Refactor the Heap into ThreadHeap to prepare for per thread heaps

third_party/WebKit/Source/platform/heap/ThreadState.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 54 matching lines @@
 #endif
 
 #include <v8.h>
 
 namespace blink {
 
 WTF::ThreadSpecific<ThreadState*>* ThreadState::s_threadSpecific = nullptr;
 uintptr_t ThreadState::s_mainThreadStackStart = 0;
 uintptr_t ThreadState::s_mainThreadUnderestimatedStackSize = 0;
 uint8_t ThreadState::s_mainThreadStateStorage[sizeof(ThreadState)];
-SafePointBarrier* ThreadState::s_safePointBarrier = nullptr;
-
-RecursiveMutex& ThreadState::threadAttachMutex()
-{
-    DEFINE_THREAD_SAFE_STATIC_LOCAL(RecursiveMutex, mutex, (new RecursiveMutex));
-    return mutex;
-}
 
 ThreadState::ThreadState()
     : m_thread(currentThread())
     , m_persistentRegion(adoptPtr(new PersistentRegion()))
 #if OS(WIN) && COMPILER(MSVC)
     , m_threadStackSize(0)
 #endif
     , m_startOfStack(reinterpret_cast<intptr_t*>(StackFrameDepth::getStackStart()))
     , m_endOfStack(reinterpret_cast<intptr_t*>(StackFrameDepth::getStackStart()))
     , m_safePointScopeMarker(nullptr)
@@ skipping 23 matching lines @@
 {
     ASSERT(checkThread());
     ASSERT(!**s_threadSpecific);
     **s_threadSpecific = this;
 
     if (isMainThread()) {
         s_mainThreadStackStart = reinterpret_cast<uintptr_t>(m_startOfStack) - sizeof(void*);
         size_t underestimatedStackSize = StackFrameDepth::getUnderestimatedStackSize();
         if (underestimatedStackSize > sizeof(void*))
             s_mainThreadUnderestimatedStackSize = underestimatedStackSize - sizeof(void*);
+        m_heap = new ThreadHeap();
+    } else {
+        m_heap = &ThreadState::mainThreadState()->heap();
     }
+    ASSERT(m_heap);
+    m_heap->attach(this);
 
     for (int arenaIndex = 0; arenaIndex < BlinkGC::LargeObjectArenaIndex; arenaIndex++)
         m_arenas[arenaIndex] = new NormalPageArena(this, arenaIndex);
     m_arenas[BlinkGC::LargeObjectArenaIndex] = new LargeObjectArena(this, BlinkGC::LargeObjectArenaIndex);
 
     m_likelyToBePromptlyFreed = adoptArrayPtr(new int[likelyToBePromptlyFreedArraySize]);
     clearArenaAges();
 
     // There is little use of weak references and collections off the main thread;
     // use a much lower initial block reservation.
@@ skipping 12 matching lines @@
     **s_threadSpecific = nullptr;
     if (isMainThread()) {
         s_mainThreadStackStart = 0;
         s_mainThreadUnderestimatedStackSize = 0;
     }
 }
 
 void ThreadState::init()
 {
     s_threadSpecific = new WTF::ThreadSpecific<ThreadState*>();
-    s_safePointBarrier = new SafePointBarrier;
-}
-
-void ThreadState::shutdown()
-{
-    delete s_safePointBarrier;
-    s_safePointBarrier = nullptr;
-
-    // Thread-local storage shouldn't be disposed, so we don't call ~ThreadSpecific().
 }
 
 #if OS(WIN) && COMPILER(MSVC)
 size_t ThreadState::threadStackSize()
 {
     if (m_threadStackSize)
         return m_threadStackSize;
 
     // Notice that we cannot use the TIB's StackLimit for the stack end, as it
     // tracks the end of the committed range. We're after the end of the reserved
@@ skipping 19 matching lines @@
     // http://blogs.msdn.com/b/satyem/archive/2012/08/13/thread-s-stack-memory-management.aspx
     // explains the details.
     RELEASE_ASSERT(m_threadStackSize > 4 * 0x1000);
     m_threadStackSize -= 4 * 0x1000;
     return m_threadStackSize;
 }
 #endif
 
 void ThreadState::attachMainThread()
 {
-    MutexLocker locker(threadAttachMutex());
-    ThreadState* state = new (s_mainThreadStateStorage) ThreadState();
-    attachedThreads().add(state);
+    RELEASE_ASSERT(!ProcessHeap::s_shutdownComplete);
+    new(s_mainThreadStateStorage) ThreadState();
 }
 
