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| 1 /* | |
| 2 * Copyright (C) 2013 Google Inc. All rights reserved. | |
| 3 * | |
| 4 * Redistribution and use in source and binary forms, with or without | |
| 5 * modification, are permitted provided that the following conditions are | |
| 6 * met: | |
| 7 * | |
| 8 * * Redistributions of source code must retain the above copyright | |
| 9 * notice, this list of conditions and the following disclaimer. | |
| 10 * * Redistributions in binary form must reproduce the above | |
| 11 * copyright notice, this list of conditions and the following disclaimer | |
| 12 * in the documentation and/or other materials provided with the | |
| 13 * distribution. | |
| 14 * * Neither the name of Google Inc. nor the names of its | |
| 15 * contributors may be used to endorse or promote products derived from | |
| 16 * this software without specific prior written permission. | |
| 17 * | |
| 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
| 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 29 */ | |
| 30 | |
| 31 #include "config.h" | |
| 32 #include "platform/heap/ThreadState.h" | |
| 33 | |
| 34 #include "platform/ScriptForbiddenScope.h" | |
| 35 #include "platform/TraceEvent.h" | |
| 36 #include "platform/heap/AddressSanitizer.h" | |
| 37 #include "platform/heap/Handle.h" | |
| 38 #include "platform/heap/Heap.h" | |
| 39 #include "public/platform/Platform.h" | |
| 40 #include "public/platform/WebThread.h" | |
| 41 #include "wtf/ThreadingPrimitives.h" | |
| 42 #if ENABLE(GC_PROFILE_HEAP) | |
| 43 #include "platform/TracedValue.h" | |
| 44 #endif | |
| 45 | |
| 46 #if defined(__GLIBC__) | |
| 47 extern "C" void* __libc_stack_end; // NOLINT | |
| 48 #endif | |
| 49 | |
| 50 #if defined(MEMORY_SANITIZER) | |
| 51 #include <sanitizer/msan_interface.h> | |
| 52 #endif | |
| 53 | |
| 54 namespace blink { | |
| 55 | |
| 56 static void* getStackStart() | |
| 57 { | |
| 58 #if defined(__GLIBC__) || OS(ANDROID) | |
| 59 pthread_attr_t attr; | |
| 60 if (!pthread_getattr_np(pthread_self(), &attr)) { | |
| 61 void* base; | |
| 62 size_t size; | |
| 63 int error = pthread_attr_getstack(&attr, &base, &size); | |
| 64 RELEASE_ASSERT(!error); | |
| 65 pthread_attr_destroy(&attr); | |
| 66 return reinterpret_cast<Address>(base) + size; | |
| 67 } | |
| 68 #if defined(__GLIBC__) | |
| 69 // pthread_getattr_np can fail for the main thread. In this case | |
| 70 // just like NaCl we rely on the __libc_stack_end to give us | |
| 71 // the start of the stack. | |
| 72 // See https://code.google.com/p/nativeclient/issues/detail?id=3431. | |
| 73 return __libc_stack_end; | |
| 74 #else | |
| 75 ASSERT_NOT_REACHED(); | |
| 76 return 0; | |
| 77 #endif | |
| 78 #elif OS(MACOSX) | |
| 79 return pthread_get_stackaddr_np(pthread_self()); | |
| 80 #else | |
| 81 #error Unsupported getStackStart on this platform. | |
| 82 #endif | |
| 83 } | |
| 84 | |
| 85 WTF::ThreadSpecific<ThreadState*>* ThreadState::s_threadSpecific = 0; | |
| 86 uint8_t ThreadState::s_mainThreadStateStorage[sizeof(ThreadState)]; | |
| 87 SafePointBarrier* ThreadState::s_safePointBarrier = 0; | |
| 88 bool ThreadState::s_inGC = false; | |
| 89 | |
| 90 static Mutex& threadAttachMutex() | |
| 91 { | |
| 92 AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex); | |
| 93 return mutex; | |
| 94 } | |
| 95 | |
| 96 class SafePointBarrier { | |
| 97 public: | |
| 98 SafePointBarrier() : m_canResume(1), m_unparkedThreadCount(0) { } | |
| 99 ~SafePointBarrier() { } | |
| 100 | |
| 101 // Request other attached threads that are not at safe points to park themse
lves on safepoints. | |
| 102 bool parkOthers() | |
| 103 { | |
| 104 return true; | |
| 105 } | |
| 106 | |
| 107 void resumeOthers(bool barrierLocked = false) | |
| 108 { | |
| 109 } | |
| 110 | |
| 111 void checkAndPark(ThreadState* state, SafePointAwareMutexLocker* locker = 0) | |
| 112 { | |
| 113 } | |
| 114 | |
| 115 void enterSafePoint(ThreadState* state) | |
| 116 { | |
| 117 } | |
| 118 | |
| 119 void leaveSafePoint(ThreadState* state, SafePointAwareMutexLocker* locker =
0) | |
| 120 { | |
| 121 } | |
| 122 | |
| 123 private: | |
| 124 void doPark(ThreadState* state, intptr_t* stackEnd) | |
| 125 { | |
