1 /* 2 This file is part of drd, a thread error detector. 3 4 Copyright (C) 2006-2015 Bart Van Assche <bvanassche (at) acm.org>. 5 6 This program is free software; you can redistribute it and/or 7 modify it under the terms of the GNU General Public License as 8 published by the Free Software Foundation; either version 2 of the 9 License, or (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307, USA. 20 21 The GNU General Public License is contained in the file COPYING. 22 */ 23 24 25 #include "drd_error.h" 26 #include "drd_barrier.h" 27 #include "drd_clientobj.h" 28 #include "drd_cond.h" 29 #include "drd_mutex.h" 30 #include "drd_segment.h" 31 #include "drd_semaphore.h" 32 #include "drd_suppression.h" 33 #include "drd_thread.h" 34 #include "pub_tool_vki.h" 35 #include "pub_tool_basics.h" // Addr, SizeT 36 #include "pub_tool_libcassert.h" // tl_assert() 37 #include "pub_tool_libcbase.h" // VG_(strlen)() 38 #include "pub_tool_libcprint.h" // VG_(printf)() 39 #include "pub_tool_machine.h" 40 #include "pub_tool_mallocfree.h" // VG_(malloc)(), VG_(free)() 41 #include "pub_tool_options.h" // VG_(clo_backtrace_size) 42 #include "pub_tool_threadstate.h" // VG_(get_pthread_id)() 43 44 45 46 /* Local functions. */ 47 48 static void thread_append_segment(const DrdThreadId tid, Segment* const sg); 49 static void thread_discard_segment(const DrdThreadId tid, Segment* const sg); 50 static void thread_compute_conflict_set(struct bitmap** conflict_set, 51 const DrdThreadId tid); 52 static Bool thread_conflict_set_up_to_date(const DrdThreadId tid); 53 54 55 /* Local variables. */ 56 57 static ULong s_context_switch_count; 58 static ULong s_discard_ordered_segments_count; 59 static ULong s_compute_conflict_set_count; 60 static ULong s_update_conflict_set_count; 61 static ULong s_update_conflict_set_new_sg_count; 62 static ULong s_update_conflict_set_sync_count; 63 static ULong s_update_conflict_set_join_count; 64 static ULong s_conflict_set_bitmap_creation_count; 65 static ULong s_conflict_set_bitmap2_creation_count; 66 static ThreadId s_vg_running_tid = VG_INVALID_THREADID; 67 DrdThreadId DRD_(g_drd_running_tid) = DRD_INVALID_THREADID; 68 ThreadInfo* DRD_(g_threadinfo); 69 struct bitmap* DRD_(g_conflict_set); 70 Bool DRD_(verify_conflict_set); 71 static Bool s_trace_context_switches = False; 72 static Bool s_trace_conflict_set = False; 73 static Bool s_trace_conflict_set_bm = False; 74 static Bool s_trace_fork_join = False; 75 static Bool s_segment_merging = True; 76 static Bool s_new_segments_since_last_merge; 77 static int s_segment_merge_interval = 10; 78 static unsigned s_join_list_vol = 10; 79 static unsigned s_deletion_head; 80 static unsigned s_deletion_tail; 81 #if defined(VGO_solaris) 82 Bool DRD_(ignore_thread_creation) = True; 83 #else 84 Bool DRD_(ignore_thread_creation) = False; 85 #endif /* VGO_solaris */ 86 87 88 /* Function definitions. */ 89 90 /** Enables/disables context switch tracing. */ 91 void DRD_(thread_trace_context_switches)(const Bool t) 92 { 93 tl_assert(t == False || t == True); 94 s_trace_context_switches = t; 95 } 96 97 /** Enables/disables conflict set tracing. */ 98 void DRD_(thread_trace_conflict_set)(const Bool t) 99 { 100 tl_assert(t == False || t == True); 101 s_trace_conflict_set = t; 102 } 103 104 /** Enables/disables conflict set bitmap tracing. */ 105 void DRD_(thread_trace_conflict_set_bm)(const Bool t) 106 { 107 tl_assert(t == False || t == True); 108 s_trace_conflict_set_bm = t; 109 } 110 111 /** Report whether fork/join tracing is enabled. */ 112 Bool DRD_(thread_get_trace_fork_join)(void) 113 { 114 return s_trace_fork_join; 115 } 116 117 /** Enables/disables fork/join tracing. */ 118 void DRD_(thread_set_trace_fork_join)(const Bool t) 119 { 120 tl_assert(t == False || t == True); 121 s_trace_fork_join = t; 122 } 123 124 /** Enables/disables segment merging. */ 125 void DRD_(thread_set_segment_merging)(const Bool m) 126 { 127 tl_assert(m == False || m == True); 128 s_segment_merging = m; 129 } 130 131 /** Get the segment merging interval. */ 132 int DRD_(thread_get_segment_merge_interval)(void) 133 { 134 return s_segment_merge_interval; 135 } 136 137 /** Set the segment merging interval. */ 138 void DRD_(thread_set_segment_merge_interval)(const int i) 139 { 140 s_segment_merge_interval = i; 141 } 142 143 void DRD_(thread_set_join_list_vol)(const int jlv) 144 { 145 s_join_list_vol = jlv; 146 } 147 148 void DRD_(thread_init)(void) 149 { 150 DRD_(g_threadinfo) = VG_(malloc)("drd.main.ti.1", 151 DRD_N_THREADS * sizeof DRD_(g_threadinfo)[0]); 152 for (UInt i = 0; i < DRD_N_THREADS; ++i) { 153 static ThreadInfo initval; 154 DRD_(g_threadinfo)[i] = initval; 155 } 156 } 157 158 /** 159 * Convert Valgrind's ThreadId into a DrdThreadId. 160 * 161 * @return DRD thread ID upon success and DRD_INVALID_THREADID if the passed 162 * Valgrind ThreadId does not yet exist. 163 */ 164 DrdThreadId DRD_(VgThreadIdToDrdThreadId)(const ThreadId tid) 165 { 166 UInt i; 167 168 if (tid == VG_INVALID_THREADID) 169 return DRD_INVALID_THREADID; 170 171 for (i = 1; i < DRD_N_THREADS; i++) 172 { 173 if (DRD_(g_threadinfo)[i].vg_thread_exists == True 174 && DRD_(g_threadinfo)[i].vg_threadid == tid) 175 { 176 return i; 177 } 178 } 179 180 return DRD_INVALID_THREADID; 181 } 182 183 /** Allocate a new DRD thread ID for the specified Valgrind thread ID. */ 184 static DrdThreadId DRD_(VgThreadIdToNewDrdThreadId)(const ThreadId tid) 185 { 186 UInt i; 187 188 tl_assert(DRD_(VgThreadIdToDrdThreadId)(tid) == DRD_INVALID_THREADID); 189 190 for (i = 1; i < DRD_N_THREADS; i++) 191 { 192 if (!DRD_(g_threadinfo)[i].valid) 193 { 194 tl_assert(! DRD_(IsValidDrdThreadId)(i)); 195 196 DRD_(g_threadinfo)[i].valid = True; 197 DRD_(g_threadinfo)[i].vg_thread_exists = True; 198 DRD_(g_threadinfo)[i].vg_threadid = tid; 199 DRD_(g_threadinfo)[i].pt_threadid = INVALID_POSIX_THREADID; 200 DRD_(g_threadinfo)[i].stack_min = 0; 201 DRD_(g_threadinfo)[i].stack_min_min = 0; 202 DRD_(g_threadinfo)[i].stack_startup = 0; 203 DRD_(g_threadinfo)[i].stack_max = 0; 204 DRD_(thread_set_name)(i, ""); 205 DRD_(g_threadinfo)[i].on_alt_stack = False; 206 DRD_(g_threadinfo)[i].is_recording_loads = True; 207 DRD_(g_threadinfo)[i].is_recording_stores = True; 208 DRD_(g_threadinfo)[i].pthread_create_nesting_level = 0; 209 DRD_(g_threadinfo)[i].synchr_nesting = 0; 210 DRD_(g_threadinfo)[i].deletion_seq = s_deletion_tail - 1; 211 DRD_(g_threadinfo)[i].creator_thread = DRD_INVALID_THREADID; 212 #if defined (VGO_solaris) 213 DRD_(g_threadinfo)[i].bind_guard_flag = 0; 214 #endif /* VGO_solaris */ 215 216 tl_assert(DRD_(g_threadinfo)[i].sg_first == NULL); 217 tl_assert(DRD_(g_threadinfo)[i].sg_last == NULL); 218 219 tl_assert(DRD_(IsValidDrdThreadId)(i)); 220 221 return i; 222 } 223 } 224 225 VG_(printf)( 226 "\nSorry, but the maximum number of threads supported by DRD has been exceeded." 