Rocket.Chat.ReactNative/ios/Pods/Flipper-Folly/folly/executors/CPUThreadPoolExecutor.cpp

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/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <folly/executors/CPUThreadPoolExecutor.h>
#include <folly/Memory.h>
#include <folly/executors/task_queue/PriorityLifoSemMPMCQueue.h>
#include <folly/executors/task_queue/PriorityUnboundedBlockingQueue.h>
#include <folly/executors/task_queue/UnboundedBlockingQueue.h>
#include <folly/portability/GFlags.h>
DEFINE_bool(
dynamic_cputhreadpoolexecutor,
true,
"CPUThreadPoolExecutor will dynamically create and destroy threads");
namespace folly {
namespace {
// queue_alloc custom allocator is necessary until C++17
// http://open-std.org/JTC1/SC22/WG21/docs/papers/2012/n3396.htm
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65122
// https://bugs.llvm.org/show_bug.cgi?id=22634
using default_queue = UnboundedBlockingQueue<CPUThreadPoolExecutor::CPUTask>;
using default_queue_alloc =
AlignedSysAllocator<default_queue, FixedAlign<alignof(default_queue)>>;
constexpr folly::StringPiece executorName = "CPUThreadPoolExecutor";
} // namespace
const size_t CPUThreadPoolExecutor::kDefaultMaxQueueSize = 1 << 14;
CPUThreadPoolExecutor::CPUThreadPoolExecutor(
size_t numThreads,
std::unique_ptr<BlockingQueue<CPUTask>> taskQueue,
std::shared_ptr<ThreadFactory> threadFactory)
: ThreadPoolExecutor(
numThreads,
FLAGS_dynamic_cputhreadpoolexecutor ? 0 : numThreads,
std::move(threadFactory)),
taskQueue_(taskQueue.release()) {
setNumThreads(numThreads);
registerThreadPoolExecutor(this);
}
CPUThreadPoolExecutor::CPUThreadPoolExecutor(
std::pair<size_t, size_t> numThreads,
std::unique_ptr<BlockingQueue<CPUTask>> taskQueue,
std::shared_ptr<ThreadFactory> threadFactory)
: ThreadPoolExecutor(
numThreads.first,
numThreads.second,
std::move(threadFactory)),
taskQueue_(taskQueue.release()) {
setNumThreads(numThreads.first);
registerThreadPoolExecutor(this);
}
CPUThreadPoolExecutor::CPUThreadPoolExecutor(
size_t numThreads,
std::shared_ptr<ThreadFactory> threadFactory)
: ThreadPoolExecutor(
numThreads,
FLAGS_dynamic_cputhreadpoolexecutor ? 0 : numThreads,
std::move(threadFactory)),
taskQueue_(std::allocate_shared<default_queue>(default_queue_alloc{})) {
setNumThreads(numThreads);
registerThreadPoolExecutor(this);
}
CPUThreadPoolExecutor::CPUThreadPoolExecutor(
std::pair<size_t, size_t> numThreads,
std::shared_ptr<ThreadFactory> threadFactory)
: ThreadPoolExecutor(
numThreads.first,
numThreads.second,
std::move(threadFactory)),
taskQueue_(std::allocate_shared<default_queue>(default_queue_alloc{})) {
setNumThreads(numThreads.first);
registerThreadPoolExecutor(this);
}
CPUThreadPoolExecutor::CPUThreadPoolExecutor(size_t numThreads)
: CPUThreadPoolExecutor(
numThreads,
std::make_shared<NamedThreadFactory>("CPUThreadPool")) {}
CPUThreadPoolExecutor::CPUThreadPoolExecutor(
size_t numThreads,
int8_t numPriorities,
std::shared_ptr<ThreadFactory> threadFactory)
: CPUThreadPoolExecutor(
numThreads,
std::make_unique<PriorityUnboundedBlockingQueue<CPUTask>>(
numPriorities),
std::move(threadFactory)) {}
CPUThreadPoolExecutor::CPUThreadPoolExecutor(
size_t numThreads,