| 126 state->recordStackEnd(stackEnd); | |
| 127 MutexLocker locker(m_mutex); | |
| 128 if (!atomicDecrement(&m_unparkedThreadCount)) | |
| 129 m_parked.signal(); | |
| 130 while (!acquireLoad(&m_canResume)) | |
| 131 m_resume.wait(m_mutex); | |
| 132 atomicIncrement(&m_unparkedThreadCount); | |
| 133 } | |
| 134 | |
| 135 static void parkAfterPushRegisters(SafePointBarrier* barrier, ThreadState* s
tate, intptr_t* stackEnd) | |
| 136 { | |
| 137 barrier->doPark(state, stackEnd); | |
| 138 } | |
| 139 | |
| 140 void doEnterSafePoint(ThreadState* state, intptr_t* stackEnd) | |
| 141 { | |
| 142 state->recordStackEnd(stackEnd); | |
| 143 state->copyStackUntilSafePointScope(); | |
| 144 // m_unparkedThreadCount tracks amount of unparked threads. It is | |
| 145 // positive if and only if we have requested other threads to park | |
| 146 // at safe-points in preparation for GC. The last thread to park | |
| 147 // itself will make the counter hit zero and should notify GC thread | |
| 148 // that it is safe to proceed. | |
| 149 // If no other thread is waiting for other threads to park then | |
| 150 // this counter can be negative: if N threads are at safe-points | |
| 151 // the counter will be -N. | |
| 152 if (!atomicDecrement(&m_unparkedThreadCount)) { | |
| 153 MutexLocker locker(m_mutex); | |
| 154 m_parked.signal(); // Safe point reached. | |
| 155 } | |
| 156 } | |
| 157 | |
| 158 static void enterSafePointAfterPushRegisters(SafePointBarrier* barrier, Thre
adState* state, intptr_t* stackEnd) | |
| 159 { | |
| 160 barrier->doEnterSafePoint(state, stackEnd); | |
| 161 } | |
| 162 | |
| 163 volatile int m_canResume; | |
| 164 volatile int m_unparkedThreadCount; | |
| 165 Mutex m_mutex; | |
| 166 ThreadCondition m_parked; | |
| 167 ThreadCondition m_resume; | |
| 168 }; | |
| 169 | |
| 170 BaseHeapPage::BaseHeapPage(PageMemory* storage, const GCInfo* gcInfo, ThreadStat
e* state) | |
| 171 : m_storage(storage) | |
| 172 , m_gcInfo(gcInfo) | |
| 173 , m_threadState(state) | |
| 174 , m_terminating(false) | |
| 175 , m_tracedAfterOrphaned(false) | |
| 176 { | |
| 177 ASSERT(isPageHeaderAddress(reinterpret_cast<Address>(this))); | |
| 178 } | |
| 179 | |
| 180 // Statically unfold the heap initialization loop so the compiler statically | |
| 181 // knows the heap index when using HeapIndexTrait. | |
| 182 template<int num> struct InitializeHeaps { | |
| 183 static const int index = num - 1; | |
| 184 static void init(BaseHeap** heaps, ThreadState* state) | |
| 185 { | |
| 186 InitializeHeaps<index>::init(heaps, state); | |
| 187 heaps[index] = new typename HeapIndexTrait<index>::HeapType(state, index
); | |
| 188 } | |
| 189 }; | |
| 190 template<> struct InitializeHeaps<0> { | |
| 191 static void init(BaseHeap** heaps, ThreadState* state) { } | |
| 192 }; | |
| 193 | |
| 194 ThreadState::ThreadState() | |
| 195 : m_thread(currentThread()) | |
| 196 , m_persistents(adoptPtr(new PersistentAnchor())) | |
| 197 , m_startOfStack(reinterpret_cast<intptr_t*>(getStackStart())) | |
| 198 , m_endOfStack(reinterpret_cast<intptr_t*>(getStackStart())) | |
| 199 , m_safePointScopeMarker(0) | |
| 200 , m_atSafePoint(false) | |
| 201 , m_interruptors() | |
| 202 , m_gcRequested(false) | |
| 203 , m_forcePreciseGCForTesting(false) | |
| 204 , m_sweepRequested(0) | |
| 205 , m_sweepInProgress(false) | |
| 206 , m_noAllocationCount(0) | |
| 207 , m_inGC(false) | |
| 208 , m_heapContainsCache(adoptPtr(new HeapContainsCache())) | |
| 209 , m_isTerminating(false) | |
| 210 , m_lowCollectionRate(false) | |
| 211 , m_numberOfSweeperTasks(0) | |
| 212 #if defined(ADDRESS_SANITIZER) | |
| 213 , m_asanFakeStack(__asan_get_current_fake_stack()) | |
| 214 #endif | |
| 215 { | |
| 216 ASSERT(!**s_threadSpecific); | |
| 217 **s_threadSpecific = this; | |
| 218 | |
| 219 InitializeHeaps<NumberOfHeaps>::init(m_heaps, this); | |
| 220 | |
| 221 CallbackStack::init(&m_weakCallbackStack); | |
| 222 } | |
| 223 | |
| 224 ThreadState::~ThreadState() | |
| 225 { | |
| 226 checkThread(); | |
| 227 CallbackStack::shutdown(&m_weakCallbackStack); | |
| 228 for (int i = 0; i < NumberOfHeaps; i++) | |
| 229 delete m_heaps[i]; | |
| 230 deleteAllValues(m_interruptors); | |
| 231 **s_threadSpecific = 0; | |
| 232 } | |
| 233 | |
