as possible and don't keep a reference to it after 3538 * returning it. If you need to keep the message, make a copy of it. 3539 * 3540 * dbus_connection_dispatch() will block if called while a borrowed 3541 * message is outstanding; only one piece of code can be playing with 3542 * the incoming queue at a time. This function will block if called 3543 * during a dbus_connection_dispatch(). 3544 * 3545 * @param connection the connection. 3546 * @returns next message in the incoming queue. 3547 */ 3548 DBusMessage* 3549 dbus_connection_borrow_message (DBusConnection *connection) 3550 { 3551 DBusDispatchStatus status; 3552 DBusMessage *message; 3553 3554 _dbus_return_val_if_fail (connection != NULL, NULL); 3555 3556 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); 3557 3558 /* this is called for the side effect that it queues 3559 * up any messages from the transport 3560 */ 3561 status = dbus_connection_get_dispatch_status (connection); 3562 if (status != DBUS_DISPATCH_DATA_REMAINS) 3563 return NULL; 3564 3565 CONNECTION_LOCK (connection); 3566 3567 _dbus_connection_acquire_dispatch (connection); 3568 3569 /* While a message is outstanding, the dispatch lock is held */ 3570 _dbus_assert (connection->message_borrowed == NULL); 3571 3572 connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages); 3573 3574 message = connection->message_borrowed; 3575 3576 check_disconnected_message_arrived_unlocked (connection, message); 3577 3578 /* Note that we KEEP the dispatch lock until the message is returned */ 3579 if (message == NULL) 3580 _dbus_connection_release_dispatch (connection); 3581 3582 CONNECTION_UNLOCK (connection); 3583 3584 /* We don't update dispatch status until it's returned or stolen */ 3585 3586 return message; 3587 } 3588 3589 /** 3590 * Used to return a message after peeking at it using 3591 * dbus_connection_borrow_message(). Only called if 3592 * message from dbus_connection_borrow_message() was non-#NULL. 3593 * 3594 * @param connection the connection 3595 * @param message the message from dbus_connection_borrow_message() 3596 */ 3597 void 3598 dbus_connection_return_message (DBusConnection *connection, 3599 DBusMessage *message) 3600 { 3601 DBusDispatchStatus status; 3602 3603 _dbus_return_if_fail (connection != NULL); 3604 _dbus_return_if_fail (message != NULL); 3605 _dbus_return_if_fail (message == connection->message_borrowed); 3606 _dbus_return_if_fail (connection->dispatch_acquired); 3607 3608 CONNECTION_LOCK (connection); 3609 3610 _dbus_assert (message == connection->message_borrowed); 3611 3612 connection->message_borrowed = NULL; 3613 3614 _dbus_connection_release_dispatch (connection); 3615 3616 status = _dbus_connection_get_dispatch_status_unlocked (connection); 3617 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 3618 } 3619 3620 /** 3621 * Used to keep a message after peeking at it using 3622 * dbus_connection_borrow_message(). Before using this function, see 3623 * the caveats/warnings in the documentation for 3624 * dbus_connection_pop_message(). 3625 * 3626 * @param connection the connection 3627 * @param message the message from dbus_connection_borrow_message() 3628 */ 3629 void 3630 dbus_connection_steal_borrowed_message (DBusConnection *connection, 3631 DBusMessage *message) 3632 { 3633 DBusMessage *pop_message; 3634 DBusDispatchStatus status; 3635 3636 _dbus_return_if_fail (connection != NULL); 3637 _dbus_return_if_fail (message != NULL); 3638 _dbus_return_if_fail (message == connection->message_borrowed); 3639 _dbus_return_if_fail (connection->dispatch_acquired); 3640 3641 CONNECTION_LOCK (connection); 3642 3643 _dbus_assert (message == connection->message_borrowed); 3644 3645 pop_message = _dbus_list_pop_first (&connection->incoming_messages); 3646 _dbus_assert (message == pop_message); 3647 3648 connection->n_incoming -= 1; 3649 3650 _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n", 3651 message, connection->n_incoming); 3652 3653 connection->message_borrowed = NULL; 3654 3655 _dbus_connection_release_dispatch (connection); 3656 3657 status = _dbus_connection_get_dispatch_status_unlocked (connection); 3658 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 3659 } 3660 3661 /* See dbus_connection_pop_message, but requires the caller to own 3662 * the lock before calling. May drop the lock while running. 3663 */ 3664 static DBusList* 3665 _dbus_connection_pop_message_link_unlocked (DBusConnection *connection) 3666 { 3667 HAVE_LOCK_CHECK (connection); 3668 3669 _dbus_assert (connection->message_borrowed == NULL); 3670 3671 if (connection->n_incoming > 0) 3672 { 3673 DBusList *link; 3674 3675 link = _dbus_list_pop_first_link (&connection->incoming_messages); 3676 connection->n_incoming -= 1; 3677 3678 _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from incoming queue %p, %d incoming\n", 3679 link->data, 3680 dbus_message_get_type (link->data), 3681 dbus_message_get_path (link->data) ? 3682 dbus_message_get_path (link->data) : 3683 "no path", 3684 dbus_message_get_interface (link->data) ? 3685 dbus_message_get_interface (link->data) : 3686 "no interface", 3687 dbus_message_get_member (link->data) ? 3688 dbus_message_get_member (link->data) : 3689 "no member", 3690 dbus_message_get_signature (link->data), 3691 connection, connection->n_incoming); 3692 3693 check_disconnected_message_arrived_unlocked (connection, link->data); 3694 3695 return link; 3696 } 3697 else 3698 return NULL; 3699 } 3700 3701 /* See dbus_connection_pop_message, but requires the caller to own 3702 * the lock before calling. May drop the lock while running. 3703 */ 3704 static DBusMessage* 3705 _dbus_connection_pop_message_unlocked (DBusConnection *connection) 3706 { 3707 DBusList *link; 3708 3709 HAVE_LOCK_CHECK (connection); 3710 3711 link = _dbus_connection_pop_message_link_unlocked (connection); 3712 3713 if (link != NULL) 3714 { 3715 DBusMessage *message; 3716 3717 message = link->data; 3718 3719 _dbus_list_free_link (link); 3720 3721 return message; 3722 } 3723 else 3724 return NULL; 3725 } 3726 3727 static void 3728 _dbus_connection_putback_message_link_unlocked (DBusConnection *connection, 3729 DBusList *message_link) 3730 { 3731 HAVE_LOCK_CHECK (connection); 3732 3733 _dbus_assert (message_link != NULL); 3734 /* You can't borrow a message while a link is outstanding */ 3735 _dbus_assert (connection->message_borrowed == NULL); 3736 /* We had to have the dispatch lock across the pop/putback */ 3737 _dbus_assert (connection->dispatch_acquired); 3738 3739 _dbus_list_prepend_link (&connection->incoming_messages, 3740 message_link); 3741 connection->n_incoming += 1; 3742 3743 _dbus_verbose ("Message %p (%d %s %s '%s') put back into queue %p, %d incoming\n", 3744 message_link->data, 3745 dbus_message_get_type (message_link->data), 3746 dbus_message_get_interface (message_link->data) ? 3747 dbus_message_get_interface (message_link->data) : 3748 "no interface", 3749 dbus_message_get_member (message_link->data) ? 3750 dbus_message_get_member (message_link->data) : 3751 "no member", 3752 dbus_message_get_signature (message_link->data), 3753 connection, connection->n_incoming); 3754 } 3755 3756 /** 3757 * Returns the first-received message from the incoming message queue, 3758 * removing it from the queue. The caller owns a reference to the 3759 * returned message. If the queue is empty, returns #NULL. 3760 * 3761 * This function bypasses any message handlers that are registered, 3762 * and so using it is usually wrong. Instead, let the main loop invoke 3763 * dbus_connection_dispatch(). Popping messages manually is only 3764 * useful in very simple programs that don't share a #DBusConnection 3765 * with any libraries or other modules. 3766 * 3767 * There is a lock that covers all ways of accessing the incoming message 3768 * queue, so dbus_connection_dispatch(), dbus_connection_pop_message(), 3769 * dbus_connection_borrow_message(), etc. will all block while one of the others 3770 * in the group is running. 3771 * 3772 * @param connection the connection. 3773 * @returns next message in the incoming queue. 3774 */ 3775 DBusMessage* 3776 dbus_connection_pop_message (DBusConnection *connection) 3777 { 3778 DBusMessage *message; 3779 DBusDispatchStatus status; 3780 3781 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); 3782 3783 /* this is called for the side effect that it queues 3784 * up any messages from the transport 3785 */ 3786 status = dbus_connection_get_dispatch_status (connection); 3787 if (status != DBUS_DISPATCH_DATA_REMAINS) 3788 return NULL; 3789 3790 CONNECTION_LOCK (connection); 3791 _dbus_connection_acquire_dispatch (connection); 3792 HAVE_LOCK_CHECK (connection); 3793 3794 message = _dbus_connection_pop_message_unlocked (connection); 3795 3796 _dbus_verbose ("Returning popped message %p\n", message); 3797 3798 _dbus_connection_release_dispatch (connection); 3799 3800 status = _dbus_connection_get_dispatch_status_unlocked (connection); 3801 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 3802 3803 return message; 3804 } 3805 3806 /** 3807 * Acquire the dispatcher. This is a separate lock so the main 3808 * connection lock can be dropped to call out to application dispatch 3809 * handlers. 