82 lines
2.1 KiB
C++
82 lines
2.1 KiB
C++
/*
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* Copyright 2016 The Cartographer Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "cartographer/common/thread_pool.h"
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#include <unistd.h>
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#include <algorithm>
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#include <chrono>
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#include <numeric>
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#include "glog/logging.h"
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namespace cartographer {
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namespace common {
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ThreadPool::ThreadPool(int num_threads) {
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MutexLocker locker(&mutex_);
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for (int i = 0; i != num_threads; ++i) {
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pool_.emplace_back([this]() { ThreadPool::DoWork(); });
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}
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}
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ThreadPool::~ThreadPool() {
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{
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MutexLocker locker(&mutex_);
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CHECK(running_);
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running_ = false;
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CHECK_EQ(work_queue_.size(), 0);
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}
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for (std::thread& thread : pool_) {
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thread.join();
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}
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}
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void ThreadPool::Schedule(const std::function<void()>& work_item) {
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MutexLocker locker(&mutex_);
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CHECK(running_);
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work_queue_.push_back(work_item);
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}
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void ThreadPool::DoWork() {
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#ifdef __linux__
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// This changes the per-thread nice level of the current thread on Linux. We
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// do this so that the background work done by the thread pool is not taking
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// away CPU resources from more important foreground threads.
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CHECK_NE(nice(10), -1);
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#endif
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for (;;) {
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std::function<void()> work_item;
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{
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MutexLocker locker(&mutex_);
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locker.Await([this]() REQUIRES(mutex_) {
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return !work_queue_.empty() || !running_;
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});
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if (!work_queue_.empty()) {
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work_item = work_queue_.front();
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work_queue_.pop_front();
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} else if (!running_) {
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return;
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}
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}
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CHECK(work_item);
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work_item();
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}
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}
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} // namespace common
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} // namespace cartographer
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