event/SocketMonitor: wrapper class for GSource + GPollFD

src/event/SocketMonitor.cxx

@@ -0,0 +1,108 @@
+/*
+ * 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 "SocketMonitor.hxx"
+#include "Loop.hxx"
+#include "fd_util.h"
+#include "gcc.h"
+
+#include <assert.h>
+
+/*
+ * GSource methods
+ *
+ */
+
+gboolean
+SocketMonitor::Prepare(gcc_unused GSource *source, gcc_unused gint *timeout_r)
+{
+	return false;
+}
+
+gboolean
+SocketMonitor::Check(GSource *_source)
+{
+	const Source &source = *(const Source *)_source;
+	const SocketMonitor &monitor = *source.monitor;
+	assert(_source == &monitor.source->base);
+
+	return monitor.Check();
+}
+
+gboolean
+SocketMonitor::Dispatch(GSource *_source,
+			gcc_unused GSourceFunc callback,
+			gcc_unused gpointer user_data)
+{
+	Source &source = *(Source *)_source;
+	SocketMonitor &monitor = *source.monitor;
+	assert(_source == &monitor.source->base);
+
+	monitor.Dispatch();
+	return true;
+}
+
+/**
+ * The vtable for our GSource implementation.  Unfortunately, we
+ * cannot declare it "const", because g_source_new() takes a non-const
+ * pointer, for whatever reason.
+ */
+static GSourceFuncs socket_monitor_source_funcs = {
+	SocketMonitor::Prepare,
+	SocketMonitor::Check,
+	SocketMonitor::Dispatch,
+	nullptr,
+	nullptr,
+	nullptr,
+};
+
+SocketMonitor::SocketMonitor(int _fd, EventLoop &_loop)
+	:fd(_fd), loop(_loop),
+	 source((Source *)g_source_new(&socket_monitor_source_funcs,
+				       sizeof(*source))),
+	 poll{fd, 0, 0} {
+	assert(fd >= 0);
+
+	source->monitor = this;
+
+	g_source_attach(&source->base, loop.GetContext());
+	g_source_add_poll(&source->base, &poll);
+}
+
+SocketMonitor::~SocketMonitor()
+{
+	if (IsDefined())
+		Close();
+}
+
+void
+SocketMonitor::Close()
+{
+	assert(IsDefined());
+
+	Cancel();
+
+	close_socket(fd);
+	fd = -1;
+
+	g_source_destroy(&source->base);
+	g_source_unref(&source->base);
+	source = nullptr;
+}