227 "Aborting.\n"); 228 229 tl_assert(False); 230 231 return DRD_INVALID_THREADID; 232 } 233 234 /** Convert a POSIX thread ID into a DRD thread ID. */ 235 DrdThreadId DRD_(PtThreadIdToDrdThreadId)(const PThreadId tid) 236 { 237 UInt i; 238 239 if (tid != INVALID_POSIX_THREADID) 240 { 241 for (i = 1; i < DRD_N_THREADS; i++) 242 { 243 if (DRD_(g_threadinfo)[i].posix_thread_exists 244 && DRD_(g_threadinfo)[i].pt_threadid == tid) 245 { 246 return i; 247 } 248 } 249 } 250 return DRD_INVALID_THREADID; 251 } 252 253 /** Convert a DRD thread ID into a Valgrind thread ID. */ 254 ThreadId DRD_(DrdThreadIdToVgThreadId)(const DrdThreadId tid) 255 { 256 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 257 && tid != DRD_INVALID_THREADID); 258 259 return (DRD_(g_threadinfo)[tid].vg_thread_exists 260 ? DRD_(g_threadinfo)[tid].vg_threadid 261 : VG_INVALID_THREADID); 262 } 263 264 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 265 /** 266 * Sanity check of the doubly linked list of segments referenced by a 267 * ThreadInfo struct. 268 * @return True if sane, False if not. 269 */ 270 static Bool DRD_(sane_ThreadInfo)(const ThreadInfo* const ti) 271 { 272 Segment* p; 273 274 for (p = ti->sg_first; p; p = p->thr_next) { 275 if (p->thr_next && p->thr_next->thr_prev != p) 276 return False; 277 if (p->thr_next == 0 && p != ti->sg_last) 278 return False; 279 } 280 for (p = ti->sg_last; p; p = p->thr_prev) { 281 if (p->thr_prev && p->thr_prev->thr_next != p) 282 return False; 283 if (p->thr_prev == 0 && p != ti->sg_first) 284 return False; 285 } 286 return True; 287 } 288 #endif 289 290 /** 291 * Create the first segment for a newly started thread. 292 * 293 * This function is called from the handler installed via 294 * VG_(track_pre_thread_ll_create)(). The Valgrind core invokes this handler 295 * from the context of the creator thread, before the new thread has been 296 * created. 297 * 298 * @param[in] creator DRD thread ID of the creator thread. 299 * @param[in] vg_created Valgrind thread ID of the created thread. 300 * 301 * @return DRD thread ID of the created thread. 302 */ 303 DrdThreadId DRD_(thread_pre_create)(const DrdThreadId creator, 304 const ThreadId vg_created) 305 { 306 DrdThreadId created; 307 308 tl_assert(DRD_(VgThreadIdToDrdThreadId)(vg_created) == DRD_INVALID_THREADID); 309 created = DRD_(VgThreadIdToNewDrdThreadId)(vg_created); 310 tl_assert(0 <= (int)created && created < DRD_N_THREADS 311 && created != DRD_INVALID_THREADID); 312 313 tl_assert(DRD_(g_threadinfo)[created].sg_first == NULL); 314 tl_assert(DRD_(g_threadinfo)[created].sg_last == NULL); 315 316 if (creator != DRD_INVALID_THREADID) { 317 if (DRD_(ignore_thread_creation)) { 318 tl_assert(DRD_(thread_get_synchr_nesting_count)(created) == 0); 319 DRD_(thread_enter_synchr)(created); 320 /* Counterpart in DRD_(thread_set_pthreadid)(). */ 321 } 322 } 323 DRD_(g_threadinfo)[created].creator_thread = creator; 324 325 /* Create an initial segment for the newly created thread. */ 326 thread_append_segment(created, DRD_(sg_new)(creator, created)); 327 328 return created; 329 } 330 331 /** 332 * Initialize DRD_(g_threadinfo)[] for a newly created thread. Must be called 333 * after the thread has been created and before any client instructions are run 334 * on the newly created thread, e.g. from the handler installed via 335 * VG_(track_pre_thread_first_insn)(). 336 * 337 * @param[in] vg_created Valgrind thread ID of the newly created thread. 338 * 339 * @return DRD thread ID for the new thread. 340 */ 341 DrdThreadId DRD_(thread_post_create)(const ThreadId vg_created) 342 { 343 const DrdThreadId created = DRD_(VgThreadIdToDrdThreadId)(vg_created); 344 345 tl_assert(0 <= (int)created && created < DRD_N_THREADS 346 && created != DRD_INVALID_THREADID); 347 348 DRD_(g_threadinfo)[created].stack_max 349 = VG_(thread_get_stack_max)(vg_created); 350 DRD_(g_threadinfo)[created].stack_startup 351 = DRD_(g_threadinfo)[created].stack_max; 352 DRD_(g_threadinfo)[created].stack_min 353 = DRD_(g_threadinfo)[created].stack_max; 354 DRD_(g_threadinfo)[created].stack_min_min 355 = DRD_(g_threadinfo)[created].stack_max; 356 DRD_(g_threadinfo)[created].stack_size 357 = VG_(thread_get_stack_size)(vg_created); 358 tl_assert(DRD_(g_threadinfo)[created].stack_max != 0); 359 360 return created; 361 } 362 363 static void DRD_(thread_delayed_delete)(const DrdThreadId tid) 364 { 365 UInt j; 366 367 DRD_(g_threadinfo)[tid].vg_thread_exists = False; 368 DRD_(g_threadinfo)[tid].posix_thread_exists = False; 369 DRD_(g_threadinfo)[tid].deletion_seq = s_deletion_head++; 370 #if 0 371 VG_(message)(Vg_DebugMsg, "Adding thread %d to the deletion list\n", tid); 372 #endif 373 if (s_deletion_head - s_deletion_tail >= s_join_list_vol) { 374 for (j = 0; j < DRD_N_THREADS; ++j) { 375 if (DRD_(IsValidDrdThreadId)(j) 376 && DRD_(g_threadinfo)[j].deletion_seq == s_deletion_tail) 377 { 378 s_deletion_tail++; 379 #if 0 380 VG_(message)(Vg_DebugMsg, "Delayed delete of thread %d\n", j); 381 #endif 382 DRD_(thread_delete)(j, False); 383 break; 384 } 385 } 386 } 387 } 388 389 /** 390 * Process VG_USERREQ__POST_THREAD_JOIN. This client request is invoked just 391 * after thread drd_joiner joined thread drd_joinee. 392 */ 393 void DRD_(thread_post_join)(DrdThreadId drd_joiner, DrdThreadId drd_joinee) 394 { 395 tl_assert(DRD_(IsValidDrdThreadId)(drd_joiner)); 396 tl_assert(DRD_(IsValidDrdThreadId)(drd_joinee)); 397 398 DRD_(thread_new_segment)(drd_joiner); 399 DRD_(thread_combine_vc_join)(drd_joiner, drd_joinee); 400 DRD_(thread_new_segment)(drd_joinee); 401 402 if (s_trace_fork_join) 403 { 404 const ThreadId joiner = DRD_(DrdThreadIdToVgThreadId)(drd_joiner); 405 const unsigned msg_size = 256; 406 HChar* msg; 407 408 msg = VG_(malloc)("drd.main.dptj.1", msg_size); 409 410 VG_(snprintf)(msg, msg_size, 411 "drd_post_thread_join joiner = %u, joinee = %u", 412 drd_joiner, drd_joinee); 413 if (joiner) 414 { 415 HChar* vc; 416 417 vc = DRD_(vc_aprint)(DRD_(thread_get_vc)(drd_joiner)); 418 VG_(snprintf)(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg), 419 ", new vc: %s", vc); 420 VG_(free)(vc); 421 } 422 DRD_(trace_msg)("%pS", msg); 423 VG_(free)(msg); 424 } 425 426 if (! DRD_(get_check_stack_accesses)()) 427 { 428 DRD_(finish_suppression)(DRD_(thread_get_stack_max)(drd_joinee) 429 - DRD_(thread_get_stack_size)(drd_joinee), 430 DRD_(thread_get_stack_max)(drd_joinee)); 431 } 432 DRD_(clientobj_delete_thread)(drd_joinee); 433 DRD_(thread_delayed_delete)(drd_joinee); 434 } 435 436 /** 437 * NPTL hack: NPTL allocates the 'struct pthread' on top of the stack, 438 * and accesses this data structure from multiple threads without locking. 439 * Any conflicting accesses in the range stack_startup..stack_max will be 440 * ignored. 