2 files changed, 137 insertions, 0 deletions
diff --git a/src/event/WakeFD.cxx b/src/event/WakeFD.cxx
new file mode 100644
index 000000000..7314342d8
--- /dev/null
+++ b/src/event/WakeFD.cxx
@@ -0,0 +1,68 @@
+/*
+ * 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 "WakeFD.hxx"
+#include "fd_util.h"
+#include "gcc.h"
+
+#include <unistd.h>
+
+bool
+WakeFD::Create()
+{
+	assert(fds[0] == -1);
+	assert(fds[1] == -1);
+
+	return pipe_cloexec_nonblock(fds) >= 0;
+}
+
+void
+WakeFD::Destroy()
+{
+#ifndef WIN32
+	/* By some strange reason this call hangs on Win32 */
+	close(fds[0]);
+#endif
+	close(fds[1]);
+
+#ifndef NDEBUG
+	fds[0] = -1;
+	fds[1] = -1;
+#endif
+}
+
+bool
+WakeFD::Read()
+{
+	assert(fds[0] >= 0);
+	assert(fds[1] >= 0);
+
+	char buffer[256];
+	return read(fds[0], buffer, sizeof(buffer)) > 0;
+}
+
+void
+WakeFD::Write()
+{
+	assert(fds[0] >= 0);
+	assert(fds[1] >= 0);
+
+	gcc_unused ssize_t nbytes = write(fds[1], "", 1);
+}
diff --git a/src/event/WakeFD.hxx b/src/event/WakeFD.hxx
new file mode 100644
index 000000000..7b2d52675
--- /dev/null
+++ b/src/event/WakeFD.hxx
@@ -0,0 +1,69 @@
+/*
+ * 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.
+ */
+
+#ifndef MPD_WAKE_FD_HXX
+#define MPD_WAKE_FD_HXX
+
+#include "check.h"
+
+#include <assert.h>
+
+/**
+ * This class can be used to wake up an I/O event loop.
+ *
+ * For optimization purposes, this class does not have a constructor
+ * or a destructor.
+ */
+class WakeFD {
+	int fds[2];
+
+public:
+#ifdef NDEBUG
+	WakeFD() = default;
+#else
+	WakeFD():fds{-1, -1} {};
+#endif
+
+	WakeFD(const WakeFD &other) = delete;
+	WakeFD &operator=(const WakeFD &other) = delete;
+
+	bool Create();
+	void Destroy();
+
+	int Get() const {
+		assert(fds[0] >= 0);
+		assert(fds[1] >= 0);
+
+		return fds[0];
+	}
+
+	/**
+	 * Checks if Write() was called at least once since the last
+	 * Read() call.
+	 */
+	bool Read();
+
+	/**
+	 * Wakes up the reader.  Multiple calls to this function will
+	 * be combined to one wakeup.
+	 */
+	void Write();
+};
+
+#endif /* MAIN_NOTIFY_H */