+void ThreadState::attach()
+{
+    RELEASE_ASSERT(!ProcessHeap::s_shutdownComplete);
+    new ThreadState();
+}
+
+void ThreadState::cleanupPages()
+{
+    ASSERT(checkThread());
+    for (int i = 0; i < BlinkGC::NumberOfArenas; ++i)
+        m_arenas[i]->cleanupPages();
+}
+
+void ThreadState::runThreadTerminationGC()
+{
+    if (isMainThread()) {
+        cleanupPages();
+        return;
+    }
+    ASSERT(checkThread());
+
+    // Finish sweeping.
+    completeSweep();
+
+    // From here on ignore all conservatively discovered
+    // pointers into the heap owned by this thread.
+    m_isTerminating = true;
+
+    // Set the terminate flag on all heap pages of this thread. This is used to
+    // ensure we don't trace pages on other threads that are not part of the
+    // thread local GC.
+    prepareForThreadStateTermination();
+
+    ProcessHeap::crossThreadPersistentRegion().prepareForThreadStateTermination(this);
+
+    // Do thread local GC's as long as the count of thread local Persistents
+    // changes and is above zero.
+    int oldCount = -1;
+    int currentCount = getPersistentRegion()->numberOfPersistents();
+    ASSERT(currentCount >= 0);
+    while (currentCount != oldCount) {
+        ThreadHeap::collectGarbageForTerminatingThread(this);
+        oldCount = currentCount;
+        currentCount = getPersistentRegion()->numberOfPersistents();
+    }
+    // We should not have any persistents left when getting to this point,
+    // if we have it is probably a bug so adding a debug ASSERT to catch this.
+    ASSERT(!currentCount);
+    // All of pre-finalizers should be consumed.
+    ASSERT(m_orderedPreFinalizers.isEmpty());
+    RELEASE_ASSERT(gcState() == NoGCScheduled);
+
+    // Add pages to the orphaned page pool to ensure any global GCs from this point
+    // on will not trace objects on this thread's arenas.
+    cleanupPages();
+}
 
 void ThreadState::cleanupMainThread()
 {
     ASSERT(isMainThread());
 
 #if defined(LEAK_SANITIZER)
     // If LSan is about to perform leak detection, release all the registered
     // static Persistent<> root references to global caches that Blink keeps,
     // followed by GCs to clear out all they referred to.
     //
     // This is not needed for caches over non-Oilpan objects, as they're
     // not scanned by LSan due to being held in non-global storage
     // ("static" references inside functions/methods.)
     releaseStaticPersistentNodes();
-    Heap::collectAllGarbage();
+    ThreadHeap::collectAllGarbage();
 #endif
 
     // Finish sweeping before shutting down V8. Otherwise, some destructor
     // may access V8 and cause crashes.
     completeSweep();
 
     // It is unsafe to trigger GCs after this point because some
     // destructor may access already-detached V8 and cause crashes.
     // Also it is useless. So we forbid GCs.
     enterGCForbiddenScope();
 }
 
 void ThreadState::detachMainThread()
 {
     // Enter a safe point before trying to acquire threadAttachMutex
     // to avoid dead lock if another thread is preparing for GC, has acquired
     // threadAttachMutex and waiting for other threads to pause or reach a
     // safepoint.
     ThreadState* state = mainThreadState();
-    ASSERT(state == ThreadState::current());
-    ASSERT(state->checkThread());
-    ASSERT(!state->isSweepingInProgress());
 
-    // The main thread must be the last thread that gets detached.
-    RELEASE_ASSERT(ThreadState::attachedThreads().size() == 1);
-
-    // Add the main thread's heap pages to the orphaned pool.
-    state->cleanupPages();
-
-    // Detach the main thread. We don't need to grab a lock because
-    // the main thread should be the last thread that gets detached.
-    ASSERT(attachedThreads().contains(state));
-    attachedThreads().remove(state);
-    state->~ThreadState();
+    // 1. Finish sweeping.
+    state->completeSweep();
+    state->detach();
 }
 
-void ThreadState::attach()
+void ThreadState::detachCurrentThread()
 {
-    MutexLocker locker(threadAttachMutex());
-    ThreadState* state = new ThreadState();
-    attachedThreads().add(state);
-}
-
-void ThreadState::cleanupPages()
-{
-    ASSERT(checkThread());
-    for (int i = 0; i < BlinkGC::NumberOfArenas; ++i)
-        m_arenas[i]->cleanupPages();
-}
-
-void ThreadState::cleanup()
-{
-    ASSERT(checkThread());
-    {
-        // Grab the threadAttachMutex to ensure only one thread can shutdown at
-        // a time and that no other thread can do a global GC. It also allows
-        // safe iteration of the attachedThreads set which happens as part of
-        // thread local GC asserts. We enter a safepoint while waiting for the
-        // lock to avoid a dead-lock where another thread has already requested
-        // GC.
-        SafePointAwareMutexLocker locker(threadAttachMutex(), BlinkGC::NoHeapPointersOnStack);
-
-        // Finish sweeping.
-        completeSweep();
-
-        // From here on ignore all conservatively discovered
-        // pointers into the heap owned by this thread.
-        m_isTerminating = true;
-
-        // Set the terminate flag on all heap pages of this thread. This is used to
-        // ensure we don't trace pages on other threads that are not part of the
-        // thread local GC.
-        prepareForThreadStateTermination();
-
-        Heap::crossThreadPersistentRegion().prepareForThreadStateTermination(this);
-
-        // Do thread local GC's as long as the count of thread local Persistents
-        // changes and is above zero.
-        int oldCount = -1;
-        int currentCount = getPersistentRegion()->numberOfPersistents();
-        ASSERT(currentCount >= 0);
-        while (currentCount != oldCount) {
-            Heap::collectGarbageForTerminatingThread(this);
-            oldCount = currentCount;
-            currentCount = getPersistentRegion()->numberOfPersistents();
-        }
-        // We should not have any persistents left when getting to this point,
-        // if we have it is probably a bug so adding a debug ASSERT to catch this.
-        ASSERT(!currentCount);
-        // All of pre-finalizers should be consumed.
-        ASSERT(m_orderedPreFinalizers.isEmpty());
-        RELEASE_ASSERT(gcState() == NoGCScheduled);
-
-        // Add pages to the orphaned page pool to ensure any global GCs from this point
-        // on will not trace objects on this thread's arenas.
-        cleanupPages();
-
-        ASSERT(attachedThreads().contains(this));
-        attachedThreads().remove(this);
-    }
+    current()->detach();
 }
 
