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)
 {
 }
 
@@ -22,39 +23,45 @@ 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) {
-		cDevice *device = NULL;
-		if (ProvidesChannel(Channel, 0))
-			device = GetDevice(Channel, 0);
-		if (device != NULL) {
-			device->SwitchChannel(Channel, false);
+	if (Channel) {
+		m_Channel = Channel;
 		struct in_addr ip;
 		ip.s_addr = Dst;
-			if (Connect(inet_ntoa(ip), m_ClientPort)) {
+		if (Connect(inet_ntoa(ip), m_ClientPort))
+			return true;
+		else
+			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(Channel, m_StreamType)) {
+		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);
-					return true;
 		}
-				else
-					esyslog("streamdev-server IGMP: SetDevice failed");
+		else {
+			esyslog("streamdev-server IGMP: SetChannel failed");
 			DELETENULL(m_LiveStreamer);
 		}
-			else
-				esyslog("streamdev-server IGMP: Connect failed: %m");
 	}
 	else
 		esyslog("streamdev-server IGMP: GetDevice failed");
-	}
-	else
-		esyslog("streamdev-server IGMP: Channel not found");
-	return false;
 }
 
 void cConnectionIGMP::Stop()

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 */