blob: 2cccf0b22c077421701b1c6f1669f290af9ddb24 [file] [log] [blame]
/*
* Copyright (C) 2014 Yoav Weiss (yoav@yoav.ws)
* Copyright (C) 2015 Akamai Technologies Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "Microtasks.h"
#include "WorkerGlobalScope.h"
#include <wtf/MainThread.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/SetForScope.h>
namespace WebCore {
void Microtask::removeSelfFromQueue(MicrotaskQueue& queue)
{
queue.remove(*this);
}
MicrotaskQueue::MicrotaskQueue()
: m_timer(*this, &MicrotaskQueue::timerFired)
{
}
MicrotaskQueue::~MicrotaskQueue() = default;
MicrotaskQueue& MicrotaskQueue::mainThreadQueue()
{
ASSERT(isMainThread());
static NeverDestroyed<MicrotaskQueue> queue;
return queue;
}
MicrotaskQueue& MicrotaskQueue::contextQueue(ScriptExecutionContext& context)
{
// While main thread has many ScriptExecutionContexts, WorkerGlobalScope and worker thread have
// one on one correspondence. The lifetime of MicrotaskQueue is aligned to this semantics.
// While main thread MicrotaskQueue is persistently held, worker's MicrotaskQueue is held by
// WorkerGlobalScope.
if (isMainThread())
return mainThreadQueue();
return downcast<WorkerGlobalScope>(context).microtaskQueue();
}
void MicrotaskQueue::append(std::unique_ptr<Microtask>&& task)
{
m_microtaskQueue.append(WTFMove(task));
m_timer.startOneShot(0_s);
}
void MicrotaskQueue::remove(const Microtask& task)
{
for (size_t i = 0; i < m_microtaskQueue.size(); ++i) {
if (m_microtaskQueue[i].get() == &task) {
m_microtaskQueue.remove(i);
return;
}
}
}
void MicrotaskQueue::timerFired()
{
performMicrotaskCheckpoint();
}
void MicrotaskQueue::performMicrotaskCheckpoint()
{
if (m_performingMicrotaskCheckpoint)
return;
SetForScope<bool> change(m_performingMicrotaskCheckpoint, true);
Vector<std::unique_ptr<Microtask>> toKeep;
while (!m_microtaskQueue.isEmpty()) {
Vector<std::unique_ptr<Microtask>> queue = WTFMove(m_microtaskQueue);
for (auto& task : queue) {
auto result = task->run();
switch (result) {
case Microtask::Result::Done:
break;
case Microtask::Result::KeepInQueue:
toKeep.append(WTFMove(task));
break;
}
}
}
m_microtaskQueue = WTFMove(toKeep);
}
} // namespace WebCore