3810 * 3811 * @param connection the connection. 3812 */ 3813 static void 3814 _dbus_connection_acquire_dispatch (DBusConnection *connection) 3815 { 3816 HAVE_LOCK_CHECK (connection); 3817 3818 _dbus_connection_ref_unlocked (connection); 3819 CONNECTION_UNLOCK (connection); 3820 3821 _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME); 3822 _dbus_mutex_lock (connection->dispatch_mutex); 3823 3824 while (connection->dispatch_acquired) 3825 { 3826 _dbus_verbose ("%s waiting for dispatch to be acquirable\n", _DBUS_FUNCTION_NAME); 3827 _dbus_condvar_wait (connection->dispatch_cond, 3828 connection->dispatch_mutex); 3829 } 3830 3831 _dbus_assert (!connection->dispatch_acquired); 3832 3833 connection->dispatch_acquired = TRUE; 3834 3835 _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME); 3836 _dbus_mutex_unlock (connection->dispatch_mutex); 3837 3838 CONNECTION_LOCK (connection); 3839 _dbus_connection_unref_unlocked (connection); 3840 } 3841 3842 /** 3843 * Release the dispatcher when you're done with it. Only call 3844 * after you've acquired the dispatcher. Wakes up at most one 3845 * thread currently waiting to acquire the dispatcher. 3846 * 3847 * @param connection the connection. 3848 */ 3849 static void 3850 _dbus_connection_release_dispatch (DBusConnection *connection) 3851 { 3852 HAVE_LOCK_CHECK (connection); 3853 3854 _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME); 3855 _dbus_mutex_lock (connection->dispatch_mutex); 3856 3857 _dbus_assert (connection->dispatch_acquired); 3858 3859 connection->dispatch_acquired = FALSE; 3860 _dbus_condvar_wake_one (connection->dispatch_cond); 3861 3862 _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME); 3863 _dbus_mutex_unlock (connection->dispatch_mutex); 3864 } 3865 3866 static void 3867 _dbus_connection_failed_pop (DBusConnection *connection, 3868 DBusList *message_link) 3869 { 3870 _dbus_list_prepend_link (&connection->incoming_messages, 3871 message_link); 3872 connection->n_incoming += 1; 3873 } 3874 3875 /* Note this may be called multiple times since we don't track whether we already did it */ 3876 static void 3877 notify_disconnected_unlocked (DBusConnection *connection) 3878 { 3879 HAVE_LOCK_CHECK (connection); 3880 3881 /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected 3882 * connection from dbus_bus_get(). We make the same guarantee for 3883 * dbus_connection_open() but in a different way since we don't want to 3884 * unref right here; we instead check for connectedness before returning 3885 * the connection from the hash. 3886 */ 3887 _dbus_bus_notify_shared_connection_disconnected_unlocked (connection); 3888 3889 /* Dump the outgoing queue, we aren't going to be able to 3890 * send it now, and we'd like accessors like 3891 * dbus_connection_get_outgoing_size() to be accurate. 3892 */ 3893 if (connection->n_outgoing > 0) 3894 { 3895 DBusList *link; 3896 3897 _dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n", 3898 connection->n_outgoing); 3899 3900 while ((link = _dbus_list_get_last_link (&connection->outgoing_messages))) 3901 { 3902 _dbus_connection_message_sent (connection, link->data); 3903 } 3904 } 3905 } 3906 3907 /* Note this may be called multiple times since we don't track whether we already did it */ 3908 static DBusDispatchStatus 3909 notify_disconnected_and_dispatch_complete_unlocked (DBusConnection *connection) 3910 { 3911 HAVE_LOCK_CHECK (connection); 3912 3913 if (connection->disconnect_message_link != NULL) 3914 { 3915 _dbus_verbose ("Sending disconnect message from %s\n", 3916 _DBUS_FUNCTION_NAME); 3917 3918 /* If we have pending calls, queue their timeouts - we want the Disconnected 3919 * to be the last message, after these timeouts. 3920 */ 3921 connection_timeout_and_complete_all_pending_calls_unlocked (connection); 3922 3923 /* We haven't sent the disconnect message already, 3924 * and all real messages have been queued up. 3925 */ 3926 _dbus_connection_queue_synthesized_message_link (connection, 3927 connection->disconnect_message_link); 3928 connection->disconnect_message_link = NULL; 3929 3930 return DBUS_DISPATCH_DATA_REMAINS; 3931 } 3932 3933 return DBUS_DISPATCH_COMPLETE; 3934 } 3935 3936 static DBusDispatchStatus 3937 _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection) 3938 { 3939 HAVE_LOCK_CHECK (connection); 3940 3941 if (connection->n_incoming > 0) 3942 return DBUS_DISPATCH_DATA_REMAINS; 3943 else if (!_dbus_transport_queue_messages (connection->transport)) 3944 return DBUS_DISPATCH_NEED_MEMORY; 3945 else 3946 { 3947 DBusDispatchStatus status; 3948 dbus_bool_t is_connected; 3949 3950 status = _dbus_transport_get_dispatch_status (connection->transport); 3951 is_connected = _dbus_transport_get_is_connected (connection->transport); 3952 3953 _dbus_verbose ("dispatch status = %s is_connected = %d\n", 3954 DISPATCH_STATUS_NAME (status), is_connected); 3955 3956 if (!is_connected) 3957 { 3958 /* It's possible this would be better done by having an explicit 3959 * notification from _dbus_transport_disconnect() that would 3960 * synchronously do this, instead of waiting for the next dispatch 3961 * status check. However, probably not good to change until it causes 3962 * a problem. 3963 */ 3964 notify_disconnected_unlocked (connection); 3965 3966 /* I'm not sure this is needed; the idea is that we want to 3967 * queue the Disconnected only after we've read all the 3968 * messages, but if we're disconnected maybe we are guaranteed 3969 * to have read them all ? 3970 */ 3971 if (status == DBUS_DISPATCH_COMPLETE) 3972 status = notify_disconnected_and_dispatch_complete_unlocked (connection); 3973 } 3974 3975 if (status != DBUS_DISPATCH_COMPLETE) 3976 return status; 3977 else if (connection->n_incoming > 0) 3978 return DBUS_DISPATCH_DATA_REMAINS; 3979 else 3980 return DBUS_DISPATCH_COMPLETE; 3981 } 3982 } 3983 3984 static void 3985 _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, 3986 DBusDispatchStatus new_status) 3987 { 3988 dbus_bool_t changed; 3989 DBusDispatchStatusFunction function; 3990 void *data; 3991 3992 HAVE_LOCK_CHECK (connection); 3993 3994 _dbus_connection_ref_unlocked (connection); 3995 3996 changed = new_status != connection->last_dispatch_status; 3997 3998 connection->last_dispatch_status = new_status; 3999 4000 function = connection->dispatch_status_function; 4001 data = connection->dispatch_status_data; 4002 4003 if (connection->disconnected_message_arrived && 4004 !connection->disconnected_message_processed) 4005 { 4006 connection->disconnected_message_processed = TRUE; 4007 4008 /* this does an unref, but we have a ref 4009 * so we should not run the finalizer here 4010 * inside the lock. 4011 */ 4012 connection_forget_shared_unlocked (connection); 4013 4014 if (connection->exit_on_disconnect) 4015 { 4016 CONNECTION_UNLOCK (connection); 4017 4018 _dbus_verbose ("Exiting on Disconnected signal\n"); 4019 _dbus_exit (1); 4020 _dbus_assert_not_reached ("Call to exit() returned"); 4021 } 4022 } 4023 4024 /* We drop the lock */ 4025 CONNECTION_UNLOCK (connection); 4026 4027 if (changed && function) 4028 { 4029 _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n", 4030 connection, new_status, 4031 DISPATCH_STATUS_NAME (new_status)); 4032 (* function) (connection, new_status, data); 4033 } 4034 4035 dbus_connection_unref (connection); 4036 } 4037 4038 /** 4039 * Gets the current state of the incoming message queue. 4040 * #DBUS_DISPATCH_DATA_REMAINS indicates that the message queue 4041 * may contain messages. #DBUS_DISPATCH_COMPLETE indicates that the 4042 * incoming queue is empty. #DBUS_DISPATCH_NEED_MEMORY indicates that 4043 * there could be data, but we can't know for sure without more 4044 * memory. 4045 * 4046 * To process the incoming message queue, use dbus_connection_dispatch() 4047 * or (in rare cases) dbus_connection_pop_message(). 4048 * 4049 * Note, #DBUS_DISPATCH_DATA_REMAINS really means that either we 4050 * have messages in the queue, or we have raw bytes buffered up 4051 * that need to be parsed. When these bytes are parsed, they 4052 * may not add up to an entire message. Thus, it's possible 4053 * to see a status of #DBUS_DISPATCH_DATA_REMAINS but not 4054 * have a message yet. 4055 * 4056 * In particular this happens on initial connection, because all sorts 4057 * of authentication protocol stuff has to be parsed before the 4058 * first message arrives. 