441 */ 442 void DRD_(thread_set_stack_startup)(const DrdThreadId tid, 443 const Addr stack_startup) 444 { 445 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 446 && tid != DRD_INVALID_THREADID); 447 tl_assert(DRD_(g_threadinfo)[tid].stack_min <= stack_startup); 448 tl_assert(stack_startup <= DRD_(g_threadinfo)[tid].stack_max); 449 DRD_(g_threadinfo)[tid].stack_startup = stack_startup; 450 } 451 452 /** Return the stack pointer for the specified thread. */ 453 Addr DRD_(thread_get_stack_min)(const DrdThreadId tid) 454 { 455 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 456 && tid != DRD_INVALID_THREADID); 457 return DRD_(g_threadinfo)[tid].stack_min; 458 } 459 460 /** 461 * Return the lowest value that was ever assigned to the stack pointer 462 * for the specified thread. 463 */ 464 Addr DRD_(thread_get_stack_min_min)(const DrdThreadId tid) 465 { 466 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 467 && tid != DRD_INVALID_THREADID); 468 return DRD_(g_threadinfo)[tid].stack_min_min; 469 } 470 471 /** Return the top address for the stack of the specified thread. */ 472 Addr DRD_(thread_get_stack_max)(const DrdThreadId tid) 473 { 474 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 475 && tid != DRD_INVALID_THREADID); 476 return DRD_(g_threadinfo)[tid].stack_max; 477 } 478 479 /** Return the maximum stack size for the specified thread. */ 480 SizeT DRD_(thread_get_stack_size)(const DrdThreadId tid) 481 { 482 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 483 && tid != DRD_INVALID_THREADID); 484 return DRD_(g_threadinfo)[tid].stack_size; 485 } 486 487 Bool DRD_(thread_get_on_alt_stack)(const DrdThreadId tid) 488 { 489 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 490 && tid != DRD_INVALID_THREADID); 491 return DRD_(g_threadinfo)[tid].on_alt_stack; 492 } 493 494 void DRD_(thread_set_on_alt_stack)(const DrdThreadId tid, 495 const Bool on_alt_stack) 496 { 497 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 498 && tid != DRD_INVALID_THREADID); 499 tl_assert(on_alt_stack == !!on_alt_stack); 500 DRD_(g_threadinfo)[tid].on_alt_stack = on_alt_stack; 501 } 502 503 Int DRD_(thread_get_threads_on_alt_stack)(void) 504 { 505 int n = 0; 506 507 for (UInt i = 1; i < DRD_N_THREADS; i++) 508 n += DRD_(g_threadinfo)[i].on_alt_stack; 509 return n; 510 } 511 512 /** 513 * Clean up thread-specific data structures. 514 */ 515 void DRD_(thread_delete)(const DrdThreadId tid, const Bool detached) 516 { 517 Segment* sg; 518 Segment* sg_prev; 519 520 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 521 522 tl_assert(DRD_(g_threadinfo)[tid].synchr_nesting >= 0); 523 for (sg = DRD_(g_threadinfo)[tid].sg_last; sg; sg = sg_prev) { 524 sg_prev = sg->thr_prev; 525 sg->thr_next = NULL; 526 sg->thr_prev = NULL; 527 DRD_(sg_put)(sg); 528 } 529 DRD_(g_threadinfo)[tid].valid = False; 530 DRD_(g_threadinfo)[tid].vg_thread_exists = False; 531 DRD_(g_threadinfo)[tid].posix_thread_exists = False; 532 if (detached) 533 DRD_(g_threadinfo)[tid].detached_posix_thread = False; 534 else 535 tl_assert(!DRD_(g_threadinfo)[tid].detached_posix_thread); 536 DRD_(g_threadinfo)[tid].sg_first = NULL; 537 DRD_(g_threadinfo)[tid].sg_last = NULL; 538 539 tl_assert(!DRD_(IsValidDrdThreadId)(tid)); 540 } 541 542 /** 543 * Called after a thread performed its last memory access and before 544 * thread_delete() is called. Note: thread_delete() is only called for 545 * joinable threads, not for detached threads. 546 */ 547 void DRD_(thread_finished)(const DrdThreadId tid) 548 { 549 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 550 && tid != DRD_INVALID_THREADID); 551 552 DRD_(g_threadinfo)[tid].vg_thread_exists = False; 553 554 if (DRD_(g_threadinfo)[tid].detached_posix_thread) 555 { 556 /* 557 * Once a detached thread has finished, its stack is deallocated and 558 * should no longer be taken into account when computing the conflict set. 559 */ 560 DRD_(g_threadinfo)[tid].stack_min = DRD_(g_threadinfo)[tid].stack_max; 561 562 /* 563 * For a detached thread, calling pthread_exit() invalidates the 564 * POSIX thread ID associated with the detached thread. For joinable 565 * POSIX threads however, the POSIX thread ID remains live after the 566 * pthread_exit() call until pthread_join() is called. 567 */ 568 DRD_(g_threadinfo)[tid].posix_thread_exists = False; 569 } 570 } 571 572 /** Called just after fork() in the child process. */ 573 void DRD_(drd_thread_atfork_child)(const DrdThreadId tid) 574 { 575 unsigned i; 576 577 for (i = 1; i < DRD_N_THREADS; i++) 578 { 579 if (i == tid) 580 continue; 581 if (DRD_(IsValidDrdThreadId(i))) 582 DRD_(thread_delete)(i, True); 583 tl_assert(!DRD_(IsValidDrdThreadId(i))); 584 } 585 586 DRD_(bm_cleanup)(DRD_(g_conflict_set)); 587 DRD_(bm_init)(DRD_(g_conflict_set)); 588 } 589 590 /** Called just before pthread_cancel(). */ 591 void DRD_(thread_pre_cancel)(const DrdThreadId tid) 592 { 593 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 594 && tid != DRD_INVALID_THREADID); 595 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 596 597 if (DRD_(thread_get_trace_fork_join)()) 598 DRD_(trace_msg)("[%u] drd_thread_pre_cancel %u", 599 DRD_(g_drd_running_tid), tid); 600 } 601 602 /** 603 * Store the POSIX thread ID for the specified thread. 604 * 605 * @note This function can be called two times for the same thread -- see also 606 * the comment block preceding the pthread_create() wrapper in 607 * drd_pthread_intercepts.c. 608 */ 609 void DRD_(thread_set_pthreadid)(const DrdThreadId tid, const PThreadId ptid) 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 || DRD_(g_threadinfo)[tid].pt_threadid == ptid); 615 tl_assert(ptid != INVALID_POSIX_THREADID); 616 DRD_(g_threadinfo)[tid].posix_thread_exists = True; 617 DRD_(g_threadinfo)[tid].pt_threadid = ptid; 618 619 if (DRD_(g_threadinfo)[tid].creator_thread != DRD_INVALID_THREADID) { 620 if (DRD_(ignore_thread_creation)) { 621 DRD_(thread_leave_synchr)(tid); 622 tl_assert(DRD_(thread_get_synchr_nesting_count)(tid) == 0); 623 } 624 } 625 } 626 627 /** Returns true for joinable threads and false for detached threads. */ 628 Bool DRD_(thread_get_joinable)(const DrdThreadId tid) 629 { 630 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 631 && tid != DRD_INVALID_THREADID); 632 return ! DRD_(g_threadinfo)[tid].detached_posix_thread; 633 } 634 635 /** Store the thread mode: joinable or detached. */ 636 #if defined(VGP_mips32_linux) || defined(VGP_mips64_linux) 637 /* There is a cse related issue in gcc for MIPS. Optimization level 638 has to be lowered, so cse related optimizations are not 639 included.