1 /* -*- mode: C; c-basic-offset: 3; indent-tabs-mode: nil; -*- */ 2 /* 3 This file is part of drd, a thread error detector. 4 5 Copyright (C) 2006-2011 Bart Van Assche <bvanassche (at) acm.org>. 6 7 This program is free software; you can redistribute it and/or 8 modify it under the terms of the GNU General Public License as 9 published by the Free Software Foundation; either version 2 of the 10 License, or (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 20 02111-1307, USA. 21 22 The GNU General Public License is contained in the file COPYING. 23 */ 24 25 26 #include "drd_error.h" 27 #include "drd_barrier.h" 28 #include "drd_clientobj.h" 29 #include "drd_cond.h" 30 #include "drd_mutex.h" 31 #include "drd_segment.h" 32 #include "drd_semaphore.h" 33 #include "drd_suppression.h" 34 #include "drd_thread.h" 35 #include "pub_tool_vki.h" 36 #include "pub_tool_basics.h" // Addr, SizeT 37 #include "pub_tool_libcassert.h" // tl_assert() 38 #include "pub_tool_libcbase.h" // VG_(strlen)() 39 #include "pub_tool_libcprint.h" // VG_(printf)() 40 #include "pub_tool_libcproc.h" // VG_(getenv)() 41 #include "pub_tool_machine.h" 42 #include "pub_tool_mallocfree.h" // VG_(malloc)(), VG_(free)() 43 #include "pub_tool_options.h" // VG_(clo_backtrace_size) 44 #include "pub_tool_threadstate.h" // VG_(get_pthread_id)() 45 46 47 48 /* Local functions. */ 49 50 static void thread_append_segment(const DrdThreadId tid, Segment* const sg); 51 static void thread_discard_segment(const DrdThreadId tid, Segment* const sg); 52 static void thread_compute_conflict_set(struct bitmap** conflict_set, 53 const DrdThreadId tid); 54 static Bool thread_conflict_set_up_to_date(const DrdThreadId tid); 55 56 57 /* Local variables. */ 58 59 static ULong s_context_switch_count; 60 static ULong s_discard_ordered_segments_count; 61 static ULong s_compute_conflict_set_count; 62 static ULong s_update_conflict_set_count; 63 static ULong s_update_conflict_set_new_sg_count; 64 static ULong s_update_conflict_set_sync_count; 65 static ULong s_update_conflict_set_join_count; 66 static ULong s_conflict_set_bitmap_creation_count; 67 static ULong s_conflict_set_bitmap2_creation_count; 68 static ThreadId s_vg_running_tid = VG_INVALID_THREADID; 69 DrdThreadId DRD_(g_drd_running_tid) = DRD_INVALID_THREADID; 70 ThreadInfo DRD_(g_threadinfo)[DRD_N_THREADS]; 71 struct bitmap* DRD_(g_conflict_set); 72 static Bool s_trace_context_switches = False; 73 static Bool s_trace_conflict_set = False; 74 static Bool s_trace_conflict_set_bm = False; 75 static Bool s_trace_fork_join = False; 76 static Bool s_segment_merging = True; 77 static Bool s_new_segments_since_last_merge; 78 static int s_segment_merge_interval = 10; 79 static unsigned s_join_list_vol = 10; 80 static unsigned s_deletion_head; 81 static unsigned s_deletion_tail; 82 83 84 /* Function definitions. */ 85 86 /** Enables/disables context switch tracing. */ 87 void DRD_(thread_trace_context_switches)(const Bool t) 88 { 89 tl_assert(t == False || t == True); 90 s_trace_context_switches = t; 91 } 92 93 /** Enables/disables conflict set tracing. */ 94 void DRD_(thread_trace_conflict_set)(const Bool t) 95 { 96 tl_assert(t == False || t == True); 97 s_trace_conflict_set = t; 98 } 99 100 /** Enables/disables conflict set bitmap tracing. */ 101 void DRD_(thread_trace_conflict_set_bm)(const Bool t) 102 { 103 tl_assert(t == False || t == True); 104 s_trace_conflict_set_bm = t; 105 } 106 107 /** Report whether fork/join tracing is enabled. */ 108 Bool DRD_(thread_get_trace_fork_join)(void) 109 { 110 return s_trace_fork_join; 111 } 112 113 /** Enables/disables fork/join tracing. */ 114 void DRD_(thread_set_trace_fork_join)(const Bool t) 115 { 116 tl_assert(t == False || t == True); 117 s_trace_fork_join = t; 118 } 119 120 /** Enables/disables segment merging. */ 121 void DRD_(thread_set_segment_merging)(const Bool m) 122 { 123 tl_assert(m == False || m == True); 124 s_segment_merging = m; 125 } 126 127 /** Get the segment merging interval. */ 128 int DRD_(thread_get_segment_merge_interval)(void) 129 { 130 return s_segment_merge_interval; 131 } 132 133 /** Set the segment merging interval. */ 134 void DRD_(thread_set_segment_merge_interval)(const int i) 135 { 136 s_segment_merge_interval = i; 137 } 138 139 void DRD_(thread_set_join_list_vol)(const int jlv) 140 { 141 s_join_list_vol = jlv; 142 } 143 144 /** 145 * Convert Valgrind's ThreadId into a DrdThreadId. 146 * 147 * @return DRD thread ID upon success and DRD_INVALID_THREADID if the passed 148 * Valgrind ThreadId does not yet exist. 149 */ 150 DrdThreadId DRD_(VgThreadIdToDrdThreadId)(const ThreadId tid) 151 { 152 int i; 153 154 if (tid == VG_INVALID_THREADID) 155 return DRD_INVALID_THREADID; 156 157 for (i = 1; i < DRD_N_THREADS; i++) 158 { 159 if (DRD_(g_threadinfo)[i].vg_thread_exists == True 160 && DRD_(g_threadinfo)[i].vg_threadid == tid) 161 { 162 return i; 163 } 164 } 165 166 return DRD_INVALID_THREADID; 167 } 168 169 /** Allocate a new DRD thread ID for the specified Valgrind thread ID. */ 170 static DrdThreadId DRD_(VgThreadIdToNewDrdThreadId)(const ThreadId tid) 171 { 172 int i; 173 174 tl_assert(DRD_(VgThreadIdToDrdThreadId)(tid) == DRD_INVALID_THREADID); 175 176 for (i = 1; i < DRD_N_THREADS; i++) 177 { 178 if (!DRD_(g_threadinfo)[i].valid) 179 { 180 tl_assert(! DRD_(IsValidDrdThreadId)(i)); 181 182 DRD_(g_threadinfo)[i].valid = True; 183 DRD_(g_threadinfo)[i].vg_thread_exists = True; 184 DRD_(g_threadinfo)[i].vg_threadid = tid; 185 DRD_(g_threadinfo)[i].pt_threadid = INVALID_POSIX_THREADID; 186 DRD_(g_threadinfo)[i].stack_min = 0; 187 DRD_(g_threadinfo)[i].stack_min_min = 0; 188 DRD_(g_threadinfo)[i].stack_startup = 0; 189 DRD_(g_threadinfo)[i].stack_max = 0; 190 DRD_(thread_set_name)(i, ""); 191 DRD_(g_threadinfo)[i].on_alt_stack = False; 192 DRD_(g_threadinfo)[i].is_recording_loads = True; 193 DRD_(g_threadinfo)[i].is_recording_stores = True; 194 DRD_(g_threadinfo)[i].pthread_create_nesting_level = 0; 195 DRD_(g_threadinfo)[i].synchr_nesting = 0; 196 DRD_(g_threadinfo)[i].deletion_seq = s_deletion_tail - 1; 197 tl_assert(DRD_(g_threadinfo)[i].first == 0); 198 tl_assert(DRD_(g_threadinfo)[i].last == 0); 199 200 tl_assert(DRD_(IsValidDrdThreadId)(i)); 201 202 return i; 203 } 204 } 205 206 VG_(printf)( 207 "\nSorry, but the maximum number of threads supported by DRD has been exceeded." 208 "Aborting.