| 234 void ThreadState::attach() | |
| 235 { | |
| 236 RELEASE_ASSERT(!Heap::s_shutdownCalled); | |
| 237 MutexLocker locker(threadAttachMutex()); | |
| 238 ThreadState* state = new ThreadState(); | |
| 239 attachedThreads().add(state); | |
| 240 } | |
| 241 | |
| 242 void ThreadState::cleanupPages() | |
| 243 { | |
| 244 for (int i = 0; i < NumberOfHeaps; ++i) | |
| 245 m_heaps[i]->cleanupPages(); | |
| 246 } | |
| 247 | |
| 248 void ThreadState::cleanup() | |
| 249 { | |
| 250 for (size_t i = 0; i < m_cleanupTasks.size(); i++) | |
| 251 m_cleanupTasks[i]->preCleanup(); | |
| 252 | |
| 253 { | |
| 254 // Grab the threadAttachMutex to ensure only one thread can shutdown at | |
| 255 // a time and that no other thread can do a global GC. It also allows | |
| 256 // safe iteration of the attachedThreads set which happens as part of | |
| 257 // thread local GC asserts. We enter a safepoint while waiting for the | |
| 258 // lock to avoid a dead-lock where another thread has already requested | |
| 259 // GC. | |
| 260 SafePointAwareMutexLocker locker(threadAttachMutex(), NoHeapPointersOnSt
ack); | |
| 261 | |
| 262 // From here on ignore all conservatively discovered | |
| 263 // pointers into the heap owned by this thread. | |
| 264 m_isTerminating = true; | |
| 265 | |
| 266 // Set the terminate flag on all heap pages of this thread. This is used
to | |
| 267 // ensure we don't trace pages on other threads that are not part of the | |
| 268 // thread local GC. | |
| 269 setupHeapsForTermination(); | |
| 270 | |
| 271 // Do thread local GC's as long as the count of thread local Persistents | |
| 272 // changes and is above zero. | |
| 273 PersistentAnchor* anchor = static_cast<PersistentAnchor*>(m_persistents.
get()); | |
| 274 int oldCount = -1; | |
| 275 int currentCount = anchor->numberOfPersistents(); | |
| 276 ASSERT(currentCount >= 0); | |
| 277 while (currentCount != oldCount) { | |
| 278 Heap::collectGarbageForTerminatingThread(this); | |
| 279 oldCount = currentCount; | |
| 280 currentCount = anchor->numberOfPersistents(); | |
| 281 } | |
| 282 // We should not have any persistents left when getting to this point, | |
| 283 // if we have it is probably a bug so adding a debug ASSERT to catch thi
s. | |
| 284 ASSERT(!currentCount); | |
| 285 | |
| 286 // Add pages to the orphaned page pool to ensure any global GCs from thi
s point | |
| 287 // on will not trace objects on this thread's heaps. | |
| 288 cleanupPages(); | |
| 289 | |
| 290 ASSERT(attachedThreads().contains(this)); | |
| 291 attachedThreads().remove(this); | |
| 292 } | |
| 293 | |
| 294 for (size_t i = 0; i < m_cleanupTasks.size(); i++) | |
| 295 m_cleanupTasks[i]->postCleanup(); | |
| 296 m_cleanupTasks.clear(); | |
| 297 } | |
| 298 | |
| 299 | |
| 300 void ThreadState::visitPersistentRoots(Visitor* visitor) | |
| 301 { | |
| 302 { | |
| 303 // All threads are at safepoints so this is not strictly necessary. | |
| 304 // However we acquire the mutex to make mutation and traversal of this | |
| 305 // list symmetrical. | |
| 306 MutexLocker locker(globalRootsMutex()); | |
| 307 globalRoots()->trace(visitor); | |
| 308 } | |
| 309 | |
| 310 AttachedThreadStateSet& threads = attachedThreads(); | |
| 311 for (AttachedThreadStateSet::iterator it = threads.begin(), end = threads.en
d(); it != end; ++it) | |
| 312 (*it)->visitPersistents(visitor); | |
| 313 } | |
| 314 | |
| 315 void ThreadState::visitStackRoots(Visitor* visitor) | |
| 316 { | |
| 317 AttachedThreadStateSet& threads = attachedThreads(); | |
| 318 for (AttachedThreadStateSet::iterator it = threads.begin(), end = threads.en
d(); it != end; ++it) | |
| 319 (*it)->visitStack(visitor); | |
| 320 } | |
| 321 | |
| 322 NO_SANITIZE_ADDRESS | |
| 323 void ThreadState::visitAsanFakeStackForPointer(Visitor* visitor, Address ptr) | |
| 324 { | |
| 325 #if defined(ADDRESS_SANITIZER) | |
| 326 Address* start = reinterpret_cast<Address*>(m_startOfStack); | |
| 327 Address* end = reinterpret_cast<Address*>(m_endOfStack); | |
| 328 Address* fakeFrameStart = 0; | |
| 329 Address* fakeFrameEnd = 0; | |
| 330 Address* maybeFakeFrame = reinterpret_cast<Address*>(ptr); | |
| 331 Address* realFrameForFakeFrame = | |
| 332 reinterpret_cast<Address*>( | |
| 333 __asan_addr_is_in_fake_stack( | |