4059 * 4060 * @param connection the connection. 4061 * @returns current dispatch status 4062 */ 4063 DBusDispatchStatus 4064 dbus_connection_get_dispatch_status (DBusConnection *connection) 4065 { 4066 DBusDispatchStatus status; 4067 4068 _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); 4069 4070 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); 4071 4072 CONNECTION_LOCK (connection); 4073 4074 status = _dbus_connection_get_dispatch_status_unlocked (connection); 4075 4076 CONNECTION_UNLOCK (connection); 4077 4078 return status; 4079 } 4080 4081 /** 4082 * Filter funtion for handling the Peer standard interface. 4083 */ 4084 static DBusHandlerResult 4085 _dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection, 4086 DBusMessage *message) 4087 { 4088 if (connection->route_peer_messages && dbus_message_get_destination (message) != NULL) 4089 { 4090 /* This means we're letting the bus route this message */ 4091 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; 4092 } 4093 else if (dbus_message_is_method_call (message, 4094 DBUS_INTERFACE_PEER, 4095 "Ping")) 4096 { 4097 DBusMessage *ret; 4098 dbus_bool_t sent; 4099 4100 ret = dbus_message_new_method_return (message); 4101 if (ret == NULL) 4102 return DBUS_HANDLER_RESULT_NEED_MEMORY; 4103 4104 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); 4105 4106 dbus_message_unref (ret); 4107 4108 if (!sent) 4109 return DBUS_HANDLER_RESULT_NEED_MEMORY; 4110 4111 return DBUS_HANDLER_RESULT_HANDLED; 4112 } 4113 else if (dbus_message_is_method_call (message, 4114 DBUS_INTERFACE_PEER, 4115 "GetMachineId")) 4116 { 4117 DBusMessage *ret; 4118 dbus_bool_t sent; 4119 DBusString uuid; 4120 4121 ret = dbus_message_new_method_return (message); 4122 if (ret == NULL) 4123 return DBUS_HANDLER_RESULT_NEED_MEMORY; 4124 4125 sent = FALSE; 4126 _dbus_string_init (&uuid); 4127 if (_dbus_get_local_machine_uuid_encoded (&uuid)) 4128 { 4129 const char *v_STRING = _dbus_string_get_const_data (&uuid); 4130 if (dbus_message_append_args (ret, 4131 DBUS_TYPE_STRING, &v_STRING, 4132 DBUS_TYPE_INVALID)) 4133 { 4134 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); 4135 } 4136 } 4137 _dbus_string_free (&uuid); 4138 4139 dbus_message_unref (ret); 4140 4141 if (!sent) 4142 return DBUS_HANDLER_RESULT_NEED_MEMORY; 4143 4144 return DBUS_HANDLER_RESULT_HANDLED; 4145 } 4146 else if (dbus_message_has_interface (message, DBUS_INTERFACE_PEER)) 4147 { 4148 /* We need to bounce anything else with this interface, otherwise apps 4149 * could start extending the interface and when we added extensions 4150 * here to DBusConnection we'd break those apps. 4151 */ 4152 4153 DBusMessage *ret; 4154 dbus_bool_t sent; 4155 4156 ret = dbus_message_new_error (message, 4157 DBUS_ERROR_UNKNOWN_METHOD, 4158 "Unknown method invoked on org.freedesktop.DBus.Peer interface"); 4159 if (ret == NULL) 4160 return DBUS_HANDLER_RESULT_NEED_MEMORY; 4161 4162 sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); 4163 4164 dbus_message_unref (ret); 4165 4166 if (!sent) 4167 return DBUS_HANDLER_RESULT_NEED_MEMORY; 4168 4169 return DBUS_HANDLER_RESULT_HANDLED; 4170 } 4171 else 4172 { 4173 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; 4174 } 4175 } 4176 4177 /** 4178 * Processes all builtin filter functions 4179 * 4180 * If the spec specifies a standard interface 4181 * they should be processed from this method 4182 **/ 4183 static DBusHandlerResult 4184 _dbus_connection_run_builtin_filters_unlocked_no_update (DBusConnection *connection, 4185 DBusMessage *message) 4186 { 4187 /* We just run one filter for now but have the option to run more 4188 if the spec calls for it in the future */ 4189 4190 return _dbus_connection_peer_filter_unlocked_no_update (connection, message); 4191 } 4192 4193 /** 4194 * Processes any incoming data. 4195 * 4196 * If there's incoming raw data that has not yet been parsed, it is 4197 * parsed, which may or may not result in adding messages to the 4198 * incoming queue. 4199 * 4200 * The incoming data buffer is filled when the connection reads from 4201 * its underlying transport (such as a socket). Reading usually 4202 * happens in dbus_watch_handle() or dbus_connection_read_write(). 4203 * 4204 * If there are complete messages in the incoming queue, 4205 * dbus_connection_dispatch() removes one message from the queue and 4206 * processes it. Processing has three steps. 4207 * 4208 * First, any method replies are passed to #DBusPendingCall or 4209 * dbus_connection_send_with_reply_and_block() in order to 4210 * complete the pending method call. 4211 * 4212 * Second, any filters registered with dbus_connection_add_filter() 4213 * are run. If any filter returns #DBUS_HANDLER_RESULT_HANDLED 4214 * then processing stops after that filter. 4215 * 4216 * Third, if the message is a method call it is forwarded to 4217 * any registered object path handlers added with 4218 * dbus_connection_register_object_path() or 4219 * dbus_connection_register_fallback(). 4220 * 4221 * A single call to dbus_connection_dispatch() will process at most 4222 * one message; it will not clear the entire message queue. 4223 * 4224 * Be careful about calling dbus_connection_dispatch() from inside a 4225 * message handler, i.e. calling dbus_connection_dispatch() 4226 * recursively. If threads have been initialized with a recursive 4227 * mutex function, then this will not deadlock; however, it can 4228 * certainly confuse your application. 4229 * 4230 * @todo some FIXME in here about handling DBUS_HANDLER_RESULT_NEED_MEMORY 4231 * 4232 * @param connection the connection 4233 * @returns dispatch status, see dbus_connection_get_dispatch_status() 4234 */ 4235 DBusDispatchStatus 4236 dbus_connection_dispatch (DBusConnection *connection) 4237 { 4238 DBusMessage *message; 4239 DBusList *link, *filter_list_copy, *message_link; 4240 DBusHandlerResult result; 4241 DBusPendingCall *pending; 4242 dbus_int32_t reply_serial; 4243 DBusDispatchStatus status; 4244 4245 _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); 4246 4247 _dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME); 4248 4249 CONNECTION_LOCK (connection); 4250 status = _dbus_connection_get_dispatch_status_unlocked (connection); 4251 if (status != DBUS_DISPATCH_DATA_REMAINS) 4252 { 4253 /* unlocks and calls out to user code */ 4254 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 4255 return status; 4256 } 4257 4258 /* We need to ref the connection since the callback could potentially 4259 * drop the last ref to it 4260 */ 4261 _dbus_connection_ref_unlocked (connection); 4262 4263 _dbus_connection_acquire_dispatch (connection); 4264 HAVE_LOCK_CHECK (connection); 4265 4266 message_link = _dbus_connection_pop_message_link_unlocked (connection); 4267 if (message_link == NULL) 4268 { 4269 /* another thread dispatched our stuff */ 4270 4271 _dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n"); 4272 4273 _dbus_connection_release_dispatch (connection); 4274 4275 status = _dbus_connection_get_dispatch_status_unlocked (connection); 4276 4277 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 4278 4279 dbus_connection_unref (connection); 4280 4281 return status; 4282 } 4283 4284 message = message_link->data; 4285 4286 _dbus_verbose (" dispatching message %p (%d %s %s '%s')\n", 4287 message, 4288 dbus_message_get_type (message), 4289 dbus_message_get_interface (message) ? 4290 dbus_message_get_interface (message) : 4291 "no interface", 4292 dbus_message_get_member (message) ? 4293 dbus_message_get_member (message) : 4294 "no member", 4295 dbus_message_get_signature (message)); 4296 4297 result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED; 4298 4299 /* Pending call handling must be first, because if you do 4300 * dbus_connection_send_with_reply_and_block() or 4301 * dbus_pending_call_block() then no handlers/filters will be run on 4302 * the reply. We want consistent semantics in the case where we 4303 * dbus_connection_dispatch() the reply. 