249 lines
7.7 KiB
C++
249 lines
7.7 KiB
C++
/*
|
|
* Copyright (C) 2016-2020 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.
|
|
*/
|
|
|
|
#include "config.h"
|
|
#include <wtf/AutomaticThread.h>
|
|
|
|
#include <wtf/DataLog.h>
|
|
#include <wtf/Threading.h>
|
|
|
|
namespace WTF {
|
|
|
|
static constexpr bool verbose = false;
|
|
|
|
Ref<AutomaticThreadCondition> AutomaticThreadCondition::create()
|
|
{
|
|
return adoptRef(*new AutomaticThreadCondition);
|
|
}
|
|
|
|
AutomaticThreadCondition::AutomaticThreadCondition()
|
|
{
|
|
}
|
|
|
|
AutomaticThreadCondition::~AutomaticThreadCondition()
|
|
{
|
|
}
|
|
|
|
void AutomaticThreadCondition::notifyOne(const AbstractLocker& locker)
|
|
{
|
|
for (AutomaticThread* thread : m_threads) {
|
|
if (thread->isWaiting(locker)) {
|
|
thread->notify(locker);
|
|
return;
|
|
}
|
|
}
|
|
|
|
for (AutomaticThread* thread : m_threads) {
|
|
if (!thread->hasUnderlyingThread(locker)) {
|
|
thread->start(locker);
|
|
return;
|
|
}
|
|
}
|
|
|
|
m_condition.notifyOne();
|
|
}
|
|
|
|
void AutomaticThreadCondition::notifyAll(const AbstractLocker& locker)
|
|
{
|
|
m_condition.notifyAll();
|
|
|
|
for (AutomaticThread* thread : m_threads) {
|
|
if (thread->isWaiting(locker))
|
|
thread->notify(locker);
|
|
else if (!thread->hasUnderlyingThread(locker))
|
|
thread->start(locker);
|
|
}
|
|
}
|
|
|
|
void AutomaticThreadCondition::wait(Lock& lock)
|
|
{
|
|
m_condition.wait(lock);
|
|
}
|
|
|
|
bool AutomaticThreadCondition::waitFor(Lock& lock, Seconds time)
|
|
{
|
|
return m_condition.waitFor(lock, time);
|
|
}
|
|
|
|
void AutomaticThreadCondition::add(const AbstractLocker&, AutomaticThread* thread)
|
|
{
|
|
ASSERT(!m_threads.contains(thread));
|
|
m_threads.append(thread);
|
|
}
|
|
|
|
void AutomaticThreadCondition::remove(const AbstractLocker&, AutomaticThread* thread)
|
|
{
|
|
m_threads.removeFirst(thread);
|
|
ASSERT(!m_threads.contains(thread));
|
|
}
|
|
|
|
bool AutomaticThreadCondition::contains(const AbstractLocker&, AutomaticThread* thread)
|
|
{
|
|
return m_threads.contains(thread);
|
|
}
|
|
|
|
AutomaticThread::AutomaticThread(const AbstractLocker& locker, Box<Lock> lock, Ref<AutomaticThreadCondition>&& condition, Seconds timeout)
|
|
: AutomaticThread(locker, lock, WTFMove(condition), ThreadType::Unknown, timeout)
|
|
{
|
|
}
|
|
|
|
AutomaticThread::AutomaticThread(const AbstractLocker& locker, Box<Lock> lock, Ref<AutomaticThreadCondition>&& condition, ThreadType type, Seconds timeout)
|
|
: m_lock(lock)
|
|
, m_condition(WTFMove(condition))
|
|
, m_timeout(timeout)
|
|
, m_threadType(type)
|
|
{
|
|
if (verbose)
|
|
dataLog(RawPointer(this), ": Allocated AutomaticThread.\n");
|
|
m_condition->add(locker, this);
|
|
}
|
|
|
|
AutomaticThread::~AutomaticThread()
|
|
{
|
|
if (verbose)
|
|
dataLog(RawPointer(this), ": Deleting AutomaticThread.\n");
|
|
Locker locker { *m_lock };
|
|
|
|
// It's possible that we're in a waiting state with the thread shut down. This is a goofy way to
|
|
// die, but it could happen.
