mpd/src/system/EventFD.cxx
2013-10-15 09:21:59 +02:00

66 lines
1.5 KiB
C++

/*
* 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.
*/
#include "config.h"
#ifdef USE_EVENTFD
#include "EventFD.hxx"
#include "system/fd_util.h"
#include "system/FatalError.hxx"
#include "Compiler.h"
#include <assert.h>
#include <unistd.h>
#include <sys/eventfd.h>
EventFD::EventFD()
:fd(eventfd_cloexec_nonblock(0, 0))
{
if (fd < 0)
FatalSystemError("eventfd() failed");
}
EventFD::~EventFD()
{
assert(fd >= 0);
close(fd);
}
bool
EventFD::Read()
{
assert(fd >= 0);
eventfd_t value;
return read(fd, &value, sizeof(value)) == (ssize_t)sizeof(value);
}
void
EventFD::Write()
{
assert(fd >= 0);
static constexpr eventfd_t value = 1;
gcc_unused ssize_t nbytes =
write(fd, &value, sizeof(value));
}
#endif /* USE_EVENTFD */