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Diffstat (limited to '')
-rw-r--r-- | src/event/EventFD.hxx | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/event/EventFD.hxx b/src/event/EventFD.hxx new file mode 100644 index 000000000..803957354 --- /dev/null +++ b/src/event/EventFD.hxx @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2003-2013 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef MPD_EVENT_FD_HXX +#define MPD_EVENT_FD_HXX + +#include "check.h" + +#include <assert.h> + +/** + * A class that wraps eventfd(). + * + * For optimization purposes, this class does not have a constructor + * or a destructor. + */ +class EventFD { + int fd; + +public: +#ifdef NDEBUG + EventFD() = default; +#else + EventFD():fd(-1) {} +#endif + + EventFD(const EventFD &other) = delete; + EventFD &operator=(const EventFD &other) = delete; + + bool Create(); + void Destroy(); + + int Get() const { + assert(fd >= 0); + + return fd; + } + + /** + * Checks if Write() was called at least once since the last + * Read() call. + */ + bool Read(); + + /** + * Wakes up the reader. Multiple calls to this function will + * be combined to one wakeup. + */ + void Write(); +}; + +#endif |