4304 */ 4305 4306 reply_serial = dbus_message_get_reply_serial (message); 4307 pending = _dbus_hash_table_lookup_int (connection->pending_replies, 4308 reply_serial); 4309 if (pending) 4310 { 4311 _dbus_verbose ("Dispatching a pending reply\n"); 4312 complete_pending_call_and_unlock (connection, pending, message); 4313 pending = NULL; /* it's probably unref'd */ 4314 4315 CONNECTION_LOCK (connection); 4316 _dbus_verbose ("pending call completed in dispatch\n"); 4317 result = DBUS_HANDLER_RESULT_HANDLED; 4318 goto out; 4319 } 4320 4321 result = _dbus_connection_run_builtin_filters_unlocked_no_update (connection, message); 4322 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) 4323 goto out; 4324 4325 if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy)) 4326 { 4327 _dbus_connection_release_dispatch (connection); 4328 HAVE_LOCK_CHECK (connection); 4329 4330 _dbus_connection_failed_pop (connection, message_link); 4331 4332 /* unlocks and calls user code */ 4333 _dbus_connection_update_dispatch_status_and_unlock (connection, 4334 DBUS_DISPATCH_NEED_MEMORY); 4335 4336 if (pending) 4337 dbus_pending_call_unref (pending); 4338 dbus_connection_unref (connection); 4339 4340 return DBUS_DISPATCH_NEED_MEMORY; 4341 } 4342 4343 _dbus_list_foreach (&filter_list_copy, 4344 (DBusForeachFunction)_dbus_message_filter_ref, 4345 NULL); 4346 4347 /* We're still protected from dispatch() reentrancy here 4348 * since we acquired the dispatcher 4349 */ 4350 CONNECTION_UNLOCK (connection); 4351 4352 link = _dbus_list_get_first_link (&filter_list_copy); 4353 while (link != NULL) 4354 { 4355 DBusMessageFilter *filter = link->data; 4356 DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link); 4357 4358 if (filter->function == NULL) 4359 { 4360 _dbus_verbose (" filter was removed in a callback function\n"); 4361 link = next; 4362 continue; 4363 } 4364 4365 _dbus_verbose (" running filter on message %p\n", message); 4366 result = (* filter->function) (connection, message, filter->user_data); 4367 4368 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) 4369 break; 4370 4371 link = next; 4372 } 4373 4374 _dbus_list_foreach (&filter_list_copy, 4375 (DBusForeachFunction)_dbus_message_filter_unref, 4376 NULL); 4377 _dbus_list_clear (&filter_list_copy); 4378 4379 CONNECTION_LOCK (connection); 4380 4381 if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) 4382 { 4383 _dbus_verbose ("No memory in %s\n", _DBUS_FUNCTION_NAME); 4384 goto out; 4385 } 4386 else if (result == DBUS_HANDLER_RESULT_HANDLED) 4387 { 4388 _dbus_verbose ("filter handled message in dispatch\n"); 4389 goto out; 4390 } 4391 4392 /* We're still protected from dispatch() reentrancy here 4393 * since we acquired the dispatcher 4394 */ 4395 _dbus_verbose (" running object path dispatch on message %p (%d %s %s '%s')\n", 4396 message, 4397 dbus_message_get_type (message), 4398 dbus_message_get_interface (message) ? 4399 dbus_message_get_interface (message) : 4400 "no interface", 4401 dbus_message_get_member (message) ? 4402 dbus_message_get_member (message) : 4403 "no member", 4404 dbus_message_get_signature (message)); 4405 4406 HAVE_LOCK_CHECK (connection); 4407 result = _dbus_object_tree_dispatch_and_unlock (connection->objects, 4408 message); 4409 4410 CONNECTION_LOCK (connection); 4411 4412 if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) 4413 { 4414 _dbus_verbose ("object tree handled message in dispatch\n"); 4415 goto out; 4416 } 4417 4418 if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL) 4419 { 4420 DBusMessage *reply; 4421 DBusString str; 4422 DBusPreallocatedSend *preallocated; 4423 4424 _dbus_verbose (" sending error %s\n", 4425 DBUS_ERROR_UNKNOWN_METHOD); 4426 4427 if (!_dbus_string_init (&str)) 4428 { 4429 result = DBUS_HANDLER_RESULT_NEED_MEMORY; 4430 _dbus_verbose ("no memory for error string in dispatch\n"); 4431 goto out; 4432 } 4433 4434 if (!_dbus_string_append_printf (&str, 4435 "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n", 4436 dbus_message_get_member (message), 4437 dbus_message_get_signature (message), 4438 dbus_message_get_interface (message))) 4439 { 4440 _dbus_string_free (&str); 4441 result = DBUS_HANDLER_RESULT_NEED_MEMORY; 4442 _dbus_verbose ("no memory for error string in dispatch\n"); 4443 goto out; 4444 } 4445 4446 reply = dbus_message_new_error (message, 4447 DBUS_ERROR_UNKNOWN_METHOD, 4448 _dbus_string_get_const_data (&str)); 4449 _dbus_string_free (&str); 4450 4451 if (reply == NULL) 4452 { 4453 result = DBUS_HANDLER_RESULT_NEED_MEMORY; 4454 _dbus_verbose ("no memory for error reply in dispatch\n"); 4455 goto out; 4456 } 4457 4458 preallocated = _dbus_connection_preallocate_send_unlocked (connection); 4459 4460 if (preallocated == NULL) 4461 { 4462 dbus_message_unref (reply); 4463 result = DBUS_HANDLER_RESULT_NEED_MEMORY; 4464 _dbus_verbose ("no memory for error send in dispatch\n"); 4465 goto out; 4466 } 4467 4468 _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, 4469 reply, NULL); 4470 4471 dbus_message_unref (reply); 4472 4473 result = DBUS_HANDLER_RESULT_HANDLED; 4474 } 4475 4476 _dbus_verbose (" done dispatching %p (%d %s %s '%s') on connection %p\n", message, 4477 dbus_message_get_type (message), 4478 dbus_message_get_interface (message) ? 4479 dbus_message_get_interface (message) : 4480 "no interface", 4481 dbus_message_get_member (message) ? 4482 dbus_message_get_member (message) : 4483 "no member", 4484 dbus_message_get_signature (message), 4485 connection); 4486 4487 out: 4488 if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) 4489 { 4490 _dbus_verbose ("out of memory in %s\n", _DBUS_FUNCTION_NAME); 4491 4492 /* Put message back, and we'll start over. 4493 * Yes this means handlers must be idempotent if they 4494 * don't return HANDLED; c'est la vie. 4495 */ 4496 _dbus_connection_putback_message_link_unlocked (connection, 4497 message_link); 4498 } 4499 else 4500 { 4501 _dbus_verbose (" ... done dispatching in %s\n", _DBUS_FUNCTION_NAME); 4502 4503 _dbus_list_free_link (message_link); 4504 dbus_message_unref (message); /* don't want the message to count in max message limits 4505 * in computing dispatch status below 4506 */ 4507 } 4508 4509 _dbus_connection_release_dispatch (connection); 4510 HAVE_LOCK_CHECK (connection); 4511 4512 _dbus_verbose ("%s before final status update\n", _DBUS_FUNCTION_NAME); 4513 status = _dbus_connection_get_dispatch_status_unlocked (connection); 4514 4515 /* unlocks and calls user code */ 4516 _dbus_connection_update_dispatch_status_and_unlock (connection, status); 4517 4518 dbus_connection_unref (connection); 4519 4520 return status; 4521 } 4522 4523 /** 4524 * Sets the watch functions for the connection. These functions are 4525 * responsible for making the application's main loop aware of file 4526 * descriptors that need to be monitored for events, using select() or 4527 * poll(). When using Qt, typically the DBusAddWatchFunction would 4528 * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction 4529 * could call g_io_add_watch(), or could be used as part of a more 4530 * elaborate GSource. Note that when a watch is added, it may 4531 * not be enabled. 4532 * 4533 * The DBusWatchToggledFunction notifies the application that the 4534 * watch has been enabled or disabled. Call dbus_watch_get_enabled() 4535 * to check this. A disabled watch should have no effect, and enabled 4536 * watch should be added to the main loop. This feature is used 4537 * instead of simply adding/removing the watch because 4538 * enabling/disabling can be done without memory allocation. The 4539 * toggled function may be NULL if a main loop re-queries 4540 * dbus_watch_get_enabled() every time anyway. 4541 * 4542 * The DBusWatch can be queried for the file descriptor to watch using 4543 * dbus_watch_get_fd(), and for the events to watch for using 4544 * dbus_watch_get_flags(). The flags returned by 4545 * dbus_watch_get_flags() will only contain DBUS_WATCH_READABLE and 4546 * DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR; 4547 * all watches implicitly include a watch for hangups, errors, and 4548 * other exceptional conditions. 4549 * 4550 * Once a file descriptor becomes readable or writable, or an exception 4551 * occurs, dbus_watch_handle() should be called to 4552 * notify the connection of the file descriptor's condition. 4553 * 4554 * dbus_watch_handle() cannot be called during the 4555 * DBusAddWatchFunction, as the connection will not be ready to handle 4556 * that watch yet. 4557 * 4558 * It is not allowed to reference a DBusWatch after it has been passed 4559 * to remove_function. 4560 * 4561 * If #FALSE is returned due to lack of memory, the failure may be due 4562 * to a #FALSE return from the new add_function. If so, the 4563 * add_function may have been called successfully one or more times, 4564 * but the remove_function will also have been called to remove any 4565 * successful adds. i.e. if #FALSE is returned the net result 4566 * should be that dbus_connection_set_watch_functions() has no effect, 4567 * but the add_function and remove_function may have been called. 