contrib/compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc

   1 //===-- tsan_libdispatch_mac.cc -------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is a part of ThreadSanitizer (TSan), a race detector.
  11 //
  12 // Mac-specific libdispatch (GCD) support.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_MAC
  17
  18 #include "sanitizer_common/sanitizer_common.h"
  19 #include "interception/interception.h"
  20 #include "tsan_interceptors.h"
  21 #include "tsan_platform.h"
  22 #include "tsan_rtl.h"
  23
  24 #include <Block.h>
  25 #include <dispatch/dispatch.h>
  26 #include <pthread.h>
  27
  28 // DISPATCH_NOESCAPE is not defined prior to XCode 8.
  29 #ifndef DISPATCH_NOESCAPE
  30 #define DISPATCH_NOESCAPE
  31 #endif
  32
  33 typedef long long_t;  // NOLINT
  34
  35 namespace __tsan {
  36
  37 typedef struct {
  38   dispatch_queue_t queue;
  39   void *orig_context;
  40   dispatch_function_t orig_work;
  41   bool free_context_in_callback;
  42   bool submitted_synchronously;
  43   bool is_barrier_block;
  44   uptr non_queue_sync_object;
  45 } tsan_block_context_t;
  46
  47 // The offsets of different fields of the dispatch_queue_t structure, exported
  48 // by libdispatch.dylib.
  49 extern "C" struct dispatch_queue_offsets_s {
  50   const uint16_t dqo_version;
  51   const uint16_t dqo_label;
  52   const uint16_t dqo_label_size;
  53   const uint16_t dqo_flags;
  54   const uint16_t dqo_flags_size;
  55   const uint16_t dqo_serialnum;
  56   const uint16_t dqo_serialnum_size;
  57   const uint16_t dqo_width;
  58   const uint16_t dqo_width_size;
  59   const uint16_t dqo_running;
  60   const uint16_t dqo_running_size;
  61   const uint16_t dqo_suspend_cnt;
  62   const uint16_t dqo_suspend_cnt_size;
  63   const uint16_t dqo_target_queue;
  64   const uint16_t dqo_target_queue_size;
  65   const uint16_t dqo_priority;
  66   const uint16_t dqo_priority_size;
  67 } dispatch_queue_offsets;
  68
  69 static bool IsQueueSerial(dispatch_queue_t q) {
  70   CHECK_EQ(dispatch_queue_offsets.dqo_width_size, 2);
  71   uptr width = *(uint16_t *)(((uptr)q) + dispatch_queue_offsets.dqo_width);
  72   CHECK_NE(width, 0);
  73   return width == 1;
  74 }
  75
  76 static dispatch_queue_t GetTargetQueueFromQueue(dispatch_queue_t q) {
  77   CHECK_EQ(dispatch_queue_offsets.dqo_target_queue_size, 8);
  78   dispatch_queue_t tq = *(
  79       dispatch_queue_t *)(((uptr)q) + dispatch_queue_offsets.dqo_target_queue);
  80   return tq;
  81 }
  82
  83 static dispatch_queue_t GetTargetQueueFromSource(dispatch_source_t source) {
  84   dispatch_queue_t tq = GetTargetQueueFromQueue((dispatch_queue_t)source);
  85   CHECK_NE(tq, 0);
  86   return tq;
  87 }
  88
  89 static tsan_block_context_t *AllocContext(ThreadState *thr, uptr pc,
  90                                           dispatch_queue_t queue,
  91                                           void *orig_context,
  92                                           dispatch_function_t orig_work) {
  93   tsan_block_context_t *new_context =
  94       (tsan_block_context_t *)user_alloc_internal(thr, pc,
  95                                                   sizeof(tsan_block_context_t));
  96   new_context->queue = queue;
  97   new_context->orig_context = orig_context;
  98   new_context->orig_work = orig_work;
  99   new_context->free_context_in_callback = true;
 100   new_context->submitted_synchronously = false;
 101   new_context->is_barrier_block = false;
 102   new_context->non_queue_sync_object = 0;
 103   return new_context;
 104 }
 105
 106 #define GET_QUEUE_SYNC_VARS(context, q)                                  \
 107   bool is_queue_serial = q && IsQueueSerial(q);                          \
 108   uptr sync_ptr = (uptr)q ?: context->non_queue_sync_object;             \
 109   uptr serial_sync = (uptr)sync_ptr;                                     \
 110   uptr concurrent_sync = sync_ptr ? ((uptr)sync_ptr) + sizeof(uptr) : 0; \
 111   bool serial_task = context->is_barrier_block || is_queue_serial
 112
 113 static void dispatch_sync_pre_execute(ThreadState *thr, uptr pc,
 114                                       tsan_block_context_t *context) {
 115   uptr submit_sync = (uptr)context;
 116   Acquire(thr, pc, submit_sync);
 117
 118   dispatch_queue_t q = context->queue;
 119   do {
 120     GET_QUEUE_SYNC_VARS(context, q);
 121     if (serial_sync) Acquire(thr, pc, serial_sync);
 122     if (serial_task && concurrent_sync) Acquire(thr, pc, concurrent_sync);
 123
 124     if (q) q = GetTargetQueueFromQueue(q);
 125   } while (q);
 126 }
 127
 128 static void dispatch_sync_post_execute(ThreadState *thr, uptr pc,
 129                                        tsan_block_context_t *context) {
 130   uptr submit_sync = (uptr)context;
 131   if (context->submitted_synchronously) Release(thr, pc, submit_sync);
 132
 133   dispatch_queue_t q = context->queue;
 134   do {
 135     GET_QUEUE_SYNC_VARS(context, q);
 136     if (serial_task && serial_sync) Release(thr, pc, serial_sync);
 137     if (!serial_task && concurrent_sync) Release(thr, pc, concurrent_sync);