| 334 m_asanFakeStack, maybeFakeFrame, | |
| 335 reinterpret_cast<void**>(&fakeFrameStart), | |
| 336 reinterpret_cast<void**>(&fakeFrameEnd))); | |
| 337 if (realFrameForFakeFrame) { | |
| 338 // This is a fake frame from the asan fake stack. | |
| 339 if (realFrameForFakeFrame > end && start > realFrameForFakeFrame) { | |
| 340 // The real stack address for the asan fake frame is | |
| 341 // within the stack range that we need to scan so we need | |
| 342 // to visit the values in the fake frame. | |
| 343 for (Address* p = fakeFrameStart; p < fakeFrameEnd; p++) | |
| 344 Heap::checkAndMarkPointer(visitor, *p); | |
| 345 } | |
| 346 } | |
| 347 #endif | |
| 348 } | |
| 349 | |
| 350 NO_SANITIZE_ADDRESS | |
| 351 void ThreadState::visitStack(Visitor* visitor) | |
| 352 { | |
| 353 if (m_stackState == NoHeapPointersOnStack) | |
| 354 return; | |
| 355 | |
| 356 Address* start = reinterpret_cast<Address*>(m_startOfStack); | |
| 357 // If there is a safepoint scope marker we should stop the stack | |
| 358 // scanning there to not touch active parts of the stack. Anything | |
| 359 // interesting beyond that point is in the safepoint stack copy. | |
| 360 // If there is no scope marker the thread is blocked and we should | |
| 361 // scan all the way to the recorded end stack pointer. | |
| 362 Address* end = reinterpret_cast<Address*>(m_endOfStack); | |
| 363 Address* safePointScopeMarker = reinterpret_cast<Address*>(m_safePointScopeM
arker); | |
| 364 Address* current = safePointScopeMarker ? safePointScopeMarker : end; | |
| 365 | |
| 366 // Ensure that current is aligned by address size otherwise the loop below | |
| 367 // will read past start address. | |
| 368 current = reinterpret_cast<Address*>(reinterpret_cast<intptr_t>(current) & ~
(sizeof(Address) - 1)); | |
| 369 | |
| 370 for (; current < start; ++current) { | |
| 371 Address ptr = *current; | |
| 372 #if defined(MEMORY_SANITIZER) | |
| 373 // |ptr| may be uninitialized by design. Mark it as initialized to keep | |
| 374 // MSan from complaining. | |
| 375 // Note: it may be tempting to get rid of |ptr| and simply use |current| | |
| 376 // here, but that would be incorrect. We intentionally use a local | |
| 377 // variable because we don't want to unpoison the original stack. | |
| 378 __msan_unpoison(&ptr, sizeof(ptr)); | |
| 379 #endif | |
| 380 Heap::checkAndMarkPointer(visitor, ptr); | |
| 381 visitAsanFakeStackForPointer(visitor, ptr); | |
| 382 } | |
| 383 | |
| 384 for (Vector<Address>::iterator it = m_safePointStackCopy.begin(); it != m_sa
fePointStackCopy.end(); ++it) { | |
| 385 Address ptr = *it; | |
| 386 #if defined(MEMORY_SANITIZER) | |
| 387 // See the comment above. | |
| 388 __msan_unpoison(&ptr, sizeof(ptr)); | |
| 389 #endif | |
| 390 Heap::checkAndMarkPointer(visitor, ptr); | |
| 391 visitAsanFakeStackForPointer(visitor, ptr); | |
| 392 } | |
| 393 } | |
| 394 | |
| 395 void ThreadState::visitPersistents(Visitor* visitor) | |
| 396 { | |
| 397 m_persistents->trace(visitor); | |
| 398 } | |
| 399 | |
| 400 bool ThreadState::checkAndMarkPointer(Visitor* visitor, Address address) | |
| 401 { | |
| 402 // If thread is terminating ignore conservative pointers. | |
| 403 if (m_isTerminating) | |
| 404 return false; | |
| 405 | |
| 406 // This checks for normal pages and for large objects which span the extent | |
| 407 // of several normal pages. | |
| 408 BaseHeapPage* page = heapPageFromAddress(address); | |
| 409 if (page) { | |
| 410 page->checkAndMarkPointer(visitor, address); | |
| 411 // Whether or not the pointer was within an object it was certainly | |
| 412 // within a page that is part of the heap, so we don't want to ask the | |
| 413 // other other heaps or put this address in the | |
| 414 // HeapDoesNotContainCache. | |
| 415 return true; | |
| 416 } | |
| 417 | |
| 418 return false; | |
| 419 } | |
| 420 | |
| 421 #if ENABLE(GC_PROFILE_MARKING) | |
| 422 const GCInfo* ThreadState::findGCInfo(Address address) | |
| 423 { | |
| 424 BaseHeapPage* page = heapPageFromAddress(address); | |
| 425 if (page) { | |
| 426 return page->findGCInfo(address); | |
| 427 } | |
| 428 return 0; | |
| 429 } | |
| 430 #endif | |
| 431 | |
| 432 #if ENABLE(GC_PROFILE_HEAP) | |
