| /* |
| * |
| * 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 |