*/ 640 __attribute__((optimize("O1"))) 641 #endif 642 void DRD_(thread_set_joinable)(const DrdThreadId tid, const Bool joinable) 643 { 644 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 645 && tid != DRD_INVALID_THREADID); 646 tl_assert((!! joinable) == joinable); 647 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 648 649 DRD_(g_threadinfo)[tid].detached_posix_thread = ! joinable; 650 } 651 652 /** Tells DRD that the calling thread is about to enter pthread_create(). */ 653 void DRD_(thread_entering_pthread_create)(const DrdThreadId tid) 654 { 655 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 656 && tid != DRD_INVALID_THREADID); 657 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 658 tl_assert(DRD_(g_threadinfo)[tid].pthread_create_nesting_level >= 0); 659 660 DRD_(g_threadinfo)[tid].pthread_create_nesting_level++; 661 662 if (DRD_(ignore_thread_creation)) { 663 tl_assert(DRD_(thread_get_synchr_nesting_count)(tid) == 0); 664 DRD_(thread_enter_synchr)(tid); 665 } 666 } 667 668 /** Tells DRD that the calling thread has left pthread_create(). */ 669 void DRD_(thread_left_pthread_create)(const DrdThreadId tid) 670 { 671 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 672 && tid != DRD_INVALID_THREADID); 673 tl_assert(DRD_(g_threadinfo)[tid].pt_threadid != INVALID_POSIX_THREADID); 674 tl_assert(DRD_(g_threadinfo)[tid].pthread_create_nesting_level > 0); 675 676 DRD_(g_threadinfo)[tid].pthread_create_nesting_level--; 677 678 if (DRD_(ignore_thread_creation)) { 679 DRD_(thread_leave_synchr)(tid); 680 tl_assert(DRD_(thread_get_synchr_nesting_count)(tid) == 0); 681 } 682 } 683 684 #if defined(VGO_solaris) 685 /** Handles the bind_guard() intercept. */ 686 void DRD_(thread_entering_rtld_bind_guard)(const DrdThreadId tid, int flags) 687 { 688 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 689 && tid != DRD_INVALID_THREADID); 690 691 Int bindflag = (flags & VKI_THR_FLG_RTLD); 692 if ((bindflag & DRD_(g_threadinfo)[tid].bind_guard_flag) == 0) { 693 DRD_(g_threadinfo)[tid].bind_guard_flag |= bindflag; 694 DRD_(thread_enter_synchr)(tid); 695 } 696 } 697 698 /** 699 * Handles the bind_clear() intercept. 700 * Call to bind_clear(0) is typically used to determine value of bind_flags. 701 */ 702 void DRD_(thread_leaving_rtld_bind_clear)(const DrdThreadId tid, int flags) 703 { 704 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 705 && tid != DRD_INVALID_THREADID); 706 707 Int bindflag = (flags & VKI_THR_FLG_RTLD); 708 if ((DRD_(g_threadinfo)[tid].bind_guard_flag & bindflag) != 0) { 709 DRD_(g_threadinfo)[tid].bind_guard_flag &= ~bindflag; 710 DRD_(thread_leave_synchr)(tid); 711 } 712 } 713 #endif /* VGO_solaris */ 714 715 /** Obtain the thread number and the user-assigned thread name. */ 716 const HChar* DRD_(thread_get_name)(const DrdThreadId tid) 717 { 718 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 719 && tid != DRD_INVALID_THREADID); 720 721 return DRD_(g_threadinfo)[tid].name; 722 } 723 724 /** Set the name of the specified thread. */ 725 void DRD_(thread_set_name)(const DrdThreadId tid, const HChar* const name) 726 { 727 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 728 && tid != DRD_INVALID_THREADID); 729 730 if (name == NULL || name[0] == 0) 731 VG_(snprintf)(DRD_(g_threadinfo)[tid].name, 732 sizeof(DRD_(g_threadinfo)[tid].name), 733 "Thread %u", 734 tid); 735 else 736 VG_(snprintf)(DRD_(g_threadinfo)[tid].name, 737 sizeof(DRD_(g_threadinfo)[tid].name), 738 "Thread %u (%s)", 739 tid, name); 740 DRD_(g_threadinfo)[tid].name[sizeof(DRD_(g_threadinfo)[tid].name) - 1] = 0; 741 } 742 743 /** 744 * Update s_vg_running_tid, DRD_(g_drd_running_tid) and recalculate the 745 * conflict set. 746 */ 747 void DRD_(thread_set_vg_running_tid)(const ThreadId vg_tid) 748 { 749 tl_assert(vg_tid != VG_INVALID_THREADID); 750 751 if (vg_tid != s_vg_running_tid) 752 { 753 DRD_(thread_set_running_tid)(vg_tid, 754 DRD_(VgThreadIdToDrdThreadId)(vg_tid)); 755 } 756 757 tl_assert(s_vg_running_tid != VG_INVALID_THREADID); 758 tl_assert(DRD_(g_drd_running_tid) != DRD_INVALID_THREADID); 759 } 760 761 /** 762 * Update s_vg_running_tid, DRD_(g_drd_running_tid) and recalculate the 763 * conflict set. 764 */ 765 void DRD_(thread_set_running_tid)(const ThreadId vg_tid, 766 const DrdThreadId drd_tid) 767 { 768 tl_assert(vg_tid != VG_INVALID_THREADID); 769 tl_assert(drd_tid != DRD_INVALID_THREADID); 770 771 if (vg_tid != s_vg_running_tid) 772 { 773 if (s_trace_context_switches 774 && DRD_(g_drd_running_tid) != DRD_INVALID_THREADID) 775 { 776 VG_(message)(Vg_DebugMsg, 777 "Context switch from thread %u to thread %u;" 778 " segments: %llu\n", 779 DRD_(g_drd_running_tid), drd_tid, 780 DRD_(sg_get_segments_alive_count)()); 781 } 782 s_vg_running_tid = vg_tid; 783 DRD_(g_drd_running_tid) = drd_tid; 784 thread_compute_conflict_set(&DRD_(g_conflict_set), drd_tid); 785 s_context_switch_count++; 786 } 787 788 tl_assert(s_vg_running_tid != VG_INVALID_THREADID); 789 tl_assert(DRD_(g_drd_running_tid) != DRD_INVALID_THREADID); 790 } 791 792 /** 793 * Increase the synchronization nesting counter. Must be called before the 794 * client calls a synchronization function. 795 */ 796 int DRD_(thread_enter_synchr)(const DrdThreadId tid) 797 { 798 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 799 return DRD_(g_threadinfo)[tid].synchr_nesting++; 800 } 801 802 /** 803 * Decrease the synchronization nesting counter. Must be called after the 804 * client left a synchronization function. 805 */ 806 int DRD_(thread_leave_synchr)(const DrdThreadId tid) 807 { 808 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 809 tl_assert(DRD_(g_threadinfo)[tid].synchr_nesting >= 1); 810 return --DRD_(g_threadinfo)[tid].synchr_nesting; 811 } 812 813 /** Returns the synchronization nesting counter. */ 814 int DRD_(thread_get_synchr_nesting_count)(const DrdThreadId tid) 815 { 816 tl_assert(DRD_(IsValidDrdThreadId)(tid)); 817 return DRD_(g_threadinfo)[tid].synchr_nesting; 818 } 819 820 /** Append a new segment at the end of the segment list. */ 821 static 822 void thread_append_segment(const DrdThreadId tid, Segment* const sg) 823 { 824 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 825 && tid != DRD_INVALID_THREADID); 826 827 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 828 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 829 #endif 830 831 // add at tail 832 sg->thr_prev = DRD_(g_threadinfo)[tid].sg_last; 833 sg->thr_next = NULL; 834 if (DRD_(g_threadinfo)[tid].sg_last) 835 DRD_(g_threadinfo)[tid].sg_last->thr_next = sg; 836 DRD_(g_threadinfo)[tid].sg_last = sg; 837 if (DRD_(g_threadinfo)[tid].sg_first == NULL) 838 DRD_(g_threadinfo)[tid].sg_first = sg; 839 840 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 841 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 842 #endif 843 } 844 845 /** 846 * Remove a segment from the segment list of thread threadid, and free the 847 * associated memory. 