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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 "event/WakeFD.hxx"
#include "mpd_error.h"
#include <atomic>
#include <assert.h>
#include <glib.h>
#include <string.h>
#include <errno.h>
#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "global_events"
namespace GlobalEvents {
static WakeFD wake_fd;
static guint source_id;
static std::atomic_uint flags;
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)
{
if (!GlobalEvents::wake_fd.Read())
return true;
const unsigned flags = GlobalEvents::flags.exchange(0);
for (unsigned i = 0; i < GlobalEvents::MAX; ++i)
if (flags & (1u << i))
/* invoke the event handler */
InvokeGlobalEvent(GlobalEvents::Event(i));
return true;
}
void
GlobalEvents::Initialize()
{
if (!wake_fd.Create())
MPD_ERROR("Couldn't open pipe: %s", strerror(errno));
#ifndef G_OS_WIN32
GIOChannel *channel = g_io_channel_unix_new(wake_fd.Get());
#else
GIOChannel *channel = g_io_channel_win32_new_socket(wake_fd.Get());
#endif
source_id = g_io_add_watch(channel, G_IO_IN,
GlobalEventCallback, NULL);
g_io_channel_unref(channel);
}
void
GlobalEvents::Deinitialize()
{
g_source_remove(source_id);
wake_fd.Destroy();
}
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);
const unsigned mask = 1u << unsigned(event);
if ((GlobalEvents::flags.fetch_or(mask) & mask) == 0)
wake_fd.Write();
}
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