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Diffstat (limited to 'src/GlobalEvents.cxx')
-rw-r--r-- | src/GlobalEvents.cxx | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/GlobalEvents.cxx b/src/GlobalEvents.cxx new file mode 100644 index 00000000..e4f335c9 --- /dev/null +++ b/src/GlobalEvents.cxx @@ -0,0 +1,114 @@ +/* + * 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.fetch_and(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(); +} |