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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 "GlobalEvents.hxx"
#include "thread/Mutex.hxx"
#include "fd_util.h"
#include "mpd_error.h"
#include <assert.h>
#include <glib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "global_events"
namespace GlobalEvents {
static int fds[2];
static GIOChannel *channel;
static guint source_id;
static Mutex mutex;
static bool flags[MAX];
static Handler handlers[MAX];
}
/**
* Invoke the callback for a certain event.
*/
static void
InvokeGlobalEvent(GlobalEvents::Event event)
{
assert((unsigned)event < GlobalEvents::MAX);
assert(GlobalEvents::handlers[event] != NULL);
GlobalEvents::handlers[event]();
}
static gboolean
GlobalEventCallback(G_GNUC_UNUSED GIOChannel *source,
G_GNUC_UNUSED GIOCondition condition,
G_GNUC_UNUSED gpointer data)
{
char buffer[256];
gsize bytes_read;
GError *error = NULL;
GIOStatus status = g_io_channel_read_chars(GlobalEvents::channel,
buffer, sizeof(buffer),
&bytes_read, &error);
if (status == G_IO_STATUS_ERROR)
MPD_ERROR("error reading from pipe: %s", error->message);
bool events[GlobalEvents::MAX];
GlobalEvents::mutex.lock();
memcpy(events, GlobalEvents::flags, sizeof(events));
memset(GlobalEvents::flags, 0,
sizeof(GlobalEvents::flags));
GlobalEvents::mutex.unlock();
for (unsigned i = 0; i < GlobalEvents::MAX; ++i)
if (events[i])
/* invoke the event handler */
InvokeGlobalEvent(GlobalEvents::Event(i));
return true;
}
void
GlobalEvents::Initialize()
{
if (pipe_cloexec_nonblock(fds) < 0)
MPD_ERROR("Couldn't open pipe: %s", strerror(errno));
#ifndef G_OS_WIN32
channel = g_io_channel_unix_new(fds[0]);
#else
channel = g_io_channel_win32_new_fd(fds[0]);
#endif
g_io_channel_set_encoding(channel, NULL, NULL);
g_io_channel_set_buffered(channel, false);
source_id = g_io_add_watch(channel, G_IO_IN,
GlobalEventCallback, NULL);
}
void
GlobalEvents::Deinitialize()
{
g_source_remove(source_id);
g_io_channel_unref(channel);
#ifndef WIN32
/* By some strange reason this call hangs on Win32 */
close(fds[0]);
#endif
close(fds[1]);
}
void
GlobalEvents::Register(Event event, Handler callback)
{
assert((unsigned)event < MAX);
assert(handlers[event] == NULL);
handlers[event] = callback;
}
void
GlobalEvents::Emit(Event event)
{
assert((unsigned)event < MAX);
mutex.lock();
if (flags[event]) {
/* already set: don't write */
mutex.unlock();
return;
}
flags[event] = true;
mutex.unlock();
ssize_t w = write(fds[1], "", 1);
if (w < 0 && errno != EAGAIN && errno != EINTR)
MPD_ERROR("error writing to pipe: %s", strerror(errno));
}
void
GlobalEvents::FastEmit(Event event)
{
assert((unsigned)event < MAX);
flags[event] = true;
G_GNUC_UNUSED ssize_t nbytes = write(fds[1], "", 1);
}
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