blob: d3013b806c0c669ee2b586435b1f68a033c57c99 [file] [log] [blame]
/*
*
* Copyright 2015, Google 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
* OWNER 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 "src/cpp/server/thread_pool.h"
namespace grpc {
ThreadPool::ThreadPool(int num_threads) : shutdown_(false) {
for (int i = 0; i < num_threads; i++) {
threads_.push_back(std::thread([this]() {
for (;;) {
// Wait until work is available or we are shutting down.
auto have_work = [this]() { return shutdown_ || !callbacks_.empty(); };
std::unique_lock<std::mutex> lock(mu_);
if (!have_work()) {
cv_.wait(lock, have_work);
}
// Drain callbacks before considering shutdown to ensure all work
// gets completed.
if (!callbacks_.empty()) {
auto cb = callbacks_.front();
callbacks_.pop();
lock.unlock();
cb();
} else if (shutdown_) {
return;
}
}
}));
}
}
ThreadPool::~ThreadPool() {
{
std::lock_guard<std::mutex> lock(mu_);
shutdown_ = true;
cv_.notify_all();
}
for (auto& t : threads_) {
t.join();
}
}
void ThreadPool::ScheduleCallback(const std::function<void()>& callback) {
std::lock_guard<std::mutex> lock(mu_);
callbacks_.push(callback);
cv_.notify_one();
}
} // namespace grpc