event_pipe: convert to C++

1 files changed, 164 insertions, 0 deletions

diff --git a/src/EventPipe.cxx b/src/EventPipe.cxx
new file mode 100644
index 000000000..b2c80a3c1
--- /dev/null
+++ b/src/EventPipe.cxx
@@ -0,0 +1,164 @@
+/*
+ * 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 "event_pipe.h"
+#include "fd_util.h"
+#include "mpd_error.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 GIOChannel *event_channel;
+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];
+	gsize bytes_read;
+	GError *error = NULL;
+	GIOStatus status = g_io_channel_read_chars(event_channel,
+						   buffer, sizeof(buffer),
+						   &bytes_read, &error);
+	if (status == G_IO_STATUS_ERROR)
+		MPD_ERROR("error reading from pipe: %s", error->message);
+
+	bool events[PIPE_EVENT_MAX];
+	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(pipe_event(i));
+
+	return true;
+}
+
+void event_pipe_init(void)
+{
+	GIOChannel *channel;
+	int ret;
+
+	ret = pipe_cloexec_nonblock(event_pipe);
+	if (ret < 0)
+		MPD_ERROR("Couldn't open pipe: %s", strerror(errno));
+
+#ifndef G_OS_WIN32
+	channel = g_io_channel_unix_new(event_pipe[0]);
+#else
+	channel = g_io_channel_win32_new_fd(event_pipe[0]);
+#endif
+	g_io_channel_set_encoding(channel, NULL, NULL);
+	g_io_channel_set_buffered(channel, false);
+
+	event_pipe_source_id = g_io_add_watch(channel, G_IO_IN,
+					      main_notify_event, NULL);
+
+	event_channel = 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);
+	g_io_channel_unref(event_channel);
+
+#ifndef WIN32
+	/* By some strange reason this call hangs on Win32 */
+	close(event_pipe[0]);
+#endif
+	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)
+		MPD_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;
+
+	G_GNUC_UNUSED ssize_t nbytes = write(event_pipe[1], "", 1);
+}