 138
 139     if (q) q = GetTargetQueueFromQueue(q);
 140   } while (q);
 141 }
 142
 143 static void dispatch_callback_wrap(void *param) {
 144   SCOPED_INTERCEPTOR_RAW(dispatch_callback_wrap);
 145   tsan_block_context_t *context = (tsan_block_context_t *)param;
 146
 147   dispatch_sync_pre_execute(thr, pc, context);
 148
 149   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 150   context->orig_work(context->orig_context);
 151   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 152
 153   dispatch_sync_post_execute(thr, pc, context);
 154
 155   if (context->free_context_in_callback) user_free(thr, pc, context);
 156 }
 157
 158 static void invoke_block(void *param) {
 159   dispatch_block_t block = (dispatch_block_t)param;
 160   block();
 161 }
 162
 163 static void invoke_and_release_block(void *param) {
 164   dispatch_block_t block = (dispatch_block_t)param;
 165   block();
 166   Block_release(block);
 167 }
 168
 169 #define DISPATCH_INTERCEPT_B(name, barrier)                                  \
 170   TSAN_INTERCEPTOR(void, name, dispatch_queue_t q, dispatch_block_t block) { \
 171     SCOPED_TSAN_INTERCEPTOR(name, q, block);                                 \
 172     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();                           \
 173     dispatch_block_t heap_block = Block_copy(block);                         \
 174     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();                             \
 175     tsan_block_context_t *new_context =                                      \
 176         AllocContext(thr, pc, q, heap_block, &invoke_and_release_block);     \
 177     new_context->is_barrier_block = barrier;                                 \
 178     Release(thr, pc, (uptr)new_context);                                     \
 179     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();                           \
 180     REAL(name##_f)(q, new_context, dispatch_callback_wrap);                  \
 181     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();                             \
 182   }
 183
 184 #define DISPATCH_INTERCEPT_SYNC_B(name, barrier)                             \
 185   TSAN_INTERCEPTOR(void, name, dispatch_queue_t q,                           \
 186                    DISPATCH_NOESCAPE dispatch_block_t block) {               \
 187     SCOPED_TSAN_INTERCEPTOR(name, q, block);                                 \
 188     tsan_block_context_t new_context = {                                     \
 189         q, block, &invoke_block, false, true, barrier, 0};                   \
 190     Release(thr, pc, (uptr)&new_context);                                    \
 191     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();                           \
 192     REAL(name##_f)(q, &new_context, dispatch_callback_wrap);                 \
 193     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();                             \
 194     Acquire(thr, pc, (uptr)&new_context);                                    \
 195   }
 196
 197 #define DISPATCH_INTERCEPT_F(name, barrier)                       \
 198   TSAN_INTERCEPTOR(void, name, dispatch_queue_t q, void *context, \
 199                    dispatch_function_t work) {                    \
 200     SCOPED_TSAN_INTERCEPTOR(name, q, context, work);              \
 201     tsan_block_context_t *new_context =                           \
 202         AllocContext(thr, pc, q, context, work);                  \
 203     new_context->is_barrier_block = barrier;                      \
 204     Release(thr, pc, (uptr)new_context);                          \
 205     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();                \
 206     REAL(name)(q, new_context, dispatch_callback_wrap);           \
 207     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();                  \
 208   }
 209
 210 #define DISPATCH_INTERCEPT_SYNC_F(name, barrier)                              \
 211   TSAN_INTERCEPTOR(void, name, dispatch_queue_t q, void *context,             \
 212                    dispatch_function_t work) {                                \
 213     SCOPED_TSAN_INTERCEPTOR(name, q, context, work);                          \
 214     tsan_block_context_t new_context = {                                      \
 215         q, context, work, false, true, barrier, 0};                           \
 216     Release(thr, pc, (uptr)&new_context);                                     \
 217     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();                            \
 218     REAL(name)(q, &new_context, dispatch_callback_wrap);                      \
 219     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();                              \
 220     Acquire(thr, pc, (uptr)&new_context);                                     \
 221   }
 222
 223 // We wrap dispatch_async, dispatch_sync and friends where we allocate a new
 224 // context, which is used to synchronize (we release the context before
 225 // submitting, and the callback acquires it before executing the original
 226 // callback).