 void ThreadState::detach()
 {
-    ThreadState* state = current();
-    state->cleanup();
-    RELEASE_ASSERT(state->gcState() == ThreadState::NoGCScheduled);
-    delete state;
-}
-
-void ThreadState::visitPersistentRoots(Visitor* visitor)
-{
-    TRACE_EVENT0("blink_gc", "ThreadState::visitPersistentRoots");
-    Heap::crossThreadPersistentRegion().tracePersistentNodes(visitor);
-
-    for (ThreadState* state : attachedThreads())
-        state->visitPersistents(visitor);
-}
-
-void ThreadState::visitStackRoots(Visitor* visitor)
-{
-    TRACE_EVENT0("blink_gc", "ThreadState::visitStackRoots");
-    for (ThreadState* state : attachedThreads())
-        state->visitStack(visitor);
+    m_heap->detach(this);
+    // Call destructor directly because we don't want to free s_mainThreadStateStorage.
+    if (isMainThread()) {
+        this->~ThreadState();
+    } else {
+        RELEASE_ASSERT(gcState() == ThreadState::NoGCScheduled);
+        delete this;
+    }
 }
 
 NO_SANITIZE_ADDRESS
 void ThreadState::visitAsanFakeStackForPointer(Visitor* visitor, Address ptr)
 {
 #if defined(ADDRESS_SANITIZER)
     Address* start = reinterpret_cast<Address*>(m_startOfStack);
     Address* end = reinterpret_cast<Address*>(m_endOfStack);
     Address* fakeFrameStart = nullptr;
     Address* fakeFrameEnd = nullptr;
     Address* maybeFakeFrame = reinterpret_cast<Address*>(ptr);
     Address* realFrameForFakeFrame =
         reinterpret_cast<Address*>(
             __asan_addr_is_in_fake_stack(
                 m_asanFakeStack, maybeFakeFrame,
                 reinterpret_cast<void**>(&fakeFrameStart),
                 reinterpret_cast<void**>(&fakeFrameEnd)));
     if (realFrameForFakeFrame) {
         // This is a fake frame from the asan fake stack.
         if (realFrameForFakeFrame > end && start > realFrameForFakeFrame) {
             // The real stack address for the asan fake frame is
             // within the stack range that we need to scan so we need
             // to visit the values in the fake frame.
             for (Address* p = fakeFrameStart; p < fakeFrameEnd; ++p)
-                Heap::checkAndMarkPointer(visitor, *p);
+                m_heap->checkAndMarkPointer(visitor, *p);
         }
     }
 #endif
 }
 
 NO_SANITIZE_ADDRESS
 void ThreadState::visitStack(Visitor* visitor)
 {
     if (m_stackState == BlinkGC::NoHeapPointersOnStack)
         return;
@@ skipping 15 matching lines @@
     for (; current < start; ++current) {
         Address ptr = *current;
 #if defined(MEMORY_SANITIZER)
         // |ptr| may be uninitialized by design. Mark it as initialized to keep
         // MSan from complaining.
         // Note: it may be tempting to get rid of |ptr| and simply use |current|
         // here, but that would be incorrect. We intentionally use a local
         // variable because we don't want to unpoison the original stack.
         __msan_unpoison(&ptr, sizeof(ptr));
 #endif
-        Heap::checkAndMarkPointer(visitor, ptr);
+        m_heap->checkAndMarkPointer(visitor, ptr);
         visitAsanFakeStackForPointer(visitor, ptr);
     }
 
     for (Address ptr : m_safePointStackCopy) {
 #if defined(MEMORY_SANITIZER)
         // See the comment above.
         __msan_unpoison(&ptr, sizeof(ptr));
 #endif
-        Heap::checkAndMarkPointer(visitor, ptr);
+        m_heap->checkAndMarkPointer(visitor, ptr);
         visitAsanFakeStackForPointer(visitor, ptr);
     }
 }
 
 void ThreadState::visitPersistents(Visitor* visitor)
 {
     m_persistentRegion->tracePersistentNodes(visitor);
     if (m_traceDOMWrappers) {
         TRACE_EVENT0("blink_gc", "V8GCController::traceDOMWrappers");
         m_traceDOMWrappers(m_isolate, visitor);
@@ skipping 14 matching lines @@
     *slot = CallbackStack::Item(object, callback);
 }
 
