Revert of [oilpan]: optimize the way we allocate persistent handles in wrappers.

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 77 matching lines @@
 #ifdef _WIN64
     return reinterpret_cast<void*>(__readgsqword(offsetof(NT_TIB64, StackBase)));
 #else
     return reinterpret_cast<void*>(__readfsdword(offsetof(NT_TIB, StackBase)));
 #endif
 #else
 #error Unsupported getStackStart on this platform.
 #endif
 }
 
-// The maximum number of WrapperPersistentRegions to keep around in the
-// m_pooledWrapperPersistentRegions pool.
-static const size_t MaxPooledWrapperPersistentRegionCount = 2;
 
 WTF::ThreadSpecific<ThreadState*>* ThreadState::s_threadSpecific = 0;
 uint8_t ThreadState::s_mainThreadStateStorage[sizeof(ThreadState)];
 SafePointBarrier* ThreadState::s_safePointBarrier = 0;
 bool ThreadState::s_inGC = false;
 
 static Mutex& threadAttachMutex()
 {
     AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex);
     return mutex;
@@ skipping 150 matching lines @@
         barrier->doEnterSafePoint(state, stackEnd);
     }
 
     volatile int m_canResume;
     volatile int m_unparkedThreadCount;
     Mutex m_mutex;
     ThreadCondition m_parked;
     ThreadCondition m_resume;
 };
 
+
 BaseHeapPage::BaseHeapPage(PageMemory* storage, const GCInfo* gcInfo, ThreadState* state)
     : m_storage(storage)
     , m_gcInfo(gcInfo)
     , m_threadState(state)
     , m_terminating(false)
     , m_tracedAfterOrphaned(false)
 {
     ASSERT(isPageHeaderAddress(reinterpret_cast<Address>(this)));
 }
 
 // Statically unfold the heap initialization loop so the compiler statically
 // knows the heap index when using HeapIndexTrait.
 template<int num> struct InitializeHeaps {
     static const int index = num - 1;
     static void init(BaseHeap** heaps, ThreadState* state)
     {
         InitializeHeaps<index>::init(heaps, state);
         heaps[index] = new typename HeapIndexTrait<index>::HeapType(state, index);
     }
 };
 template<> struct InitializeHeaps<0> {
     static void init(BaseHeap** heaps, ThreadState* state) { }
 };
 
 ThreadState::ThreadState()
     : m_thread(currentThread())
-    , m_liveWrapperPersistents(new WrapperPersistentRegion())
-    , m_pooledWrapperPersistents(0)
-    , m_pooledWrapperPersistentRegionCount(0)
     , m_persistents(adoptPtr(new PersistentAnchor()))
     , m_startOfStack(reinterpret_cast<intptr_t*>(getStackStart()))
     , m_endOfStack(reinterpret_cast<intptr_t*>(getStackStart()))
     , m_safePointScopeMarker(0)
     , m_atSafePoint(false)
     , m_interruptors()
     , m_gcRequested(false)
     , m_forcePreciseGCForTesting(false)
     , m_sweepRequested(0)
     , m_sweepInProgress(false)
@@ skipping 18 matching lines @@
         m_sweeperThread = adoptPtr(blink::Platform::current()->createThread("Blink GC Sweeper"));
 }
 
 ThreadState::~ThreadState()
 {
     checkThread();
     CallbackStack::shutdown(&m_weakCallbackStack);
     for (int i = 0; i < NumberOfHeaps; i++)
         delete m_heaps[i];
     deleteAllValues(m_interruptors);
-    while (m_liveWrapperPersistents) {
-        WrapperPersistentRegion* region = WrapperPersistentRegion::removeHead(&m_liveWrapperPersistents);
-        delete region;
-    }
-    while (m_pooledWrapperPersistents) {
-        WrapperPersistentRegion* region = WrapperPersistentRegion::removeHead(&m_pooledWrapperPersistents);
-        delete region;
-    }
     **s_threadSpecific = 0;
 }
 
 void ThreadState::init()
 {
     s_threadSpecific = new WTF::ThreadSpecific<ThreadState*>();
     s_safePointBarrier = new SafePointBarrier;
 }
 
 void ThreadState::shutdown()
@@ skipping 211 matching lines @@
         __msan_unpoison(&ptr, sizeof(ptr));
 #endif
         Heap::checkAndMarkPointer(visitor, ptr);
         visitAsanFakeStackForPointer(visitor, ptr);
     }
 }
 
 void ThreadState::visitPersistents(Visitor* visitor)
 {
     m_persistents->trace(visitor);
-    WrapperPersistentRegion::trace(m_liveWrapperPersistents, visitor);
 }
 
 bool ThreadState::checkAndMarkPointer(Visitor* visitor, Address address)
 {
     // If thread is terminating ignore conservative pointers.
     if (m_isTerminating)
         return false;
 
     // This checks for normal pages and for large objects which span the extent
     // of several normal pages.
@@ skipping 99 matching lines @@
 {
     CallbackStack::Item* slot = m_weakCallbackStack->allocateEntry(&m_weakCallbackStack);
     *slot = CallbackStack::Item(object, callback);
 }
 
 bool ThreadState::popAndInvokeWeakPointerCallback(Visitor* visitor)
 {
     return m_weakCallbackStack->popAndInvokeCallback<WeaknessProcessing>(&m_weakCallbackStack, visitor);
 }
 
-WrapperPersistentRegion* ThreadState::takeWrapperPersistentRegion()
-{
-    WrapperPersistentRegion* region;
-    if (m_pooledWrapperPersistentRegionCount) {
-        region = WrapperPersistentRegion::removeHead(&m_pooledWrapperPersistents);
-        m_pooledWrapperPersistentRegionCount--;
-    } else {
-        region = new WrapperPersistentRegion();
-    }
-    ASSERT(region);
-    WrapperPersistentRegion::insertHead(&m_liveWrapperPersistents, region);
-    return region;
-}
-
-void ThreadState::freeWrapperPersistentRegion(WrapperPersistentRegion* region)
-{
-    if (!region->removeIfNotLast(&m_liveWrapperPersistents))
-        return;
-
-    // Region was removed, ie. it was not the last region in the list.
-    if (m_pooledWrapperPersistentRegionCount < MaxPooledWrapperPersistentRegionCount) {
-        WrapperPersistentRegion::insertHead(&m_pooledWrapperPersistents, region);
-        m_pooledWrapperPersistentRegionCount++;
-    } else {
-        delete region;
-    }
-}
-
 PersistentNode* ThreadState::globalRoots()
 {
     AtomicallyInitializedStatic(PersistentNode*, anchor = new PersistentAnchor);
     return anchor;
 }
 
 Mutex& ThreadState::globalRootsMutex()
 {
     AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex);
     return mutex;
@@ skipping 505 matching lines @@
             return gcInfo;
         }
     }
     if (needLockForIteration)
         threadAttachMutex().unlock();
     return 0;
 }
 #endif
 
 }