| 433 size_t ThreadState::SnapshotInfo::getClassTag(const GCInfo* gcinfo) | |
| 434 { | |
| 435 HashMap<const GCInfo*, size_t>::AddResult result = classTags.add(gcinfo, cla
ssTags.size()); | |
| 436 if (result.isNewEntry) { | |
| 437 liveCount.append(0); | |
| 438 deadCount.append(0); | |
| 439 liveSize.append(0); | |
| 440 deadSize.append(0); | |
| 441 generations.append(Vector<int, 8>()); | |
| 442 generations.last().fill(0, 8); | |
| 443 } | |
| 444 return result.storedValue->value; | |
| 445 } | |
| 446 | |
| 447 void ThreadState::snapshot() | |
| 448 { | |
| 449 SnapshotInfo info(this); | |
| 450 RefPtr<TracedValue> json = TracedValue::create(); | |
| 451 | |
| 452 #define SNAPSHOT_HEAP(HeapType) \ | |
| 453 { \ | |
| 454 json->beginDictionary(); \ | |
| 455 json->setString("name", #HeapType); \ | |
| 456 m_heaps[HeapType##Heap]->snapshot(json.get(), &info); \ | |
| 457 json->endDictionary(); \ | |
| 458 json->beginDictionary(); \ | |
| 459 json->setString("name", #HeapType"NonFinalized"); \ | |
| 460 m_heaps[HeapType##HeapNonFinalized]->snapshot(json.get(), &info); \ | |
| 461 json->endDictionary(); \ | |
| 462 } | |
| 463 json->beginArray("heaps"); | |
| 464 SNAPSHOT_HEAP(General); | |
| 465 SNAPSHOT_HEAP(CollectionBacking); | |
| 466 FOR_EACH_TYPED_HEAP(SNAPSHOT_HEAP); | |
| 467 json->endArray(); | |
| 468 #undef SNAPSHOT_HEAP | |
| 469 | |
| 470 json->setInteger("allocatedSpace", m_stats.totalAllocatedSpace()); | |
| 471 json->setInteger("objectSpace", m_stats.totalObjectSpace()); | |
| 472 json->setInteger("pageCount", info.pageCount); | |
| 473 json->setInteger("freeSize", info.freeSize); | |
| 474 | |
| 475 Vector<String> classNameVector(info.classTags.size()); | |
| 476 for (HashMap<const GCInfo*, size_t>::iterator it = info.classTags.begin(); i
t != info.classTags.end(); ++it) | |
| 477 classNameVector[it->value] = it->key->m_className; | |
| 478 | |
| 479 size_t liveSize = 0; | |
| 480 size_t deadSize = 0; | |
| 481 json->beginArray("classes"); | |
| 482 for (size_t i = 0; i < classNameVector.size(); ++i) { | |
| 483 json->beginDictionary(); | |
| 484 json->setString("name", classNameVector[i]); | |
| 485 json->setInteger("liveCount", info.liveCount[i]); | |
| 486 json->setInteger("deadCount", info.deadCount[i]); | |
| 487 json->setInteger("liveSize", info.liveSize[i]); | |
| 488 json->setInteger("deadSize", info.deadSize[i]); | |
| 489 liveSize += info.liveSize[i]; | |
| 490 deadSize += info.deadSize[i]; | |
| 491 | |
| 492 json->beginArray("generations"); | |
| 493 for (size_t j = 0; j < heapObjectGenerations; ++j) | |
| 494 json->pushInteger(info.generations[i][j]); | |
| 495 json->endArray(); | |
| 496 json->endDictionary(); | |
| 497 } | |
| 498 json->endArray(); | |
| 499 json->setInteger("liveSize", liveSize); | |
| 500 json->setInteger("deadSize", deadSize); | |
| 501 | |
| 502 TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID("blink_gc", "ThreadState", this, json.re
lease()); | |
| 503 } | |
| 504 #endif | |
| 505 | |
| 506 void ThreadState::pushWeakObjectPointerCallback(void* object, WeakPointerCallbac
k callback) | |
| 507 { | |
| 508 CallbackStack::Item* slot = m_weakCallbackStack->allocateEntry(&m_weakCallba
ckStack); | |
| 509 *slot = CallbackStack::Item(object, callback); | |
| 510 } | |
| 511 | |
| 512 bool ThreadState::popAndInvokeWeakPointerCallback(Visitor* visitor) | |
| 513 { | |
| 514 return m_weakCallbackStack->popAndInvokeCallback<WeaknessProcessing>(&m_weak
CallbackStack, visitor); | |
| 515 } | |
| 516 | |
| 517 PersistentNode* ThreadState::globalRoots() | |
| 518 { | |
| 519 AtomicallyInitializedStatic(PersistentNode*, anchor = new PersistentAnchor); | |
| 520 return anchor; | |
| 521 } | |
| 522 | |
| 523 Mutex& ThreadState::globalRootsMutex() | |
| 524 { | |
| 525 AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex); | |
| 526 return mutex; | |
| 527 } | |
| 528 | |
| 529 // Trigger garbage collection on a 50% increase in size, but not for | |
| 530 // less than 512kbytes. | |
| 531 bool ThreadState::increasedEnoughToGC(size_t newSize, size_t oldSize) | |
| 532 { | |
| 533 if (newSize < 1 << 19) | |
| 534 return false; | |
| 535 size_t limit = oldSize + (oldSize >> 1); | |
| 536 return newSize > limit; | |
| 537 } | |
| 538 | |