\n"); 209 210 tl_assert(False); 211 212 return DRD_INVALID_THREADID; 213 } 214 215 /** Convert a POSIX thread ID into a DRD thread ID. */ 216 DrdThreadId DRD_(PtThreadIdToDrdThreadId)(const PThreadId tid) 217 { 218 int i; 219 220 if (tid != INVALID_POSIX_THREADID) 221 { 222 for (i = 1; i < DRD_N_THREADS; i++) 223 { 224 if (DRD_(g_threadinfo)[i].posix_thread_exists 225 && DRD_(g_threadinfo)[i].pt_threadid == tid) 226 { 227 return i; 228 } 229 } 230 } 231 return DRD_INVALID_THREADID; 232 } 233 234 /** Convert a DRD thread ID into a Valgrind thread ID. */ 235 ThreadId DRD_(DrdThreadIdToVgThreadId)(const DrdThreadId tid) 236 { 237 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 238 && tid != DRD_INVALID_THREADID); 239 240 return (DRD_(g_threadinfo)[tid].vg_thread_exists 241 ? DRD_(g_threadinfo)[tid].vg_threadid 242 : VG_INVALID_THREADID); 243 } 244 245 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 246 /** 247 * Sanity check of the doubly linked list of segments referenced by a 248 * ThreadInfo struct. 249 * @return True if sane, False if not. 250 */ 251 static Bool DRD_(sane_ThreadInfo)(const ThreadInfo* const ti) 252 { 253 Segment* p; 254 255 for (p = ti->first; p; p = p->next) { 256 if (p->next && p->next->prev != p) 257 return False; 258 if (p->next == 0 && p != ti->last) 259 return False; 260 } 261 for (p = ti->last; p; p = p->prev) { 262 if (p->prev && p->prev->next != p) 263 return False; 264 if (p->prev == 0 && p != ti->first) 265 return False; 266 } 267 return True; 268 } 269 #endif 270 271 /** 272 * Create the first segment for a newly started thread. 273 * 274 * This function is called from the handler installed via 275 * VG_(track_pre_thread_ll_create)(). The Valgrind core invokes this handler 276 * from the context of the creator thread, before the new thread has been 277 * created. 278 * 279 * @param[in] creator DRD thread ID of the creator thread. 280 * @param[in] vg_created Valgrind thread ID of the created thread. 281 * 282 * @return DRD thread ID of the created thread. 283 */ 284 DrdThreadId DRD_(thread_pre_create)(const DrdThreadId creator, 285 const ThreadId vg_created) 286 { 287 DrdThreadId created; 288 289 tl_assert(DRD_(VgThreadIdToDrdThreadId)(vg_created) == DRD_INVALID_THREADID); 290 created = DRD_(VgThreadIdToNewDrdThreadId)(vg_created); 291 tl_assert(0 <= (int)created && created < DRD_N_THREADS 292 && created != DRD_INVALID_THREADID); 293 294 tl_assert(DRD_(g_threadinfo)[created].first == 0); 295 tl_assert(DRD_(g_threadinfo)[created].last == 0); 296 /* Create an initial segment for the newly created thread. */ 297 thread_append_segment(created, DRD_(sg_new)(creator, created)); 298 299 return created; 300 } 301 302 /** 303 * Initialize DRD_(g_threadinfo)[] for a newly created thread. Must be called 304 * after the thread has been created and before any client instructions are run 305 * on the newly created thread, e.g. from the handler installed via 306 * VG_(track_pre_thread_first_insn)(). 307 * 308 * @param[in] vg_created Valgrind thread ID of the newly created thread. 309 * 310 * @return DRD thread ID for the new thread. 311 */ 312 DrdThreadId DRD_(thread_post_create)(const ThreadId vg_created) 313 { 314 const DrdThreadId created = DRD_(VgThreadIdToDrdThreadId)(vg_created); 315 316 tl_assert(0 <= (int)created && created < DRD_N_THREADS 317 && created != DRD_INVALID_THREADID); 318 319 DRD_(g_threadinfo)[created].stack_max 320 = VG_(thread_get_stack_max)(vg_created); 321 DRD_(g_threadinfo)[created].stack_startup 322 = DRD_(g_threadinfo)[created].stack_max; 323 DRD_(g_threadinfo)[created].stack_min 324 = DRD_(g_threadinfo)[created].stack_max; 325 DRD_(g_threadinfo)[created].stack_min_min 326 = DRD_(g_threadinfo)[created].stack_max; 327 DRD_(g_threadinfo)[created].stack_size 328 = VG_(thread_get_stack_size)(vg_created); 329 tl_assert(DRD_(g_threadinfo)[created].stack_max != 0); 330 331 return created; 332 } 333 334 static void DRD_(thread_delayed_delete)(const DrdThreadId tid) 335 { 336 int j; 337 338 DRD_(g_threadinfo)[tid].vg_thread_exists = False; 339 DRD_(g_threadinfo)[tid].posix_thread_exists = False; 340 DRD_(g_threadinfo)[tid].deletion_seq = s_deletion_head++; 341 #if 0 342 VG_(message)(Vg_DebugMsg, "Adding thread %d to the deletion list\n", tid); 343 #endif 344 if (s_deletion_head - s_deletion_tail >= s_join_list_vol) { 345 for (j = 0; j < DRD_N_THREADS; ++j) { 346 if (DRD_(IsValidDrdThreadId)(j) 347 && DRD_(g_threadinfo)[j].deletion_seq == s_deletion_tail) 348 { 349 s_deletion_tail++; 350 #if 0 351 VG_(message)(Vg_DebugMsg, "Delayed delete of thread %d\n", j); 352 #endif 353 DRD_(thread_delete)(j, False); 354 break; 355 } 356 } 357 } 358 } 359 360 /** 361 * Process VG_USERREQ__POST_THREAD_JOIN. This client request is invoked just 362 * after thread drd_joiner joined thread drd_joinee. 363 */ 364 void DRD_(thread_post_join)(DrdThreadId drd_joiner, DrdThreadId drd_joinee) 365 { 366 tl_assert(DRD_(IsValidDrdThreadId)(drd_joiner)); 367 tl_assert(DRD_(IsValidDrdThreadId)(drd_joinee)); 368 369 DRD_(thread_new_segment)(drd_joiner); 370 DRD_(thread_combine_vc_join)(drd_joiner, drd_joinee); 371 DRD_(thread_new_segment)(drd_joinee); 372 373 if (s_trace_fork_join) 374 { 375 const ThreadId joiner = DRD_(DrdThreadIdToVgThreadId)(drd_joiner); 376 const unsigned msg_size = 256; 377 char* msg; 378 379 msg = VG_(malloc)("drd.main.dptj.1", msg_size); 380 tl_assert(msg); 381 VG_(snprintf)(msg, msg_size, 382 "drd_post_thread_join joiner = %d, joinee = %d", 383 drd_joiner, drd_joinee); 384 if (joiner) 385 { 386 char* vc; 387 388 vc = DRD_(vc_aprint)(DRD_(thread_get_vc)(drd_joiner)); 389 VG_(snprintf)(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg), 390 ", new vc: %s", vc); 391 VG_(free)(vc); 392 } 393 DRD_(trace_msg)("%pS", msg); 394 VG_(free)(msg); 395 } 396 397 if (! DRD_(get_check_stack_accesses)()) 398 { 399 DRD_(finish_suppression)(DRD_(thread_get_stack_max)(drd_joinee) 400 - DRD_(thread_get_stack_size)(drd_joinee), 401 DRD_(thread_get_stack_max)(drd_joinee)); 402 } 403 DRD_(clientobj_delete_thread)(drd_joinee); 404 DRD_(thread_delayed_delete)(drd_joinee); 405 } 406 407 /** 408 * NPTL hack: NPTL allocates the 'struct pthread' on top of the stack, 409 * and accesses this data structure from multiple threads without locking. 410 * Any conflicting accesses in the range stack_startup..stack_max will be 411 * ignored. 