upnp: initialize the client handle only once

Eliminate class LibUPnP and move the code to ClientInit.cxx.  Its
initialization function can be called multiple times, but
UpnpRegisterClient() is called at most once.

1 files changed, 93 insertions, 0 deletions

diff --git a/src/lib/upnp/ClientInit.cxx b/src/lib/upnp/ClientInit.cxx
new file mode 100644
index 000000000..77d9cf03d
--- /dev/null
+++ b/src/lib/upnp/ClientInit.cxx
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2003-2014 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 "ClientInit.hxx"
+#include "Init.hxx"
+#include "Callback.hxx"
+#include "Domain.hxx"
+#include "thread/Mutex.hxx"
+#include "util/Error.hxx"
+
+#include <upnp/upnptools.h>
+
+static Mutex upnp_client_init_mutex;
+static unsigned upnp_client_ref;
+static UpnpClient_Handle upnp_client_handle;
+
+static int
+UpnpClientCallback(Upnp_EventType et, void *evp, void *cookie)
+{
+	if (cookie == nullptr)
+		/* this is the cookie passed to UpnpRegisterClient();
+		   but can this ever happen?  Will libupnp ever invoke
+		   the registered callback without that cookie? */
+		return UPNP_E_SUCCESS;
+
+	UpnpCallback &callback = UpnpCallback::FromUpnpCookie(cookie);
+	return callback.Invoke(et, evp);
+}
+
+static bool
+DoInit(Error &error)
+{
+	auto code = UpnpRegisterClient(UpnpClientCallback, nullptr,
+				       &upnp_client_handle);
+	if (code != UPNP_E_SUCCESS) {
+		error.Format(upnp_domain, code,
+			     "UpnpRegisterClient() failed: %s",
+			     UpnpGetErrorMessage(code));
+		return false;
+	}
+
+	return true;
+}
+
+bool
+UpnpClientGlobalInit(UpnpClient_Handle &handle, Error &error)
+{
+	if (!UpnpGlobalInit(error))
+		return false;
+
+	upnp_client_init_mutex.lock();
+	bool success = upnp_client_ref > 0 || DoInit(error);
+	upnp_client_init_mutex.unlock();
+
+	if (success) {
+		++upnp_client_ref;
+		handle = upnp_client_handle;
+	} else
+		UpnpGlobalFinish();
+
+	return success;
+}
+
+void
+UpnpClientGlobalFinish()
+{
+	upnp_client_init_mutex.lock();
+
+	assert(upnp_client_ref > 0);
+	if (--upnp_client_ref == 0)
+		UpnpUnRegisterClient(upnp_client_handle);
+
+	upnp_client_init_mutex.unlock();
+
+	UpnpGlobalFinish();
+}