|
|
m_condition->remove(locker, this);
|
|
}
|
|
|
|
bool AutomaticThread::tryStop(const AbstractLocker&)
|
|
{
|
|
if (!m_isRunning)
|
|
return true;
|
|
if (m_hasUnderlyingThread)
|
|
return false;
|
|
m_isRunning = false;
|
|
return true;
|
|
}
|
|
|
|
bool AutomaticThread::isWaiting(const AbstractLocker& locker)
|
|
{
|
|
return hasUnderlyingThread(locker) && m_isWaiting;
|
|
}
|
|
|
|
bool AutomaticThread::notify(const AbstractLocker& locker)
|
|
{
|
|
ASSERT_UNUSED(locker, hasUnderlyingThread(locker));
|
|
m_isWaiting = false;
|
|
return m_waitCondition.notifyOne();
|
|
}
|
|
|
|
void AutomaticThread::join()
|
|
{
|
|
Locker locker { *m_lock };
|
|
while (m_isRunning)
|
|
m_isRunningCondition.wait(*m_lock);
|
|
}
|
|
|
|
void AutomaticThread::start(const AbstractLocker&)
|
|
{
|
|
RELEASE_ASSERT(m_isRunning);
|
|
|
|
RefPtr<AutomaticThread> preserveThisForThread = this;
|
|
|
|
m_hasUnderlyingThread = true;
|
|
|
|
Thread::create(
|
|
name(),
|
|
[=] () {
|
|
if (verbose)
|
|
dataLog(RawPointer(this), ": Running automatic thread!\n");
|
|
|
|
RefPtr<AutomaticThread> thread = preserveThisForThread;
|
|
thread->threadDidStart();
|
|
|
|
if (ASSERT_ENABLED) {
|
|
Locker locker { *m_lock };
|
|
ASSERT(m_condition->contains(locker, this));
|
|
}
|
|
|
|
auto stopImpl = [&] (const AbstractLocker& locker) {
|
|
thread->threadIsStopping(locker);
|
|
thread->m_hasUnderlyingThread = false;
|
|
};
|
|
|
|
auto stopPermanently = [&] (const AbstractLocker& locker) {
|
|
m_isRunning = false;
|
|
m_isRunningCondition.notifyAll();
|
|
stopImpl(locker);
|
|
};
|
|
|
|
auto stopForTimeout = [&] (const AbstractLocker& locker) {
|
|
stopImpl(locker);
|
|
};
|
|
|
|
for (;;) {
|
|
{
|
|
Locker locker { *m_lock };
|
|
for (;;) {
|
|
PollResult result = poll(locker);
|
|
if (result == PollResult::Work)
|
|
break;
|
|
if (result == PollResult::Stop)
|
|
return stopPermanently(locker);
|
|
RELEASE_ASSERT(result == PollResult::Wait);
|
|
|
|
// Shut the thread down after a timeout.
|
|
m_isWaiting = true;
|
|
bool awokenByNotify =
|
|
m_waitCondition.waitFor(*m_lock, m_timeout);
|
|
if (verbose && !awokenByNotify && !m_isWaiting)
|
|
dataLog(RawPointer(this), ": waitFor timed out, but notified via m_isWaiting flag!\n");
|
|
if (m_isWaiting && shouldSleep(locker)) {
|
|
m_isWaiting = false;
|
|
if (verbose)
|
|
dataLog(RawPointer(this), ": Going to sleep!\n");
|
|
// It's important that we don't release the lock until we have completely
|
|
// indicated that the thread is kaput. Otherwise we'll have a a notify
|
|
// race that manifests as a deadlock on VM shutdown.
|
|
return stopForTimeout(locker);
|
|
}
|
|
}
|
|
}
|
|
|
|
WorkResult result = work();
|
|
if (result == WorkResult::Stop) {
|
|
Locker locker { *m_lock };
|
|
return stopPermanently(locker);
|
|
}
|
|
RELEASE_ASSERT(result == WorkResult::Continue);
|
|
}
|
|
}, m_threadType)->detach();
|
|
}
|
|
|
|
void AutomaticThread::threadDidStart()
|
|
{
|
|
}
|
|
|
|
void AutomaticThread::threadIsStopping(const AbstractLocker&)
|
|
{
|
|
}
|
|
|
|
} // namespace WTF
|
|
|