darling-JavaScriptCore/heap/ParallelSourceAdapter.h

72 lines
2.6 KiB
C++

/*
* Copyright (C) 2017 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. ``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
* 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 <wtf/Lock.h>
#include <wtf/SharedTask.h>
namespace JSC {
template<typename OuterType, typename InnerType, typename UnwrapFunc>
class ParallelSourceAdapter final : public SharedTask<InnerType()> {
public:
ParallelSourceAdapter(RefPtr<SharedTask<OuterType()>> outerSource, const UnwrapFunc& unwrapFunc)
: m_outerSource(outerSource)
, m_unwrapFunc(unwrapFunc)
{
}
InnerType run() final
{
auto locker = holdLock(m_lock);
do {
if (m_innerSource) {
if (InnerType result = m_innerSource->run())
return result;
m_innerSource = nullptr;
}
m_innerSource = m_unwrapFunc(m_outerSource->run());
} while (m_innerSource);
return InnerType();
}
private:
RefPtr<SharedTask<OuterType()>> m_outerSource;
RefPtr<SharedTask<InnerType()>> m_innerSource;
UnwrapFunc m_unwrapFunc;
Lock m_lock;
};
template<typename OuterType, typename InnerType, typename UnwrapFunc>
Ref<ParallelSourceAdapter<OuterType, InnerType, UnwrapFunc>> createParallelSourceAdapter(RefPtr<SharedTask<OuterType()>> outerSource, const UnwrapFunc& unwrapFunc)
{
return adoptRef(*new ParallelSourceAdapter<OuterType, InnerType, UnwrapFunc>(outerSource, unwrapFunc));
}
} // namespace JSC