1 /* Copyright 2019 The TensorFlow Authors. All Rights Reserved. 2 3 Licensed under the Apache License, Version 2.0 (the "License"); 4 you may not use this file except in compliance with the License. 5 You may obtain a copy of the License at 6 7 http://www.apache.org/licenses/LICENSE-2.0 8 9 Unless required by applicable law or agreed to in writing, software 10 distributed under the License is distributed on an "AS IS" BASIS, 11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 See the License for the specific language governing permissions and 13 limitations under the License. 14 ==============================================================================*/ 15 #ifndef TENSORFLOW_CORE_KERNELS_DATA_UNBOUNDED_THREAD_POOL_H_ 16 #define TENSORFLOW_CORE_KERNELS_DATA_UNBOUNDED_THREAD_POOL_H_ 17 18 #include <deque> 19 #include <memory> 20 #include <vector> 21 22 #include "tensorflow/core/framework/thread_factory.h" 23 #include "tensorflow/core/lib/core/notification.h" 24 #include "tensorflow/core/lib/core/threadpool_interface.h" 25 #include "tensorflow/core/platform/env.h" 26 #include "tensorflow/core/platform/unbounded_work_queue.h" 27 28 namespace tensorflow { 29 namespace data { 30 31 // An `UnboundedThreadPool` provides a mechanism for temporally multiplexing a 32 // potentially large number of "logical" threads onto a smaller number of 33 // "physical" threads. The multiplexing is achieved by using an 34 // `UnboundedWorkQueue`. 35 class UnboundedThreadPool : public thread::ThreadPoolInterface { 36 public: UnboundedThreadPool(Env * env,const string & thread_name)37 UnboundedThreadPool(Env* env, const string& thread_name) 38 : unbounded_work_queue_(env, thread_name) {} UnboundedThreadPool(Env * env,const string & thread_name,const ThreadOptions & thread_options)39 UnboundedThreadPool(Env* env, const string& thread_name, 40 const ThreadOptions& thread_options) 41 : unbounded_work_queue_(env, thread_name, thread_options) {} 42 ~UnboundedThreadPool() override = default; 43 44 // Returns an implementation of `ThreadFactory` that can be used to create 45 // logical threads in this pool. 46 std::shared_ptr<ThreadFactory> get_thread_factory(); 47 48 void Schedule(std::function<void()> fn) override; 49 int NumThreads() const override; 50 int CurrentThreadId() const override; 51 52 private: 53 class LogicalThreadFactory; 54 class LogicalThreadWrapper; 55 56 void ScheduleOnWorkQueue(std::function<void()> fn, 57 std::shared_ptr<Notification> done); 58 59 UnboundedWorkQueue unbounded_work_queue_; 60 }; 61 62 } // namespace data 63 } // namespace tensorflow 64 65 #endif // TENSORFLOW_CORE_KERNELS_DATA_UNBOUNDED_THREAD_POOL_H_ 66