412 */ 413 void DRD_(thread_set_stack_startup)(const DrdThreadId tid, 414 const Addr stack_startup) 415 { 416 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 417 && tid != DRD_INVALID_THREADID); 418 tl_assert(DRD_(g_threadinfo)[tid].stack_min <= stack_startup); 419 tl_assert(stack_startup <= DRD_(g_threadinfo)[tid].stack_max); 420 DRD_(g_threadinfo)[tid].stack_startup = stack_startup; 421 } 422 423 /** Return the stack pointer for the specified thread. */ 424 Addr DRD_(thread_get_stack_min)(const DrdThreadId tid) 425 { 426 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 427 && tid != DRD_INVALID_THREADID); 428 return DRD_(g_threadinfo)[tid].stack_min; 429 } 430 431 /** 432 * Return the lowest value that was ever assigned to the stack pointer 433 * for the specified thread. 434 */ 435 Addr DRD_(thread_get_stack_min_min)(const DrdThreadId tid) 436 { 437 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 438 && tid != DRD_INVALID_THREADID); 439 return DRD_(g_threadinfo)[tid].stack_min_min; 440 } 441 442 /** Return the top address for the stack of the specified thread. */ 443 Addr DRD_(thread_get_stack_max)(const DrdThreadId tid) 444 { 445 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 446 && tid != DRD_INVALID_THREADID); 447 return DRD_(g_threadinfo)[tid].stack_max; 448 } 449 450 /** Return the maximum stack size for the specified thread. */ 451 SizeT DRD_(thread_get_stack_size)(const DrdThreadId tid) 452 { 453 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 454 && tid != DRD_INVALID_THREADID); 455 return DRD_(g_threadinfo)[tid].stack_size; 456 } 457 458 Bool DRD_(thread_get_on_alt_stack)(const DrdThreadId tid) 459 { 460 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 461 && tid != DRD_INVALID_THREADID); 462 return DRD_(g_threadinfo)[tid].on_alt_stack; 463 } 464 465 void DRD_(thread_set_on_alt_stack)(const DrdThreadId tid, 466 const Bool on_alt_stack) 467 { 468 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 469 && tid != DRD_INVALID_THREADID); 470 tl_assert(on_alt_stack == !!on_alt_stack); 471 DRD_(g_threadinfo)[tid].on_alt_stack = on_alt_stack; 472 } 473 474 Int DRD_(thread_get_threads_on_alt_stack)(void) 475 { 476 int i, n = 0; 477 478 for (i = 1; i < DRD_N_THREADS; i++) 479 n += DRD_(g_threadinfo)[i].on_alt_stack; 480 return n; 481 } 482 483 /** 484 * Clean up thread-specific data structures. 485 */ 486 void DRD_(thread_delete)(const DrdThreadId tid, const Bool detached) 487 { 488 Segment* sg; 489 Segment* sg_prev; 490 491 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 492 493 tl_assert(DRD_(g_threadinfo)[tid].synchr_nesting >= 0); 494 for (sg = DRD_(g_threadinfo)[tid].last; sg; sg = sg_prev) 495 { 496 sg_prev = sg->prev; 497 sg->prev = 0; 498 sg->next = 0; 499 DRD_(sg_put)(sg); 500 } 501 DRD_(g_threadinfo)[tid].valid = False; 502 DRD_(g_threadinfo)[tid].vg_thread_exists = False; 503 DRD_(g_threadinfo)[tid].posix_thread_exists = False; 504 if (detached) 505 DRD_(g_threadinfo)[tid].detached_posix_thread = False; 506 else 507 tl_assert(!DRD_(g_threadinfo)[tid].detached_posix_thread); 508 DRD_(g_threadinfo)[tid].first = 0; 509 DRD_(g_threadinfo)[tid].last = 0; 510 511 tl_assert(! DRD_(IsValidDrdThreadId)(tid)); 512 } 513 514 /** 515 * Called after a thread performed its last memory access and before 516 * thread_delete() is called. Note: thread_delete() is only called for 517 * joinable threads, not for detached threads. 518 */ 519 void DRD_(thread_finished)(const DrdThreadId tid) 520 { 521 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 522 && tid != DRD_INVALID_THREADID); 523 524 DRD_(g_threadinfo)[tid].vg_thread_exists = False; 525 526 if (DRD_(g_threadinfo)[tid].detached_posix_thread) 527 { 528 /* 529 * Once a detached thread has finished, its stack is deallocated and 530 * should no longer be taken into account when computing the conflict set. 531 */ 532 DRD_(g_threadinfo)[tid].stack_min = DRD_(g_threadinfo)[tid].stack_max; 533 534 /* 535 * For a detached thread, calling pthread_exit() invalidates the 536 * POSIX thread ID associated with the detached thread. For joinable 537 * POSIX threads however, the POSIX thread ID remains live after the 538 * pthread_exit() call until pthread_join() is called. 539 */ 540 DRD_(g_threadinfo)[tid].posix_thread_exists = False; 541 } 542 } 543 544 /** Called just after fork() in the child process. */ 545 void DRD_(drd_thread_atfork_child)(const DrdThreadId tid) 546 { 547 unsigned i; 548 549 for (i = 1; i < DRD_N_THREADS; i++) 550 { 551 if (i == tid) 552 continue; 553 if (DRD_(IsValidDrdThreadId(i))) 554 DRD_(thread_delete)(i, True); 555 tl_assert(!DRD_(IsValidDrdThreadId(i))); 556 } 557 } 558 559 /** Called just before pthread_cancel(). */ 560 void DRD_(thread_pre_cancel)(const DrdThreadId tid) 561 { 562 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 563 && tid != DRD_INVALID_THREADID); 564 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 565 566 if (DRD_(thread_get_trace_fork_join)()) 567 DRD_(trace_msg)("[%d] drd_thread_pre_cancel %d", 568 DRD_(g_drd_running_tid), tid); 569 } 570 571 /** 572 * Store the POSIX thread ID for the specified thread. 573 * 574 * @note This function can be called two times for the same thread -- see also 575 * the comment block preceding the pthread_create() wrapper in 576 * drd_pthread_intercepts.c. 577 */ 578 void DRD_(thread_set_pthreadid)(const DrdThreadId tid, const PThreadId ptid) 579 { 580 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 581 && tid != DRD_INVALID_THREADID); 582 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid == INVALID_POSIX_THREADID 583 || DRD_(g_threadinfo)[tid].pt_threadid == ptid); 584 tl_assert(ptid != INVALID_POSIX_THREADID); 585 DRD_(g_threadinfo)[tid].posix_thread_exists = True; 586 DRD_(g_threadinfo)[tid].pt_threadid = ptid; 587 } 588 589 /** Returns true for joinable threads and false for detached threads. */ 590 Bool DRD_(thread_get_joinable)(const DrdThreadId tid) 591 { 592 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 593 && tid != DRD_INVALID_THREADID); 594 return ! DRD_(g_threadinfo)[tid].detached_posix_thread; 595 } 596 597 /** Store the thread mode: joinable or detached. */ 598 void DRD_(thread_set_joinable)(const DrdThreadId tid, const Bool joinable) 599 { 600 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 601 && tid != DRD_INVALID_THREADID); 602 tl_assert(!! joinable == joinable); 603 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 604 605 DRD_(g_threadinfo)[tid].detached_posix_thread = ! joinable; 606 } 607 608 /** Tells DRD that the calling thread is about to