1 /* 2 * Copyright 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 #pragma once 18 19 #include <functional> 20 #include <memory> 21 #include <mutex> 22 #include <queue> 23 24 #include "common/callback.h" 25 #include "os/thread.h" 26 #include "os/utils.h" 27 28 namespace bluetooth { 29 namespace os { 30 31 // A message-queue style handler for reactor-based thread to handle incoming events from different threads. When it's 32 // constructed, it will register a reactable on the specified thread; when it's destroyed, it will unregister itself 33 // from the thread. 34 class Handler { 35 public: 36 // Create and register a handler on given thread 37 explicit Handler(Thread* thread); 38 39 // Unregister this handler from the thread and release resource. Unhandled events will be discarded and not executed. 40 ~Handler(); 41 42 DISALLOW_COPY_AND_ASSIGN(Handler); 43 44 // Enqueue a closure to the queue of this handler 45 void Post(OnceClosure closure); 46 47 // Remove all pending events from the queue of this handler 48 void Clear(); 49 50 // Die if the current reactable doesn't stop before the timeout. Must be called after Clear() 51 void WaitUntilStopped(std::chrono::milliseconds timeout); 52 53 template <typename T> 54 friend class Queue; 55 56 friend class Alarm; 57 58 friend class RepeatingAlarm; 59 60 private: was_cleared()61 inline bool was_cleared() const { 62 return tasks_ == nullptr; 63 }; 64 std::queue<OnceClosure>* tasks_; 65 Thread* thread_; 66 int fd_; 67 Reactor::Reactable* reactable_; 68 mutable std::mutex mutex_; 69 void handle_next_event(); 70 }; 71 72 } // namespace os 73 } // namespace bluetooth 74