aboutsummaryrefslogtreecommitdiffstats
path: root/src/GlobalEvents.cxx
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/GlobalEvents.cxx153
1 files changed, 153 insertions, 0 deletions
diff --git a/src/GlobalEvents.cxx b/src/GlobalEvents.cxx
new file mode 100644
index 000000000..4bc607dfb
--- /dev/null
+++ b/src/GlobalEvents.cxx
@@ -0,0 +1,153 @@
+/*
+ * 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);
+}