4568 * 4569 * @todo We need to drop the lock when we call the 4570 * add/remove/toggled functions which can be a side effect 4571 * of setting the watch functions. 4572 * 4573 * @param connection the connection. 4574 * @param add_function function to begin monitoring a new descriptor. 4575 * @param remove_function function to stop monitoring a descriptor. 4576 * @param toggled_function function to notify of enable/disable 4577 * @param data data to pass to add_function and remove_function. 4578 * @param free_data_function function to be called to free the data. 4579 * @returns #FALSE on failure (no memory) 4580 */ 4581 dbus_bool_t 4582 dbus_connection_set_watch_functions (DBusConnection *connection, 4583 DBusAddWatchFunction add_function, 4584 DBusRemoveWatchFunction remove_function, 4585 DBusWatchToggledFunction toggled_function, 4586 void *data, 4587 DBusFreeFunction free_data_function) 4588 { 4589 dbus_bool_t retval; 4590 DBusWatchList *watches; 4591 4592 _dbus_return_val_if_fail (connection != NULL, FALSE); 4593 4594 CONNECTION_LOCK (connection); 4595 4596 #ifndef DBUS_DISABLE_CHECKS 4597 if (connection->watches == NULL) 4598 { 4599 _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n", 4600 _DBUS_FUNCTION_NAME); 4601 return FALSE; 4602 } 4603 #endif 4604 4605 /* ref connection for slightly better reentrancy */ 4606 _dbus_connection_ref_unlocked (connection); 4607 4608 /* This can call back into user code, and we need to drop the 4609 * connection lock when it does. This is kind of a lame 4610 * way to do it. 4611 */ 4612 watches = connection->watches; 4613 connection->watches = NULL; 4614 CONNECTION_UNLOCK (connection); 4615 4616 retval = _dbus_watch_list_set_functions (watches, 4617 add_function, remove_function, 4618 toggled_function, 4619 data, free_data_function); 4620 CONNECTION_LOCK (connection); 4621 connection->watches = watches; 4622 4623 CONNECTION_UNLOCK (connection); 4624 /* drop our paranoid refcount */ 4625 dbus_connection_unref (connection); 4626 4627 return retval; 4628 } 4629 4630 /** 4631 * Sets the timeout functions for the connection. These functions are 4632 * responsible for making the application's main loop aware of timeouts. 4633 * When using Qt, typically the DBusAddTimeoutFunction would create a 4634 * QTimer. When using GLib, the DBusAddTimeoutFunction would call 4635 * g_timeout_add. 4636 * 4637 * The DBusTimeoutToggledFunction notifies the application that the 4638 * timeout has been enabled or disabled. Call 4639 * dbus_timeout_get_enabled() to check this. A disabled timeout should 4640 * have no effect, and enabled timeout should be added to the main 4641 * loop. This feature is used instead of simply adding/removing the 4642 * timeout because enabling/disabling can be done without memory 4643 * allocation. With Qt, QTimer::start() and QTimer::stop() can be used 4644 * to enable and disable. The toggled function may be NULL if a main 4645 * loop re-queries dbus_timeout_get_enabled() every time anyway. 4646 * Whenever a timeout is toggled, its interval may change. 4647 * 4648 * The DBusTimeout can be queried for the timer interval using 4649 * dbus_timeout_get_interval(). dbus_timeout_handle() should be called 4650 * repeatedly, each time the interval elapses, starting after it has 4651 * elapsed once. The timeout stops firing when it is removed with the 4652 * given remove_function. The timer interval may change whenever the 4653 * timeout is added, removed, or toggled. 4654 * 4655 * @param connection the connection. 4656 * @param add_function function to add a timeout. 4657 * @param remove_function function to remove a timeout. 4658 * @param toggled_function function to notify of enable/disable 4659 * @param data data to pass to add_function and remove_function. 4660 * @param free_data_function function to be called to free the data. 4661 * @returns #FALSE on failure (no memory) 4662 */ 4663 dbus_bool_t 4664 dbus_connection_set_timeout_functions (DBusConnection *connection, 4665 DBusAddTimeoutFunction add_function, 4666 DBusRemoveTimeoutFunction remove_function, 4667 DBusTimeoutToggledFunction toggled_function, 4668 void *data, 4669 DBusFreeFunction free_data_function) 4670 { 4671 dbus_bool_t retval; 4672 DBusTimeoutList *timeouts; 4673 4674 _dbus_return_val_if_fail (connection != NULL, FALSE); 4675 4676 CONNECTION_LOCK (connection); 4677 4678 #ifndef DBUS_DISABLE_CHECKS 4679 if (connection->timeouts == NULL) 4680 { 4681 _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n", 4682 _DBUS_FUNCTION_NAME); 4683 return FALSE; 4684 } 4685 #endif 4686 4687 /* ref connection for slightly better reentrancy */ 4688 _dbus_connection_ref_unlocked (connection); 4689 4690 timeouts = connection->timeouts; 4691 connection->timeouts = NULL; 4692 CONNECTION_UNLOCK (connection); 4693 4694 retval = _dbus_timeout_list_set_functions (timeouts, 4695 add_function, remove_function, 4696 toggled_function, 4697 data, free_data_function); 4698 CONNECTION_LOCK (connection); 4699 connection->timeouts = timeouts; 4700 4701 CONNECTION_UNLOCK (connection); 4702 /* drop our paranoid refcount */ 4703 dbus_connection_unref (connection); 4704 4705 return retval; 4706 } 4707 4708 /** 4709 * Sets the mainloop wakeup function for the connection. This function 4710 * is responsible for waking up the main loop (if its sleeping in 4711 * another thread) when some some change has happened to the 4712 * connection that the mainloop needs to reconsider (e.g. a message 4713 * has been queued for writing). When using Qt, this typically 4714 * results in a call to QEventLoop::wakeUp(). When using GLib, it 4715 * would call g_main_context_wakeup(). 4716 * 4717 * @param connection the connection. 4718 * @param wakeup_main_function function to wake up the mainloop 4719 * @param data data to pass wakeup_main_function 4720 * @param free_data_function function to be called to free the data. 4721 */ 4722 void 4723 dbus_connection_set_wakeup_main_function (DBusConnection *connection, 4724 DBusWakeupMainFunction wakeup_main_function, 4725 void *data, 4726 DBusFreeFunction free_data_function) 4727 { 4728 void *old_data; 4729 DBusFreeFunction old_free_data; 4730 4731 _dbus_return_if_fail (connection != NULL); 4732 4733 CONNECTION_LOCK (connection); 4734 old_data = connection->wakeup_main_data; 4735 old_free_data = connection->free_wakeup_main_data; 4736 4737 connection->wakeup_main_function = wakeup_main_function; 4738 connection->wakeup_main_data = data; 4739 connection->free_wakeup_main_data = free_data_function; 4740 4741 CONNECTION_UNLOCK (connection); 4742 4743 /* Callback outside the lock */ 4744 if (old_free_data) 4745 (*old_free_data) (old_data); 4746 } 4747 4748 /** 4749 * Set a function to be invoked when the dispatch status changes. 4750 * If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then 4751 * dbus_connection_dispatch() needs to be called to process incoming 4752 * messages. However, dbus_connection_dispatch() MUST NOT BE CALLED 4753 * from inside the DBusDispatchStatusFunction. Indeed, almost 4754 * any reentrancy in this function is a bad idea. Instead, 4755 * the DBusDispatchStatusFunction should simply save an indication 4756 * that messages should be dispatched later, when the main loop 4757 * is re-entered. 4758 * 4759 * If you don't set a dispatch status function, you have to be sure to 4760 * dispatch on every iteration of your main loop, especially if 4761 * dbus_watch_handle() or dbus_timeout_handle() were called. 4762 * 4763 * @param connection the connection 4764 * @param function function to call on dispatch status changes 4765 * @param data data for function 4766 * @param free_data_function free the function data 4767 */ 4768 void 4769 dbus_connection_set_dispatch_status_function (DBusConnection *connection, 4770 DBusDispatchStatusFunction function, 4771 void *data, 4772 DBusFreeFunction free_data_function) 4773 { 4774 void *old_data; 4775 DBusFreeFunction old_free_data; 4776 4777 _dbus_return_if_fail (connection != NULL); 4778 4779 CONNECTION_LOCK (connection); 4780 old_data = connection->dispatch_status_data; 4781 old_free_data = connection->free_dispatch_status_data; 4782 4783 connection->dispatch_status_function = function; 4784 connection->dispatch_status_data = data; 4785 connection->free_dispatch_status_data = free_data_function; 4786 4787 CONNECTION_UNLOCK (connection); 4788 4789 /* Callback outside the lock */ 4790 if (old_free_data) 4791 (*old_free_data) (old_data); 4792 } 4793 4794 /** 4795 * Get the UNIX file descriptor of the connection, if any. This can 4796 * be used for SELinux access control checks with getpeercon() for 4797 * example. DO NOT read or write to the file descriptor, or try to 4798 * select() on it; use DBusWatch for main loop integration. Not all 4799 * connections will have a file descriptor. So for adding descriptors 4800 * to the main loop, use dbus_watch_get_fd() and so forth. 