fixed regression of "live TV must be switched in VDR main thread" change:

deadlock in IGMP streaming server when switching live TV.

Previously cComponentIGMP::Accept did all the work including the channel
switch with the new cConnectionIGMP waiting for MainThreadHook. But as the
new connection is stored *after* Accept, MainThreadHook didn't see it and
so wasn't able to switch. The streamdev main thread waited forever.

Moved the main work into cComponentIGMP::Welcome.

HISTORY

@@ -1,6 +1,8 @@
 VDR Plugin 'streamdev' Revision History
 ---------------------------------------
  
+- fixed regression of "live TV must be switched in VDR main thread" change:
+  deadlock in IGMP streaming server when switching live TV.
 - streamdev-client returns true in its AvoidRecording() method introduced
   with VDR 1.7.19. Note however that the impact of NumProvidedSystems is
   higher.

server/componentIGMP.c

@@ -434,7 +434,7 @@ void cComponentIGMP::IGMPStartMulticast(cMulticastGroup* Group)
 	if (g > MULTICAST_PRIV_MIN && g <= MULTICAST_PRIV_MAX) {
 		cChannel *channel = Channels.GetByNumber(g - MULTICAST_PRIV_MIN);
 		Group->connection = (cConnectionIGMP*) NewClient();
-		if (!Group->connection->Start(channel, Group->group)) {
+		if (!Group->connection->SetChannel(channel, Group->group)) {
 			DELETENULL(Group->connection);
 		}
 	}

server/connectionIGMP.c

@@ -13,7 +13,8 @@ cConnectionIGMP::cConnectionIGMP(const char* Name, int ClientPort, eStreamType S
 		cServerConnection(Name, SOCK_DGRAM),
 		m_LiveStreamer(NULL),
 		m_ClientPort(ClientPort),
-		m_StreamType(StreamType)
+		m_StreamType(StreamType),
+		m_Channel(NULL)
 {
 }
 
@@ -22,41 +23,47 @@ cConnectionIGMP::~cConnectionIGMP()
 	delete m_LiveStreamer;
 }
 
-bool cConnectionIGMP::Start(cChannel *Channel, in_addr_t Dst)
+bool cConnectionIGMP::SetChannel(cChannel *Channel, in_addr_t Dst)
 {
-	if (Channel != NULL) {
+	if (Channel) {
-		cDevice *device = NULL;
+		m_Channel = Channel;
-		if (ProvidesChannel(Channel, 0))
+		struct in_addr ip;
-			device = GetDevice(Channel, 0);
+		ip.s_addr = Dst;
-		if (device != NULL) {
+		if (Connect(inet_ntoa(ip), m_ClientPort))
-			device->SwitchChannel(Channel, false);
+			return true;
-			struct in_addr ip;
-			ip.s_addr = Dst;
-			if (Connect(inet_ntoa(ip), m_ClientPort)) {
-				m_LiveStreamer = new cStreamdevLiveStreamer(0, this);
-				if (m_LiveStreamer->SetChannel(Channel, m_StreamType)) {
-					m_LiveStreamer->SetDevice(device);
-					if (!SetDSCP())
-						LOG_ERROR_STR("unable to set DSCP sockopt");
-					Dprintf("streamer start\n");
-					m_LiveStreamer->Start(this);
-					return true;
-				}
-				else
-					esyslog("streamdev-server IGMP: SetDevice failed");
-				DELETENULL(m_LiveStreamer);
-			}
-			else
-				esyslog("streamdev-server IGMP: Connect failed: %m");
-		}
 		else
-			esyslog("streamdev-server IGMP: GetDevice failed");
+			esyslog("streamdev-server IGMP: Connect failed: %m");
+		return false;
 	}
 	else
 		esyslog("streamdev-server IGMP: Channel not found");
 	return false;
 }
 
+void cConnectionIGMP::Welcome()
+{
+	cDevice *device = NULL;
+	if (ProvidesChannel(m_Channel, 0))
+		device = GetDevice(m_Channel, 0);
+	if (device != NULL) {
+		device->SwitchChannel(m_Channel, false);
+		m_LiveStreamer = new cStreamdevLiveStreamer(0, this);
+		if (m_LiveStreamer->SetChannel(m_Channel, m_StreamType)) {
+			m_LiveStreamer->SetDevice(device);
+			if (!SetDSCP())
+				LOG_ERROR_STR("unable to set DSCP sockopt");
+			Dprintf("streamer start\n");
+			m_LiveStreamer->Start(this);
+		}
+		else {
+			esyslog("streamdev-server IGMP: SetChannel failed");
+			DELETENULL(m_LiveStreamer);
+		}
+	}
+	else
+		esyslog("streamdev-server IGMP: GetDevice failed");
+}
+
 void cConnectionIGMP::Stop()
 {
 	if (m_LiveStreamer) {

server/connectionIGMP.h

@@ -20,12 +20,14 @@ private:
 	cStreamdevLiveStreamer           *m_LiveStreamer;
 	int                               m_ClientPort;
 	eStreamType                       m_StreamType;
+	cChannel                         *m_Channel;
 
 public:
 	cConnectionIGMP(const char* Name, int ClientPort, eStreamType StreamType);
 	virtual ~cConnectionIGMP();
 
-	bool Start(cChannel *Channel, in_addr_t Dst);
+	bool SetChannel(cChannel *Channel, in_addr_t Dst);
+	virtual void Welcome(void);
 	void Stop();
 
 	/* Not used here */