| 539 // FIXME: The heuristics are local for a thread at this | |
| 540 // point. Consider using heuristics that take memory for all threads | |
| 541 // into account. | |
| 542 bool ThreadState::shouldGC() | |
| 543 { | |
| 544 // Do not GC during sweeping. We allow allocation during | |
| 545 // finalization, but those allocations are not allowed | |
| 546 // to lead to nested garbage collections. | |
| 547 return !m_sweepInProgress && increasedEnoughToGC(m_stats.totalObjectSpace(),
m_statsAfterLastGC.totalObjectSpace()); | |
| 548 } | |
| 549 | |
| 550 // Trigger conservative garbage collection on a 100% increase in size, | |
| 551 // but not for less than 4Mbytes. If the system currently has a low | |
| 552 // collection rate, then require a 300% increase in size. | |
| 553 bool ThreadState::increasedEnoughToForceConservativeGC(size_t newSize, size_t ol
dSize) | |
| 554 { | |
| 555 if (newSize < 1 << 22) | |
| 556 return false; | |
| 557 size_t limit = (m_lowCollectionRate ? 4 : 2) * oldSize; | |
| 558 return newSize > limit; | |
| 559 } | |
| 560 | |
| 561 // FIXME: The heuristics are local for a thread at this | |
| 562 // point. Consider using heuristics that take memory for all threads | |
| 563 // into account. | |
| 564 bool ThreadState::shouldForceConservativeGC() | |
| 565 { | |
| 566 // Do not GC during sweeping. We allow allocation during | |
| 567 // finalization, but those allocations are not allowed | |
| 568 // to lead to nested garbage collections. | |
| 569 return !m_sweepInProgress && increasedEnoughToForceConservativeGC(m_stats.to
talObjectSpace(), m_statsAfterLastGC.totalObjectSpace()); | |
| 570 } | |
| 571 | |
| 572 bool ThreadState::sweepRequested() | |
| 573 { | |
| 574 ASSERT(isAnyThreadInGC() || checkThread()); | |
| 575 return m_sweepRequested; | |
| 576 } | |
| 577 | |
| 578 void ThreadState::setSweepRequested() | |
| 579 { | |
| 580 // Sweep requested is set from the thread that initiates garbage | |
| 581 // collection which could be different from the thread for this | |
| 582 // thread state. Therefore the setting of m_sweepRequested needs a | |
| 583 // barrier. | |
| 584 atomicTestAndSetToOne(&m_sweepRequested); | |
| 585 } | |
| 586 | |
| 587 void ThreadState::clearSweepRequested() | |
| 588 { | |
| 589 checkThread(); | |
| 590 m_sweepRequested = 0; | |
| 591 } | |
| 592 | |
| 593 bool ThreadState::gcRequested() | |
| 594 { | |
| 595 checkThread(); | |
| 596 return m_gcRequested; | |
| 597 } | |
| 598 | |
| 599 void ThreadState::setGCRequested() | |
| 600 { | |
| 601 checkThread(); | |
| 602 m_gcRequested = true; | |
| 603 } | |
| 604 | |
| 605 void ThreadState::clearGCRequested() | |
| 606 { | |
| 607 checkThread(); | |
| 608 m_gcRequested = false; | |
| 609 } | |
| 610 | |
| 611 void ThreadState::performPendingGC(StackState stackState) | |
| 612 { | |
| 613 if (stackState == NoHeapPointersOnStack) { | |
| 614 if (forcePreciseGCForTesting()) { | |
| 615 setForcePreciseGCForTesting(false); | |
| 616 Heap::collectAllGarbage(); | |
| 617 } else if (gcRequested()) { | |
| 618 Heap::collectGarbage(NoHeapPointersOnStack); | |
| 619 } | |
| 620 } | |
| 621 } | |
| 622 | |
| 623 void ThreadState::setForcePreciseGCForTesting(bool value) | |
| 624 { | |
| 625 checkThread(); | |
| 626 m_forcePreciseGCForTesting = value; | |
| 627 } | |
| 628 | |
| 629 bool ThreadState::forcePreciseGCForTesting() | |
| 630 { | |
| 631 checkThread(); | |
| 632 return m_forcePreciseGCForTesting; | |
| 633 } | |
| 634 | |
| 635 void ThreadState::makeConsistentForSweeping() | |
| 636 { | |
| 637 for (int i = 0; i < NumberOfHeaps; i++) | |
| 638 m_heaps[i]->makeConsistentForSweeping(); | |
| 639 } | |
| 640 | |
| 641 #if ENABLE(ASSERT) | |
| 642 bool ThreadState::isConsistentForSweeping() | |
| 643 { | |
| 644 for (int i = 0; i < NumberOfHeaps; i++) { | |
| 645 if (!m_heaps[i]->isConsistentForSweeping()) | |
| 646 return false; | |
| 647 } | |
| 648 return true; | |
| 649 } | |
| 650 #endif | |
| 651 | |
| 652 void ThreadState::prepareForGC() | |
| 653 { | |
| 654 for (int i = 0; i < NumberOfHeaps; i++) { | |
| 655 BaseHeap* heap = m_heaps[i]; | |
| 656 heap->makeConsistentForSweeping(); | |
| 657 // If a new GC is requested before this thread got around to sweep, ie.