4801 * 4802 * If the connection is socket-based, you can also use 4803 * dbus_connection_get_socket(), which will work on Windows too. 4804 * This function always fails on Windows. 4805 * 4806 * Right now the returned descriptor is always a socket, but 4807 * that is not guaranteed. 4808 * 4809 * @param connection the connection 4810 * @param fd return location for the file descriptor. 4811 * @returns #TRUE if fd is successfully obtained. 4812 */ 4813 dbus_bool_t 4814 dbus_connection_get_unix_fd (DBusConnection *connection, 4815 int *fd) 4816 { 4817 _dbus_return_val_if_fail (connection != NULL, FALSE); 4818 _dbus_return_val_if_fail (connection->transport != NULL, FALSE); 4819 4820 #ifdef DBUS_WIN 4821 /* FIXME do this on a lower level */ 4822 return FALSE; 4823 #endif 4824 4825 return dbus_connection_get_socket(connection, fd); 4826 } 4827 4828 /** 4829 * Gets the underlying Windows or UNIX socket file descriptor 4830 * of the connection, if any. DO NOT read or write to the file descriptor, or try to 4831 * select() on it; use DBusWatch for main loop integration. Not all 4832 * connections will have a socket. So for adding descriptors 4833 * to the main loop, use dbus_watch_get_fd() and so forth. 4834 * 4835 * If the connection is not socket-based, this function will return FALSE, 4836 * even if the connection does have a file descriptor of some kind. 4837 * i.e. this function always returns specifically a socket file descriptor. 4838 * 4839 * @param connection the connection 4840 * @param fd return location for the file descriptor. 4841 * @returns #TRUE if fd is successfully obtained. 4842 */ 4843 dbus_bool_t 4844 dbus_connection_get_socket(DBusConnection *connection, 4845 int *fd) 4846 { 4847 dbus_bool_t retval; 4848 4849 _dbus_return_val_if_fail (connection != NULL, FALSE); 4850 _dbus_return_val_if_fail (connection->transport != NULL, FALSE); 4851 4852 CONNECTION_LOCK (connection); 4853 4854 retval = _dbus_transport_get_socket_fd (connection->transport, 4855 fd); 4856 4857 CONNECTION_UNLOCK (connection); 4858 4859 return retval; 4860 } 4861 4862 4863 /** 4864 * Gets the UNIX user ID of the connection if known. Returns #TRUE if 4865 * the uid is filled in. Always returns #FALSE on non-UNIX platforms. 4866 * Always returns #FALSE prior to authenticating the connection. 4867 * 4868 * The UID is only read by servers from clients; clients can't usually 4869 * get the UID of servers, because servers do not authenticate to 4870 * clients. The returned UID is the UID the connection authenticated 4871 * as. 4872 * 4873 * The message bus is a server and the apps connecting to the bus 4874 * are clients. 4875 * 4876 * You can ask the bus to tell you the UID of another connection though 4877 * if you like; this is done with dbus_bus_get_unix_user(). 4878 * 4879 * @param connection the connection 4880 * @param uid return location for the user ID 4881 * @returns #TRUE if uid is filled in with a valid user ID 4882 */ 4883 dbus_bool_t 4884 dbus_connection_get_unix_user (DBusConnection *connection, 4885 unsigned long *uid) 4886 { 4887 dbus_bool_t result; 4888 4889 _dbus_return_val_if_fail (connection != NULL, FALSE); 4890 _dbus_return_val_if_fail (uid != NULL, FALSE); 4891 4892 #ifdef DBUS_WIN 4893 /* FIXME this should be done at a lower level, but it's kind of hard, 4894 * just want to be sure we don't ship with this API returning 4895 * some weird internal fake uid for 1.0 4896 */ 4897 return FALSE; 4898 #endif 4899 4900 CONNECTION_LOCK (connection); 4901 4902 if (!_dbus_transport_get_is_authenticated (connection->transport)) 4903 result = FALSE; 4904 else 4905 result = _dbus_transport_get_unix_user (connection->transport, 4906 uid); 4907 CONNECTION_UNLOCK (connection); 4908 4909 return result; 4910 } 4911 4912 /** 4913 * Gets the process ID of the connection if any. 4914 * Returns #TRUE if the uid is filled in. 4915 * Always returns #FALSE prior to authenticating the 4916 * connection. 4917 * 4918 * @param connection the connection 4919 * @param pid return location for the process ID 4920 * @returns #TRUE if uid is filled in with a valid process ID 4921 */ 4922 dbus_bool_t 4923 dbus_connection_get_unix_process_id (DBusConnection *connection, 4924 unsigned long *pid) 4925 { 4926 dbus_bool_t result; 4927 4928 _dbus_return_val_if_fail (connection != NULL, FALSE); 4929 _dbus_return_val_if_fail (pid != NULL, FALSE); 4930 4931 #ifdef DBUS_WIN 4932 /* FIXME this should be done at a lower level, but it's kind of hard, 4933 * just want to be sure we don't ship with this API returning 4934 * some weird internal fake uid for 1.0 4935 */ 4936 return FALSE; 4937 #endif 4938 4939 CONNECTION_LOCK (connection); 4940 4941 if (!_dbus_transport_get_is_authenticated (connection->transport)) 4942 result = FALSE; 4943 else 4944 result = _dbus_transport_get_unix_process_id (connection->transport, 4945 pid); 4946 CONNECTION_UNLOCK (connection); 4947 4948 return result; 4949 } 4950 4951 /** 4952 * Sets a predicate function used to determine whether a given user ID 4953 * is allowed to connect. When an incoming connection has 4954 * authenticated with a particular user ID, this function is called; 4955 * if it returns #TRUE, the connection is allowed to proceed, 4956 * otherwise the connection is disconnected. 4957 * 4958 * If the function is set to #NULL (as it is by default), then 4959 * only the same UID as the server process will be allowed to 4960 * connect. 4961 * 4962 * On Windows, the function will be set and its free_data_function will 4963 * be invoked when the connection is freed or a new function is set. 4964 * However, the function will never be called, because there are 4965 * no UNIX user ids to pass to it. 4966 * 4967 * @todo add a Windows API analogous to dbus_connection_set_unix_user_function() 4968 * 4969 * @param connection the connection 4970 * @param function the predicate 4971 * @param data data to pass to the predicate 4972 * @param free_data_function function to free the data 4973 */ 4974 void 4975 dbus_connection_set_unix_user_function (DBusConnection *connection, 4976 DBusAllowUnixUserFunction function, 4977 void *data, 4978 DBusFreeFunction free_data_function) 4979 { 4980 void *old_data = NULL; 4981 DBusFreeFunction old_free_function = NULL; 4982 4983 _dbus_return_if_fail (connection != NULL); 4984 4985 CONNECTION_LOCK (connection); 4986 _dbus_transport_set_unix_user_function (connection->transport, 4987 function, data, free_data_function, 4988 &old_data, &old_free_function); 4989 CONNECTION_UNLOCK (connection); 4990 4991 if (old_free_function != NULL) 4992 (* old_free_function) (old_data); 4993 } 4994 4995 /** 4996 * 4997 * Normally #DBusConnection automatically handles all messages to the 4998 * org.freedesktop.DBus.Peer interface. However, the message bus wants 4999 * to be able to route methods on that interface through the bus and 5000 * to other applications. If routing peer messages is enabled, then 5001 * messages with the org.freedesktop.DBus.Peer interface that also 5002 * have a bus destination name set will not be automatically 5003 * handled by the #DBusConnection and instead will be dispatched 5004 * normally to the application. 5005 * 5006 * 5007 * If a normal application sets this flag, it can break things badly. 5008 * So don't set this unless you are the message bus. 5009 * 5010 * @param connection the connection 5011 * @param value #TRUE to pass through org.freedesktop.DBus.Peer messages with a bus name set 5012 */ 5013 void 5014 dbus_connection_set_route_peer_messages (DBusConnection *connection, 5015 dbus_bool_t value) 5016 { 5017 _dbus_return_if_fail (connection != NULL); 5018 5019 CONNECTION_LOCK (connection); 5020 connection->route_peer_messages = TRUE; 5021 CONNECTION_UNLOCK (connection); 5022 } 5023 5024 /** 5025 * Adds a message filter. Filters are handlers that are run on all 5026 * incoming messages, prior to the objects registered with 5027 * dbus_connection_register_object_path(). Filters are run in the 5028 * order that they were added. The same handler can be added as a 5029 * filter more than once, in which case it will be run more than once. 5030 * Filters added during a filter callback won't be run on the message 5031 * being processed. 5032 * 5033 * @todo we don't run filters on messages while blocking without 5034 * entering the main loop, since filters are run as part of 5035 * dbus_connection_dispatch(). This is probably a feature, as filters 5036 * could create arbitrary reentrancy. But kind of sucks if you're 5037 * trying to filter METHOD_RETURN for some reason. 