 bool ThreadState::popAndInvokeThreadLocalWeakCallback(Visitor* visitor)
 {
     ASSERT(checkThread());
     // For weak processing we should never reach orphaned pages since orphaned
     // pages are not traced and thus objects on those pages are never be
     // registered as objects on orphaned pages. We cannot assert this here since
     // we might have an off-heap collection. We assert it in
-    // Heap::pushThreadLocalWeakCallback.
+    // ThreadHeap::pushThreadLocalWeakCallback.
     if (CallbackStack::Item* item = m_threadLocalWeakCallbackStack->pop()) {
         // Note that the thread-local weak processing can be called for
         // an already dead object (for which isHeapObjectAlive(object) can
         // return false). This can happen in the following scenario:
         //
         // 1) Marking runs. A weak callback for an object X is registered
         //    to the thread that created the object X (say, thread P).
         // 2) Marking finishes. All other threads are resumed.
         // 3) The object X becomes unreachable.
         // 4) A next GC hits before the thread P wakes up.
@@ skipping 45 matching lines @@
 
     if (isMainThread()) {
         double timeForThreadLocalWeakProcessing = WTF::currentTimeMS() - startTime;
         DEFINE_STATIC_LOCAL(CustomCountHistogram, timeForWeakHistogram, ("BlinkGC.TimeForThreadLocalWeakProcessing", 1, 10 * 1000, 50));
         timeForWeakHistogram.count(timeForThreadLocalWeakProcessing);
     }
 }
 
 size_t ThreadState::totalMemorySize()
 {
-    return Heap::allocatedObjectSize() + Heap::markedObjectSize() + WTF::Partitions::totalSizeOfCommittedPages();
+    return m_heap->heapStats().allocatedObjectSize() + m_heap->heapStats().markedObjectSize() + WTF::Partitions::totalSizeOfCommittedPages();
 }
 
 size_t ThreadState::estimatedLiveSize(size_t estimationBaseSize, size_t sizeAtLastGC)
 {
-    if (Heap::wrapperCountAtLastGC() == 0) {
+    if (m_heap->heapStats().wrapperCountAtLastGC() == 0) {
         // We'll reach here only before hitting the first GC.
         return 0;
     }
 
     // (estimated size) = (estimation base size) - (heap size at the last GC) / (# of persistent handles at the last GC) * (# of persistent handles collected since the last GC);
-    size_t sizeRetainedByCollectedPersistents = static_cast<size_t>(1.0 * sizeAtLastGC / Heap::wrapperCountAtLastGC() * Heap::collectedWrapperCount());
+    size_t sizeRetainedByCollectedPersistents = static_cast<size_t>(1.0 * sizeAtLastGC / m_heap->heapStats().wrapperCountAtLastGC() * m_heap->heapStats().collectedWrapperCount());
     if (estimationBaseSize < sizeRetainedByCollectedPersistents)
         return 0;
     return estimationBaseSize - sizeRetainedByCollectedPersistents;
 }
 
 double ThreadState::heapGrowingRate()
 {
-    size_t currentSize = Heap::allocatedObjectSize() + Heap::markedObjectSize();
-    size_t estimatedSize = estimatedLiveSize(Heap::markedObjectSizeAtLastCompleteSweep(), Heap::markedObjectSizeAtLastCompleteSweep());
+    size_t currentSize = m_heap->heapStats().allocatedObjectSize() + m_heap->heapStats().markedObjectSize();
+    size_t estimatedSize = estimatedLiveSize(m_heap->heapStats().markedObjectSizeAtLastCompleteSweep(), m_heap->heapStats().markedObjectSizeAtLastCompleteSweep());
 
     // If the estimatedSize is 0, we set a high growing rate to trigger a GC.
     double growingRate = estimatedSize > 0 ? 1.0 * currentSize / estimatedSize : 100;
     TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"), "ThreadState::heapEstimatedSizeKB", std::min(estimatedSize / 1024, static_cast<size_t>(INT_MAX)));
     TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"), "ThreadState::heapGrowingRate", static_cast<int>(100 * growingRate));
     return growingRate;
 }
 
 double ThreadState::partitionAllocGrowingRate()
 {
     size_t currentSize = WTF::Partitions::totalSizeOfCommittedPages();
-    size_t estimatedSize = estimatedLiveSize(currentSize, Heap::partitionAllocSizeAtLastGC());
+    size_t estimatedSize = estimatedLiveSize(currentSize, m_heap->heapStats().partitionAllocSizeAtLastGC());
 
     // If the estimatedSize is 0, we set a high growing rate to trigger a GC.
     double growingRate = estimatedSize > 0 ? 1.0 * currentSize / estimatedSize : 100;
     TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"), "ThreadState::partitionAllocEstimatedSizeKB", std::min(estimatedSize / 1024, static_cast<size_t>(INT_MAX)));
     TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"), "ThreadState::partitionAllocGrowingRate", static_cast<int>(100 * growingRate));
     return growingRate;
 }
 