 227 DISPATCH_INTERCEPT_B(dispatch_async, false)
 228 DISPATCH_INTERCEPT_B(dispatch_barrier_async, true)
 229 DISPATCH_INTERCEPT_F(dispatch_async_f, false)
 230 DISPATCH_INTERCEPT_F(dispatch_barrier_async_f, true)
 231 DISPATCH_INTERCEPT_SYNC_B(dispatch_sync, false)
 232 DISPATCH_INTERCEPT_SYNC_B(dispatch_barrier_sync, true)
 233 DISPATCH_INTERCEPT_SYNC_F(dispatch_sync_f, false)
 234 DISPATCH_INTERCEPT_SYNC_F(dispatch_barrier_sync_f, true)
 235
 236 TSAN_INTERCEPTOR(void, dispatch_after, dispatch_time_t when,
 237                  dispatch_queue_t queue, dispatch_block_t block) {
 238   SCOPED_TSAN_INTERCEPTOR(dispatch_after, when, queue, block);
 239   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 240   dispatch_block_t heap_block = Block_copy(block);
 241   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 242   tsan_block_context_t *new_context =
 243       AllocContext(thr, pc, queue, heap_block, &invoke_and_release_block);
 244   Release(thr, pc, (uptr)new_context);
 245   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 246   REAL(dispatch_after_f)(when, queue, new_context, dispatch_callback_wrap);
 247   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 248 }
 249
 250 TSAN_INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when,
 251                  dispatch_queue_t queue, void *context,
 252                  dispatch_function_t work) {
 253   SCOPED_TSAN_INTERCEPTOR(dispatch_after_f, when, queue, context, work);
 254   WRAP(dispatch_after)(when, queue, ^(void) {
 255     work(context);
 256   });
 257 }
 258
 259 // GCD's dispatch_once implementation has a fast path that contains a racy read
 260 // and it's inlined into user's code. Furthermore, this fast path doesn't
 261 // establish a proper happens-before relations between the initialization and
 262 // code following the call to dispatch_once. We could deal with this in
 263 // instrumented code, but there's not much we can do about it in system
 264 // libraries. Let's disable the fast path (by never storing the value ~0 to
 265 // predicate), so the interceptor is always called, and let's add proper release
 266 // and acquire semantics. Since TSan does not see its own atomic stores, the
 267 // race on predicate won't be reported - the only accesses to it that TSan sees
 268 // are the loads on the fast path. Loads don't race. Secondly, dispatch_once is
 269 // both a macro and a real function, we want to intercept the function, so we
 270 // need to undefine the macro.