848 */ 849 static 850 void thread_discard_segment(const DrdThreadId tid, Segment* const sg) 851 { 852 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 853 && tid != DRD_INVALID_THREADID); 854 855 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 856 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 857 #endif 858 859 if (sg->thr_prev) 860 sg->thr_prev->thr_next = sg->thr_next; 861 if (sg->thr_next) 862 sg->thr_next->thr_prev = sg->thr_prev; 863 if (sg == DRD_(g_threadinfo)[tid].sg_first) 864 DRD_(g_threadinfo)[tid].sg_first = sg->thr_next; 865 if (sg == DRD_(g_threadinfo)[tid].sg_last) 866 DRD_(g_threadinfo)[tid].sg_last = sg->thr_prev; 867 DRD_(sg_put)(sg); 868 869 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 870 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[tid])); 871 #endif 872 } 873 874 /** 875 * Returns a pointer to the vector clock of the most recent segment associated 876 * with thread 'tid'. 877 */ 878 VectorClock* DRD_(thread_get_vc)(const DrdThreadId tid) 879 { 880 Segment* latest_sg; 881 882 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 883 && tid != DRD_INVALID_THREADID); 884 latest_sg = DRD_(g_threadinfo)[tid].sg_last; 885 tl_assert(latest_sg); 886 return &latest_sg->vc; 887 } 888 889 /** 890 * Return the latest segment of thread 'tid' and increment its reference count. 891 */ 892 void DRD_(thread_get_latest_segment)(Segment** sg, const DrdThreadId tid) 893 { 894 Segment* latest_sg; 895 896 tl_assert(sg); 897 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 898 && tid != DRD_INVALID_THREADID); 899 latest_sg = DRD_(g_threadinfo)[tid].sg_last; 900 tl_assert(latest_sg); 901 902 DRD_(sg_put)(*sg); 903 *sg = DRD_(sg_get)(latest_sg); 904 } 905 906 /** 907 * Compute the minimum of all latest vector clocks of all threads 908 * (Michiel Ronsse calls this "clock snooping" in his papers about DIOTA). 909 * 910 * @param vc pointer to a vectorclock, holds result upon return. 911 */ 912 static void DRD_(thread_compute_minimum_vc)(VectorClock* vc) 913 { 914 unsigned i; 915 Bool first; 916 Segment* latest_sg; 917 918 first = True; 919 for (i = 0; i < DRD_N_THREADS; i++) 920 { 921 latest_sg = DRD_(g_threadinfo)[i].sg_last; 922 if (latest_sg) { 923 if (first) 924 DRD_(vc_assign)(vc, &latest_sg->vc); 925 else 926 DRD_(vc_min)(vc, &latest_sg->vc); 927 first = False; 928 } 929 } 930 } 931 932 /** 933 * Compute the maximum of all latest vector clocks of all threads. 934 * 935 * @param vc pointer to a vectorclock, holds result upon return. 936 */ 937 static void DRD_(thread_compute_maximum_vc)(VectorClock* vc) 938 { 939 unsigned i; 940 Bool first; 941 Segment* latest_sg; 942 943 first = True; 944 for (i = 0; i < DRD_N_THREADS; i++) 945 { 946 latest_sg = DRD_(g_threadinfo)[i].sg_last; 947 if (latest_sg) { 948 if (first) 949 DRD_(vc_assign)(vc, &latest_sg->vc); 950 else 951 DRD_(vc_combine)(vc, &latest_sg->vc); 952 first = False; 953 } 954 } 955 } 956 957 /** 958 * Discard all segments that have a defined order against the latest vector 959 * clock of all threads -- these segments can no longer be involved in a 960 * data race. 961 */ 962 static void thread_discard_ordered_segments(void) 963 { 964 unsigned i; 965 VectorClock thread_vc_min; 966 967 s_discard_ordered_segments_count++; 968 969 DRD_(vc_init)(&thread_vc_min, 0, 0); 970 DRD_(thread_compute_minimum_vc)(&thread_vc_min); 971 if (DRD_(sg_get_trace)()) 972 { 973 HChar *vc_min, *vc_max; 974 VectorClock thread_vc_max; 975 976 DRD_(vc_init)(&thread_vc_max, 0, 0); 977 DRD_(thread_compute_maximum_vc)(&thread_vc_max); 978 vc_min = DRD_(vc_aprint)(&thread_vc_min); 979 vc_max = DRD_(vc_aprint)(&thread_vc_max); 980 VG_(message)(Vg_DebugMsg, 981 "Discarding ordered segments -- min vc is %s, max vc is %s\n", 982 vc_min, vc_max); 983 VG_(free)(vc_min); 984 VG_(free)(vc_max); 985 DRD_(vc_cleanup)(&thread_vc_max); 986 } 987 988 for (i = 0; i < DRD_N_THREADS; i++) { 989 Segment* sg; 990 Segment* sg_next; 991 992 for (sg = DRD_(g_threadinfo)[i].sg_first; 993 sg && (sg_next = sg->thr_next) 994 && DRD_(vc_lte)(&sg->vc, &thread_vc_min); 995 sg = sg_next) 996 { 997 thread_discard_segment(i, sg); 998 } 999 } 1000 DRD_(vc_cleanup)(&thread_vc_min); 1001 } 1002 1003 /** 1004 * An implementation of the property 'equiv(sg1, sg2)' as defined in the paper 1005 * by Mark Christiaens e.a. The property equiv(sg1, sg2) holds if and only if 1006 * all segments in the set CS are ordered consistently against both sg1 and 1007 * sg2. The set CS is defined as the set of segments that can immediately 1008 * precede future segments via inter-thread synchronization operations. In 1009 * DRD the set CS consists of the latest segment of each thread combined with 1010 * all segments for which the reference count is strictly greater than one. 1011 * The code below is an optimized version of the following: 1012 * 1013 * for (i = 0; i < DRD_N_THREADS; i++) 1014 * { 1015 * Segment* sg; 1016 * 1017 * for (sg = DRD_(g_threadinfo)[i].first; sg; sg = sg->next) 1018 * { 1019 * if (sg == DRD_(g_threadinfo)[i].last || DRD_(sg_get_refcnt)(sg) > 1) 1020 * { 1021 * if ( DRD_(vc_lte)(&sg1->vc, &sg->vc) 1022 * != DRD_(vc_lte)(&sg2->vc, &sg->vc) 1023 * || DRD_(vc_lte)(&sg->vc, &sg1->vc) 1024 * != DRD_(vc_lte)(&sg->vc, &sg2->vc)) 1025 * { 1026 * return False; 1027 * } 1028 * } 1029 * } 1030 * } 1031 */ 1032 static Bool thread_consistent_segment_ordering(const DrdThreadId tid, 1033 Segment* const sg1, 1034 Segment* const sg2) 1035 { 1036 unsigned i; 1037 1038 tl_assert(sg1->thr_next); 1039 tl_assert(sg2->thr_next); 1040 tl_assert(sg1->thr_next == sg2); 1041 tl_assert(DRD_(vc_lte)(&sg1->vc, &sg2->vc)); 1042 1043 for (i = 0; i < DRD_N_THREADS; i++) 1044 { 1045 Segment* sg; 1046 1047 for (sg = DRD_(g_threadinfo)[i].sg_first; sg; sg = sg->thr_next) { 1048 if (!sg->thr_next || DRD_(sg_get_refcnt)(sg) > 1) { 1049 if (DRD_(vc_lte)(&sg2->vc, &sg->vc)) 1050 break; 1051 if (DRD_(vc_lte)(&sg1->vc, &sg->vc)) 1052 return False; 1053 } 1054 } 1055 for (sg = DRD_(g_threadinfo)[i].sg_last; sg; sg = sg->thr_prev) { 1056 if (!sg->thr_next || DRD_(sg_get_refcnt)(sg) > 1) { 1057 if (DRD_(vc_lte)(&sg->vc, &sg1->vc)) 1058 break; 1059 if (DRD_(vc_lte)(&sg->vc, &sg2->vc)) 1060 return False; 1061 } 1062 } 1063 } 1064 return True; 1065 } 1066 1067 /** 1068 * Merge all segments that may be merged without triggering false positives 1069 * or discarding real data races. For the theoretical background of segment 1070 * merging, see also the following paper: Mark Christiaens, Michiel Ronsse 1071 * and Koen De Bosschere. Bounding the number of segment histories during 1072 * data race detection. Parallel Computing archive, Volume 28, Issue 9, 1073 * pp 1221-1238, September 2002. This paper contains a proof that merging 1074 * consecutive segments for which the property equiv(s1,s2) holds can be 1075 * merged without reducing the accuracy of datarace detection. Furthermore 1076 * it is also proven that the total number of all segments will never grow 1077 * unbounded if all segments s1, s2 for which equiv(s1, s2) holds are merged 1078 * every time a new segment is created. The property equiv(s1, s2) is defined 1079 * as follows: equiv(s1, s2) <=> for all segments in the set CS, the vector 1080 * clocks of segments s and s1 are ordered in the same way as those of segments 1081 * s and s2. The set CS is defined as the set of existing segments s that have 1082 * the potential to conflict with not yet created segments, either because the 1083 * segment s is the latest segment of a thread or because it can become the 1084 * immediate predecessor of a new segment due to a synchronization operation. 