Sync remaining allocation size on in-place backing store recycling.

third_party/WebKit/Source/platform/heap/HeapPage.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 553 matching lines @@
     size_t size = header->size();
     size_t payloadSize = header->payloadSize();
     ASSERT(size > 0);
     ASSERT(pageFromObject(address) == findPageFromAddress(address));
 
     {
         ThreadState::SweepForbiddenScope forbiddenScope(threadState());
         header->finalize(payload, payloadSize);
         if (address + size == m_currentAllocationPoint) {
             m_currentAllocationPoint = address;
-            m_remainingAllocationSize += size;
-            // Sync recorded allocated-object size:
-            //  - if previous alloc checkpoint is larger, allocation size has increased.
-            //  - if smaller, a net reduction in size since last call to updateRemainingAllocationSize().
-            if (m_lastRemainingAllocationSize > m_remainingAllocationSize)
-                Heap::increaseAllocatedObjectSize(m_lastRemainingAllocationSize - m_remainingAllocationSize);
-            else if (m_lastRemainingAllocationSize != m_remainingAllocationSize)
-                Heap::decreaseAllocatedObjectSize(m_remainingAllocationSize - m_lastRemainingAllocationSize);
-            m_lastRemainingAllocationSize = m_remainingAllocationSize;
+            setRemainingAllocationSize(m_remainingAllocationSize + size);
             SET_MEMORY_INACCESSIBLE(address, size);
             return;
         }
         SET_MEMORY_INACCESSIBLE(payload, payloadSize);
         header->markPromptlyFreed();
     }
 
     m_promptlyFreedSize += size;
 }
 
 bool NormalPageHeap::expandObject(HeapObjectHeader* header, size_t newSize)
 {
     // It's possible that Vector requests a smaller expanded size because
     // Vector::shrinkCapacity can set a capacity smaller than the actual payload
     // size.
     ASSERT(header->checkHeader());
     if (header->payloadSize() >= newSize)
         return true;
     size_t allocationSize = Heap::allocationSizeFromSize(newSize);
     ASSERT(allocationSize > header->size());
     size_t expandSize = allocationSize - header->size();
     if (isObjectAllocatedAtAllocationPoint(header) && expandSize <= m_remainingAllocationSize) {
         m_currentAllocationPoint += expandSize;
-        m_remainingAllocationSize -= expandSize;
-
+        ASSERT(m_remainingAllocationSize >= expandSize);
+        setRemainingAllocationSize(m_remainingAllocationSize - expandSize);
         // Unpoison the memory used for the object (payload).
         SET_MEMORY_ACCESSIBLE(header->payloadEnd(), expandSize);
         header->setSize(allocationSize);
         ASSERT(findPageFromAddress(header->payloadEnd() - 1));
         return true;
     }
     return false;
 }
 
 bool NormalPageHeap::shrinkObject(HeapObjectHeader* header, size_t newSize)
 {
     ASSERT(header->checkHeader());
     ASSERT(header->payloadSize() > newSize);
     size_t allocationSize = Heap::allocationSizeFromSize(newSize);
     ASSERT(header->size() > allocationSize);
     size_t shrinkSize = header->size() - allocationSize;
     if (isObjectAllocatedAtAllocationPoint(header)) {
         m_currentAllocationPoint -= shrinkSize;
-        m_remainingAllocationSize += shrinkSize;
+        setRemainingAllocationSize(m_remainingAllocationSize + shrinkSize);
         SET_MEMORY_INACCESSIBLE(m_currentAllocationPoint, shrinkSize);
         header->setSize(allocationSize);
         return true;
     }
     ASSERT(shrinkSize >= sizeof(HeapObjectHeader));
     ASSERT(header->gcInfoIndex() > 0);
     Address shrinkAddress = header->payloadEnd() - shrinkSize;
     HeapObjectHeader* freedHeader = new (NotNull, shrinkAddress) HeapObjectHeader(shrinkSize, header->gcInfoIndex());
     freedHeader->markPromptlyFreed();
     ASSERT(pageFromObject(reinterpret_cast<Address>(header)) == findPageFromAddress(reinterpret_cast<Address>(header)));
@@ skipping 23 matching lines @@
             // For NormalPage, stop lazy sweeping once we find a slot to
             // allocate a new object.
             result = allocateFromFreeList(allocationSize, gcInfoIndex);
             if (result)
                 break;
         }
     }
     return result;
 }
 
+void NormalPageHeap::setRemainingAllocationSize(size_t newRemainingAllocationSize)
+{
+    m_remainingAllocationSize = newRemainingAllocationSize;
+
+    // Sync recorded allocated-object size:
+    //  - if previous alloc checkpoint is larger, allocation size has increased.
+    //  - if smaller, a net reduction in size since last call to updateRemainingAllocationSize().
+    if (m_lastRemainingAllocationSize > m_remainingAllocationSize)
+        Heap::increaseAllocatedObjectSize(m_lastRemainingAllocationSize - m_remainingAllocationSize);
+    else if (m_lastRemainingAllocationSize != m_remainingAllocationSize)
+        Heap::decreaseAllocatedObjectSize(m_remainingAllocationSize - m_lastRemainingAllocationSize);
+    m_lastRemainingAllocationSize = m_remainingAllocationSize;
+}
+
 void NormalPageHeap::updateRemainingAllocationSize()
 {
     if (m_lastRemainingAllocationSize > remainingAllocationSize()) {
         Heap::increaseAllocatedObjectSize(m_lastRemainingAllocationSize - remainingAllocationSize());
         m_lastRemainingAllocationSize = remainingAllocationSize();
     }
     ASSERT(m_lastRemainingAllocationSize == remainingAllocationSize());
 }
 
 void NormalPageHeap::setAllocationPoint(Address point, size_t size)
@@ skipping 898 matching lines @@
 
     m_hasEntries = true;
     size_t index = hash(address);
     ASSERT(!(index & 1));
     Address cachePage = roundToBlinkPageStart(address);
     m_entries[index + 1] = m_entries[index];
     m_entries[index] = cachePage;
 }
 
 } // namespace blink