due to the | |
| 658 // thread doing a long running operation, we clear the mark bits and mar
k any of | |
| 659 // the dead objects as dead. The latter is used to ensure the next GC ma
rking does | |
| 660 // not trace already dead objects. If we trace a dead object we could en
d up tracing | |
| 661 // into garbage or the middle of another object via the newly conservati
vely found | |
| 662 // object. | |
| 663 if (sweepRequested()) | |
| 664 heap->clearLiveAndMarkDead(); | |
| 665 } | |
| 666 setSweepRequested(); | |
| 667 } | |
| 668 | |
| 669 void ThreadState::setupHeapsForTermination() | |
| 670 { | |
| 671 for (int i = 0; i < NumberOfHeaps; i++) | |
| 672 m_heaps[i]->prepareHeapForTermination(); | |
| 673 } | |
| 674 | |
| 675 BaseHeapPage* ThreadState::heapPageFromAddress(Address address) | |
| 676 { | |
| 677 BaseHeapPage* cachedPage = heapContainsCache()->lookup(address); | |
| 678 #if !ENABLE(ASSERT) | |
| 679 if (cachedPage) | |
| 680 return cachedPage; | |
| 681 #endif | |
| 682 | |
| 683 for (int i = 0; i < NumberOfHeaps; i++) { | |
| 684 BaseHeapPage* page = m_heaps[i]->heapPageFromAddress(address); | |
| 685 if (page) { | |
| 686 // Asserts that make sure heapPageFromAddress takes addresses from | |
| 687 // the whole aligned blinkPageSize memory area. This is necessary | |
| 688 // for the negative cache to work. | |
| 689 ASSERT(page->isLargeObject() || page == m_heaps[i]->heapPageFromAddr
ess(roundToBlinkPageStart(address))); | |
| 690 if (roundToBlinkPageStart(address) != roundToBlinkPageEnd(address)) | |
| 691 ASSERT(page->isLargeObject() || page == m_heaps[i]->heapPageFrom
Address(roundToBlinkPageEnd(address) - 1)); | |
| 692 ASSERT(!cachedPage || page == cachedPage); | |
| 693 if (!cachedPage) | |
| 694 heapContainsCache()->addEntry(address, page); | |
| 695 return page; | |
| 696 } | |
| 697 } | |
| 698 ASSERT(!cachedPage); | |
| 699 return 0; | |
| 700 } | |
| 701 | |
| 702 void ThreadState::getStats(HeapStats& stats) | |
| 703 { | |
| 704 stats = m_stats; | |
| 705 #if ENABLE(ASSERT) | |
| 706 if (isConsistentForSweeping()) { | |
| 707 HeapStats scannedStats; | |
| 708 for (int i = 0; i < NumberOfHeaps; i++) | |
| 709 m_heaps[i]->getScannedStats(scannedStats); | |
| 710 ASSERT(scannedStats == stats); | |
| 711 } | |
| 712 #endif | |
| 713 } | |
| 714 | |
| 715 bool ThreadState::stopThreads() | |
| 716 { | |
| 717 return s_safePointBarrier->parkOthers(); | |
| 718 } | |
| 719 | |
| 720 void ThreadState::resumeThreads() | |
| 721 { | |
| 722 s_safePointBarrier->resumeOthers(); | |
| 723 } | |
| 724 | |
| 725 void ThreadState::safePoint(StackState stackState) | |
| 726 { | |
| 727 checkThread(); | |
| 728 performPendingGC(stackState); | |
| 729 ASSERT(!m_atSafePoint); | |
| 730 m_stackState = stackState; | |
| 731 m_atSafePoint = true; | |
| 732 s_safePointBarrier->checkAndPark(this); | |
| 733 m_atSafePoint = false; | |
| 734 m_stackState = HeapPointersOnStack; | |
| 735 performPendingSweep(); | |
| 736 } | |
| 737 | |
| 738 #ifdef ADDRESS_SANITIZER | |
| 739 // When we are running under AddressSanitizer with detect_stack_use_after_return
=1 | |
| 740 // then stack marker obtained from SafePointScope will point into a fake stack. | |
| 741 // Detect this case by checking if it falls in between current stack frame | |
| 742 // and stack start and use an arbitrary high enough value for it. | |
| 743 // Don't adjust stack marker in any other case to match behavior of code running | |
| 744 // without AddressSanitizer. | |
| 745 NO_SANITIZE_ADDRESS static void* adjustScopeMarkerForAdressSanitizer(void* scope
Marker) | |
| 746 { | |
| 747 Address start = reinterpret_cast<Address>(getStackStart()); | |
| 748 Address end = reinterpret_cast<Address>(&start); | |
| 749 RELEASE_ASSERT(end < start); | |
| 750 | |
| 751 if (end <= scopeMarker && scopeMarker < start) | |
| 752 return scopeMarker; | |
| 753 | |
| 754 // 256 is as good an approximation as any else. | |
| 755 const size_t bytesToCopy = sizeof(Address) * 256; | |
| 756 if (static_cast<size_t>(start - end) < bytesToCopy) | |
| 757 return start; | |
| 758 | |
| 759 return end + bytesToCopy; | |
| 760 } | |
| 761 #endif | |
| 762 | |
| 763 void ThreadState::enterSafePoint(StackState stackState, void* scopeMarker) | |
| 764 { | |
| 765 #ifdef ADDRESS_SANITIZER | |
| 766 if (stackState == HeapPointersOnStack) | |
| 767 scopeMarker = adjustScopeMarkerForAdressSanitizer(scopeMarker); | |
| 768 #endif | |
| 769 ASSERT(stackState == NoHeapPointersOnStack || scopeMarker); | |
| 770 performPendingGC(stackState); | |
