C++ CopiedBlock::isOld方法代码示例

CheckedBoolean CopiedSpace::tryReallocateOversize(void** ptr, size_t oldSize, size_t newSize)
{
    ASSERT(isOversize(oldSize) || isOversize(newSize));
    ASSERT(newSize > oldSize);

    void* oldPtr = *ptr;
    
    void* newPtr = 0;
    if (!tryAllocateOversize(newSize, &newPtr)) {
        *ptr = 0;
        return false;
    }

    memcpy(newPtr, oldPtr, oldSize);

    CopiedBlock* oldBlock = CopiedSpace::blockFor(oldPtr);
    if (oldBlock->isOversize()) {
        if (oldBlock->isOld())
            m_oldGen.oversizeBlocks.remove(oldBlock);
        else
            m_newGen.oversizeBlocks.remove(oldBlock);
        m_blockSet.remove(oldBlock);
        m_heap->blockAllocator().deallocateCustomSize(CopiedBlock::destroy(oldBlock));
    }
    
    *ptr = newPtr;
    return true;
}

CheckedBoolean CopiedSpace::tryReallocateOversize(void** ptr, size_t oldSize, size_t newSize)
{
    ASSERT(isOversize(oldSize) || isOversize(newSize));
    ASSERT(newSize > oldSize);

    void* oldPtr = *ptr;
    
    void* newPtr = 0;
    if (!tryAllocateOversize(newSize, &newPtr)) {
        *ptr = 0;
        return false;
    }

    memcpy(newPtr, oldPtr, oldSize);

    CopiedBlock* oldBlock = CopiedSpace::blockFor(oldPtr);
    if (oldBlock->isOversize()) {
        // FIXME: Eagerly deallocating the old space block probably buys more confusion than
        // value.
        // https://bugs.webkit.org/show_bug.cgi?id=144750
        if (oldBlock->isOld()) {
            m_bytesRemovedFromOldSpaceDueToReallocation += oldBlock->size();
            m_oldGen.oversizeBlocks.remove(oldBlock);
        } else
            m_newGen.oversizeBlocks.remove(oldBlock);
        m_blockSet.remove(oldBlock);
        CopiedBlock::destroy(*heap(), oldBlock);
    }
    
    *ptr = newPtr;
    return true;
}

void SlotVisitor::copyLater(JSCell* owner, CopyToken token, void* ptr, size_t bytes)
{
    ASSERT(bytes);
    CopiedBlock* block = CopiedSpace::blockFor(ptr);
    if (block->isOversize()) {
        ASSERT(bytes <= block->size());
        // FIXME: We should be able to shrink the allocation if bytes went below the block size.
        // For now, we just make sure that our accounting of how much memory we are actually using
        // is correct.
        // https://bugs.webkit.org/show_bug.cgi?id=144749
        bytes = block->size();
        m_heap.m_storageSpace.pin(block);
    }

    ASSERT(heap()->m_storageSpace.contains(block));

    LockHolder locker(&block->workListLock());
    // We always report live bytes, except if during an eden collection we see an old object pointing to an
    // old backing store and the old object is being marked because of the remembered set. Note that if we
    // ask the object itself, it will always tell us that it's an old black object - because even during an
    // eden collection we have already indicated that the object is old. That's why we use the
    // SlotVisitor's cache of the object's old state.
    if (heap()->operationInProgress() == FullCollection
        || !block->isOld()
        || m_currentObjectCellStateBeforeVisiting != CellState::OldGrey) {
        m_bytesCopied += bytes;
        block->reportLiveBytes(locker, owner, token, bytes);
    }
}

CheckedBoolean CopiedSpace::tryAllocateOversize(size_t bytes, void** outPtr)
{
    ASSERT(isOversize(bytes));
    
    CopiedBlock* block = CopiedBlock::create(m_heap->blockAllocator().allocateCustomSize(sizeof(CopiedBlock) + bytes, CopiedBlock::blockSize));
    m_newGen.oversizeBlocks.push(block);
    m_newGen.blockFilter.add(reinterpret_cast<Bits>(block));
    m_blockSet.add(block);
    ASSERT(!block->isOld());
    
    CopiedAllocator allocator;
    allocator.setCurrentBlock(block);
    *outPtr = allocator.forceAllocate(bytes);
    allocator.resetCurrentBlock();

    m_heap->didAllocate(block->region()->blockSize());

    return true;
}

CheckedBoolean CopiedSpace::tryAllocateOversize(size_t bytes, void** outPtr)
{
    ASSERT(isOversize(bytes));
    
    CopiedBlock* block = CopiedBlock::create(*m_heap, WTF::roundUpToMultipleOf<sizeof(double)>(sizeof(CopiedBlock) + bytes));
    m_newGen.oversizeBlocks.push(block);
    m_newGen.blockFilter.add(reinterpret_cast<Bits>(block));
    m_blockSet.add(block);
    ASSERT(!block->isOld());
    
    CopiedAllocator allocator;
    allocator.setCurrentBlock(block);
    *outPtr = allocator.forceAllocate(bytes);
    allocator.resetCurrentBlock();

    m_heap->didAllocate(block->capacity());

    return true;
}