 271 #undef dispatch_once
 272 TSAN_INTERCEPTOR(void, dispatch_once, dispatch_once_t *predicate,
 273                  DISPATCH_NOESCAPE dispatch_block_t block) {
 274   SCOPED_INTERCEPTOR_RAW(dispatch_once, predicate, block);
 275   atomic_uint32_t *a = reinterpret_cast<atomic_uint32_t *>(predicate);
 276   u32 v = atomic_load(a, memory_order_acquire);
 277   if (v == 0 &&
 278       atomic_compare_exchange_strong(a, &v, 1, memory_order_relaxed)) {
 279     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 280     block();
 281     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 282     Release(thr, pc, (uptr)a);
 283     atomic_store(a, 2, memory_order_release);
 284   } else {
 285     while (v != 2) {
 286       internal_sched_yield();
 287       v = atomic_load(a, memory_order_acquire);
 288     }
 289     Acquire(thr, pc, (uptr)a);
 290   }
 291 }
 292
 293 #undef dispatch_once_f
 294 TSAN_INTERCEPTOR(void, dispatch_once_f, dispatch_once_t *predicate,
 295                  void *context, dispatch_function_t function) {
 296   SCOPED_INTERCEPTOR_RAW(dispatch_once_f, predicate, context, function);
 297   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 298   WRAP(dispatch_once)(predicate, ^(void) {
 299     function(context);
 300   });
 301   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 302 }
 303
 304 TSAN_INTERCEPTOR(long_t, dispatch_semaphore_signal,
 305                  dispatch_semaphore_t dsema) {
 306   SCOPED_TSAN_INTERCEPTOR(dispatch_semaphore_signal, dsema);
 307   Release(thr, pc, (uptr)dsema);
 308   return REAL(dispatch_semaphore_signal)(dsema);
 309 }
 310
 311 TSAN_INTERCEPTOR(long_t, dispatch_semaphore_wait, dispatch_semaphore_t dsema,
 312                  dispatch_time_t timeout) {
 313   SCOPED_TSAN_INTERCEPTOR(dispatch_semaphore_wait, dsema, timeout);
 314   long_t result = REAL(dispatch_semaphore_wait)(dsema, timeout);
 315   if (result == 0) Acquire(thr, pc, (uptr)dsema);
 316   return result;
 317 }
 318
 319 TSAN_INTERCEPTOR(long_t, dispatch_group_wait, dispatch_group_t group,
 320                  dispatch_time_t timeout) {
 321   SCOPED_TSAN_INTERCEPTOR(dispatch_group_wait, group, timeout);
 322   long_t result = REAL(dispatch_group_wait)(group, timeout);
 323   if (result == 0) Acquire(thr, pc, (uptr)group);
 324   return result;
 325 }
 326
 327 TSAN_INTERCEPTOR(void, dispatch_group_leave, dispatch_group_t group) {
 328   SCOPED_TSAN_INTERCEPTOR(dispatch_group_leave, group);
 329   // Acquired in the group noticifaction callback in dispatch_group_notify[_f].
 330   Release(thr, pc, (uptr)group);
 331   REAL(dispatch_group_leave)(group);
 332 }
 333
 334 TSAN_INTERCEPTOR(void, dispatch_group_async, dispatch_group_t group,
 335                  dispatch_queue_t queue, dispatch_block_t block) {
 336   SCOPED_TSAN_INTERCEPTOR(dispatch_group_async, group, queue, block);
 337   dispatch_retain(group);
 338   dispatch_group_enter(group);
 339   __block dispatch_block_t block_copy = (dispatch_block_t)_Block_copy(block);
 340   WRAP(dispatch_async)(queue, ^(void) {
 341     block_copy();
 342     _Block_release(block_copy);
 343     WRAP(dispatch_group_leave)(group);
 344     dispatch_release(group);
 345   });
 346 }
 347
 348 TSAN_INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,
 349                  dispatch_queue_t queue, void *context,
 350                  dispatch_function_t work) {
 351   SCOPED_TSAN_INTERCEPTOR(dispatch_group_async_f, group, queue, context, work);
 352   dispatch_retain(group);
 353   dispatch_group_enter(group);
 354   WRAP(dispatch_async)(queue, ^(void) {
 355     work(context);
 356     WRAP(dispatch_group_leave)(group);
 357     dispatch_release(group);
 358   });
 359 }
 360
 361 TSAN_INTERCEPTOR(void, dispatch_group_notify, dispatch_group_t group,
 362                  dispatch_queue_t q, dispatch_block_t block) {
 363   SCOPED_TSAN_INTERCEPTOR(dispatch_group_notify, group, q, block);
 364
 365   // To make sure the group is still available in the callback (otherwise
 366   // it can be already destroyed).  Will be released in the callback.
 367   dispatch_retain(group);
 368
 369   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 370   dispatch_block_t heap_block = Block_copy(^(void) {
 371     {
 372       SCOPED_INTERCEPTOR_RAW(dispatch_read_callback);
 373       // Released when leaving the group (dispatch_group_leave).
