blob: 83c20751f85f4e4d201561441ca83141cb5c37ff [file] [log] [blame]
/*
* 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. 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 <wtf/CrossThreadTaskHandler.h>
#include <wtf/AutodrainedPool.h>
namespace WTF {
CrossThreadTaskHandler::CrossThreadTaskHandler(const char* threadName, AutodrainedPoolForRunLoop useAutodrainedPool)
: m_useAutodrainedPool(useAutodrainedPool)
{
ASSERT(isMainThread());
Locker<Lock> locker(m_taskThreadCreationLock);
Thread::create(threadName, [this] {
taskRunLoop();
})->detach();
}
CrossThreadTaskHandler::~CrossThreadTaskHandler()
{
ASSERT(isMainThread());
}
void CrossThreadTaskHandler::postTask(CrossThreadTask&& task)
{
m_taskQueue.append(WTFMove(task));
}
void CrossThreadTaskHandler::postTaskReply(CrossThreadTask&& task)
{
m_taskReplyQueue.append(WTFMove(task));
Locker<Lock> locker(m_mainThreadReplyLock);
if (m_mainThreadReplyScheduled)
return;
m_mainThreadReplyScheduled = true;
callOnMainThread([this] {
handleTaskRepliesOnMainThread();
});
}
void CrossThreadTaskHandler::taskRunLoop()
{
ASSERT(!isMainThread());
{
Locker<Lock> locker(m_taskThreadCreationLock);
}
while (!m_taskQueue.isKilled()) {
{
std::unique_ptr<AutodrainedPool> autodrainedPool = (m_useAutodrainedPool == AutodrainedPoolForRunLoop::Use) ? std::make_unique<AutodrainedPool>() : nullptr;
m_taskQueue.waitForMessage().performTask();
}
Locker<Lock> shouldSuspendLocker(m_shouldSuspendLock);
while (m_shouldSuspend) {
m_suspendedLock.lock();
if (!m_suspended) {
m_suspended = true;
m_suspendedCondition.notifyOne();
}
m_suspendedLock.unlock();
m_shouldSuspendCondition.wait(m_shouldSuspendLock);
}
}
}
void CrossThreadTaskHandler::handleTaskRepliesOnMainThread()
{
{
Locker<Lock> locker(m_mainThreadReplyLock);
m_mainThreadReplyScheduled = false;
}
while (auto task = m_taskReplyQueue.tryGetMessage())
task->performTask();
}
void CrossThreadTaskHandler::suspendAndWait()
{
ASSERT(isMainThread());
{
Locker<Lock> locker(m_shouldSuspendLock);
m_shouldSuspend = true;
}
// Post an empty task to ensure database thread knows m_shouldSuspend and sets m_suspended.
postTask(CrossThreadTask([]() { }));
Locker<Lock> locker(m_suspendedLock);
while (!m_suspended)
m_suspendedCondition.wait(m_suspendedLock);
}
void CrossThreadTaskHandler::resume()
{
ASSERT(isMainThread());
Locker<Lock> locker(m_shouldSuspendLock);
if (m_shouldSuspend) {
m_suspendedLock.lock();
if (m_suspended)
m_suspended = false;
m_suspendedLock.unlock();
m_shouldSuspend = false;
m_shouldSuspendCondition.notifyOne();
}
}
} // namespace WTF