 // TODO(haraken): We should improve the GC heuristics. The heuristics affect
 // performance significantly.
 bool ThreadState::judgeGCThreshold(size_t totalMemorySizeThreshold, double heapGrowingRateThreshold)
 {
     // If the allocated object size or the total memory size is small, don't trigger a GC.
-    if (Heap::allocatedObjectSize() < 100 * 1024 || totalMemorySize() < totalMemorySizeThreshold)
+    if (m_heap->heapStats().allocatedObjectSize() < 100 * 1024 || totalMemorySize() < totalMemorySizeThreshold)
         return false;
     // If the growing rate of Oilpan's heap or PartitionAlloc is high enough,
     // trigger a GC.
 #if PRINT_HEAP_STATS
     dataLogF("heapGrowingRate=%.1lf, partitionAllocGrowingRate=%.1lf\n", heapGrowingRate(), partitionAllocGrowingRate());
 #endif
     return heapGrowingRate() >= heapGrowingRateThreshold || partitionAllocGrowingRate() >= heapGrowingRateThreshold;
 }
 
 bool ThreadState::shouldScheduleIdleGC()
@@ skipping 27 matching lines @@
 bool ThreadState::shouldForceMemoryPressureGC()
 {
     if (totalMemorySize() < 300 * 1024 * 1024)
         return false;
     return judgeGCThreshold(0, 1.5);
 }
 
 void ThreadState::scheduleV8FollowupGCIfNeeded(BlinkGC::V8GCType gcType)
 {
     ASSERT(checkThread());
-    Heap::reportMemoryUsageForTracing();
+    ThreadHeap::reportMemoryUsageForTracing();
 
 #if PRINT_HEAP_STATS
     dataLogF("ThreadState::scheduleV8FollowupGCIfNeeded (gcType=%s)\n", gcType == BlinkGC::V8MajorGC ? "MajorGC" : "MinorGC");
 #endif
 
     if (isGCForbidden())
         return;
 
     // This completeSweep() will do nothing in common cases since we've
     // called completeSweep() before V8 starts minor/major GCs.
@@ skipping 27 matching lines @@
     // completeSweep() here, because gcPrologue for a major GC is called
     // not at the point where the major GC started but at the point where
     // the major GC requests object grouping.
     if (gcType == BlinkGC::V8MajorGC)
         completeSweep();
 }
 
 void ThreadState::schedulePageNavigationGCIfNeeded(float estimatedRemovalRatio)
 {
     ASSERT(checkThread());
-    Heap::reportMemoryUsageForTracing();
+    ThreadHeap::reportMemoryUsageForTracing();
 
 #if PRINT_HEAP_STATS
     dataLogF("ThreadState::schedulePageNavigationGCIfNeeded (estimatedRemovalRatio=%.2lf)\n", estimatedRemovalRatio);
 #endif
 
     if (isGCForbidden())
         return;
 
     // Finish on-going lazy sweeping.
     // TODO(haraken): It might not make sense to force completeSweep() for all
     // page navigations.
     completeSweep();
     ASSERT(!isSweepingInProgress());
     ASSERT(!sweepForbidden());
 
     if (shouldForceMemoryPressureGC()) {
 #if PRINT_HEAP_STATS
         dataLogF("Scheduled MemoryPressureGC\n");
 #endif
-        Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::MemoryPressureGC);
+        ThreadHeap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::MemoryPressureGC);
         return;
     }
     if (shouldSchedulePageNavigationGC(estimatedRemovalRatio)) {
 #if PRINT_HEAP_STATS
         dataLogF("Scheduled PageNavigationGC\n");
 #endif
         schedulePageNavigationGC();
     }
 }
 
 void ThreadState::schedulePageNavigationGC()
 {
     ASSERT(checkThread());
     ASSERT(!isSweepingInProgress());
     setGCState(PageNavigationGCScheduled);
 }
 
 void ThreadState::scheduleGCIfNeeded()
 {
     ASSERT(checkThread());
-    Heap::reportMemoryUsageForTracing();
+    ThreadHeap::reportMemoryUsageForTracing();
 
 #if PRINT_HEAP_STATS
     dataLogF("ThreadState::scheduleGCIfNeeded\n");
 #endif
 
     // Allocation is allowed during sweeping, but those allocations should not
     // trigger nested GCs.
     if (isGCForbidden())
         return;
 
     if (isSweepingInProgress())
         return;
     ASSERT(!sweepForbidden());
 
     reportMemoryToV8();
 
     if (shouldForceMemoryPressureGC()) {
         completeSweep();
         if (shouldForceMemoryPressureGC()) {
 #if PRINT_HEAP_STATS
             dataLogF("Scheduled MemoryPressureGC\n");
 #endif
-            Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::MemoryPressureGC);
+            ThreadHeap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::MemoryPressureGC);
             return;
         }
     }
 
     if (shouldForceConservativeGC()) {
         completeSweep();
         if (shouldForceConservativeGC()) {
 #if PRINT_HEAP_STATS
             dataLogF("Scheduled ConservativeGC\n");
 #endif
-            Heap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::ConservativeGC);
+            ThreadHeap::collectGarbage(BlinkGC::HeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::ConservativeGC);
             return;
         }
     }
     if (shouldScheduleIdleGC()) {
 #if PRINT_HEAP_STATS
         dataLogF("Scheduled IdleGC\n");
 #endif
         scheduleIdleGC();
         return;
     }
 }
 