enter pthread_create(). */ 609 void DRD_(thread_entering_pthread_create)(const DrdThreadId tid) 610 { 611 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 612 && tid != DRD_INVALID_THREADID); 613 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 614 tl_assert(DRD_(g_threadinfo)[tid].pthread_create_nesting_level >= 0); 615 616 DRD_(g_threadinfo)[tid].pthread_create_nesting_level++; 617 } 618 619 /** Tells DRD that the calling thread has left pthread_create(). */ 620 void DRD_(thread_left_pthread_create)(const DrdThreadId tid) 621 { 622 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 623 && tid != DRD_INVALID_THREADID); 624 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 625 tl_assert(DRD_(g_threadinfo)[tid].pthread_create_nesting_level > 0); 626 627 DRD_(g_threadinfo)[tid].pthread_create_nesting_level--; 628 } 629 630 /** Obtain the thread number and the user-assigned thread name. */ 631 const char* DRD_(thread_get_name)(const DrdThreadId tid) 632 { 633 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 634 && tid != DRD_INVALID_THREADID); 635 636 return DRD_(g_threadinfo)[tid].name; 637 } 638 639 /** Set the name of the specified thread. */ 640 void DRD_(thread_set_name)(const DrdThreadId tid, const char* const name) 641 { 642 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 643 && tid != DRD_INVALID_THREADID); 644 645 if (name == NULL || name[0] == 0) 646 VG_(snprintf)(DRD_(g_threadinfo)[tid].name, 647 sizeof(DRD_(g_threadinfo)[tid].name), 648 "Thread %d", 649 tid); 650 else 651 VG_(snprintf)(DRD_(g_threadinfo)[tid].name, 652 sizeof(DRD_(g_threadinfo)[tid].name), 653 "Thread %d (%s)", 654 tid, name); 655 DRD_(g_threadinfo)[tid].name[sizeof(DRD_(g_threadinfo)[tid].name) - 1] = 0; 656 } 657 658 /** 659 * Update s_vg_running_tid, DRD_(g_drd_running_tid) and recalculate the 660 * conflict set. 661 */ 662 void DRD_(thread_set_vg_running_tid)(const ThreadId vg_tid) 663 { 664 tl_assert(vg_tid != VG_INVALID_THREADID); 665 666 if (vg_tid != s_vg_running_tid) 667 { 668 DRD_(thread_set_running_tid)(vg_tid, 669 DRD_(VgThreadIdToDrdThreadId)(vg_tid)); 670 } 671 672 tl_assert(s_vg_running_tid != VG_INVALID_THREADID); 673 tl_assert(DRD_(g_drd_running_tid) != DRD_INVALID_THREADID); 674 } 675 676 /** 677 * Update s_vg_running_tid, DRD_(g_drd_running_tid) and recalculate the 678 * conflict set. 679 */ 680 void DRD_(thread_set_running_tid)(const ThreadId vg_tid, 681 const DrdThreadId drd_tid) 682 { 683 tl_assert(vg_tid != VG_INVALID_THREADID); 684 tl_assert(drd_tid != DRD_INVALID_THREADID); 685 686 if (vg_tid != s_vg_running_tid) 687 { 688 if (s_trace_context_switches 689 && DRD_(g_drd_running_tid) != DRD_INVALID_THREADID) 690 { 691 VG_(message)(Vg_DebugMsg, 692 "Context switch from thread %d to thread %d;" 693 " segments: %llu\n", 694 DRD_(g_drd_running_tid), drd_tid, 695 DRD_(sg_get_segments_alive_count)()); 696 } 697 s_vg_running_tid = vg_tid; 698 DRD_(g_drd_running_tid) = drd_tid; 699 thread_compute_conflict_set(&DRD_(g_conflict_set), drd_tid); 700 s_context_switch_count++; 701 } 702 703 tl_assert(s_vg_running_tid != VG_INVALID_THREADID); 704 tl_assert(DRD_(g_drd_running_tid) != DRD_INVALID_THREADID); 705 } 706 707 /** 708 * Increase the synchronization nesting counter. Must be called before the 709 * client calls a synchronization function. 710 */ 711 int DRD_(thread_enter_synchr)(const DrdThreadId tid) 712 { 713 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 714 return DRD_(g_threadinfo)[tid].synchr_nesting++; 715 } 716 717 /** 718 * Decrease the synchronization nesting counter. Must be called after the 719 * client left a synchronization function. 720 */ 721 int DRD_(thread_leave_synchr)(const DrdThreadId tid) 722 { 723 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 724 tl_assert(DRD_(g_threadinfo)[tid].synchr_nesting >= 1); 725 return --DRD_(g_threadinfo)[tid].synchr_nesting; 726 } 727 728 /** Returns the synchronization nesting counter. */ 729 int DRD_(thread_get_synchr_nesting_count)(const DrdThreadId tid) 730 { 731 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 732 return DRD_(g_threadinfo)[tid].synchr_nesting; 733 } 734 735 /** Append a new segment at the end of the segment list. */ 736 static 737 void thread_append_segment(const DrdThreadId tid, Segment* const sg) 738 { 739 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 740 && tid != DRD_INVALID_THREADID); 741 742 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 743 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 744 #endif 745 746 sg->prev = DRD_(g_threadinfo)[tid].last; 747 sg->next = 0; 748 if (DRD_(g_threadinfo)[tid].last) 749 DRD_(g_threadinfo)[tid].last->next = sg; 750 DRD_(g_threadinfo)[tid].last = sg; 751 if (DRD_(g_threadinfo)[tid].first == 0) 752 DRD_(g_threadinfo)[tid].first = sg; 753 754 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 755 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 756 #endif 757 } 758 759 /** 760 * Remove a segment from the segment list of thread threadid, and free the 761 * associated memory. 762 */ 763 static 764 void thread_discard_segment(const DrdThreadId tid, Segment* const sg) 765 { 766 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 767 && tid != DRD_INVALID_THREADID); 768 769 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 770 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 771 #endif 772 773 if (sg->prev) 774 sg->prev->next = sg->next; 775 if (sg->next) 776 sg->next->prev = sg->prev; 777 if (sg == DRD_(g_threadinfo)[tid].first) 778 DRD_(g_threadinfo)[tid].first = sg->next; 779 if (sg == DRD_(g_threadinfo)[tid].last) 780 DRD_(g_threadinfo)[tid].last = sg->prev; 781 DRD_(sg_put)(sg); 782 783 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 784 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 785 #endif 786 } 787 788 /** 789 * Returns a pointer to the vector clock of the most recent segment associated 790 * with thread 'tid'. 791 */ 792 VectorClock* DRD_(thread_get_vc)(const DrdThreadId tid) 793 { 794 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 795 && tid != DRD_INVALID_THREADID); 796 tl_assert(DRD_(g_threadinfo)[tid].last); 797 return &DRD_(g_threadinfo)[tid].last->vc; 798 } 799 800 /** 801 * Return the latest segment of thread 'tid' and increment its reference count. 