5038 * 5039 * @param connection the connection 5040 * @param function function to handle messages 5041 * @param user_data user data to pass to the function 5042 * @param free_data_function function to use for freeing user data 5043 * @returns #TRUE on success, #FALSE if not enough memory. 5044 */ 5045 dbus_bool_t 5046 dbus_connection_add_filter (DBusConnection *connection, 5047 DBusHandleMessageFunction function, 5048 void *user_data, 5049 DBusFreeFunction free_data_function) 5050 { 5051 DBusMessageFilter *filter; 5052 5053 _dbus_return_val_if_fail (connection != NULL, FALSE); 5054 _dbus_return_val_if_fail (function != NULL, FALSE); 5055 5056 filter = dbus_new0 (DBusMessageFilter, 1); 5057 if (filter == NULL) 5058 return FALSE; 5059 5060 filter->refcount.value = 1; 5061 5062 CONNECTION_LOCK (connection); 5063 5064 if (!_dbus_list_append (&connection->filter_list, 5065 filter)) 5066 { 5067 _dbus_message_filter_unref (filter); 5068 CONNECTION_UNLOCK (connection); 5069 return FALSE; 5070 } 5071 5072 /* Fill in filter after all memory allocated, 5073 * so we don't run the free_user_data_function 5074 * if the add_filter() fails 5075 */ 5076 5077 filter->function = function; 5078 filter->user_data = user_data; 5079 filter->free_user_data_function = free_data_function; 5080 5081 CONNECTION_UNLOCK (connection); 5082 return TRUE; 5083 } 5084 5085 /** 5086 * Removes a previously-added message filter. It is a programming 5087 * error to call this function for a handler that has not been added 5088 * as a filter. If the given handler was added more than once, only 5089 * one instance of it will be removed (the most recently-added 5090 * instance). 5091 * 5092 * @param connection the connection 5093 * @param function the handler to remove 5094 * @param user_data user data for the handler to remove 5095 * 5096 */ 5097 void 5098 dbus_connection_remove_filter (DBusConnection *connection, 5099 DBusHandleMessageFunction function, 5100 void *user_data) 5101 { 5102 DBusList *link; 5103 DBusMessageFilter *filter; 5104 5105 _dbus_return_if_fail (connection != NULL); 5106 _dbus_return_if_fail (function != NULL); 5107 5108 CONNECTION_LOCK (connection); 5109 5110 filter = NULL; 5111 5112 link = _dbus_list_get_last_link (&connection->filter_list); 5113 while (link != NULL) 5114 { 5115 filter = link->data; 5116 5117 if (filter->function == function && 5118 filter->user_data == user_data) 5119 { 5120 _dbus_list_remove_link (&connection->filter_list, link); 5121 filter->function = NULL; 5122 5123 break; 5124 } 5125 5126 link = _dbus_list_get_prev_link (&connection->filter_list, link); 5127 } 5128 5129 CONNECTION_UNLOCK (connection); 5130 5131 #ifndef DBUS_DISABLE_CHECKS 5132 if (filter == NULL) 5133 { 5134 _dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added\n", 5135 function, user_data); 5136 return; 5137 } 5138 #endif 5139 5140 /* Call application code */ 5141 if (filter->free_user_data_function) 5142 (* filter->free_user_data_function) (filter->user_data); 5143 5144 filter->free_user_data_function = NULL; 5145 filter->user_data = NULL; 5146 5147 _dbus_message_filter_unref (filter); 5148 } 5149 5150 /** 5151 * Registers a handler for a given path in the object hierarchy. 5152 * The given vtable handles messages sent to exactly the given path. 5153 * 5154 * 5155 * @param connection the connection 5156 * @param path a '/' delimited string of path elements 5157 * @param vtable the virtual table 5158 * @param user_data data to pass to functions in the vtable 5159 * @returns #FALSE if not enough memory 5160 */ 5161 dbus_bool_t 5162 dbus_connection_register_object_path (DBusConnection *connection, 5163 const char *path, 5164 const DBusObjectPathVTable *vtable, 5165 void *user_data) 5166 { 5167 char **decomposed_path; 5168 dbus_bool_t retval; 5169 5170 _dbus_return_val_if_fail (connection != NULL, FALSE); 5171 _dbus_return_val_if_fail (path != NULL, FALSE); 5172 _dbus_return_val_if_fail (path[0] == '/', FALSE); 5173 _dbus_return_val_if_fail (vtable != NULL, FALSE); 5174 5175 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) 5176 return FALSE; 5177 5178 CONNECTION_LOCK (connection); 5179 5180 retval = _dbus_object_tree_register (connection->objects, 5181 FALSE, 5182 (const char **) decomposed_path, vtable, 5183 user_data); 5184 5185 CONNECTION_UNLOCK (connection); 5186 5187 dbus_free_string_array (decomposed_path); 5188 5189 return retval; 5190 } 5191 5192 /** 5193 * Registers a fallback handler for a given subsection of the object 5194 * hierarchy. The given vtable handles messages at or below the given 5195 * path. You can use this to establish a default message handling 5196 * policy for a whole "subdirectory." 5197 * 5198 * @param connection the connection 5199 * @param path a '/' delimited string of path elements 5200 * @param vtable the virtual table 5201 * @param user_data data to pass to functions in the vtable 5202 * @returns #FALSE if not enough memory 5203 */ 5204 dbus_bool_t 5205 dbus_connection_register_fallback (DBusConnection *connection, 5206 const char *path, 5207 const DBusObjectPathVTable *vtable, 5208 void *user_data) 5209 { 5210 char **decomposed_path; 5211 dbus_bool_t retval; 5212 5213 _dbus_return_val_if_fail (connection != NULL, FALSE); 5214 _dbus_return_val_if_fail (path != NULL, FALSE); 5215 _dbus_return_val_if_fail (path[0] == '/', FALSE); 5216 _dbus_return_val_if_fail (vtable != NULL, FALSE); 5217 5218 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) 5219 return FALSE; 5220 5221 CONNECTION_LOCK (connection); 5222 5223 retval = _dbus_object_tree_register (connection->objects, 5224 TRUE, 5225 (const char **) decomposed_path, vtable, 5226 user_data); 5227 5228 CONNECTION_UNLOCK (connection); 5229 5230 dbus_free_string_array (decomposed_path); 5231 5232 return retval; 5233 } 5234 5235 /** 5236 * Unregisters the handler registered with exactly the given path. 5237 * It's a bug to call this function for a path that isn't registered. 5238 * Can unregister both fallback paths and object paths. 5239 * 5240 * @param connection the connection 5241 * @param path a '/' delimited string of path elements 5242 * @returns #FALSE if not enough memory 5243 */ 5244 dbus_bool_t 5245 dbus_connection_unregister_object_path (DBusConnection *connection, 5246 const char *path) 5247 { 5248 char **decomposed_path; 5249 5250 _dbus_return_val_if_fail (connection != NULL, FALSE); 5251 _dbus_return_val_if_fail (path != NULL, FALSE); 5252 _dbus_return_val_if_fail (path[0] == '/', FALSE); 5253 5254 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) 5255 return FALSE; 5256 5257 CONNECTION_LOCK (connection); 5258 5259 _dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path); 5260 5261 dbus_free_string_array (decomposed_path); 5262 5263 return TRUE; 5264 } 5265 5266 /** 5267 * Gets the user data passed to dbus_connection_register_object_path() 5268 * or dbus_connection_register_fallback(). If nothing was registered 5269 * at this path, the data is filled in with #NULL. 5270 * 5271 * @param connection the connection 5272 * @param path the path you registered with 5273 * @param data_p location to store the user data, or #NULL 5274 * @returns #FALSE if not enough memory 5275 */ 5276 dbus_bool_t 5277 dbus_connection_get_object_path_data (DBusConnection *connection, 5278 const char *path, 5279 void **data_p) 5280 { 5281 char **decomposed_path; 5282 5283 _dbus_return_val_if_fail (connection != NULL, FALSE); 5284 _dbus_return_val_if_fail (path != NULL, FALSE); 5285 _dbus_return_val_if_fail (data_p != NULL, FALSE); 5286 5287 *data_p = NULL; 5288 5289 if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) 5290 return FALSE; 5291 5292 CONNECTION_LOCK (connection); 5293 5294 *data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path); 5295 5296 CONNECTION_UNLOCK (connection); 5297 5298 dbus_free_string_array (decomposed_path); 5299 5300 return TRUE; 5301 } 5302 5303 /** 5304 * Lists the registered fallback handlers and object path handlers at 5305 * the given parent_path. The returned array should be freed with 5306 * dbus_free_string_array(). 