int8_t numPriorities,
size_t maxQueueSize,
std::shared_ptr<ThreadFactory> threadFactory)
: CPUThreadPoolExecutor(
numThreads,
std::make_unique<PriorityLifoSemMPMCQueue<CPUTask>>(
numPriorities,
maxQueueSize),
std::move(threadFactory)) {}
CPUThreadPoolExecutor::~CPUThreadPoolExecutor() {
deregisterThreadPoolExecutor(this);
stop();
CHECK(threadsToStop_ == 0);
}
void CPUThreadPoolExecutor::add(Func func) {
add(std::move(func), std::chrono::milliseconds(0));
}
void CPUThreadPoolExecutor::add(
Func func,
std::chrono::milliseconds expiration,
Func expireCallback) {
auto result = taskQueue_->add(
CPUTask(std::move(func), expiration, std::move(expireCallback)));
if (!result.reusedThread) {
ensureActiveThreads();
}
}
void CPUThreadPoolExecutor::addWithPriority(Func func, int8_t priority) {
add(std::move(func), priority, std::chrono::milliseconds(0));
}
void CPUThreadPoolExecutor::add(
Func func,
int8_t priority,
std::chrono::milliseconds expiration,
Func expireCallback) {
CHECK(getNumPriorities() > 0);
auto result = taskQueue_->addWithPriority(
CPUTask(std::move(func), expiration, std::move(expireCallback)),
priority);
if (!result.reusedThread) {
ensureActiveThreads();
}
}
uint8_t CPUThreadPoolExecutor::getNumPriorities() const {
return taskQueue_->getNumPriorities();
}
size_t CPUThreadPoolExecutor::getTaskQueueSize() const {
return taskQueue_->size();
}
BlockingQueue<CPUThreadPoolExecutor::CPUTask>*
CPUThreadPoolExecutor::getTaskQueue() {
return taskQueue_.get();
}
// threadListLock_ must be writelocked.
bool CPUThreadPoolExecutor::tryDecrToStop() {
auto toStop = threadsToStop_.load(std::memory_order_relaxed);
if (toStop <= 0) {
return false;
}
threadsToStop_.store(toStop - 1, std::memory_order_relaxed);
return true;
}
bool CPUThreadPoolExecutor::taskShouldStop(folly::Optional<CPUTask>& task) {
if (tryDecrToStop()) {
return true;
}
if (task) {
return false;
} else {
return tryTimeoutThread();
}
return true;
}
void CPUThreadPoolExecutor::threadRun(ThreadPtr thread) {
this->threadPoolHook_.registerThread();
auto guard = folly::makeBlockingDisallowedGuard(executorName);
thread->startupBaton.post();
while (true) {
auto task = taskQueue_->try_take_for(threadTimeout_);
// Handle thread stopping, either by task timeout, or
// by 'poison' task added in join() or stop().
if (UNLIKELY(!task || task.value().poison)) {
// Actually remove the thread from the list.
SharedMutex::WriteHolder w{&threadListLock_};
if (taskShouldStop(task)) {
for (auto& o : observers_) {
o->threadStopped(thread.get());
}
threadList_.remove(thread);
stoppedThreads_.add(thread);
return;
} else {
continue;
}
}
runTask(thread, std::move(task.value()));
if (UNLIKELY(threadsToStop_ > 0 && !isJoin_)) {
SharedMutex::WriteHolder w{&threadListLock_};
if (tryDecrToStop()) {
threadList_.remove(thread);
stoppedThreads_.add(thread);
return;
}
}
}
}
void CPUThreadPoolExecutor::stopThreads(size_t n) {
threadsToStop_ += n;
for (size_t i = 0; i < n; i++) {
taskQueue_->addWithPriority(CPUTask(), Executor::LO_PRI);
}
}
// threadListLock_ is read (or write) locked.
size_t CPUThreadPoolExecutor::getPendingTaskCountImpl() const {
return taskQueue_->size();
}
} // namespace folly