802 */ 803 void DRD_(thread_get_latest_segment)(Segment** sg, const DrdThreadId tid) 804 { 805 tl_assert(sg); 806 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 807 && tid != DRD_INVALID_THREADID); 808 tl_assert(DRD_(g_threadinfo)[tid].last); 809 810 DRD_(sg_put)(*sg); 811 *sg = DRD_(sg_get)(DRD_(g_threadinfo)[tid].last); 812 } 813 814 /** 815 * Compute the minimum of all latest vector clocks of all threads 816 * (Michiel Ronsse calls this "clock snooping" in his papers about DIOTA). 817 * 818 * @param vc pointer to a vectorclock, holds result upon return. 819 */ 820 static void DRD_(thread_compute_minimum_vc)(VectorClock* vc) 821 { 822 unsigned i; 823 Bool first; 824 Segment* latest_sg; 825 826 first = True; 827 for (i = 0; i < DRD_N_THREADS; i++) 828 { 829 latest_sg = DRD_(g_threadinfo)[i].last; 830 if (latest_sg) 831 { 832 if (first) 833 DRD_(vc_assign)(vc, &latest_sg->vc); 834 else 835 DRD_(vc_min)(vc, &latest_sg->vc); 836 first = False; 837 } 838 } 839 } 840 841 /** 842 * Compute the maximum of all latest vector clocks of all threads. 843 * 844 * @param vc pointer to a vectorclock, holds result upon return. 845 */ 846 static void DRD_(thread_compute_maximum_vc)(VectorClock* vc) 847 { 848 unsigned i; 849 Bool first; 850 Segment* latest_sg; 851 852 first = True; 853 for (i = 0; i < DRD_N_THREADS; i++) 854 { 855 latest_sg = DRD_(g_threadinfo)[i].last; 856 if (latest_sg) 857 { 858 if (first) 859 DRD_(vc_assign)(vc, &latest_sg->vc); 860 else 861 DRD_(vc_combine)(vc, &latest_sg->vc); 862 first = False; 863 } 864 } 865 } 866 867 /** 868 * Discard all segments that have a defined order against the latest vector 869 * clock of all threads -- these segments can no longer be involved in a 870 * data race. 871 */ 872 static void thread_discard_ordered_segments(void) 873 { 874 unsigned i; 875 VectorClock thread_vc_min; 876 877 s_discard_ordered_segments_count++; 878 879 DRD_(vc_init)(&thread_vc_min, 0, 0); 880 DRD_(thread_compute_minimum_vc)(&thread_vc_min); 881 if (DRD_(sg_get_trace)()) 882 { 883 char *vc_min, *vc_max; 884 VectorClock thread_vc_max; 885 886 DRD_(vc_init)(&thread_vc_max, 0, 0); 887 DRD_(thread_compute_maximum_vc)(&thread_vc_max); 888 vc_min = DRD_(vc_aprint)(&thread_vc_min); 889 vc_max = DRD_(vc_aprint)(&thread_vc_max); 890 VG_(message)(Vg_DebugMsg, 891 "Discarding ordered segments -- min vc is %s, max vc is %s\n", 892 vc_min, vc_max); 893 VG_(free)(vc_min); 894 VG_(free)(vc_max); 895 DRD_(vc_cleanup)(&thread_vc_max); 896 } 897 898 for (i = 0; i < DRD_N_THREADS; i++) 899 { 900 Segment* sg; 901 Segment* sg_next; 902 for (sg = DRD_(g_threadinfo)[i].first; 903 sg && (sg_next = sg->next) && DRD_(vc_lte)(&sg->vc, &thread_vc_min); 904 sg = sg_next) 905 { 906 thread_discard_segment(i, sg); 907 } 908 } 909 DRD_(vc_cleanup)(&thread_vc_min); 910 } 911 912 /** 913 * An implementation of the property 'equiv(sg1, sg2)' as defined in the paper 914 * by Mark Christiaens e.a. The property equiv(sg1, sg2) holds if and only if 915 * all segments in the set CS are ordered consistently against both sg1 and 916 * sg2. The set CS is defined as the set of segments that can immediately 917 * precede future segments via inter-thread synchronization operations. In 918 * DRD the set CS consists of the latest segment of each thread combined with 919 * all segments for which the reference count is strictly greater than one. 920 * The code below is an optimized version of the following: 921 * 922 * for (i = 0; i < DRD_N_THREADS; i++) 923 * { 924 * Segment* sg; 925 * 926 * for (sg = DRD_(g_threadinfo)[i].first; sg; sg = sg->next) 927 * { 928 * if (sg == DRD_(g_threadinfo)[i].last || DRD_(sg_get_refcnt)(sg) > 1) 929 * { 930 * if ( DRD_(vc_lte)(&sg1->vc, &sg->vc) 931 * != DRD_(vc_lte)(&sg2->vc, &sg->vc) 932 * || DRD_(vc_lte)(&sg->vc, &sg1->vc) 933 * != DRD_(vc_lte)(&sg->vc, &sg2->vc)) 934 * { 935 * return False; 936 * } 937 * } 938 * } 939 * } 940 */ 941 static Bool thread_consistent_segment_ordering(const DrdThreadId tid, 942 Segment* const sg1, 943 Segment* const sg2) 944 { 945 unsigned i; 946 947 tl_assert(sg1->next); 948 tl_assert(sg2->next); 949 tl_assert(sg1->next == sg2); 950 tl_assert(DRD_(vc_lte)(&sg1->vc, &sg2->vc)); 951 952 for (i = 0; i < DRD_N_THREADS; i++) 953 { 954 Segment* sg; 955 956 for (sg = DRD_(g_threadinfo)[i].first; sg; sg = sg->next) 957 { 958 if (! sg->next || DRD_(sg_get_refcnt)(sg) > 1) 959 { 960 if (DRD_(vc_lte)(&sg2->vc, &sg->vc)) 961 break; 962 if (DRD_(vc_lte)(&sg1->vc, &sg->vc)) 963 return False; 964 } 965 } 966 for (sg = DRD_(g_threadinfo)[i].last; sg; sg = sg->prev) 967 { 968 if (! sg->next || DRD_(sg_get_refcnt)(sg) > 1) 969 { 970 if (DRD_(vc_lte)(&sg->vc, &sg1->vc)) 971 break; 972 if (DRD_(vc_lte)(&sg->vc, &sg2->vc)) 973 return False; 974 } 975 } 976 } 977 return True; 978 } 979 980 /** 981 * Merge all segments that may be merged without triggering false positives 982 * or discarding real data races. For the theoretical background of segment 983 * merging, see also the following paper: Mark Christiaens, Michiel Ronsse 984 * and Koen De Bosschere. Bounding the number of segment histories during 985 * data race detection. Parallel Computing archive, Volume 28, Issue 9, 986 * pp 1221-1238, September 2002. This paper contains a proof that merging 987 * consecutive segments for which the property equiv(s1,s2) holds can be 988 * merged without reducing the accuracy of datarace detection. Furthermore 989 * it is also proven that the total number of all segments will never grow 990 * unbounded if all segments s1, s2 for which equiv(s1, s2) holds are merged 991 * every time a new segment is created. The property equiv(s1, s2) is defined 992 * as follows: equiv(s1, s2) <=> for all segments in the set CS, the vector 993 * clocks of segments s and s1 are ordered in the same way as those of segments 994 * s and s2. The set CS is defined as the set of existing segments s that have 995 * the potential to conflict with not yet created segments, either because the 996 * segment s is the latest segment of a thread or because it can become the 997 * immediate predecessor of a new segment due to a synchronization operation. 