1 /* 2 * Copyright (C) 2019 The Android Open Source Project 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 #ifndef INCLUDE_PERFETTO_BASE_THREAD_TASK_RUNNER_H_ 18 #define INCLUDE_PERFETTO_BASE_THREAD_TASK_RUNNER_H_ 19 20 #include <functional> 21 #include <thread> 22 23 #include "perfetto/base/unix_task_runner.h" 24 25 namespace perfetto { 26 namespace base { 27 28 // A UnixTaskRunner backed by a dedicated task thread. Shuts down the runner and 29 // joins the thread upon destruction. Can be moved to transfer ownership. 30 // 31 // Guarantees that: 32 // * the UnixTaskRunner will be constructed and destructed on the task thread. 33 // * the task thread will live for the lifetime of the UnixTaskRunner. 34 // 35 class ThreadTaskRunner { 36 public: CreateAndStart()37 static ThreadTaskRunner CreateAndStart() { return ThreadTaskRunner(); } 38 39 ThreadTaskRunner(const ThreadTaskRunner&) = delete; 40 ThreadTaskRunner& operator=(const ThreadTaskRunner&) = delete; 41 42 ThreadTaskRunner(ThreadTaskRunner&&) noexcept; 43 ThreadTaskRunner& operator=(ThreadTaskRunner&&); 44 ~ThreadTaskRunner(); 45 46 // Returns a pointer to the UnixTaskRunner, which is valid for the lifetime of 47 // this ThreadTaskRunner object (unless this object is moved-from, in which 48 // case the pointer remains valid for the lifetime of the new owning 49 // ThreadTaskRunner). 50 // 51 // Warning: do not call Quit() on the returned runner pointer, the termination 52 // should be handled exclusively by this class' destructor. get()53 UnixTaskRunner* get() const { return task_runner_; } 54 55 private: 56 ThreadTaskRunner(); 57 void RunTaskThread(std::function<void(UnixTaskRunner*)> initializer); 58 59 std::thread thread_; 60 UnixTaskRunner* task_runner_ = nullptr; 61 }; 62 63 } // namespace base 64 } // namespace perfetto 65 66 #endif // INCLUDE_PERFETTO_BASE_THREAD_TASK_RUNNER_H_ 67