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/*
* 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"
#include "WakeFD.hxx"
#include "fd_util.h"
#include "gcc.h"
#include <unistd.h>
#ifdef HAVE_EVENTFD
#include <sys/eventfd.h>
#endif
bool
WakeFD::Create()
{
assert(fds[0] == -1);
assert(fds[1] == -1);
#ifdef HAVE_EVENTFD
fds[0] = eventfd_cloexec_nonblock(0, 0);
if (fds[0] >= 0) {
fds[1] = -2;
return true;
}
#endif
return pipe_cloexec_nonblock(fds) >= 0;
}
void
WakeFD::Destroy()
{
#ifndef WIN32
/* By some strange reason this call hangs on Win32 */
close(fds[0]);
#endif
#ifdef HAVE_EVENTFD
if (!IsEventFD())
#endif
close(fds[1]);
#ifndef NDEBUG
fds[0] = -1;
fds[1] = -1;
#endif
}
bool
WakeFD::Read()
{
assert(fds[0] >= 0);
#ifdef HAVE_EVENTFD
if (IsEventFD()) {
eventfd_t value;
return read(fds[0], &value,
sizeof(value)) == (ssize_t)sizeof(value);
}
#endif
assert(fds[1] >= 0);
char buffer[256];
return read(fds[0], buffer, sizeof(buffer)) > 0;
}
void
WakeFD::Write()
{
assert(fds[0] >= 0);
#ifdef HAVE_EVENTFD
if (IsEventFD()) {
static constexpr eventfd_t value = 1;
gcc_unused ssize_t nbytes =
write(fds[0], &value, sizeof(value));
return;
}
#endif
assert(fds[1] >= 0);
gcc_unused ssize_t nbytes = write(fds[1], "", 1);
}
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