 374       Acquire(thr, pc, (uptr)group);
 375     }
 376     dispatch_release(group);
 377     block();
 378   });
 379   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 380   tsan_block_context_t *new_context =
 381       AllocContext(thr, pc, q, heap_block, &invoke_and_release_block);
 382   new_context->is_barrier_block = true;
 383   Release(thr, pc, (uptr)new_context);
 384   REAL(dispatch_group_notify_f)(group, q, new_context, dispatch_callback_wrap);
 385 }
 386
 387 TSAN_INTERCEPTOR(void, dispatch_group_notify_f, dispatch_group_t group,
 388                  dispatch_queue_t q, void *context, dispatch_function_t work) {
 389   WRAP(dispatch_group_notify)(group, q, ^(void) { work(context); });
 390 }
 391
 392 TSAN_INTERCEPTOR(void, dispatch_source_set_event_handler,
 393                  dispatch_source_t source, dispatch_block_t handler) {
 394   SCOPED_TSAN_INTERCEPTOR(dispatch_source_set_event_handler, source, handler);
 395   if (handler == nullptr)
 396     return REAL(dispatch_source_set_event_handler)(source, nullptr);
 397   dispatch_queue_t q = GetTargetQueueFromSource(source);
 398   __block tsan_block_context_t new_context = {
 399       q, handler, &invoke_block, false, false, false, 0 };
 400   dispatch_block_t new_handler = Block_copy(^(void) {
 401     new_context.orig_context = handler;  // To explicitly capture "handler".
 402     dispatch_callback_wrap(&new_context);
 403   });
 404   uptr submit_sync = (uptr)&new_context;
 405   Release(thr, pc, submit_sync);
 406   REAL(dispatch_source_set_event_handler)(source, new_handler);
 407   Block_release(new_handler);
 408 }
 409
 410 TSAN_INTERCEPTOR(void, dispatch_source_set_event_handler_f,
 411                  dispatch_source_t source, dispatch_function_t handler) {
 412   SCOPED_TSAN_INTERCEPTOR(dispatch_source_set_event_handler_f, source, handler);
 413   if (handler == nullptr)
 414     return REAL(dispatch_source_set_event_handler)(source, nullptr);
 415   dispatch_block_t block = ^(void) {
 416     handler(dispatch_get_context(source));
 417   };
 418   WRAP(dispatch_source_set_event_handler)(source, block);
 419 }
 420
 421 TSAN_INTERCEPTOR(void, dispatch_source_set_cancel_handler,
 422                  dispatch_source_t source, dispatch_block_t handler) {
 423   SCOPED_TSAN_INTERCEPTOR(dispatch_source_set_cancel_handler, source, handler);
 424   if (handler == nullptr)
 425     return REAL(dispatch_source_set_cancel_handler)(source, nullptr);
 426   dispatch_queue_t q = GetTargetQueueFromSource(source);
 427   __block tsan_block_context_t new_context = {
 428       q, handler, &invoke_block, false, false, false, 0};
 429   dispatch_block_t new_handler = Block_copy(^(void) {
 430     new_context.orig_context = handler;  // To explicitly capture "handler".
 431     dispatch_callback_wrap(&new_context);
 432   });
 433   uptr submit_sync = (uptr)&new_context;
 434   Release(thr, pc, submit_sync);
 435   REAL(dispatch_source_set_cancel_handler)(source, new_handler);
 436   Block_release(new_handler);
 437 }
 438
 439 TSAN_INTERCEPTOR(void, dispatch_source_set_cancel_handler_f,
 440                  dispatch_source_t source, dispatch_function_t handler) {
 441   SCOPED_TSAN_INTERCEPTOR(dispatch_source_set_cancel_handler_f, source,
 442                           handler);
 443   if (handler == nullptr)
 444     return REAL(dispatch_source_set_cancel_handler)(source, nullptr);
 445   dispatch_block_t block = ^(void) {
 446     handler(dispatch_get_context(source));
 447   };
 448   WRAP(dispatch_source_set_cancel_handler)(source, block);
 449 }
 450
 451 TSAN_INTERCEPTOR(void, dispatch_source_set_registration_handler,
 452                  dispatch_source_t source, dispatch_block_t handler) {
 453   SCOPED_TSAN_INTERCEPTOR(dispatch_source_set_registration_handler, source,
 454                           handler);
 455   if (handler == nullptr)
 456     return REAL(dispatch_source_set_registration_handler)(source, nullptr);
 457   dispatch_queue_t q = GetTargetQueueFromSource(source);
 458   __block tsan_block_context_t new_context = {
 459       q, handler, &invoke_block, false, false, false, 0};
 460   dispatch_block_t new_handler = Block_copy(^(void) {
 461     new_context.orig_context = handler;  // To explicitly capture "handler".