+ThreadState* ThreadState::fromObject(const void* object)
+{
+    if (!object)
+        return nullptr;
+    BasePage* page = pageFromObject(object);
+    ASSERT(page);
+    ASSERT(page->arena());
+    return page->arena()->getThreadState();
+}
+
 void ThreadState::performIdleGC(double deadlineSeconds)
 {
     ASSERT(checkThread());
     ASSERT(isMainThread());
     ASSERT(Platform::current()->currentThread()->scheduler());
 
     if (gcState() != IdleGCScheduled)
         return;
 
     double idleDeltaInSeconds = deadlineSeconds - monotonicallyIncreasingTime();
-    TRACE_EVENT2("blink_gc", "ThreadState::performIdleGC", "idleDeltaInSeconds", idleDeltaInSeconds, "estimatedMarkingTime", Heap::estimatedMarkingTime());
-    if (idleDeltaInSeconds <= Heap::estimatedMarkingTime() && !Platform::current()->currentThread()->scheduler()->canExceedIdleDeadlineIfRequired()) {
+    TRACE_EVENT2("blink_gc", "ThreadState::performIdleGC", "idleDeltaInSeconds", idleDeltaInSeconds, "estimatedMarkingTime", m_heap->heapStats().estimatedMarkingTime());
+    if (idleDeltaInSeconds <= m_heap->heapStats().estimatedMarkingTime() && !Platform::current()->currentThread()->scheduler()->canExceedIdleDeadlineIfRequired()) {
         // If marking is estimated to take longer than the deadline and we can't
         // exceed the deadline, then reschedule for the next idle period.
         scheduleIdleGC();
         return;
     }
 
-    Heap::collectGarbage(BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::IdleGC);
+    ThreadHeap::collectGarbage(BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::IdleGC);
 }
 
 void ThreadState::performIdleLazySweep(double deadlineSeconds)
 {
     ASSERT(checkThread());
     ASSERT(isMainThread());
 
     // If we are not in a sweeping phase, there is nothing to do here.
     if (!isSweepingInProgress())
         return;
@@ skipping 155 matching lines @@
     // If a safe point is entered while initiating a GC, we clearly do
     // not want to do another as part that -- the safe point is only
     // entered after checking if a scheduled GC ought to run first.
     // Prevent that from happening by marking GCs as forbidden while
     // one is initiated and later running.
     if (isGCForbidden())
         return;
 
     switch (gcState()) {
     case FullGCScheduled:
-        Heap::collectAllGarbage();
+        ThreadHeap::collectAllGarbage();
         break;
     case PreciseGCScheduled:
-        Heap::collectGarbage(BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::PreciseGC);
+        ThreadHeap::collectGarbage(BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithoutSweep, BlinkGC::PreciseGC);
         break;
     case PageNavigationGCScheduled:
-        Heap::collectGarbage(BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithSweep, BlinkGC::PageNavigationGC);
+        ThreadHeap::collectGarbage(BlinkGC::NoHeapPointersOnStack, BlinkGC::GCWithSweep, BlinkGC::PageNavigationGC);
         break;
     case IdleGCScheduled:
         // Idle time GC will be scheduled by Blink Scheduler.
         break;
     default:
         break;
     }
 }
 
 void ThreadState::flushHeapDoesNotContainCacheIfNeeded()
 {
     if (m_shouldFlushHeapDoesNotContainCache) {
-        Heap::flushHeapDoesNotContainCache();
+        m_heap->flushHeapDoesNotContainCache();
         m_shouldFlushHeapDoesNotContainCache = false;
     }
 }
 
 void ThreadState::makeConsistentForGC()
 {
     ASSERT(isInGC());
     TRACE_EVENT0("blink_gc", "ThreadState::makeConsistentForGC");
     for (int i = 0; i < BlinkGC::NumberOfArenas; ++i)
         m_arenas[i]->makeConsistentForGC();
@@ skipping 129 matching lines @@
     if (sweepForbidden())
         return;
 
     SweepForbiddenScope scope(this);
     {
         ScriptForbiddenIfMainThreadScope scriptForbiddenScope;
 
         TRACE_EVENT0("blink_gc,devtools.timeline", "ThreadState::completeSweep");
         double startTime = WTF::currentTimeMS();
 
-        static_assert(BlinkGC::EagerSweepArenaIndex == 0, "Eagerly swept arenas must be processed first.");
+        static_assert(BlinkGC::EagerSweepArenaIndex == 0, "Eagerly swept heaps must be processed first.");
         for (int i = 0; i < BlinkGC::NumberOfArenas; i++)
             m_arenas[i]->completeSweep();
 
         double timeForCompleteSweep = WTF::currentTimeMS() - startTime;
         accumulateSweepingTime(timeForCompleteSweep);
 
         if (isMainThread()) {
             DEFINE_STATIC_LOCAL(CustomCountHistogram, completeSweepHistogram, ("BlinkGC.CompleteSweep", 1, 10 * 1000, 50));
             completeSweepHistogram.count(timeForCompleteSweep);
         }
     }
 
     postSweep();
 }
 
 void ThreadState::postSweep()
 {
     ASSERT(checkThread());
-    Heap::reportMemoryUsageForTracing();
+    ThreadHeap::reportMemoryUsageForTracing();
 
     if (isMainThread()) {
         double collectionRate = 0;
-        if (Heap::objectSizeAtLastGC() > 0)
-            collectionRate = 1 - 1.0 * Heap::markedObjectSize() / Heap::objectSizeAtLastGC();
+        if (m_heap->heapStats().objectSizeAtLastGC() > 0)
+            collectionRate = 1 - 1.0 * m_heap->heapStats().markedObjectSize() / m_heap->heapStats().objectSizeAtLastGC();
         TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("blink_gc"), "ThreadState::collectionRate", static_cast<int>(100 * collectionRate));
 
