1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_JDWP_JDWP_H_ 18 #define ART_RUNTIME_JDWP_JDWP_H_ 19 20 #include "atomic.h" 21 #include "base/mutex.h" 22 #include "jdwp/jdwp_bits.h" 23 #include "jdwp/jdwp_constants.h" 24 #include "jdwp/jdwp_expand_buf.h" 25 26 #include <pthread.h> 27 #include <stddef.h> 28 #include <stdint.h> 29 #include <string.h> 30 #include <vector> 31 32 struct iovec; 33 34 namespace art { 35 36 class ArtField; 37 class ArtMethod; 38 union JValue; 39 class Thread; 40 41 namespace mirror { 42 class Class; 43 class Object; 44 class Throwable; 45 } // namespace mirror 46 class Thread; 47 48 namespace JDWP { 49 50 /* 51 * Fundamental types. 52 * 53 * ObjectId and RefTypeId must be the same size. 54 * Its OK to change MethodId and FieldId sizes as long as the size is <= 8 bytes. 55 * Note that ArtFields are 64 bit pointers on 64 bit targets. So this one must remain 8 bytes. 56 */ 57 typedef uint64_t FieldId; /* static or instance field */ 58 typedef uint64_t MethodId; /* any kind of method, including constructors */ 59 typedef uint64_t ObjectId; /* any object (threadID, stringID, arrayID, etc) */ 60 typedef uint64_t RefTypeId; /* like ObjectID, but unique for Class objects */ 61 typedef uint64_t FrameId; /* short-lived stack frame ID */ 62 63 ObjectId ReadObjectId(const uint8_t** pBuf); 64 65 static inline void SetFieldId(uint8_t* buf, FieldId val) { return Set8BE(buf, val); } 66 static inline void SetMethodId(uint8_t* buf, MethodId val) { return Set8BE(buf, val); } 67 static inline void SetObjectId(uint8_t* buf, ObjectId val) { return Set8BE(buf, val); } 68 static inline void SetRefTypeId(uint8_t* buf, RefTypeId val) { return Set8BE(buf, val); } 69 static inline void SetFrameId(uint8_t* buf, FrameId val) { return Set8BE(buf, val); } 70 static inline void expandBufAddFieldId(ExpandBuf* pReply, FieldId id) { expandBufAdd8BE(pReply, id); } 71 static inline void expandBufAddMethodId(ExpandBuf* pReply, MethodId id) { expandBufAdd8BE(pReply, id); } 72 static inline void expandBufAddObjectId(ExpandBuf* pReply, ObjectId id) { expandBufAdd8BE(pReply, id); } 73 static inline void expandBufAddRefTypeId(ExpandBuf* pReply, RefTypeId id) { expandBufAdd8BE(pReply, id); } 74 static inline void expandBufAddFrameId(ExpandBuf* pReply, FrameId id) { expandBufAdd8BE(pReply, id); } 75 76 struct EventLocation { 77 ArtMethod* method; 78 uint32_t dex_pc; 79 }; 80 81 /* 82 * Holds a JDWP "location". 83 */ 84 struct JdwpLocation { 85 JdwpTypeTag type_tag; 86 RefTypeId class_id; 87 MethodId method_id; 88 uint64_t dex_pc; 89 }; 90 std::ostream& operator<<(std::ostream& os, const JdwpLocation& rhs) 91 SHARED_REQUIRES(Locks::mutator_lock_); 92 bool operator==(const JdwpLocation& lhs, const JdwpLocation& rhs); 93 bool operator!=(const JdwpLocation& lhs, const JdwpLocation& rhs); 94 95 /* 96 * How we talk to the debugger. 97 */ 98 enum JdwpTransportType { 99 kJdwpTransportUnknown = 0, 100 kJdwpTransportSocket, // transport=dt_socket 101 kJdwpTransportAndroidAdb, // transport=dt_android_adb 102 }; 103 std::ostream& operator<<(std::ostream& os, const JdwpTransportType& rhs); 104 105 struct JdwpOptions { 106 JdwpTransportType transport = kJdwpTransportUnknown; 107 bool server = false; 108 bool suspend = false; 109 std::string host = ""; 110 uint16_t port = static_cast<uint16_t>(-1); 111 }; 112 113 bool operator==(const JdwpOptions& lhs, const JdwpOptions& rhs); 114 115 struct JdwpEvent; 116 class JdwpNetStateBase; 117 struct ModBasket; 118 class Request; 119 120 /* 121 * State for JDWP functions. 