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/*
* Copyright (C) 2020 Apple 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:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "SharedDisplayListHandle.h"
#include <wtf/FastMalloc.h>
namespace WebKit {
class DisplayListWriterHandle : public SharedDisplayListHandle {
WTF_MAKE_NONCOPYABLE(DisplayListWriterHandle); WTF_MAKE_FAST_ALLOCATED;
public:
static RefPtr<DisplayListWriterHandle> create(WebCore::DisplayList::ItemBufferIdentifier identifier, Ref<SharedMemory>&& sharedMemory)
{
if (sharedMemory->size() <= headerSize())
return nullptr;
return adoptRef(new DisplayListWriterHandle(identifier, WTFMove(sharedMemory)));
}
size_t writableOffset() const { return m_writableOffset; }
size_t availableCapacity() const;
bool moveWritableOffsetToStartIfPossible();
size_t advance(size_t amount);
WebCore::DisplayList::ItemBufferHandle createHandle() const;
bool tryToResume(SharedDisplayListHandle::ResumeReadingInformation&& info)
{
auto& header = this->header();
header.resumeReadingInfo = WTFMove(info);
return header.waitingStatus.compareExchangeWeak(
static_cast<SharedDisplayListHandle::WaitingStatusStorageType>(SharedDisplayListHandle::WaitingStatus::Waiting),
static_cast<SharedDisplayListHandle::WaitingStatusStorageType>(SharedDisplayListHandle::WaitingStatus::Resuming)
);
}
private:
DisplayListWriterHandle(WebCore::DisplayList::ItemBufferIdentifier identifier, Ref<SharedMemory>&& sharedMemory)
: SharedDisplayListHandle(identifier, WTFMove(sharedMemory))
, m_writableOffset(SharedDisplayListHandle::headerSize())
{
}
size_t m_writableOffset { 0 };
};
} // namespace WebKit
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