1085 */ 1086 static void thread_merge_segments(void) 1087 { 1088 unsigned i; 1089 1090 s_new_segments_since_last_merge = 0; 1091 1092 for (i = 0; i < DRD_N_THREADS; i++) 1093 { 1094 Segment* sg; 1095 1096 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 1097 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[i])); 1098 #endif 1099 1100 for (sg = DRD_(g_threadinfo)[i].sg_first; sg; sg = sg->thr_next) { 1101 if (DRD_(sg_get_refcnt)(sg) == 1 && sg->thr_next) { 1102 Segment* const sg_next = sg->thr_next; 1103 if (DRD_(sg_get_refcnt)(sg_next) == 1 1104 && sg_next->thr_next 1105 && thread_consistent_segment_ordering(i, sg, sg_next)) 1106 { 1107 /* Merge sg and sg_next into sg. */ 1108 DRD_(sg_merge)(sg, sg_next); 1109 thread_discard_segment(i, sg_next); 1110 } 1111 } 1112 } 1113 1114 #ifdef ENABLE_DRD_CONSISTENCY_CHECKS 1115 tl_assert(DRD_(sane_ThreadInfo)(&DRD_(g_threadinfo)[i])); 1116 #endif 1117 } 1118 } 1119 1120 /** 1121 * Create a new segment for the specified thread, and discard any segments 1122 * that cannot cause races anymore. 1123 */ 1124 void DRD_(thread_new_segment)(const DrdThreadId tid) 1125 { 1126 Segment* last_sg; 1127 Segment* new_sg; 1128 1129 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1130 && tid != DRD_INVALID_THREADID); 1131 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1132 1133 last_sg = DRD_(g_threadinfo)[tid].sg_last; 1134 new_sg = DRD_(sg_new)(tid, tid); 1135 thread_append_segment(tid, new_sg); 1136 if (tid == DRD_(g_drd_running_tid) && last_sg) 1137 { 1138 DRD_(thread_update_conflict_set)(tid, &last_sg->vc); 1139 s_update_conflict_set_new_sg_count++; 1140 } 1141 1142 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1143 1144 if (s_segment_merging 1145 && ++s_new_segments_since_last_merge >= s_segment_merge_interval) 1146 { 1147 thread_discard_ordered_segments(); 1148 thread_merge_segments(); 1149 } 1150 } 1151 1152 /** Call this function after thread 'joiner' joined thread 'joinee'. */ 1153 void DRD_(thread_combine_vc_join)(DrdThreadId joiner, DrdThreadId joinee) 1154 { 1155 tl_assert(joiner != joinee); 1156 tl_assert(0 <= (int)joiner && joiner < DRD_N_THREADS 1157 && joiner != DRD_INVALID_THREADID); 1158 tl_assert(0 <= (int)joinee && joinee < DRD_N_THREADS 1159 && joinee != DRD_INVALID_THREADID); 1160 tl_assert(DRD_(g_threadinfo)[joiner].sg_first); 1161 tl_assert(DRD_(g_threadinfo)[joiner].sg_last); 1162 tl_assert(DRD_(g_threadinfo)[joinee].sg_first); 1163 tl_assert(DRD_(g_threadinfo)[joinee].sg_last); 1164 1165 if (DRD_(sg_get_trace)()) 1166 { 1167 HChar *str1, *str2; 1168 str1 = DRD_(vc_aprint)(DRD_(thread_get_vc)(joiner)); 1169 str2 = DRD_(vc_aprint)(DRD_(thread_get_vc)(joinee)); 1170 VG_(message)(Vg_DebugMsg, "Before join: joiner %s, joinee %s\n", 1171 str1, str2); 1172 VG_(free)(str1); 1173 VG_(free)(str2); 1174 } 1175 if (joiner == DRD_(g_drd_running_tid)) { 1176 VectorClock old_vc; 1177 1178 DRD_(vc_copy)(&old_vc, DRD_(thread_get_vc)(joiner)); 1179 DRD_(vc_combine)(DRD_(thread_get_vc)(joiner), 1180 DRD_(thread_get_vc)(joinee)); 1181 DRD_(thread_update_conflict_set)(joiner, &old_vc); 1182 s_update_conflict_set_join_count++; 1183 DRD_(vc_cleanup)(&old_vc); 1184 } else { 1185 DRD_(vc_combine)(DRD_(thread_get_vc)(joiner), 1186 DRD_(thread_get_vc)(joinee)); 1187 } 1188 1189 thread_discard_ordered_segments(); 1190 1191 if (DRD_(sg_get_trace)()) { 1192 HChar* str; 1193 1194 str = DRD_(vc_aprint)(DRD_(thread_get_vc)(joiner)); 1195 VG_(message)(Vg_DebugMsg, "After join: %s\n", str); 1196 VG_(free)(str); 1197 } 1198 } 1199 1200 /** 1201 * Update the vector clock of the last segment of thread tid with the 1202 * the vector clock of segment sg. 1203 */ 1204 static void thread_combine_vc_sync(DrdThreadId tid, const Segment* sg) 1205 { 1206 const VectorClock* const vc = &sg->vc; 1207 1208 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1209 && tid != DRD_INVALID_THREADID); 1210 tl_assert(DRD_(g_threadinfo)[tid].sg_first); 1211 tl_assert(DRD_(g_threadinfo)[tid].sg_last); 1212 tl_assert(sg); 1213 tl_assert(vc); 1214 1215 if (tid != sg->tid) { 1216 VectorClock old_vc; 1217 1218 DRD_(vc_copy)(&old_vc, DRD_(thread_get_vc)(tid)); 1219 DRD_(vc_combine)(DRD_(thread_get_vc)(tid), vc); 1220 if (DRD_(sg_get_trace)()) { 1221 HChar *str1, *str2; 1222 str1 = DRD_(vc_aprint)(&old_vc); 1223 str2 = DRD_(vc_aprint)(DRD_(thread_get_vc)(tid)); 1224 VG_(message)(Vg_DebugMsg, "thread %u: vc %s -> %s\n", tid, str1, str2); 1225 VG_(free)(str1); 1226 VG_(free)(str2); 1227 } 1228 1229 thread_discard_ordered_segments(); 1230 1231 DRD_(thread_update_conflict_set)(tid, &old_vc); 1232 s_update_conflict_set_sync_count++; 1233 1234 DRD_(vc_cleanup)(&old_vc); 1235 } else { 1236 tl_assert(DRD_(vc_lte)(vc, DRD_(thread_get_vc)(tid))); 1237 } 1238 } 1239 1240 /** 1241 * Create a new segment for thread tid and update the vector clock of the last 1242 * segment of this thread with the vector clock of segment sg. Call this 1243 * function after thread tid had to wait because of thread synchronization 1244 * until the memory accesses in the segment sg finished. 1245 */ 1246 void DRD_(thread_new_segment_and_combine_vc)(DrdThreadId tid, const Segment* sg) 1247 { 1248 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1249 && tid != DRD_INVALID_THREADID); 1250 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1251 tl_assert(sg); 1252 1253 thread_append_segment(tid, DRD_(sg_new)(tid, tid)); 1254 1255 thread_combine_vc_sync(tid, sg); 1256 1257 if (s_segment_merging 1258 && ++s_new_segments_since_last_merge >= s_segment_merge_interval) 1259 { 1260 thread_discard_ordered_segments(); 1261 thread_merge_segments(); 1262 } 1263 } 1264 1265 /** 1266 * Call this function whenever a thread is no longer using the memory 1267 * [ a1, a2 [, e.g. because of a call to free() or a stack pointer 1268 * increase. 