/* * Copyright (C) 2018 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 "GenericTaskQueue.h" namespace WebCore { template <typename T> class DeferrableTask : public CanMakeWeakPtr<DeferrableTask<T>> { public: DeferrableTask() : m_dispatcher() { } DeferrableTask(T& t) : m_dispatcher(&t) { } typedef WTF::Function<void ()> TaskFunction; void scheduleTask(TaskFunction&& task) { if (m_isClosed) return; cancelTask(); m_pendingTask = true; m_dispatcher.postTask([weakThis = makeWeakPtr(*this), task = WTFMove(task)] { if (!weakThis) return; ASSERT(weakThis->m_pendingTask); weakThis->m_pendingTask = false; task(); }); } void close() { cancelTask(); m_isClosed = true; } void cancelTask() { CanMakeWeakPtr<DeferrableTask<T>>::weakPtrFactory().revokeAll(); m_pendingTask = false; } bool hasPendingTask() const { return m_pendingTask; } private: TaskDispatcher<T> m_dispatcher; bool m_pendingTask { false }; bool m_isClosed { false }; }; }