1 /* 2 * Copyright 2003-2021 The Music Player Daemon Project 3 * http://www.musicpd.org 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License along 16 * with this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 18 */ 19 20 #ifndef MPD_EVENT_MASK_MONITOR_HXX 21 #define MPD_EVENT_MASK_MONITOR_HXX 22 23 #include "InjectEvent.hxx" 24 #include "util/BindMethod.hxx" 25 26 #include <atomic> 27 28 /** 29 * Manage a bit mask of events that have occurred. Every time the 30 * mask becomes non-zero, OnMask() is called in #EventLoop's thread. 31 * 32 * This class is thread-safe. 33 */ 34 class MaskMonitor final { 35 InjectEvent event; 36 37 using Callback = BoundMethod<void(unsigned) noexcept>; 38 const Callback callback; 39 40 std::atomic_uint pending_mask; 41 42 public: MaskMonitor(EventLoop & _loop,Callback _callback)43 MaskMonitor(EventLoop &_loop, Callback _callback) noexcept 44 :event(_loop, BIND_THIS_METHOD(RunDeferred)), 45 callback(_callback), pending_mask(0) {} 46 GetEventLoop() const47 auto &GetEventLoop() const noexcept { 48 return event.GetEventLoop(); 49 } 50 Cancel()51 void Cancel() noexcept { 52 event.Cancel(); 53 } 54 55 void OrMask(unsigned new_mask) noexcept; 56 57 protected: 58 /* InjectEvent callback */ 59 void RunDeferred() noexcept; 60 }; 61 62 #endif 63