 462     dispatch_callback_wrap(&new_context);
 463   });
 464   uptr submit_sync = (uptr)&new_context;
 465   Release(thr, pc, submit_sync);
 466   REAL(dispatch_source_set_registration_handler)(source, new_handler);
 467   Block_release(new_handler);
 468 }
 469
 470 TSAN_INTERCEPTOR(void, dispatch_source_set_registration_handler_f,
 471                  dispatch_source_t source, dispatch_function_t handler) {
 472   SCOPED_TSAN_INTERCEPTOR(dispatch_source_set_registration_handler_f, source,
 473                           handler);
 474   if (handler == nullptr)
 475     return REAL(dispatch_source_set_registration_handler)(source, nullptr);
 476   dispatch_block_t block = ^(void) {
 477     handler(dispatch_get_context(source));
 478   };
 479   WRAP(dispatch_source_set_registration_handler)(source, block);
 480 }
 481
 482 TSAN_INTERCEPTOR(void, dispatch_apply, size_t iterations,
 483                  dispatch_queue_t queue,
 484                  DISPATCH_NOESCAPE void (^block)(size_t)) {
 485   SCOPED_TSAN_INTERCEPTOR(dispatch_apply, iterations, queue, block);
 486
 487   void *parent_to_child_sync = nullptr;
 488   uptr parent_to_child_sync_uptr = (uptr)&parent_to_child_sync;
 489   void *child_to_parent_sync = nullptr;
 490   uptr child_to_parent_sync_uptr = (uptr)&child_to_parent_sync;
 491
 492   Release(thr, pc, parent_to_child_sync_uptr);
 493   void (^new_block)(size_t) = ^(size_t iteration) {
 494     SCOPED_INTERCEPTOR_RAW(dispatch_apply);
 495     Acquire(thr, pc, parent_to_child_sync_uptr);
 496     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 497     block(iteration);
 498     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 499     Release(thr, pc, child_to_parent_sync_uptr);
 500   };
 501   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 502   REAL(dispatch_apply)(iterations, queue, new_block);
 503   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 504   Acquire(thr, pc, child_to_parent_sync_uptr);
 505 }
 506
 507 TSAN_INTERCEPTOR(void, dispatch_apply_f, size_t iterations,
 508                  dispatch_queue_t queue, void *context,
 509                  void (*work)(void *, size_t)) {
 510   SCOPED_TSAN_INTERCEPTOR(dispatch_apply_f, iterations, queue, context, work);
 511   void (^new_block)(size_t) = ^(size_t iteration) {
 512     work(context, iteration);
 513   };
 514   WRAP(dispatch_apply)(iterations, queue, new_block);
 515 }
 516
 517 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
 518 DECLARE_REAL_AND_INTERCEPTOR(int, munmap, void *addr, long_t sz)
 519
 520 TSAN_INTERCEPTOR(dispatch_data_t, dispatch_data_create, const void *buffer,
 521                  size_t size, dispatch_queue_t q, dispatch_block_t destructor) {
 522   SCOPED_TSAN_INTERCEPTOR(dispatch_data_create, buffer, size, q, destructor);
 523   if ((q == nullptr) || (destructor == DISPATCH_DATA_DESTRUCTOR_DEFAULT))
 524     return REAL(dispatch_data_create)(buffer, size, q, destructor);
 525
 526   if (destructor == DISPATCH_DATA_DESTRUCTOR_FREE)
 527     destructor = ^(void) { WRAP(free)((void *)(uintptr_t)buffer); };
 528   else if (destructor == DISPATCH_DATA_DESTRUCTOR_MUNMAP)
 529     destructor = ^(void) { WRAP(munmap)((void *)(uintptr_t)buffer, size); };
 530
 531   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
 532   dispatch_block_t heap_block = Block_copy(destructor);
 533   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 534   tsan_block_context_t *new_context =
 535       AllocContext(thr, pc, q, heap_block, &invoke_and_release_block);
 536   uptr submit_sync = (uptr)new_context;
 537   Release(thr, pc, submit_sync);
 538   return REAL(dispatch_data_create)(buffer, size, q, ^(void) {
 539     dispatch_callback_wrap(new_context);
 540   });
 541 }
 542
 543 typedef void (^fd_handler_t)(dispatch_data_t data, int error);
 544 typedef void (^cleanup_handler_t)(int error);
 545
 546 TSAN_INTERCEPTOR(void, dispatch_read, dispatch_fd_t fd, size_t length,
 547                  dispatch_queue_t q, fd_handler_t h) {
 548   SCOPED_TSAN_INTERCEPTOR(dispatch_read, fd, length, q, h);
