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/*
* Copyright (C) 2003-2010 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 "event_pipe.h"
#include "fd_util.h"
#include <stdbool.h>
#include <assert.h>
#include <glib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#ifdef WIN32
/* for _O_BINARY */
#include <fcntl.h>
#endif
#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "event_pipe"
static int event_pipe[2];
static guint event_pipe_source_id;
static GMutex *event_pipe_mutex;
static bool pipe_events[PIPE_EVENT_MAX];
static event_pipe_callback_t event_pipe_callbacks[PIPE_EVENT_MAX];
/**
* Invoke the callback for a certain event.
*/
static void
event_pipe_invoke(enum pipe_event event)
{
assert((unsigned)event < PIPE_EVENT_MAX);
assert(event_pipe_callbacks[event] != NULL);
event_pipe_callbacks[event]();
}
static gboolean
main_notify_event(G_GNUC_UNUSED GIOChannel *source,
G_GNUC_UNUSED GIOCondition condition,
G_GNUC_UNUSED gpointer data)
{
char buffer[256];
ssize_t r = read(event_pipe[0], buffer, sizeof(buffer));
bool events[PIPE_EVENT_MAX];
if (r < 0 && errno != EAGAIN && errno != EINTR)
g_error("error reading from pipe: %s", strerror(errno));
g_mutex_lock(event_pipe_mutex);
memcpy(events, pipe_events, sizeof(events));
memset(pipe_events, 0, sizeof(pipe_events));
g_mutex_unlock(event_pipe_mutex);
for (unsigned i = 0; i < PIPE_EVENT_MAX; ++i)
if (events[i])
/* invoke the event handler */
event_pipe_invoke(i);
return true;
}
void event_pipe_init(void)
{
GIOChannel *channel;
int ret;
ret = pipe_cloexec_nonblock(event_pipe);
if (ret < 0)
g_error("Couldn't open pipe: %s", strerror(errno));
channel = g_io_channel_unix_new(event_pipe[0]);
event_pipe_source_id = g_io_add_watch(channel, G_IO_IN,
main_notify_event, NULL);
g_io_channel_unref(channel);
event_pipe_mutex = g_mutex_new();
}
void event_pipe_deinit(void)
{
g_mutex_free(event_pipe_mutex);
g_source_remove(event_pipe_source_id);
close(event_pipe[0]);
close(event_pipe[1]);
}
void
event_pipe_register(enum pipe_event event, event_pipe_callback_t callback)
{
assert((unsigned)event < PIPE_EVENT_MAX);
assert(event_pipe_callbacks[event] == NULL);
event_pipe_callbacks[event] = callback;
}
void event_pipe_emit(enum pipe_event event)
{
ssize_t w;
assert((unsigned)event < PIPE_EVENT_MAX);
g_mutex_lock(event_pipe_mutex);
if (pipe_events[event]) {
/* already set: don't write */
g_mutex_unlock(event_pipe_mutex);
return;
}
pipe_events[event] = true;
g_mutex_unlock(event_pipe_mutex);
w = write(event_pipe[1], "", 1);
if (w < 0 && errno != EAGAIN && errno != EINTR)
g_error("error writing to pipe: %s", strerror(errno));
}
void event_pipe_emit_fast(enum pipe_event event)
{
assert((unsigned)event < PIPE_EVENT_MAX);
pipe_events[event] = true;
(void)write(event_pipe[1], "", 1);
}
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