998 */ 999 static void thread_merge_segments(void) 1000 { 1001 unsigned i; 1002 1003 s_new_segments_since_last_merge = 0; 1004 1005 for (i = 0; i < DRD_N_THREADS; i++) 1006 { 1007 Segment* sg; 1008 1009 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 1010 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[i])); 1011 #endif 1012 1013 for (sg = DRD_(g_threadinfo)[i].first; sg; sg = sg->next) 1014 { 1015 if (DRD_(sg_get_refcnt)(sg) == 1 1016 && sg->next 1017 && DRD_(sg_get_refcnt)(sg->next) == 1 1018 && sg->next->next 1019 && thread_consistent_segment_ordering(i, sg, sg->next)) 1020 { 1021 /* Merge sg and sg->next into sg. */ 1022 DRD_(sg_merge)(sg, sg->next); 1023 thread_discard_segment(i, sg->next); 1024 } 1025 } 1026 1027 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 1028 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[i])); 1029 #endif 1030 } 1031 } 1032 1033 /** 1034 * Create a new segment for the specified thread, and discard any segments 1035 * that cannot cause races anymore. 1036 */ 1037 void DRD_(thread_new_segment)(const DrdThreadId tid) 1038 { 1039 Segment* last_sg; 1040 Segment* new_sg; 1041 1042 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1043 && tid != DRD_INVALID_THREADID); 1044 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1045 1046 last_sg = DRD_(g_threadinfo)[tid].last; 1047 new_sg = DRD_(sg_new)(tid, tid); 1048 thread_append_segment(tid, new_sg); 1049 if (tid == DRD_(g_drd_running_tid) && last_sg) 1050 { 1051 DRD_(thread_update_conflict_set)(tid, &last_sg->vc); 1052 s_update_conflict_set_new_sg_count++; 1053 } 1054 1055 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1056 1057 if (s_segment_merging 1058 && ++s_new_segments_since_last_merge >= s_segment_merge_interval) 1059 { 1060 thread_discard_ordered_segments(); 1061 thread_merge_segments(); 1062 } 1063 } 1064 1065 /** Call this function after thread 'joiner' joined thread 'joinee'. */ 1066 void DRD_(thread_combine_vc_join)(DrdThreadId joiner, DrdThreadId joinee) 1067 { 1068 tl_assert(joiner != joinee); 1069 tl_assert(0 <= (int)joiner && joiner < DRD_N_THREADS 1070 && joiner != DRD_INVALID_THREADID); 1071 tl_assert(0 <= (int)joinee && joinee < DRD_N_THREADS 1072 && joinee != DRD_INVALID_THREADID); 1073 tl_assert(DRD_(g_threadinfo)[joiner].last); 1074 tl_assert(DRD_(g_threadinfo)[joinee].last); 1075 1076 if (DRD_(sg_get_trace)()) 1077 { 1078 char *str1, *str2; 1079 str1 = DRD_(vc_aprint)(&DRD_(g_threadinfo)[joiner].last->vc); 1080 str2 = DRD_(vc_aprint)(&DRD_(g_threadinfo)[joinee].last->vc); 1081 VG_(message)(Vg_DebugMsg, "Before join: joiner %s, joinee %s\n", 1082 str1, str2); 1083 VG_(free)(str1); 1084 VG_(free)(str2); 1085 } 1086 if (joiner == DRD_(g_drd_running_tid)) 1087 { 1088 VectorClock old_vc; 1089 1090 DRD_(vc_copy)(&old_vc, &DRD_(g_threadinfo)[joiner].last->vc); 1091 DRD_(vc_combine)(&DRD_(g_threadinfo)[joiner].last->vc, 1092 &DRD_(g_threadinfo)[joinee].last->vc); 1093 DRD_(thread_update_conflict_set)(joiner, &old_vc); 1094 s_update_conflict_set_join_count++; 1095 DRD_(vc_cleanup)(&old_vc); 1096 } 1097 else 1098 { 1099 DRD_(vc_combine)(&DRD_(g_threadinfo)[joiner].last->vc, 1100 &DRD_(g_threadinfo)[joinee].last->vc); 1101 } 1102 1103 thread_discard_ordered_segments(); 1104 1105 if (DRD_(sg_get_trace)()) 1106 { 1107 char* str; 1108 str = DRD_(vc_aprint)(&DRD_(g_threadinfo)[joiner].last->vc); 1109 VG_(message)(Vg_DebugMsg, "After join: %s\n", str); 1110 VG_(free)(str); 1111 } 1112 } 1113 1114 /** 1115 * Update the vector clock of the last segment of thread tid with the 1116 * the vector clock of segment sg. 1117 */ 1118 static void thread_combine_vc_sync(DrdThreadId tid, const Segment* sg) 1119 { 1120 const VectorClock* const vc = &sg->vc; 1121 1122 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1123 && tid != DRD_INVALID_THREADID); 1124 tl_assert(DRD_(g_threadinfo)[tid].last); 1125 tl_assert(sg); 1126 tl_assert(vc); 1127 1128 if (tid != sg->tid) 1129 { 1130 VectorClock old_vc; 1131 1132 DRD_(vc_copy)(&old_vc, &DRD_(g_threadinfo)[tid].last->vc); 1133 DRD_(vc_combine)(&DRD_(g_threadinfo)[tid].last->vc, vc); 1134 if (DRD_(sg_get_trace)()) 1135 { 1136 char *str1, *str2; 1137 str1 = DRD_(vc_aprint)(&old_vc); 1138 str2 = DRD_(vc_aprint)(&DRD_(g_threadinfo)[tid].last->vc); 1139 VG_(message)(Vg_DebugMsg, "thread %d: vc %s -> %s\n", tid, str1, str2); 1140 VG_(free)(str1); 1141 VG_(free)(str2); 1142 } 1143 1144 thread_discard_ordered_segments(); 1145 1146 DRD_(thread_update_conflict_set)(tid, &old_vc); 1147 s_update_conflict_set_sync_count++; 1148 1149 DRD_(vc_cleanup)(&old_vc); 1150 } 1151 else 1152 { 1153 tl_assert(DRD_(vc_lte)(vc, &DRD_(g_threadinfo)[tid].last->vc)); 1154 } 1155 } 1156 1157 /** 1158 * Create a new segment for thread tid and update the vector clock of the last 1159 * segment of this thread with the the vector clock of segment sg. Call this 1160 * function after thread tid had to wait because of thread synchronization 1161 * until the memory accesses in the segment sg finished. 1162 */ 1163 void DRD_(thread_new_segment_and_combine_vc)(DrdThreadId tid, const Segment* sg) 1164 { 1165 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1166 && tid != DRD_INVALID_THREADID); 1167 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1168 tl_assert(sg); 1169 1170 thread_append_segment(tid, DRD_(sg_new)(tid, tid)); 1171 1172 thread_combine_vc_sync(tid, sg); 1173 1174 if (s_segment_merging 1175 && ++s_new_segments_since_last_merge >= s_segment_merge_interval) 1176 { 1177 thread_discard_ordered_segments(); 1178 thread_merge_segments(); 1179 } 1180 } 1181 1182 /** 1183 * Call this function whenever a thread is no longer using the memory 1184 * [ a1, a2 [, e.g. because of a call to free() or a stack pointer 1185 * increase. 1186 */ 1187 void DRD_(thread_stop_using_mem)(const Addr a1, const Addr a2) 1188 { 1189 unsigned i; 1190 Segment* p; 1191 1192 for (i = 0; i < DRD_N_THREADS; i++) 1193 for (p = DRD_(g_threadinfo)[i].first; p; p = p->next) 1194 DRD_(bm_clear)(DRD_(sg_bm)(p), a1, a2); 1195 1196 DRD_(bm_clear)(DRD_(g_conflict_set), a1, a2); 1197 } 1198 1199 /** Specify whether memory loads should be recorded. */ 1200 void DRD_(thread_set_record_loads)(const DrdThreadId tid, const Bool enabled) 1201 { 1202 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1203 && tid != DRD_INVALID_THREADID); 1204 tl_assert(enabled == !! enabled); 1205 1206 DRD_(g_threadinfo)[tid].is_recording_loads = enabled; 1207 } 1208 1209 /** Specify whether memory stores should be recorded. */ 1210 void DRD_(thread_set_record_stores)(const DrdThreadId tid, const Bool enabled) 1211 { 1212 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1213 && tid != DRD_INVALID_THREADID); 1214 tl_assert(enabled == !! enabled); 1215 1216 DRD_(g_threadinfo)[tid].is_recording_stores = enabled; 1217 } 1218 1219 /** 1220 * Print the segment information for all threads. 