 #if PRINT_HEAP_STATS
         dataLogF("ThreadState::postSweep (collectionRate=%d%%)\n", static_cast<int>(100 * collectionRate));
 #endif
 
-        // Heap::markedObjectSize() may be underestimated here if any other
+        // ThreadHeap::markedObjectSize() may be underestimated here if any other
         // thread has not yet finished lazy sweeping.
-        Heap::setMarkedObjectSizeAtLastCompleteSweep(Heap::markedObjectSize());
+        m_heap->heapStats().setMarkedObjectSizeAtLastCompleteSweep(m_heap->heapStats().markedObjectSize());
 
         DEFINE_STATIC_LOCAL(CustomCountHistogram, objectSizeBeforeGCHistogram, ("BlinkGC.ObjectSizeBeforeGC", 1, 4 * 1024 * 1024, 50));
-        objectSizeBeforeGCHistogram.count(Heap::objectSizeAtLastGC() / 1024);
+        objectSizeBeforeGCHistogram.count(m_heap->heapStats().objectSizeAtLastGC() / 1024);
         DEFINE_STATIC_LOCAL(CustomCountHistogram, objectSizeAfterGCHistogram, ("BlinkGC.ObjectSizeAfterGC", 1, 4 * 1024 * 1024, 50));
-        objectSizeAfterGCHistogram.count(Heap::markedObjectSize() / 1024);
+        objectSizeAfterGCHistogram.count(m_heap->heapStats().markedObjectSize() / 1024);
         DEFINE_STATIC_LOCAL(CustomCountHistogram, collectionRateHistogram, ("BlinkGC.CollectionRate", 1, 100, 20));
         collectionRateHistogram.count(static_cast<int>(100 * collectionRate));
         DEFINE_STATIC_LOCAL(CustomCountHistogram, timeForSweepHistogram, ("BlinkGC.TimeForSweepingAllObjects", 1, 10 * 1000, 50));
         timeForSweepHistogram.count(m_accumulatedSweepingTime);
 
 
 #define COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(GCReason)                \
     case BlinkGC::GCReason: {                                                 \
         DEFINE_STATIC_LOCAL(CustomCountHistogram, histogram,                  \
             ("BlinkGC.CollectionRate_" #GCReason, 1, 100, 20));             \
         histogram.count(static_cast<int>(100 * collectionRate));              \
         break;                                                                \
     }
 
-        switch (Heap::lastGCReason()) {
+        switch (m_heap->lastGCReason()) {
             COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(IdleGC)
             COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(PreciseGC)
             COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(ConservativeGC)
             COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(ForcedGC)
             COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(MemoryPressureGC)
             COUNT_COLLECTION_RATE_HISTOGRAM_BY_GC_REASON(PageNavigationGC)
         default:
             break;
         }
     }
@@ skipping 33 matching lines @@
 #endif
 
 size_t ThreadState::objectPayloadSizeForTesting()
 {
     size_t objectPayloadSize = 0;
     for (int i = 0; i < BlinkGC::NumberOfArenas; ++i)
         objectPayloadSize += m_arenas[i]->objectPayloadSizeForTesting();
     return objectPayloadSize;
 }
 
-bool ThreadState::stopThreads()
-{
-    return s_safePointBarrier->parkOthers();
-}
-
-void ThreadState::resumeThreads()
-{
-    s_safePointBarrier->resumeOthers();
-}
-
 void ThreadState::safePoint(BlinkGC::StackState stackState)
 {
     ASSERT(checkThread());
-    Heap::reportMemoryUsageForTracing();
+    ThreadHeap::reportMemoryUsageForTracing();
 
     runScheduledGC(stackState);
     ASSERT(!m_atSafePoint);
     m_stackState = stackState;
     m_atSafePoint = true;
-    s_safePointBarrier->checkAndPark(this);
+    m_heap->checkAndPark(this, nullptr);
     m_atSafePoint = false;
     m_stackState = BlinkGC::HeapPointersOnStack;
     preSweep();
 }
 
