wait for UPnP discovery during startup

UPnP.cpp

@@ -49,7 +49,9 @@ namespace transport
 		m_IsRunning = true;
         LogPrint(eLogInfo, "UPnP: starting");
 		m_Service.post (std::bind (&UPnP::Discover, this));
+		std::unique_lock<std::mutex> l(m_StartedMutex);
         m_Thread.reset (new std::thread (std::bind (&UPnP::Run, this)));
+		m_Started.wait_for (l, std::chrono::seconds (5)); // 5 seconds maximum
     }
     
     UPnP::~UPnP ()
@@ -80,6 +82,11 @@ namespace transport
 #else
         m_Devlist = upnpDiscover (2000, m_MulticastIf, m_Minissdpdpath, 0, 0, &nerror);
 #endif
+		{
+			// notify satrting thread			
+			std::unique_lock<std::mutex> l(m_StartedMutex);
+			m_Started.notify_all ();
+		}	
 		
         int r;
         r = UPNP_GetValidIGD (m_Devlist, &m_upnpUrls, &m_upnpData, m_NetworkAddr, sizeof (m_NetworkAddr));

UPnP.h

@@ -4,6 +4,8 @@
 #ifdef USE_UPNP
 #include <string>
 #include <thread>
+#include <condition_variable>
+#include <mutex>
 #include <memory>
 
 #include <miniupnpc/miniwget.h>
@@ -43,6 +45,8 @@ namespace transport
 	
 		bool m_IsRunning;
         std::unique_ptr<std::thread> m_Thread;
+		std::condition_variable m_Started;	
+		std::mutex m_StartedMutex;	
 		boost::asio::io_service m_Service;
 		boost::asio::deadline_timer m_Timer;	
         struct UPNPUrls m_upnpUrls;