1221 * 1222 * This function is only used for debugging purposes. 1223 */ 1224 void DRD_(thread_print_all)(void) 1225 { 1226 unsigned i; 1227 Segment* p; 1228 1229 for (i = 0; i < DRD_N_THREADS; i++) 1230 { 1231 if (DRD_(g_threadinfo)[i].first) 1232 { 1233 VG_(printf)("**************\n" 1234 "* thread %3d (%d/%d/%d/%d/0x%lx/%d) *\n" 1235 "**************\n", 1236 i, 1237 DRD_(g_threadinfo)[i].valid, 1238 DRD_(g_threadinfo)[i].vg_thread_exists, 1239 DRD_(g_threadinfo)[i].vg_threadid, 1240 DRD_(g_threadinfo)[i].posix_thread_exists, 1241 DRD_(g_threadinfo)[i].pt_threadid, 1242 DRD_(g_threadinfo)[i].detached_posix_thread); 1243 for (p = DRD_(g_threadinfo)[i].first; p; p = p->next) 1244 { 1245 DRD_(sg_print)(p); 1246 } 1247 } 1248 } 1249 } 1250 1251 /** Show a call stack involved in a data race. */ 1252 static void show_call_stack(const DrdThreadId tid, ExeContext* const callstack) 1253 { 1254 const ThreadId vg_tid = DRD_(DrdThreadIdToVgThreadId)(tid); 1255 1256 if (vg_tid != VG_INVALID_THREADID) { 1257 if (callstack) 1258 VG_(pp_ExeContext)(callstack); 1259 else 1260 VG_(get_and_pp_StackTrace)(vg_tid, VG_(clo_backtrace_size)); 1261 } else { 1262 if (!VG_(clo_xml)) 1263 VG_(message)(Vg_UserMsg, 1264 " (thread finished, call stack no longer available)\n"); 1265 } 1266 } 1267 1268 /** Print information about the segments involved in a data race. */ 1269 static void 1270 thread_report_conflicting_segments_segment(const DrdThreadId tid, 1271 const Addr addr, 1272 const SizeT size, 1273 const BmAccessTypeT access_type, 1274 const Segment* const p) 1275 { 1276 unsigned i; 1277 1278 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1279 && tid != DRD_INVALID_THREADID); 1280 tl_assert(p); 1281 1282 for (i = 0; i < DRD_N_THREADS; i++) 1283 { 1284 if (i != tid) 1285 { 1286 Segment* q; 1287 for (q = DRD_(g_threadinfo)[i].last; q; q = q->prev) 1288 { 1289 /* 1290 * Since q iterates over the segments of thread i in order of 1291 * decreasing vector clocks, if q->vc <= p->vc, then 1292 * q->next->vc <= p->vc will also hold. Hence, break out of the 1293 * loop once this condition is met. 1294 */ 1295 if (DRD_(vc_lte)(&q->vc, &p->vc)) 1296 break; 1297 if (! DRD_(vc_lte)(&p->vc, &q->vc)) 1298 { 1299 if (DRD_(bm_has_conflict_with)(DRD_(sg_bm)(q), addr, addr + size, 1300 access_type)) 1301 { 1302 tl_assert(q->stacktrace); 1303 if (VG_(clo_xml)) 1304 VG_(printf_xml)(" <other_segment_start>\n"); 1305 else 1306 VG_(message)(Vg_UserMsg, 1307 "Other segment start (thread %d)\n", i); 1308 show_call_stack(i, q->stacktrace); 1309 if (VG_(clo_xml)) 1310 VG_(printf_xml)(" </other_segment_start>\n" 1311 " <other_segment_end>\n"); 1312 else 1313 VG_(message)(Vg_UserMsg, 1314 "Other segment end (thread %d)\n", i); 1315 show_call_stack(i, q->next ? q->next->stacktrace : 0); 1316 if (VG_(clo_xml)) 1317 VG_(printf_xml)(" </other_segment_end>\n"); 1318 } 1319 } 1320 } 1321 } 1322 } 1323 } 1324 1325 /** Print information about all segments involved in a data race. */ 1326 void DRD_(thread_report_conflicting_segments)(const DrdThreadId tid, 1327 const Addr addr, 1328 const SizeT size, 1329 const BmAccessTypeT access_type) 1330 { 1331 Segment* p; 1332 1333 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1334 && tid != DRD_INVALID_THREADID); 1335 1336 for (p = DRD_(g_threadinfo)[tid].first; p; p = p->next) 1337 { 1338 if (DRD_(bm_has)(DRD_(sg_bm)(p), addr, addr + size, access_type)) 1339 { 1340 thread_report_conflicting_segments_segment(tid, addr, size, 1341 access_type, p); 1342 } 1343 } 1344 } 1345 1346 /** 1347 * Verify whether the conflict set for thread tid is up to date. Only perform 1348 * the check if the environment variable DRD_VERIFY_CONFLICT_SET has been set. 1349 */ 1350 static Bool thread_conflict_set_up_to_date(const DrdThreadId tid) 1351 { 1352 static int do_verify_conflict_set = -1; 1353 Bool result; 1354 struct bitmap* computed_conflict_set = 0; 1355 1356 if (do_verify_conflict_set < 0) 1357 do_verify_conflict_set = VG_(getenv)("DRD_VERIFY_CONFLICT_SET") != 0; 1358 1359 if (do_verify_conflict_set == 0) 1360 return True; 1361 1362 thread_compute_conflict_set(&computed_conflict_set, tid); 1363 result = DRD_(bm_equal)(DRD_(g_conflict_set), computed_conflict_set); 1364 if (! result) 1365 { 1366 VG_(printf)("actual conflict set:\n"); 1367 DRD_(bm_print)(DRD_(g_conflict_set)); 1368 VG_(printf)("\n"); 1369 VG_(printf)("computed conflict set:\n"); 1370 DRD_(bm_print)(computed_conflict_set); 1371 VG_(printf)("\n"); 1372 } 1373 DRD_(bm_delete)(computed_conflict_set); 1374 return result; 1375 } 1376 1377 /** 1378 * Compute the conflict set: a bitmap that represents the union of all memory 1379 * accesses of all segments that are unordered to the current segment of the 1380 * thread tid. 1381 */ 1382 static void thread_compute_conflict_set(struct bitmap** conflict_set, 1383 const DrdThreadId tid) 1384 { 1385 Segment* p; 1386 1387 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1388 && tid != DRD_INVALID_THREADID); 1389 tl_assert(tid == DRD_(g_drd_running_tid)); 1390 1391 s_compute_conflict_set_count++; 1392 s_conflict_set_bitmap_creation_count 1393 -= DRD_(bm_get_bitmap_creation_count)(); 1394 s_conflict_set_bitmap2_creation_count 1395 -= DRD_(bm_get_bitmap2_creation_count)(); 1396 1397 if (*conflict_set) 1398 { 1399 DRD_(bm_cleanup)(*conflict_set); 1400 DRD_(bm_init)(*conflict_set); 1401 } 1402 else 1403 { 1404 *conflict_set = DRD_(bm_new)(); 1405 } 1406 1407 if (s_trace_conflict_set) 1408 { 1409 char* str; 1410 1411 str = DRD_(vc_aprint)(&DRD_(g_threadinfo)[tid].last->vc); 1412 VG_(message)(Vg_DebugMsg, 1413 "computing conflict set for thread %d with vc %s\n", 1414 tid, str); 1415 VG_(free)(str); 1416 } 1417 1418 p = DRD_(g_threadinfo)[tid].last; 1419 { 1420 unsigned j; 1421 1422 if (s_trace_conflict_set) 1423 { 1424 char* vc; 1425 1426 vc = DRD_(vc_aprint)(&p->vc); 1427 VG_(message)(Vg_DebugMsg, "conflict set: thread [%d] at vc %s\n", 1428 tid, vc); 1429 VG_(free)(vc); 1430 } 1431 1432 for (j = 0; j < DRD_N_THREADS; j++) 1433 { 1434 if (j != tid && DRD_(IsValidDrdThreadId)(j)) 1435 { 1436 Segment* q; 1437 for (q = DRD_(g_threadinfo)[j].last; q; q = q->prev) 1438 { 1439 if (! DRD_(vc_lte)(&q->vc, &p->vc) 1440 && ! DRD_(vc_lte)(&p->vc, &q->vc)) 1441 { 1442 if (s_trace_conflict_set) 1443 { 1444 char* str; 1445 1446 str = DRD_(vc_aprint)(&q->vc); 1447 VG_(message)(Vg_DebugMsg, 1448 "conflict set: [%d] merging segment %s\n", 1449 j, str); 1450 VG_(free)(str); 1451 } 1452 DRD_(bm_merge2)(*conflict_set, DRD_(sg_bm)(q)); 1453 } 1454 else 1455 { 1456 if (s_trace_conflict_set) 1457 { 1458 char* str; 1459 1460 str = DRD_(vc_aprint)(&q->vc); 1461 VG_(message)(Vg_DebugMsg, 1462 "conflict set: [%d] ignoring segment %s\n", 1463 j, str); 1464 VG_(free)(str); 1465 } 1466 } 1467 } 1468 } 1469 } 1470 } 1471 1472 s_conflict_set_bitmap_creation_count 1473 += DRD_(bm_get_bitmap_creation_count)(); 1474 s_conflict_set_bitmap2_creation_count 1475 += DRD_(bm_get_bitmap2_creation_count)(); 1476 1477 if (s_trace_conflict_set_bm) 1478 { 1479 VG_(message)(Vg_DebugMsg, "[%d] new conflict set:\n", tid); 1480 DRD_(bm_print)(*conflict_set); 1481 VG_(message)(Vg_DebugMsg, "[%d] end of new conflict set.