 549   __block tsan_block_context_t new_context = {
 550       q, nullptr, &invoke_block, false, false, false, 0};
 551   fd_handler_t new_h = Block_copy(^(dispatch_data_t data, int error) {
 552     new_context.orig_context = ^(void) {
 553       h(data, error);
 554     };
 555     dispatch_callback_wrap(&new_context);
 556   });
 557   uptr submit_sync = (uptr)&new_context;
 558   Release(thr, pc, submit_sync);
 559   REAL(dispatch_read)(fd, length, q, new_h);
 560   Block_release(new_h);
 561 }
 562
 563 TSAN_INTERCEPTOR(void, dispatch_write, dispatch_fd_t fd, dispatch_data_t data,
 564                  dispatch_queue_t q, fd_handler_t h) {
 565   SCOPED_TSAN_INTERCEPTOR(dispatch_write, fd, data, q, h);
 566   __block tsan_block_context_t new_context = {
 567       q, nullptr, &invoke_block, false, false, false, 0};
 568   fd_handler_t new_h = Block_copy(^(dispatch_data_t data, int error) {
 569     new_context.orig_context = ^(void) {
 570       h(data, error);
 571     };
 572     dispatch_callback_wrap(&new_context);
 573   });
 574   uptr submit_sync = (uptr)&new_context;
 575   Release(thr, pc, submit_sync);
 576   REAL(dispatch_write)(fd, data, q, new_h);
 577   Block_release(new_h);
 578 }
 579
 580 TSAN_INTERCEPTOR(void, dispatch_io_read, dispatch_io_t channel, off_t offset,
 581                  size_t length, dispatch_queue_t q, dispatch_io_handler_t h) {
 582   SCOPED_TSAN_INTERCEPTOR(dispatch_io_read, channel, offset, length, q, h);
 583   __block tsan_block_context_t new_context = {
 584       q, nullptr, &invoke_block, false, false, false, 0};
 585   dispatch_io_handler_t new_h =
 586       Block_copy(^(bool done, dispatch_data_t data, int error) {
 587         new_context.orig_context = ^(void) {
 588           h(done, data, error);
 589         };
 590         dispatch_callback_wrap(&new_context);
 591       });
 592   uptr submit_sync = (uptr)&new_context;
 593   Release(thr, pc, submit_sync);
 594   REAL(dispatch_io_read)(channel, offset, length, q, new_h);
 595   Block_release(new_h);
 596 }
 597
 598 TSAN_INTERCEPTOR(void, dispatch_io_write, dispatch_io_t channel, off_t offset,
 599                  dispatch_data_t data, dispatch_queue_t q,
 600                  dispatch_io_handler_t h) {
 601   SCOPED_TSAN_INTERCEPTOR(dispatch_io_write, channel, offset, data, q, h);
 602   __block tsan_block_context_t new_context = {
 603       q, nullptr, &invoke_block, false, false, false, 0};
 604   dispatch_io_handler_t new_h =
 605       Block_copy(^(bool done, dispatch_data_t data, int error) {
 606         new_context.orig_context = ^(void) {
 607           h(done, data, error);
 608         };
 609         dispatch_callback_wrap(&new_context);
 610       });
 611   uptr submit_sync = (uptr)&new_context;
 612   Release(thr, pc, submit_sync);
 613   REAL(dispatch_io_write)(channel, offset, data, q, new_h);
 614   Block_release(new_h);
 615 }
 616
 617 TSAN_INTERCEPTOR(void, dispatch_io_barrier, dispatch_io_t channel,
 618                  dispatch_block_t barrier) {
 619   SCOPED_TSAN_INTERCEPTOR(dispatch_io_barrier, channel, barrier);
 620   __block tsan_block_context_t new_context = {
 621       nullptr, nullptr, &invoke_block, false, false, false, 0};
 622   new_context.non_queue_sync_object = (uptr)channel;
 623   new_context.is_barrier_block = true;
 624   dispatch_block_t new_block = Block_copy(^(void) {
 625     new_context.orig_context = ^(void) {
 626       barrier();
 627     };
 628     dispatch_callback_wrap(&new_context);
 629   });
 630   uptr submit_sync = (uptr)&new_context;
 631   Release(thr, pc, submit_sync);
 632   REAL(dispatch_io_barrier)(channel, new_block);
 633   Block_release(new_block);
 634 }
 635
 636 TSAN_INTERCEPTOR(dispatch_io_t, dispatch_io_create, dispatch_io_type_t type,
 637                  dispatch_fd_t fd, dispatch_queue_t q, cleanup_handler_t h) {
 638   SCOPED_TSAN_INTERCEPTOR(dispatch_io_create, type, fd, q, h);
 639   __block dispatch_io_t new_channel = nullptr;
 640   __block tsan_block_context_t new_context = {
 641       q, nullptr, &invoke_block, false, false, false, 0};
