2013-01-09 23:47:38 +01:00
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/*
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* Copyright (C) 2003-2013 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef MPD_WAKE_FD_HXX
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#define MPD_WAKE_FD_HXX
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#include "check.h"
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#include <assert.h>
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/**
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* This class can be used to wake up an I/O event loop.
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*
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* For optimization purposes, this class does not have a constructor
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* or a destructor.
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*/
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class WakeFD {
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int fds[2];
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public:
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#ifdef NDEBUG
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WakeFD() = default;
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#else
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WakeFD():fds{-1, -1} {};
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#endif
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WakeFD(const WakeFD &other) = delete;
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WakeFD &operator=(const WakeFD &other) = delete;
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bool Create();
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void Destroy();
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int Get() const {
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assert(fds[0] >= 0);
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2013-01-10 00:08:25 +01:00
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#ifndef HAVE_EVENTFD
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2013-01-09 23:47:38 +01:00
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assert(fds[1] >= 0);
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2013-01-10 00:08:25 +01:00
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#endif
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2013-01-09 23:47:38 +01:00
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return fds[0];
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}
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/**
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* Checks if Write() was called at least once since the last
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* Read() call.
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*/
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bool Read();
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/**
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* Wakes up the reader. Multiple calls to this function will
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* be combined to one wakeup.
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*/
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void Write();
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2013-01-10 00:08:25 +01:00
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private:
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#ifdef HAVE_EVENTFD
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bool IsEventFD() {
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assert(fds[0] >= 0);
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return fds[1] == -2;
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}
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#endif
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2013-01-09 23:47:38 +01:00
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};
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#endif /* MAIN_NOTIFY_H */
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