| 771 checkThread(); | |
| 772 ASSERT(!m_atSafePoint); | |
| 773 m_atSafePoint = true; | |
| 774 m_stackState = stackState; | |
| 775 m_safePointScopeMarker = scopeMarker; | |
| 776 s_safePointBarrier->enterSafePoint(this); | |
| 777 } | |
| 778 | |
| 779 void ThreadState::leaveSafePoint(SafePointAwareMutexLocker* locker) | |
| 780 { | |
| 781 checkThread(); | |
| 782 ASSERT(m_atSafePoint); | |
| 783 s_safePointBarrier->leaveSafePoint(this, locker); | |
| 784 m_atSafePoint = false; | |
| 785 m_stackState = HeapPointersOnStack; | |
| 786 clearSafePointScopeMarker(); | |
| 787 performPendingSweep(); | |
| 788 } | |
| 789 | |
| 790 void ThreadState::copyStackUntilSafePointScope() | |
| 791 { | |
| 792 if (!m_safePointScopeMarker || m_stackState == NoHeapPointersOnStack) | |
| 793 return; | |
| 794 | |
| 795 Address* to = reinterpret_cast<Address*>(m_safePointScopeMarker); | |
| 796 Address* from = reinterpret_cast<Address*>(m_endOfStack); | |
| 797 RELEASE_ASSERT(from < to); | |
| 798 RELEASE_ASSERT(to <= reinterpret_cast<Address*>(m_startOfStack)); | |
| 799 size_t slotCount = static_cast<size_t>(to - from); | |
| 800 // Catch potential performance issues. | |
| 801 #if defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) | |
| 802 // ASan/LSan use more space on the stack and we therefore | |
| 803 // increase the allowed stack copying for those builds. | |
| 804 ASSERT(slotCount < 2048); | |
| 805 #else | |
| 806 ASSERT(slotCount < 1024); | |
| 807 #endif | |
| 808 | |
| 809 ASSERT(!m_safePointStackCopy.size()); | |
| 810 m_safePointStackCopy.resize(slotCount); | |
| 811 for (size_t i = 0; i < slotCount; ++i) { | |
| 812 m_safePointStackCopy[i] = from[i]; | |
| 813 } | |
| 814 } | |
| 815 | |
| 816 void ThreadState::registerSweepingTask() | |
| 817 { | |
| 818 MutexLocker locker(m_sweepMutex); | |
| 819 ++m_numberOfSweeperTasks; | |
| 820 } | |
| 821 | |
| 822 void ThreadState::unregisterSweepingTask() | |
| 823 { | |
| 824 MutexLocker locker(m_sweepMutex); | |
| 825 ASSERT(m_numberOfSweeperTasks > 0); | |
| 826 if (!--m_numberOfSweeperTasks) | |
| 827 m_sweepThreadCondition.signal(); | |
| 828 } | |
| 829 | |
| 830 void ThreadState::waitUntilSweepersDone() | |
| 831 { | |
| 832 MutexLocker locker(m_sweepMutex); | |
| 833 while (m_numberOfSweeperTasks > 0) | |
| 834 m_sweepThreadCondition.wait(m_sweepMutex); | |
| 835 } | |
| 836 | |
| 837 void ThreadState::performPendingSweep() | |
| 838 { | |
| 839 } | |
| 840 | |
| 841 void ThreadState::addInterruptor(Interruptor* interruptor) | |
| 842 { | |
| 843 SafePointScope scope(HeapPointersOnStack, SafePointScope::AllowNesting); | |
| 844 | |
| 845 { | |
| 846 MutexLocker locker(threadAttachMutex()); | |
| 847 m_interruptors.append(interruptor); | |
| 848 } | |
| 849 } | |
| 850 | |
| 851 void ThreadState::removeInterruptor(Interruptor* interruptor) | |
| 852 { | |
| 853 SafePointScope scope(HeapPointersOnStack, SafePointScope::AllowNesting); | |
| 854 | |
| 855 { | |
| 856 MutexLocker locker(threadAttachMutex()); | |
| 857 size_t index = m_interruptors.find(interruptor); | |
| 858 RELEASE_ASSERT(index >= 0); | |
| 859 m_interruptors.remove(index); | |
| 860 } | |
| 861 } | |
| 862 | |
| 863 void ThreadState::Interruptor::onInterrupted() | |
| 864 { | |
| 865 ThreadState* state = ThreadState::current(); | |
| 866 ASSERT(state); | |
| 867 ASSERT(!state->isAtSafePoint()); | |
| 868 state->safePoint(HeapPointersOnStack); | |
| 869 } | |
| 870 | |
| 871 ThreadState::AttachedThreadStateSet& ThreadState::attachedThreads() | |
| 872 { | |
| 873 DEFINE_STATIC_LOCAL(AttachedThreadStateSet, threads, ()); | |
| 874 return threads; | |
| 875 } | |
| 876 | |
| 877 #if ENABLE(GC_PROFILE_MARKING) | |
| 878 const GCInfo* ThreadState::findGCInfoFromAllThreads(Address address) | |
| 879 { | |
| 880 bool needLockForIteration = !isAnyThreadInGC(); | |
| 881 if (needLockForIteration) | |
| 882 threadAttachMutex().lock(); | |
| 883 | |
| 884 ThreadState::AttachedThreadStateSet& threads = attachedThreads(); | |
| 885 for (ThreadState::AttachedThreadStateSet::iterator it = threads.begin(), end
= threads.end(); it != end; ++it) { | |
| 886 if (const GCInfo* gcInfo = (*it)->findGCInfo(address)) { | |
| 887 if (needLockForIteration) | |
| 888 threadAttachMutex().unlock(); | |
| 889 return gcInfo; | |
| 890 } | |
| 891 } | |
| 892 if (needLockForIteration) | |
| 893 threadAttachMutex().unlock(); | |
| 894 return 0; | |
| 895 } | |
| 896 #endif | |
| 897 | |
| 898 } | |
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