122 */ 123 struct JdwpState { 124 /* 125 * Perform one-time initialization. 126 * 127 * Among other things, this binds to a port to listen for a connection from 128 * the debugger. 129 * 130 * Returns a newly-allocated JdwpState struct on success, or nullptr on failure. 131 * 132 * NO_THREAD_SAFETY_ANALYSIS since we can't annotate that we do not have 133 * state->thread_start_lock_ held. 134 */ 135 static JdwpState* Create(const JdwpOptions* options) 136 REQUIRES(!Locks::mutator_lock_) NO_THREAD_SAFETY_ANALYSIS; 137 138 ~JdwpState(); 139 140 /* 141 * Returns "true" if a debugger or DDM is connected. 142 */ 143 bool IsActive(); 144 145 /** 146 * Returns the Thread* for the JDWP daemon thread. 147 */ 148 Thread* GetDebugThread(); 149 150 /* 151 * Get time, in milliseconds, since the last debugger activity. 152 */ 153 int64_t LastDebuggerActivity(); 154 155 void ExitAfterReplying(int exit_status); 156 157 // Acquires/releases the JDWP synchronization token for the debugger 158 // thread (command handler) so no event thread posts an event while 159 // it processes a command. This must be called only from the debugger 160 // thread. 161 void AcquireJdwpTokenForCommand() REQUIRES(!jdwp_token_lock_); 162 void ReleaseJdwpTokenForCommand() REQUIRES(!jdwp_token_lock_); 163 164 // Acquires/releases the JDWP synchronization token for the event thread 165 // so no other thread (debugger thread or event thread) interleaves with 166 // it when posting an event. This must NOT be called from the debugger 167 // thread, only event thread. 168 void AcquireJdwpTokenForEvent(ObjectId threadId) REQUIRES(!jdwp_token_lock_); 169 void ReleaseJdwpTokenForEvent() REQUIRES(!jdwp_token_lock_); 170 171 /* 172 * These notify the debug code that something interesting has happened. This 173 * could be a thread starting or ending, an exception, or an opportunity 174 * for a breakpoint. These calls do not mean that an event the debugger 175 * is interested has happened, just that something has happened that the 176 * debugger *might* be interested in. 177 * 178 * The item of interest may trigger multiple events, some or all of which 179 * are grouped together in a single response. 180 * 181 * The event may cause the current thread or all threads (except the 182 * JDWP support thread) to be suspended. 183 */ 184 185 /* 186 * The VM has finished initializing. Only called when the debugger is 187 * connected at the time initialization completes. 188 */ 189 void PostVMStart() SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!jdwp_token_lock_); 190 191 /* 192 * A location of interest has been reached. This is used for breakpoints, 193 * single-stepping, and method entry/exit. (JDWP requires that these four 194 * events are grouped together in a single response.) 195 * 196 * In some cases "*pLoc" will just have a method and class name, e.g. when 197 * issuing a MethodEntry on a native method. 198 * 199 * "eventFlags" indicates the types of events that have occurred. 200 * 201 * "returnValue" is non-null for MethodExit events only. 202 */ 203 void PostLocationEvent(const EventLocation* pLoc, mirror::Object* thisPtr, int eventFlags, 204 const JValue* returnValue) 205 REQUIRES(!event_list_lock_, !jdwp_token_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 206 207 /* 208 * A field of interest has been accessed or modified. This is used for field access and field 209 * modification events. 210 * 211 * "fieldValue" is non-null for field modification events only. 212 * "is_modification" is true for field modification, false for field access. 