/* * Copyright (C) 2016 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. */ #include "config.h" #include "GenericTaskQueue.h" #include <wtf/MainThread.h> #include <wtf/NeverDestroyed.h> namespace WebCore { TaskDispatcher<Timer>::TaskDispatcher() { } void TaskDispatcher<Timer>::postTask(Function<void()>&& function) { m_pendingTasks.append(WTFMove(function)); pendingDispatchers().append(m_weakPtrFactory.createWeakPtr(*this)); if (!sharedTimer().isActive()) sharedTimer().startOneShot(0_s); } Timer& TaskDispatcher<Timer>::sharedTimer() { ASSERT(isMainThread()); static NeverDestroyed<Timer> timer([] { TaskDispatcher<Timer>::sharedTimerFired(); }); return timer.get(); } void TaskDispatcher<Timer>::sharedTimerFired() { ASSERT(!sharedTimer().isActive()); ASSERT(!pendingDispatchers().isEmpty()); // Copy the pending events first because we don't want to process synchronously the new events // queued by the JS events handlers that are executed in the loop below. Deque<WeakPtr<TaskDispatcher<Timer>>> queuedDispatchers = WTFMove(pendingDispatchers()); while (!queuedDispatchers.isEmpty()) { WeakPtr<TaskDispatcher<Timer>> dispatcher = queuedDispatchers.takeFirst(); if (!dispatcher) continue; dispatcher->dispatchOneTask(); } } Deque<WeakPtr<TaskDispatcher<Timer>>>& TaskDispatcher<Timer>::pendingDispatchers() { ASSERT(isMainThread()); static NeverDestroyed<Deque<WeakPtr<TaskDispatcher<Timer>>>> dispatchers; return dispatchers.get(); } void TaskDispatcher<Timer>::dispatchOneTask() { ASSERT(!m_pendingTasks.isEmpty()); auto task = m_pendingTasks.takeFirst(); task(); } }