1 /**
2 * Copyright 2021 Huawei Technologies Co., Ltd
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "ps/core/communicator/task_executor.h"
18
19 namespace mindspore {
20 namespace ps {
21 namespace core {
TaskExecutor(size_t thread_num,size_t max_task_num,size_t submit_timeout)22 TaskExecutor::TaskExecutor(size_t thread_num, size_t max_task_num, size_t submit_timeout)
23 : running_(true),
24 thread_num_(thread_num),
25 idle_thread_num_(0),
26 submit_timeout_(submit_timeout),
27 max_task_num_(max_task_num),
28 task_num_(0) {
29 for (size_t i = 0; i < thread_num; i++) {
30 working_threads_.emplace_back([this]() {
31 std::function<void()> task;
32 while (true) {
33 std::unique_lock<std::mutex> lock(mtx_);
34 // Idle thread number increases when the mtx_ is locked.
35 idle_thread_num_++;
36
37 if (!running_) {
38 // To avoid thread from blocking after destructor.
39 return;
40 }
41
42 cv_.wait(lock);
43
44 if (!running_ || task_queue_.empty()) {
45 return;
46 }
47
48 task = task_queue_.front();
49 task_queue_.pop();
50 if (lock.owns_lock()) {
51 lock.unlock();
52 }
53
54 task();
55 }
56 });
57 }
58 notify_thread_ = std::thread([this]() {
59 // If there is no idle thread, wait until the working thread is available.
60 while (running_) {
61 {
62 std::unique_lock<std::mutex> lock(mtx_);
63 if (idle_thread_num_ > 0 && task_num_ > 0) {
64 idle_thread_num_--;
65 task_num_--;
66 lock.unlock();
67 cv_.notify_one();
68 }
69 }
70 std::this_thread::sleep_for(std::chrono::milliseconds(kSubmitTaskIntervalInMs));
71 }
72 });
73 }
74
~TaskExecutor()75 TaskExecutor::~TaskExecutor() {
76 {
77 std::unique_lock<std::mutex> lock(mtx_);
78 running_ = false;
79 }
80 cv_.notify_all();
81 for (auto &t : working_threads_) {
82 t.join();
83 }
84 notify_thread_.join();
85 }
86 } // namespace core
87 } // namespace ps
88 } // namespace mindspore
89