213 */ 214 void PostFieldEvent(const EventLocation* pLoc, ArtField* field, mirror::Object* thisPtr, 215 const JValue* fieldValue, bool is_modification) 216 REQUIRES(!event_list_lock_, !jdwp_token_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 217 218 /* 219 * An exception has been thrown. 220 * 221 * Pass in a zeroed-out "*pCatchLoc" if the exception wasn't caught. 222 */ 223 void PostException(const EventLocation* pThrowLoc, mirror::Throwable* exception_object, 224 const EventLocation* pCatchLoc, mirror::Object* thisPtr) 225 REQUIRES(!event_list_lock_, !jdwp_token_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 226 227 /* 228 * A thread has started or stopped. 229 */ 230 void PostThreadChange(Thread* thread, bool start) 231 REQUIRES(!event_list_lock_, !jdwp_token_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 232 233 /* 234 * Class has been prepared. 235 */ 236 void PostClassPrepare(mirror::Class* klass) 237 REQUIRES(!event_list_lock_, !jdwp_token_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 238 239 /* 240 * The VM is about to stop. 241 */ 242 bool PostVMDeath(); 243 244 // Called if/when we realize we're talking to DDMS. 245 void NotifyDdmsActive() SHARED_REQUIRES(Locks::mutator_lock_); 246 247 248 void SetupChunkHeader(uint32_t type, size_t data_len, size_t header_size, uint8_t* out_header); 249 250 /* 251 * Send up a chunk of DDM data. 252 */ 253 void DdmSendChunkV(uint32_t type, const iovec* iov, int iov_count) 254 SHARED_REQUIRES(Locks::mutator_lock_); 255 256 bool HandlePacket() REQUIRES(!shutdown_lock_, !jdwp_token_lock_); 257 258 void SendRequest(ExpandBuf* pReq); 259 260 void ResetState() 261 REQUIRES(!event_list_lock_) 262 SHARED_REQUIRES(Locks::mutator_lock_); 263 264 /* atomic ops to get next serial number */ 265 uint32_t NextRequestSerial(); 266 uint32_t NextEventSerial(); 267 268 void Run() 269 REQUIRES(!Locks::mutator_lock_, !Locks::thread_suspend_count_lock_, !thread_start_lock_, 270 !attach_lock_, !event_list_lock_); 271 272 /* 273 * Register an event by adding it to the event list. 274 * 275 * "*pEvent" must be storage allocated with jdwpEventAlloc(). The caller 276 * may discard its pointer after calling this. 277 */ 278 JdwpError RegisterEvent(JdwpEvent* pEvent) 279 REQUIRES(!event_list_lock_) 280 SHARED_REQUIRES(Locks::mutator_lock_); 281 282 /* 283 * Unregister an event, given the requestId. 284 */ 285 void UnregisterEventById(uint32_t requestId) 286 REQUIRES(!event_list_lock_) 287 SHARED_REQUIRES(Locks::mutator_lock_); 288 289 /* 290 * Unregister all events. 291 */ 292 void UnregisterAll() 293 REQUIRES(!event_list_lock_) 294 SHARED_REQUIRES(Locks::mutator_lock_); 295 296 private: 297 explicit JdwpState(const JdwpOptions* options); 298 size_t ProcessRequest(Request* request, ExpandBuf* pReply, bool* skip_reply) 299 REQUIRES(!jdwp_token_lock_); 300 bool InvokeInProgress(); 301 bool IsConnected(); 302 void SuspendByPolicy(JdwpSuspendPolicy suspend_policy, JDWP::ObjectId thread_self_id) 303 REQUIRES(!Locks::mutator_lock_); 304 void SendRequestAndPossiblySuspend(ExpandBuf* pReq, JdwpSuspendPolicy suspend_policy, 305 ObjectId threadId) 306 SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!jdwp_token_lock_); 307 void CleanupMatchList(const std::vector<JdwpEvent*>& match_list) 308 REQUIRES(event_list_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 309 void EventFinish(ExpandBuf* pReq); 310 bool FindMatchingEvents(JdwpEventKind eventKind, const ModBasket& basket, 311 std::vector<JdwpEvent*>* match_list) 312 REQUIRES(!event_list_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 