 642   cleanup_handler_t new_h = Block_copy(^(int error) {
 643     {
 644       SCOPED_INTERCEPTOR_RAW(dispatch_io_create_callback);
 645       Acquire(thr, pc, (uptr)new_channel);  // Release() in dispatch_io_close.
 646     }
 647     new_context.orig_context = ^(void) {
 648       h(error);
 649     };
 650     dispatch_callback_wrap(&new_context);
 651   });
 652   uptr submit_sync = (uptr)&new_context;
 653   Release(thr, pc, submit_sync);
 654   new_channel = REAL(dispatch_io_create)(type, fd, q, new_h);
 655   Block_release(new_h);
 656   return new_channel;
 657 }
 658
 659 TSAN_INTERCEPTOR(dispatch_io_t, dispatch_io_create_with_path,
 660                  dispatch_io_type_t type, const char *path, int oflag,
 661                  mode_t mode, dispatch_queue_t q, cleanup_handler_t h) {
 662   SCOPED_TSAN_INTERCEPTOR(dispatch_io_create_with_path, type, path, oflag, mode,
 663                           q, h);
 664   __block dispatch_io_t new_channel = nullptr;
 665   __block tsan_block_context_t new_context = {
 666       q, nullptr, &invoke_block, false, false, false, 0};
 667   cleanup_handler_t new_h = Block_copy(^(int error) {
 668     {
 669       SCOPED_INTERCEPTOR_RAW(dispatch_io_create_callback);
 670       Acquire(thr, pc, (uptr)new_channel);  // Release() in dispatch_io_close.
 671     }
 672     new_context.orig_context = ^(void) {
 673       h(error);
 674     };
 675     dispatch_callback_wrap(&new_context);
 676   });
 677   uptr submit_sync = (uptr)&new_context;
 678   Release(thr, pc, submit_sync);
 679   new_channel =
 680       REAL(dispatch_io_create_with_path)(type, path, oflag, mode, q, new_h);
 681   Block_release(new_h);
 682   return new_channel;
 683 }
 684
 685 TSAN_INTERCEPTOR(dispatch_io_t, dispatch_io_create_with_io,
 686                  dispatch_io_type_t type, dispatch_io_t io, dispatch_queue_t q,
 687                  cleanup_handler_t h) {
 688   SCOPED_TSAN_INTERCEPTOR(dispatch_io_create_with_io, type, io, q, h);
 689   __block dispatch_io_t new_channel = nullptr;
 690   __block tsan_block_context_t new_context = {
 691       q, nullptr, &invoke_block, false, false, false, 0};
 692   cleanup_handler_t new_h = Block_copy(^(int error) {
 693     {
 694       SCOPED_INTERCEPTOR_RAW(dispatch_io_create_callback);
 695       Acquire(thr, pc, (uptr)new_channel);  // Release() in dispatch_io_close.
 696     }
 697     new_context.orig_context = ^(void) {
 698       h(error);
 699     };
 700     dispatch_callback_wrap(&new_context);
 701   });
 702   uptr submit_sync = (uptr)&new_context;
 703   Release(thr, pc, submit_sync);
 704   new_channel = REAL(dispatch_io_create_with_io)(type, io, q, new_h);
 705   Block_release(new_h);
 706   return new_channel;
 707 }
 708
 709 TSAN_INTERCEPTOR(void, dispatch_io_close, dispatch_io_t channel,
 710                  dispatch_io_close_flags_t flags) {
 711   SCOPED_TSAN_INTERCEPTOR(dispatch_io_close, channel, flags);
 712   Release(thr, pc, (uptr)channel);  // Acquire() in dispatch_io_create[_*].
 713   return REAL(dispatch_io_close)(channel, flags);
 714 }
 715
 716 // Resuming a suspended queue needs to synchronize with all subsequent
 717 // executions of blocks in that queue.
 718 TSAN_INTERCEPTOR(void, dispatch_resume, dispatch_object_t o) {
 719   SCOPED_TSAN_INTERCEPTOR(dispatch_resume, o);
 720   Release(thr, pc, (uptr)o);  // Synchronizes with the Acquire() on serial_sync
 721                               // in dispatch_sync_pre_execute
 722   return REAL(dispatch_resume)(o);
 723 }
 724
 725 }  // namespace __tsan
 726
 727 #endif  // SANITIZER_MAC