\n", tid); 1482 } 1483 } 1484 1485 /** 1486 * Update the conflict set after the vector clock of thread tid has been 1487 * updated from old_vc to its current value, either because a new segment has 1488 * been created or because of a synchronization operation. 1489 */ 1490 void DRD_(thread_update_conflict_set)(const DrdThreadId tid, 1491 const VectorClock* const old_vc) 1492 { 1493 const VectorClock* new_vc; 1494 Segment* p; 1495 unsigned j; 1496 1497 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1498 && tid != DRD_INVALID_THREADID); 1499 tl_assert(old_vc); 1500 tl_assert(tid == DRD_(g_drd_running_tid)); 1501 tl_assert(DRD_(g_conflict_set)); 1502 1503 if (s_trace_conflict_set) 1504 { 1505 char* str; 1506 1507 str = DRD_(vc_aprint)(&DRD_(g_threadinfo)[tid].last->vc); 1508 VG_(message)(Vg_DebugMsg, 1509 "updating conflict set for thread %d with vc %s\n", 1510 tid, str); 1511 VG_(free)(str); 1512 } 1513 1514 new_vc = &DRD_(g_threadinfo)[tid].last->vc; 1515 tl_assert(DRD_(vc_lte)(old_vc, new_vc)); 1516 1517 DRD_(bm_unmark)(DRD_(g_conflict_set)); 1518 1519 for (j = 0; j < DRD_N_THREADS; j++) 1520 { 1521 Segment* q; 1522 1523 if (j == tid || ! DRD_(IsValidDrdThreadId)(j)) 1524 continue; 1525 1526 for (q = DRD_(g_threadinfo)[j].last; 1527 q && !DRD_(vc_lte)(&q->vc, new_vc); 1528 q = q->prev) { 1529 const Bool included_in_old_conflict_set 1530 = !DRD_(vc_lte)(old_vc, &q->vc); 1531 const Bool included_in_new_conflict_set 1532 = !DRD_(vc_lte)(new_vc, &q->vc); 1533 1534 if (UNLIKELY(s_trace_conflict_set)) { 1535 char* str; 1536 1537 str = DRD_(vc_aprint)(&q->vc); 1538 VG_(message)(Vg_DebugMsg, 1539 "conflict set: [%d] %s segment %s\n", j, 1540 included_in_old_conflict_set 1541 != included_in_new_conflict_set 1542 ? "merging" : "ignoring", str); 1543 VG_(free)(str); 1544 } 1545 if (included_in_old_conflict_set != included_in_new_conflict_set) 1546 DRD_(bm_mark)(DRD_(g_conflict_set), DRD_(sg_bm)(q)); 1547 } 1548 1549 for ( ; q && !DRD_(vc_lte)(&q->vc, old_vc); q = q->prev) { 1550 const Bool included_in_old_conflict_set 1551 = !DRD_(vc_lte)(old_vc, &q->vc); 1552 const Bool included_in_new_conflict_set 1553 = !DRD_(vc_lte)(&q->vc, new_vc) 1554 && !DRD_(vc_lte)(new_vc, &q->vc); 1555 1556 if (UNLIKELY(s_trace_conflict_set)) { 1557 char* str; 1558 1559 str = DRD_(vc_aprint)(&q->vc); 1560 VG_(message)(Vg_DebugMsg, 1561 "conflict set: [%d] %s segment %s\n", j, 1562 included_in_old_conflict_set 1563 != included_in_new_conflict_set 1564 ? "merging" : "ignoring", str); 1565 VG_(free)(str); 1566 } 1567 if (included_in_old_conflict_set != included_in_new_conflict_set) 1568 DRD_(bm_mark)(DRD_(g_conflict_set), DRD_(sg_bm)(q)); 1569 } 1570 } 1571 1572 DRD_(bm_clear_marked)(DRD_(g_conflict_set)); 1573 1574 p = DRD_(g_threadinfo)[tid].last; 1575 for (j = 0; j < DRD_N_THREADS; j++) 1576 { 1577 if (j != tid && DRD_(IsValidDrdThreadId)(j)) 1578 { 1579 Segment* q; 1580 for (q = DRD_(g_threadinfo)[j].last; 1581 q && !DRD_(vc_lte)(&q->vc, &p->vc); 1582 q = q->prev) { 1583 if (!DRD_(vc_lte)(&p->vc, &q->vc)) 1584 DRD_(bm_merge2_marked)(DRD_(g_conflict_set), DRD_(sg_bm)(q)); 1585 } 1586 } 1587 } 1588 1589 DRD_(bm_remove_cleared_marked)(DRD_(g_conflict_set)); 1590 1591 s_update_conflict_set_count++; 1592 1593 if (s_trace_conflict_set_bm) 1594 { 1595 VG_(message)(Vg_DebugMsg, "[%d] updated conflict set:\n", tid); 1596 DRD_(bm_print)(DRD_(g_conflict_set)); 1597 VG_(message)(Vg_DebugMsg, "[%d] end of updated conflict set.\n", tid); 1598 } 1599 1600 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1601 } 1602 1603 /** Report the number of context switches performed. */ 1604 ULong DRD_(thread_get_context_switch_count)(void) 1605 { 1606 return s_context_switch_count; 1607 } 1608 1609 /** Report the number of ordered segments that have been discarded. */ 1610 ULong DRD_(thread_get_discard_ordered_segments_count)(void) 1611 { 1612 return s_discard_ordered_segments_count; 1613 } 1614 1615 /** Return how many times the conflict set has been updated entirely. */ 1616 ULong DRD_(thread_get_compute_conflict_set_count)() 1617 { 1618 return s_compute_conflict_set_count; 1619 } 1620 1621 /** Return how many times the conflict set has been updated partially. */ 1622 ULong DRD_(thread_get_update_conflict_set_count)(void) 1623 { 1624 return s_update_conflict_set_count; 1625 } 1626 1627 /** 1628 * Return how many times the conflict set has been updated partially 1629 * because a new segment has been created. 1630 */ 1631 ULong DRD_(thread_get_update_conflict_set_new_sg_count)(void) 1632 { 1633 return s_update_conflict_set_new_sg_count; 1634 } 1635 1636 /** 1637 * Return how many times the conflict set has been updated partially 1638 * because of combining vector clocks due to synchronization operations 1639 * other than reader/writer lock or barrier operations. 1640 */ 1641 ULong DRD_(thread_get_update_conflict_set_sync_count)(void) 1642 { 1643 return s_update_conflict_set_sync_count; 1644 } 1645 1646 /** 1647 * Return how many times the conflict set has been updated partially 1648 * because of thread joins. 1649 */ 1650 ULong DRD_(thread_get_update_conflict_set_join_count)(void) 1651 { 1652 return s_update_conflict_set_join_count; 1653 } 1654 1655 /** 1656 * Return the number of first-level bitmaps that have been created during 1657 * conflict set updates. 1658 */ 1659 ULong DRD_(thread_get_conflict_set_bitmap_creation_count)(void) 1660 { 1661 return s_conflict_set_bitmap_creation_count; 1662 } 1663 1664 /** 1665 * Return the number of second-level bitmaps that have been created during 1666 * conflict set updates. 1667 */ 1668 ULong DRD_(thread_get_conflict_set_bitmap2_creation_count)(void) 1669 { 1670 return s_conflict_set_bitmap2_creation_count; 1671 } 1672