1269 */ 1270 void DRD_(thread_stop_using_mem)(const Addr a1, const Addr a2) 1271 { 1272 Segment* p; 1273 1274 for (p = DRD_(g_sg_list); p; p = p->g_next) 1275 DRD_(bm_clear)(DRD_(sg_bm)(p), a1, a2); 1276 1277 DRD_(bm_clear)(DRD_(g_conflict_set), a1, a2); 1278 } 1279 1280 /** Specify whether memory loads should be recorded. */ 1281 void DRD_(thread_set_record_loads)(const DrdThreadId tid, const Bool enabled) 1282 { 1283 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1284 && tid != DRD_INVALID_THREADID); 1285 tl_assert(enabled == !! enabled); 1286 1287 DRD_(g_threadinfo)[tid].is_recording_loads = enabled; 1288 } 1289 1290 /** Specify whether memory stores should be recorded. */ 1291 void DRD_(thread_set_record_stores)(const DrdThreadId tid, const Bool enabled) 1292 { 1293 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1294 && tid != DRD_INVALID_THREADID); 1295 tl_assert(enabled == !! enabled); 1296 1297 DRD_(g_threadinfo)[tid].is_recording_stores = enabled; 1298 } 1299 1300 /** 1301 * Print the segment information for all threads. 1302 * 1303 * This function is only used for debugging purposes. 1304 */ 1305 void DRD_(thread_print_all)(void) 1306 { 1307 UInt i; 1308 Segment* p; 1309 1310 for (i = 0; i < DRD_N_THREADS; i++) 1311 { 1312 p = DRD_(g_threadinfo)[i].sg_first; 1313 if (p) { 1314 VG_(printf)("**************\n" 1315 "* thread %3u (%d/%u/%u/%u/0x%lx/%d) *\n" 1316 "**************\n", 1317 i, 1318 DRD_(g_threadinfo)[i].valid, 1319 DRD_(g_threadinfo)[i].vg_thread_exists, 1320 DRD_(g_threadinfo)[i].vg_threadid, 1321 DRD_(g_threadinfo)[i].posix_thread_exists, 1322 DRD_(g_threadinfo)[i].pt_threadid, 1323 DRD_(g_threadinfo)[i].detached_posix_thread); 1324 for ( ; p; p = p->thr_next) 1325 DRD_(sg_print)(p); 1326 } 1327 } 1328 } 1329 1330 /** Show a call stack involved in a data race. */ 1331 static void show_call_stack(const DrdThreadId tid, ExeContext* const callstack) 1332 { 1333 const ThreadId vg_tid = DRD_(DrdThreadIdToVgThreadId)(tid); 1334 1335 if (vg_tid != VG_INVALID_THREADID) { 1336 if (callstack) 1337 VG_(pp_ExeContext)(callstack); 1338 else 1339 VG_(get_and_pp_StackTrace)(vg_tid, VG_(clo_backtrace_size)); 1340 } else { 1341 if (!VG_(clo_xml)) 1342 VG_(message)(Vg_UserMsg, 1343 " (thread finished, call stack no longer available)\n"); 1344 } 1345 } 1346 1347 /** Print information about the segments involved in a data race. */ 1348 static void 1349 thread_report_conflicting_segments_segment(const DrdThreadId tid, 1350 const Addr addr, 1351 const SizeT size, 1352 const BmAccessTypeT access_type, 1353 const Segment* const p) 1354 { 1355 unsigned i; 1356 1357 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1358 && tid != DRD_INVALID_THREADID); 1359 tl_assert(p); 1360 1361 for (i = 0; i < DRD_N_THREADS; i++) { 1362 if (i != tid) { 1363 Segment* q; 1364 1365 for (q = DRD_(g_threadinfo)[i].sg_last; q; q = q->thr_prev) { 1366 /* 1367 * Since q iterates over the segments of thread i in order of 1368 * decreasing vector clocks, if q->vc <= p->vc, then 1369 * q->next->vc <= p->vc will also hold. Hence, break out of the 1370 * loop once this condition is met. 1371 */ 1372 if (DRD_(vc_lte)(&q->vc, &p->vc)) 1373 break; 1374 if (!DRD_(vc_lte)(&p->vc, &q->vc)) { 1375 if (DRD_(bm_has_conflict_with)(DRD_(sg_bm)(q), addr, addr + size, 1376 access_type)) { 1377 Segment* q_next; 1378 1379 tl_assert(q->stacktrace); 1380 if (VG_(clo_xml)) 1381 VG_(printf_xml)(" <other_segment_start>\n"); 1382 else 1383 VG_(message)(Vg_UserMsg, 1384 "Other segment start (thread %u)\n", i); 1385 show_call_stack(i, q->stacktrace); 1386 if (VG_(clo_xml)) 1387 VG_(printf_xml)(" </other_segment_start>\n" 1388 " <other_segment_end>\n"); 1389 else 1390 VG_(message)(Vg_UserMsg, 1391 "Other segment end (thread %u)\n", i); 1392 q_next = q->thr_next; 1393 show_call_stack(i, q_next ? q_next->stacktrace : 0); 1394 if (VG_(clo_xml)) 1395 VG_(printf_xml)(" </other_segment_end>\n"); 1396 } 1397 } 1398 } 1399 } 1400 } 1401 } 1402 1403 /** Print information about all segments involved in a data race. */ 1404 void DRD_(thread_report_conflicting_segments)(const DrdThreadId tid, 1405 const Addr addr, 1406 const SizeT size, 1407 const BmAccessTypeT access_type) 1408 { 1409 Segment* p; 1410 1411 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1412 && tid != DRD_INVALID_THREADID); 1413 1414 for (p = DRD_(g_threadinfo)[tid].sg_first; p; p = p->thr_next) { 1415 if (DRD_(bm_has)(DRD_(sg_bm)(p), addr, addr + size, access_type)) 1416 thread_report_conflicting_segments_segment(tid, addr, size, 1417 access_type, p); 1418 } 1419 } 1420 1421 /** 1422 * Verify whether the conflict set for thread tid is up to date. Only perform 1423 * the check if the environment variable DRD_VERIFY_CONFLICT_SET has been set. 1424 */ 1425 static Bool thread_conflict_set_up_to_date(const DrdThreadId tid) 1426 { 1427 Bool result; 1428 struct bitmap* computed_conflict_set = 0; 1429 1430 if (!DRD_(verify_conflict_set)) 1431 return True; 1432 1433 thread_compute_conflict_set(&computed_conflict_set, tid); 1434 result = DRD_(bm_equal)(DRD_(g_conflict_set), computed_conflict_set); 1435 if (! result) 1436 { 1437 VG_(printf)("actual conflict set:\n"); 1438 DRD_(bm_print)(DRD_(g_conflict_set)); 1439 VG_(printf)("\n"); 1440 VG_(printf)("computed conflict set:\n"); 1441 DRD_(bm_print)(computed_conflict_set); 1442 VG_(printf)("\n"); 1443 } 1444 DRD_(bm_delete)(computed_conflict_set); 1445 return result; 1446 } 1447 1448 /** 1449 * Compute the conflict set: a bitmap that represents the union of all memory 1450 * accesses of all segments that are unordered to the current segment of the 1451 * thread tid. 1452 */ 1453 static void thread_compute_conflict_set(struct bitmap** conflict_set, 1454 const DrdThreadId tid) 1455 { 1456 Segment* p; 1457 1458 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1459 && tid != DRD_INVALID_THREADID); 1460 tl_assert(tid == DRD_(g_drd_running_tid)); 1461 1462 s_compute_conflict_set_count++; 1463 s_conflict_set_bitmap_creation_count 1464 -= DRD_(bm_get_bitmap_creation_count)(); 1465 s_conflict_set_bitmap2_creation_count 1466 -= DRD_(bm_get_bitmap2_creation_count)(); 1467 1468 if (*conflict_set) { 1469 DRD_(bm_cleanup)(*conflict_set); 1470 DRD_(bm_init)(*conflict_set); 1471 } else { 1472 *conflict_set = DRD_(bm_new)(); 1473 } 1474 1475 if (s_trace_conflict_set) { 1476 HChar* str; 1477 1478 str = DRD_(vc_aprint)(DRD_(thread_get_vc)(tid)); 1479 VG_(message)(Vg_DebugMsg, 1480 "computing conflict set for thread %u with vc %s\n", 1481 tid, str); 1482 VG_(free)(str); 1483 } 1484 1485 p = DRD_(g_threadinfo)[tid].sg_last; 1486 { 1487 unsigned j; 1488 1489 if (s_trace_conflict_set) { 1490 HChar* vc; 1491 1492 vc = DRD_(vc_aprint)(&p->vc); 1493 VG_(message)(Vg_DebugMsg, "conflict set: thread [%u] at vc %s\n", 1494 tid, vc); 1495 VG_(free)(vc); 1496 } 1497 1498 for (j = 0; j < DRD_N_THREADS; j++) { 1499 if (j != tid && DRD_(IsValidDrdThreadId)(j)) { 1500 