 #ifdef ADDRESS_SANITIZER
 // When we are running under AddressSanitizer with detect_stack_use_after_return=1
 // then stack marker obtained from SafePointScope will point into a fake stack.
 // Detect this case by checking if it falls in between current stack frame
 // and stack start and use an arbitrary high enough value for it.
@@ skipping 23 matching lines @@
 #ifdef ADDRESS_SANITIZER
     if (stackState == BlinkGC::HeapPointersOnStack)
         scopeMarker = adjustScopeMarkerForAdressSanitizer(scopeMarker);
 #endif
     ASSERT(stackState == BlinkGC::NoHeapPointersOnStack || scopeMarker);
     runScheduledGC(stackState);
     ASSERT(!m_atSafePoint);
     m_atSafePoint = true;
     m_stackState = stackState;
     m_safePointScopeMarker = scopeMarker;
-    s_safePointBarrier->enterSafePoint(this);
+    m_heap->enterSafePoint(this);
 }
 
 void ThreadState::leaveSafePoint(SafePointAwareMutexLocker* locker)
 {
     ASSERT(checkThread());
     ASSERT(m_atSafePoint);
-    s_safePointBarrier->leaveSafePoint(this, locker);
+    m_heap->leaveSafePoint(this, locker);
     m_atSafePoint = false;
     m_stackState = BlinkGC::HeapPointersOnStack;
     clearSafePointScopeMarker();
     preSweep();
 }
 
 void ThreadState::reportMemoryToV8()
 {
     if (!m_isolate)
         return;
 
     size_t currentHeapSize = m_allocatedObjectSize + m_markedObjectSize;
     int64_t diff = static_cast<int64_t>(currentHeapSize) - static_cast<int64_t>(m_reportedMemoryToV8);
     m_isolate->AdjustAmountOfExternalAllocatedMemory(diff);
     m_reportedMemoryToV8 = currentHeapSize;
 }
 
 void ThreadState::resetHeapCounters()
 {
     m_allocatedObjectSize = 0;
     m_markedObjectSize = 0;
 }
 
 void ThreadState::increaseAllocatedObjectSize(size_t delta)
 {
     m_allocatedObjectSize += delta;
-    Heap::increaseAllocatedObjectSize(delta);
+    m_heap->heapStats().increaseAllocatedObjectSize(delta);
 }
 
 void ThreadState::decreaseAllocatedObjectSize(size_t delta)
 {
     m_allocatedObjectSize -= delta;
-    Heap::decreaseAllocatedObjectSize(delta);
+    m_heap->heapStats().decreaseAllocatedObjectSize(delta);
 }
 
 void ThreadState::increaseMarkedObjectSize(size_t delta)
 {
     m_markedObjectSize += delta;
-    Heap::increaseMarkedObjectSize(delta);
+    m_heap->heapStats().increaseMarkedObjectSize(delta);
 }
 
 void ThreadState::copyStackUntilSafePointScope()
 {
     if (!m_safePointScopeMarker || m_stackState == BlinkGC::NoHeapPointersOnStack)
         return;
 
     Address* to = reinterpret_cast<Address*>(m_safePointScopeMarker);
     Address* from = reinterpret_cast<Address*>(m_endOfStack);
     RELEASE_ASSERT(from < to);
@@ skipping 13 matching lines @@
     for (size_t i = 0; i < slotCount; ++i) {
         m_safePointStackCopy[i] = from[i];
     }
 }
 
 void ThreadState::addInterruptor(PassOwnPtr<BlinkGCInterruptor> interruptor)
 {
     ASSERT(checkThread());
     SafePointScope scope(BlinkGC::HeapPointersOnStack);
     {
-        MutexLocker locker(threadAttachMutex());
+        MutexLocker locker(m_heap->threadAttachMutex());
         m_interruptors.append(interruptor);
     }
 }
 
 #if defined(LEAK_SANITIZER)
 void ThreadState::registerStaticPersistentNode(PersistentNode* node)
 {
     if (m_disabledStaticPersistentsRegistration)
         return;
 
@@ skipping 14 matching lines @@
     m_disabledStaticPersistentsRegistration++;
 }
 
 void ThreadState::leaveStaticReferenceRegistrationDisabledScope()
 {
     ASSERT(m_disabledStaticPersistentsRegistration);
     m_disabledStaticPersistentsRegistration--;
 }
 #endif
 
-ThreadState::AttachedThreadStateSet& ThreadState::attachedThreads()
-{
-    DEFINE_STATIC_LOCAL(AttachedThreadStateSet, threads, ());
-    return threads;
-}
-
 void ThreadState::lockThreadAttachMutex()
 {
-    threadAttachMutex().lock();
+    m_heap->threadAttachMutex().lock();
 }
 
 void ThreadState::unlockThreadAttachMutex()
 {
-    threadAttachMutex().unlock();
+    m_heap->threadAttachMutex().unlock();
 }
 
 void ThreadState::invokePreFinalizers()
 {
     ASSERT(checkThread());
     ASSERT(!sweepForbidden());
     TRACE_EVENT0("blink_gc", "ThreadState::invokePreFinalizers");
 
     double startTime = WTF::currentTimeMS();
     if (!m_orderedPreFinalizers.isEmpty()) {
@@ skipping 135 matching lines @@
     threadDump->addScalar("dead_count", "objects", totalDeadCount);
     threadDump->addScalar("live_size", "bytes", totalLiveSize);
     threadDump->addScalar("dead_size", "bytes", totalDeadSize);
 
     WebMemoryAllocatorDump* heapsDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(heapsDumpName);
     WebMemoryAllocatorDump* classesDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForCurrentGC(classesDumpName);
     BlinkGCMemoryDumpProvider::instance()->currentProcessMemoryDump()->addOwnershipEdge(classesDump->guid(), heapsDump->guid());
 }
 
 } // namespace blink