5307 * 5308 * @param connection the connection 5309 * @param parent_path the path to list the child handlers of 5310 * @param child_entries returns #NULL-terminated array of children 5311 * @returns #FALSE if no memory to allocate the child entries 5312 */ 5313 dbus_bool_t 5314 dbus_connection_list_registered (DBusConnection *connection, 5315 const char *parent_path, 5316 char ***child_entries) 5317 { 5318 char **decomposed_path; 5319 dbus_bool_t retval; 5320 _dbus_return_val_if_fail (connection != NULL, FALSE); 5321 _dbus_return_val_if_fail (parent_path != NULL, FALSE); 5322 _dbus_return_val_if_fail (parent_path[0] == '/', FALSE); 5323 _dbus_return_val_if_fail (child_entries != NULL, FALSE); 5324 5325 if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL)) 5326 return FALSE; 5327 5328 CONNECTION_LOCK (connection); 5329 5330 retval = _dbus_object_tree_list_registered_and_unlock (connection->objects, 5331 (const char **) decomposed_path, 5332 child_entries); 5333 dbus_free_string_array (decomposed_path); 5334 5335 return retval; 5336 } 5337 5338 static DBusDataSlotAllocator slot_allocator; 5339 _DBUS_DEFINE_GLOBAL_LOCK (connection_slots); 5340 5341 /** 5342 * Allocates an integer ID to be used for storing application-specific 5343 * data on any DBusConnection. The allocated ID may then be used 5344 * with dbus_connection_set_data() and dbus_connection_get_data(). 5345 * The passed-in slot must be initialized to -1, and is filled in 5346 * with the slot ID. If the passed-in slot is not -1, it's assumed 5347 * to be already allocated, and its refcount is incremented. 5348 * 5349 * The allocated slot is global, i.e. all DBusConnection objects will 5350 * have a slot with the given integer ID reserved. 5351 * 5352 * @param slot_p address of a global variable storing the slot 5353 * @returns #FALSE on failure (no memory) 5354 */ 5355 dbus_bool_t 5356 dbus_connection_allocate_data_slot (dbus_int32_t *slot_p) 5357 { 5358 return _dbus_data_slot_allocator_alloc (&slot_allocator, 5359 &_DBUS_LOCK_NAME (connection_slots), 5360 slot_p); 5361 } 5362 5363 /** 5364 * Deallocates a global ID for connection data slots. 5365 * dbus_connection_get_data() and dbus_connection_set_data() may no 5366 * longer be used with this slot. Existing data stored on existing 5367 * DBusConnection objects will be freed when the connection is 5368 * finalized, but may not be retrieved (and may only be replaced if 5369 * someone else reallocates the slot). When the refcount on the 5370 * passed-in slot reaches 0, it is set to -1. 5371 * 5372 * @param slot_p address storing the slot to deallocate 5373 */ 5374 void 5375 dbus_connection_free_data_slot (dbus_int32_t *slot_p) 5376 { 5377 _dbus_return_if_fail (*slot_p >= 0); 5378 5379 _dbus_data_slot_allocator_free (&slot_allocator, slot_p); 5380 } 5381 5382 /** 5383 * Stores a pointer on a DBusConnection, along 5384 * with an optional function to be used for freeing 5385 * the data when the data is set again, or when 5386 * the connection is finalized. The slot number 5387 * must have been allocated with dbus_connection_allocate_data_slot(). 5388 * 5389 * @param connection the connection 5390 * @param slot the slot number 5391 * @param data the data to store 5392 * @param free_data_func finalizer function for the data 5393 * @returns #TRUE if there was enough memory to store the data 5394 */ 5395 dbus_bool_t 5396 dbus_connection_set_data (DBusConnection *connection, 5397 dbus_int32_t slot, 5398 void *data, 5399 DBusFreeFunction free_data_func) 5400 { 5401 DBusFreeFunction old_free_func; 5402 void *old_data; 5403 dbus_bool_t retval; 5404 5405 _dbus_return_val_if_fail (connection != NULL, FALSE); 5406 _dbus_return_val_if_fail (slot >= 0, FALSE); 5407 5408 CONNECTION_LOCK (connection); 5409 5410 retval = _dbus_data_slot_list_set (&slot_allocator, 5411 &connection->slot_list, 5412 slot, data, free_data_func, 5413 &old_free_func, &old_data); 5414 5415 CONNECTION_UNLOCK (connection); 5416 5417 if (retval) 5418 { 5419 /* Do the actual free outside the connection lock */ 5420 if (old_free_func) 5421 (* old_free_func) (old_data); 5422 } 5423 5424 return retval; 5425 } 5426 5427 /** 5428 * Retrieves data previously set with dbus_connection_set_data(). 5429 * The slot must still be allocated (must not have been freed). 5430 * 5431 * @param connection the connection 5432 * @param slot the slot to get data from 5433 * @returns the data, or #NULL if not found 5434 */ 5435 void* 5436 dbus_connection_get_data (DBusConnection *connection, 5437 dbus_int32_t slot) 5438 { 5439 void *res; 5440 5441 _dbus_return_val_if_fail (connection != NULL, NULL); 5442 5443 CONNECTION_LOCK (connection); 5444 5445 res = _dbus_data_slot_list_get (&slot_allocator, 5446 &connection->slot_list, 5447 slot); 5448 5449 CONNECTION_UNLOCK (connection); 5450 5451 return res; 5452 } 5453 5454 /** 5455 * This function sets a global flag for whether dbus_connection_new() 5456 * will set SIGPIPE behavior to SIG_IGN. 5457 * 5458 * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN 5459 */ 5460 void 5461 dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe) 5462 { 5463 _dbus_modify_sigpipe = will_modify_sigpipe != FALSE; 5464 } 5465 5466 /** 5467 * Specifies the maximum size message this connection is allowed to 5468 * receive. Larger messages will result in disconnecting the 5469 * connection. 5470 * 5471 * @param connection a #DBusConnection 5472 * @param size maximum message size the connection can receive, in bytes 5473 */ 5474 void 5475 dbus_connection_set_max_message_size (DBusConnection *connection, 5476 long size) 5477 { 5478 _dbus_return_if_fail (connection != NULL); 5479 5480 CONNECTION_LOCK (connection); 5481 _dbus_transport_set_max_message_size (connection->transport, 5482 size); 5483 CONNECTION_UNLOCK (connection); 5484 } 5485 5486 /** 5487 * Gets the value set by dbus_connection_set_max_message_size(). 5488 * 5489 * @param connection the connection 5490 * @returns the max size of a single message 5491 */ 5492 long 5493 dbus_connection_get_max_message_size (DBusConnection *connection) 5494 { 5495 long res; 5496 5497 _dbus_return_val_if_fail (connection != NULL, 0); 5498 5499 CONNECTION_LOCK (connection); 5500 res = _dbus_transport_get_max_message_size (connection->transport); 5501 CONNECTION_UNLOCK (connection); 5502 return res; 5503 } 5504 5505 /** 5506 * Sets the maximum total number of bytes that can be used for all messages 5507 * received on this connection. Messages count toward the maximum until 5508 * they are finalized. When the maximum is reached, the connection will 5509 * not read more data until some messages are finalized. 5510 * 5511 * The semantics of the maximum are: if outstanding messages are 5512 * already above the maximum, additional messages will not be read. 5513 * The semantics are not: if the next message would cause us to exceed 5514 * the maximum, we don't read it. The reason is that we don't know the 5515 * size of a message until after we read it. 5516 * 5517 * Thus, the max live messages size can actually be exceeded 5518 * by up to the maximum size of a single message. 5519 * 5520 * Also, if we read say 1024 bytes off the wire in a single read(), 5521 * and that contains a half-dozen small messages, we may exceed the 5522 * size max by that amount. But this should be inconsequential. 5523 * 5524 * This does imply that we can't call read() with a buffer larger 5525 * than we're willing to exceed this limit by. 5526 * 5527 * @param connection the connection 5528 * @param size the maximum size in bytes of all outstanding messages 5529 */ 5530 void 5531 dbus_connection_set_max_received_size (DBusConnection *connection, 5532 long size) 5533 { 5534 _dbus_return_if_fail (connection != NULL); 5535 5536 CONNECTION_LOCK (connection); 5537 _dbus_transport_set_max_received_size (connection->transport, 5538 size); 5539 CONNECTION_UNLOCK (connection); 5540 } 5541 5542 /** 5543 * Gets the value set by dbus_connection_set_max_received_size(). 5544 * 5545 * @param connection the connection 5546 * @returns the max size of all live messages 5547 */ 5548 long 5549 dbus_connection_get_max_received_size (DBusConnection *connection) 5550 { 5551 long res; 5552 5553 _dbus_return_val_if_fail (connection != NULL, 0); 5554 5555 CONNECTION_LOCK (connection); 5556 res = _dbus_transport_get_max_received_size (connection->transport); 5557 CONNECTION_UNLOCK (connection); 5558 return res; 5559 } 5560 5561 /** 5562 * Gets the approximate size in bytes of all messages in the outgoing 5563 * message queue. The size is approximate in that you shouldn't use 5564 * it to decide how many bytes to read off the network or anything 5565 * of that nature, as optimizations may choose to tell small white lies 5566 * to avoid performance overhead. 5567 * 5568 * @param connection the connection 5569 * @returns the number of bytes that have been queued up but not sent 5570 */ 5571 long 5572 dbus_connection_get_outgoing_size (DBusConnection *connection) 5573 { 5574 long res; 5575 5576 _dbus_return_val_if_fail (connection != NULL, 0); 5577 5578 CONNECTION_LOCK (connection); 5579 res = _dbus_counter_get_value (connection->outgoing_counter); 5580 CONNECTION_UNLOCK (connection); 5581 return res; 5582 } 5583 5584 /** @} */ 5585