Segment* q; 1501 1502 for (q = DRD_(g_threadinfo)[j].sg_last; q; q = q->thr_prev) { 1503 if (!DRD_(vc_lte)(&q->vc, &p->vc) 1504 && !DRD_(vc_lte)(&p->vc, &q->vc)) { 1505 if (s_trace_conflict_set) { 1506 HChar* str; 1507 1508 str = DRD_(vc_aprint)(&q->vc); 1509 VG_(message)(Vg_DebugMsg, 1510 "conflict set: [%u] merging segment %s\n", 1511 j, str); 1512 VG_(free)(str); 1513 } 1514 DRD_(bm_merge2)(*conflict_set, DRD_(sg_bm)(q)); 1515 } else { 1516 if (s_trace_conflict_set) { 1517 HChar* str; 1518 1519 str = DRD_(vc_aprint)(&q->vc); 1520 VG_(message)(Vg_DebugMsg, 1521 "conflict set: [%u] ignoring segment %s\n", 1522 j, str); 1523 VG_(free)(str); 1524 } 1525 } 1526 } 1527 } 1528 } 1529 } 1530 1531 s_conflict_set_bitmap_creation_count 1532 += DRD_(bm_get_bitmap_creation_count)(); 1533 s_conflict_set_bitmap2_creation_count 1534 += DRD_(bm_get_bitmap2_creation_count)(); 1535 1536 if (s_trace_conflict_set_bm) { 1537 VG_(message)(Vg_DebugMsg, "[%u] new conflict set:\n", tid); 1538 DRD_(bm_print)(*conflict_set); 1539 VG_(message)(Vg_DebugMsg, "[%u] end of new conflict set.\n", tid); 1540 } 1541 } 1542 1543 /** 1544 * Update the conflict set after the vector clock of thread tid has been 1545 * updated from old_vc to its current value, either because a new segment has 1546 * been created or because of a synchronization operation. 1547 */ 1548 void DRD_(thread_update_conflict_set)(const DrdThreadId tid, 1549 const VectorClock* const old_vc) 1550 { 1551 const VectorClock* new_vc; 1552 Segment* p; 1553 unsigned j; 1554 1555 tl_assert(0 <= (int)tid && tid < DRD_N_THREADS 1556 && tid != DRD_INVALID_THREADID); 1557 tl_assert(old_vc); 1558 tl_assert(tid == DRD_(g_drd_running_tid)); 1559 tl_assert(DRD_(g_conflict_set)); 1560 1561 if (s_trace_conflict_set) { 1562 HChar* str; 1563 1564 str = DRD_(vc_aprint)(DRD_(thread_get_vc)(tid)); 1565 VG_(message)(Vg_DebugMsg, 1566 "updating conflict set for thread %u with vc %s\n", 1567 tid, str); 1568 VG_(free)(str); 1569 } 1570 1571 new_vc = DRD_(thread_get_vc)(tid); 1572 tl_assert(DRD_(vc_lte)(old_vc, new_vc)); 1573 1574 DRD_(bm_unmark)(DRD_(g_conflict_set)); 1575 1576 for (j = 0; j < DRD_N_THREADS; j++) 1577 { 1578 Segment* q; 1579 1580 if (j == tid || ! DRD_(IsValidDrdThreadId)(j)) 1581 continue; 1582 1583 for (q = DRD_(g_threadinfo)[j].sg_last; 1584 q && !DRD_(vc_lte)(&q->vc, new_vc); 1585 q = q->thr_prev) { 1586 const Bool included_in_old_conflict_set 1587 = !DRD_(vc_lte)(old_vc, &q->vc); 1588 const Bool included_in_new_conflict_set 1589 = !DRD_(vc_lte)(new_vc, &q->vc); 1590 1591 if (UNLIKELY(s_trace_conflict_set)) { 1592 HChar* str; 1593 1594 str = DRD_(vc_aprint)(&q->vc); 1595 VG_(message)(Vg_DebugMsg, 1596 "conflict set: [%u] %s segment %s\n", j, 1597 included_in_old_conflict_set 1598 != included_in_new_conflict_set 1599 ? "merging" : "ignoring", str); 1600 VG_(free)(str); 1601 } 1602 if (included_in_old_conflict_set != included_in_new_conflict_set) 1603 DRD_(bm_mark)(DRD_(g_conflict_set), DRD_(sg_bm)(q)); 1604 } 1605 1606 for ( ; q && !DRD_(vc_lte)(&q->vc, old_vc); q = q->thr_prev) { 1607 const Bool included_in_old_conflict_set 1608 = !DRD_(vc_lte)(old_vc, &q->vc); 1609 const Bool included_in_new_conflict_set 1610 = !DRD_(vc_lte)(&q->vc, new_vc) 1611 && !DRD_(vc_lte)(new_vc, &q->vc); 1612 1613 if (UNLIKELY(s_trace_conflict_set)) { 1614 HChar* str; 1615 1616 str = DRD_(vc_aprint)(&q->vc); 1617 VG_(message)(Vg_DebugMsg, 1618 "conflict set: [%u] %s segment %s\n", j, 1619 included_in_old_conflict_set 1620 != included_in_new_conflict_set 1621 ? "merging" : "ignoring", str); 1622 VG_(free)(str); 1623 } 1624 if (included_in_old_conflict_set != included_in_new_conflict_set) 1625 DRD_(bm_mark)(DRD_(g_conflict_set), DRD_(sg_bm)(q)); 1626 } 1627 } 1628 1629 DRD_(bm_clear_marked)(DRD_(g_conflict_set)); 1630 1631 p = DRD_(g_threadinfo)[tid].sg_last; 1632 for (j = 0; j < DRD_N_THREADS; j++) { 1633 if (j != tid && DRD_(IsValidDrdThreadId)(j)) { 1634 Segment* q; 1635 for (q = DRD_(g_threadinfo)[j].sg_last; 1636 q && !DRD_(vc_lte)(&q->vc, &p->vc); 1637 q = q->thr_prev) { 1638 if (!DRD_(vc_lte)(&p->vc, &q->vc)) 1639 DRD_(bm_merge2_marked)(DRD_(g_conflict_set), DRD_(sg_bm)(q)); 1640 } 1641 } 1642 } 1643 1644 DRD_(bm_remove_cleared_marked)(DRD_(g_conflict_set)); 1645 1646 s_update_conflict_set_count++; 1647 1648 if (s_trace_conflict_set_bm) 1649 { 1650 VG_(message)(Vg_DebugMsg, "[%u] updated conflict set:\n", tid); 1651 DRD_(bm_print)(DRD_(g_conflict_set)); 1652 VG_(message)(Vg_DebugMsg, "[%u] end of updated conflict set.\n", tid); 1653 } 1654 1655 tl_assert(thread_conflict_set_up_to_date(DRD_(g_drd_running_tid))); 1656 } 1657 1658 /** Report the number of context switches performed. */ 1659 ULong DRD_(thread_get_context_switch_count)(void) 1660 { 1661 return s_context_switch_count; 1662 } 1663 1664 /** Report the number of ordered segments that have been discarded. */ 1665 ULong DRD_(thread_get_discard_ordered_segments_count)(void) 1666 { 1667 return s_discard_ordered_segments_count; 1668 } 1669 1670 /** Return how many times the conflict set has been updated entirely. */ 1671 ULong DRD_(thread_get_compute_conflict_set_count)() 1672 { 1673 return s_compute_conflict_set_count; 1674 } 1675 1676 /** Return how many times the conflict set has been updated partially. */ 1677 ULong DRD_(thread_get_update_conflict_set_count)(void) 1678 { 1679 return s_update_conflict_set_count; 1680 } 1681 1682 /** 1683 * Return how many times the conflict set has been updated partially 1684 * because a new segment has been created. 1685 */ 1686 ULong DRD_(thread_get_update_conflict_set_new_sg_count)(void) 1687 { 1688 return s_update_conflict_set_new_sg_count; 1689 } 1690 1691 /** 1692 * Return how many times the conflict set has been updated partially 1693 * because of combining vector clocks due to synchronization operations 1694 * other than reader/writer lock or barrier operations. 1695 */ 1696 ULong DRD_(thread_get_update_conflict_set_sync_count)(void) 1697 { 1698 return s_update_conflict_set_sync_count; 1699 } 1700 1701 /** 1702 * Return how many times the conflict set has been updated partially 1703 * because of thread joins. 1704 */ 1705 ULong DRD_(thread_get_update_conflict_set_join_count)(void) 1706 { 1707 return s_update_conflict_set_join_count; 1708 } 1709 1710 /** 1711 * Return the number of first-level bitmaps that have been created during 1712 * conflict set updates. 1713 */ 1714 ULong DRD_(thread_get_conflict_set_bitmap_creation_count)(void) 1715 { 1716 return s_conflict_set_bitmap_creation_count; 1717 } 1718 1719 /** 1720 * Return the number of second-level bitmaps that have been created during 1721 * conflict set updates. 1722 */ 1723 ULong DRD_(thread_get_conflict_set_bitmap2_creation_count)(void) 1724 { 1725 return s_conflict_set_bitmap2_creation_count; 1726 } 1727