313 void FindMatchingEventsLocked(JdwpEventKind eventKind, const ModBasket& basket, 314 std::vector<JdwpEvent*>* match_list) 315 REQUIRES(event_list_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 316 void UnregisterEvent(JdwpEvent* pEvent) 317 REQUIRES(event_list_lock_) SHARED_REQUIRES(Locks::mutator_lock_); 318 void SendBufferedRequest(uint32_t type, const std::vector<iovec>& iov); 319 320 /* 321 * When we hit a debugger event that requires suspension, it's important 322 * that we wait for the thread to suspend itself before processing any 323 * additional requests. Otherwise, if the debugger immediately sends a 324 * "resume thread" command, the resume might arrive before the thread has 325 * suspended itself. 326 * 327 * It's also important no event thread suspends while we process a command 328 * from the debugger. Otherwise we could post an event ("thread death") 329 * before sending the reply of the command being processed ("resume") and 330 * cause bad synchronization with the debugger. 331 * 332 * The thread wanting "exclusive" access to the JDWP world must call the 333 * SetWaitForJdwpToken method before processing a command from the 334 * debugger or sending an event to the debugger. 335 * Once the command is processed or the event thread has posted its event, 336 * it must call the ClearWaitForJdwpToken method to allow another thread 337 * to do JDWP stuff. 338 * 339 * Therefore the main JDWP handler loop will wait for the event thread 340 * suspension before processing the next command. Once the event thread 341 * has suspended itself and cleared the token, the JDWP handler continues 342 * processing commands. This works in the suspend-all case because the 343 * event thread doesn't suspend itself until everything else has suspended. 344 * 345 * It's possible that multiple threads could encounter thread-suspending 346 * events at the same time, so we grab a mutex in the SetWaitForJdwpToken 347 * call, and release it in the ClearWaitForJdwpToken call. 348 */ 349 void SetWaitForJdwpToken(ObjectId threadId) REQUIRES(!jdwp_token_lock_); 350 void ClearWaitForJdwpToken() REQUIRES(!jdwp_token_lock_); 351 352 public: // TODO: fix privacy 353 const JdwpOptions* options_; 354 355 private: 356 /* wait for creation of the JDWP thread */ 357 Mutex thread_start_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 358 ConditionVariable thread_start_cond_ GUARDED_BY(thread_start_lock_); 359 360 pthread_t pthread_; 361 Thread* thread_; 362 363 volatile int32_t debug_thread_started_ GUARDED_BY(thread_start_lock_); 364 ObjectId debug_thread_id_; 365 366 private: 367 bool run; 368 369 public: // TODO: fix privacy 370 JdwpNetStateBase* netState; 371 372 private: 373 // For wait-for-debugger. 374 Mutex attach_lock_ ACQUIRED_AFTER(thread_start_lock_); 375 ConditionVariable attach_cond_ GUARDED_BY(attach_lock_); 376 377 // Time of last debugger activity, in milliseconds. 378 Atomic<int64_t> last_activity_time_ms_; 379 380 // Global counters and a mutex to protect them. 381 AtomicInteger request_serial_; 382 AtomicInteger event_serial_; 383 384 // Linked list of events requested by the debugger (breakpoints, class prep, etc). 385 Mutex event_list_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER ACQUIRED_BEFORE(Locks::breakpoint_lock_); 386 JdwpEvent* event_list_ GUARDED_BY(event_list_lock_); 387 size_t event_list_size_ GUARDED_BY(event_list_lock_); // Number of elements in event_list_. 388 389 // Used to synchronize JDWP command handler thread and event threads so only one 390 // thread does JDWP stuff at a time. This prevent from interleaving command handling 391 // and event notification. Otherwise we could receive a "resume" command for an 392 // event thread that is not suspended yet, or post a "thread death" or event "VM death" 393 // event before sending the reply of the "resume" command that caused it. 394 Mutex jdwp_token_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 395 ConditionVariable jdwp_token_cond_ GUARDED_BY(jdwp_token_lock_); 396 ObjectId jdwp_token_owner_thread_id_; 397 398 bool ddm_is_active_; 399 400 // Used for VirtualMachine.Exit command handling. 401 bool should_exit_; 402 int exit_status_; 403 404 // Used to synchronize runtime shutdown with JDWP command handler thread. 405 // When the runtime shuts down, it needs to stop JDWP command handler thread by closing the 406 // JDWP connection. However, if the JDWP thread is processing a command, it needs to wait 407 // for the command to finish so we can send its reply before closing the connection. 408 Mutex shutdown_lock_ ACQUIRED_AFTER(event_list_lock_); 409 ConditionVariable shutdown_cond_ GUARDED_BY(shutdown_lock_); 410 bool processing_request_ GUARDED_BY(shutdown_lock_); 411 }; 412 413 std::string DescribeField(const FieldId& field_id) SHARED_REQUIRES(Locks::mutator_lock_); 414 std::string DescribeMethod(const MethodId& method_id) SHARED_REQUIRES(Locks::mutator_lock_); 415 std::string DescribeRefTypeId(const RefTypeId& ref_type_id) SHARED_REQUIRES(Locks::mutator_lock_); 416 417 class Request { 418 public: 419 Request(const uint8_t* bytes, uint32_t available); 420 ~Request(); 421 422 std::string ReadUtf8String(); 423 424 // Helper function: read a variable-width value from the input buffer. 425 uint64_t ReadValue(size_t width); 426 427 int32_t ReadSigned32(const char* what); 428 429 uint32_t ReadUnsigned32(const char* what); 430 431 FieldId ReadFieldId() SHARED_REQUIRES(Locks::mutator_lock_); 432 433 MethodId ReadMethodId() SHARED_REQUIRES(Locks::mutator_lock_); 434 435 ObjectId ReadObjectId(const char* specific_kind); 436 437 ObjectId ReadArrayId(); 438 439 ObjectId ReadObjectId(); 440 441 ObjectId ReadThreadId(); 442 443 ObjectId ReadThreadGroupId(); 444 445 RefTypeId ReadRefTypeId() SHARED_REQUIRES(Locks::mutator_lock_); 446 447 FrameId ReadFrameId(); 448 449 template <typename T> T ReadEnum1(const char* specific_kind) { 450 T value = static_cast<T>(Read1()); 451 VLOG(jdwp) << " " << specific_kind << " " << value; 452 return value; 453 } 454 455 JdwpTag ReadTag(); 456 457 JdwpTypeTag ReadTypeTag(); 458 459 JdwpLocation ReadLocation() SHARED_REQUIRES(Locks::mutator_lock_); 460 461 JdwpModKind ReadModKind(); 462 463 // 464 // Return values from this JDWP packet's header. 465 // 466 size_t GetLength() { return byte_count_; } 467 uint32_t GetId() { return id_; } 468 uint8_t GetCommandSet() { return command_set_; } 469 uint8_t GetCommand() { return command_; } 470 471 // Returns the number of bytes remaining. 472 size_t size() { return end_ - p_; } 473 474 // Returns a pointer to the next byte. 475 const uint8_t* data() { return p_; } 476 477 void Skip(size_t count) { p_ += count; } 478 479 void CheckConsumed(); 480 481 private: 482 uint8_t Read1(); 483 uint16_t Read2BE(); 484 uint32_t Read4BE(); 485 uint64_t Read8BE(); 486 487 uint32_t byte_count_; 488 uint32_t id_; 489 uint8_t command_set_; 490 uint8_t command_; 491 492 const uint8_t* p_; 493 const uint8_t* end_; 494 495 DISALLOW_COPY_AND_ASSIGN(Request); 496 }; 497 498 } // namespace JDWP 499 500 } // namespace art 501 502 #endif // ART_RUNTIME_JDWP_JDWP_H_ 503
