Better recovery of network overload situations, now resynchronize by skipping cycles.

git-svn-id: http://subversion.jackaudio.org/jack/jack2/trunk/jackmp@3268 0c269be4-1314-0410-8aa9-9f06e86f4224

ChangeLog

@@ -23,6 +23,10 @@ Michael Voigt
   Jackdmp changes log
 ---------------------------
 
+2009-01-27 Stephane Letz  <letz@grame.fr>
+
+	* Better recovery of network overload situations, now "resynchronize" by skipping cycles."
+
 2009-01-26 Stephane Letz  <letz@grame.fr>
 
 	* Fix JackNetInterface::SetNetBufferSize for socket buffer size computation and JackNetMasterInterface::DataRecv if synch packet is received, various cleanup.

common/JackNetInterface.cpp

@@ -357,7 +357,15 @@ namespace Jack
         }
         return rx_bytes;
     }
-
+    
+    bool JackNetMasterInterface::IsSynched()
+    {
+        if (fParams.fNetworkMode == 's')
+            return (fCycleOffset < 3);
+        else 
+            return true;
+    }
+    
     int JackNetMasterInterface::SyncSend()
     {
         fTxHeader.fCycle++;
@@ -411,14 +419,13 @@ namespace Jack
 
     int JackNetMasterInterface::SyncRecv()
     {
-        int rx_bytes = 0;
-        int cycle_offset = 0;
         packet_header_t* rx_head = reinterpret_cast<packet_header_t*> ( fRxBuffer );
-        rx_bytes = Recv ( fParams.fMtu, MSG_PEEK );
+        int rx_bytes = Recv ( fParams.fMtu, MSG_PEEK );
+        
         if ( ( rx_bytes == 0 ) || ( rx_bytes == SOCKET_ERROR ) )
             return rx_bytes;
 
-        cycle_offset = fTxHeader.fCycle - rx_head->fCycle;
+        fCycleOffset = fTxHeader.fCycle - rx_head->fCycle;
       
         switch ( fParams.fNetworkMode )
         {
@@ -428,13 +435,14 @@ namespace Jack
                 //  - if the network is two fast, just wait the next cycle, this mode allows a shorter cycle duration for the master
                 //  - this mode will skip the two first cycles, thus it lets time for data to be processed and queued on the socket rx buffer
                 //the slow mode is the safest mode because it wait twice the bandwidth relative time (send/return + process)
-                
-                if ( cycle_offset < 2 )
+                if (fCycleOffset < 2)
                      return 0;
                 else
                     rx_bytes = Recv ( rx_head->fPacketSize, 0 );
-                if (cycle_offset > 2) 
-                    jack_log("Warning : '%s' runs in slow network mode, but data received too late (%d cycle(s) offset)", fParams.fName, cycle_offset);
+                    
+                if (fCycleOffset > 2) {
+                    jack_info("Warning : '%s' runs in slow network mode, but data received too late (%d cycle(s) offset)", fParams.fName, fCycleOffset);
+                }
                 break;
 
             case 'n' :
@@ -442,12 +450,13 @@ namespace Jack
                 //  - extra latency is set to one cycle, what is the time needed to receive streams using full network bandwidth
                 //  - if the network is too fast, just wait the next cycle, the benefit here is the master's cycle is shorter
                 //  - indeed, data is supposed to be on the network rx buffer, so we don't have to wait for it
-                if ( cycle_offset < 1 )
+                if (fCycleOffset < 1)
                     return 0;
                 else
                     rx_bytes = Recv ( rx_head->fPacketSize, 0 );
-                if (cycle_offset != 1) 
-                    jack_info("'%s' can't run in normal network mode, data received too late (%d cycle(s) offset)", fParams.fName, cycle_offset);
+                    
+                if (fCycleOffset != 1) 
+                    jack_info("'%s' can't run in normal network mode, data received too late (%d cycle(s) offset)", fParams.fName, fCycleOffset);
                 break;
 
             case 'f' :
@@ -456,8 +465,9 @@ namespace Jack
                 //    - here, receive data, we can't keep it queued on the rx buffer,
                 //    - but if there is a cycle offset, tell the user, that means we're not in fast mode anymore, network is too slow
                 rx_bytes = Recv ( rx_head->fPacketSize, 0 );
-                if (cycle_offset != 0)
-                    jack_info("'%s' can't run in fast network mode, data received too late (%d cycle(s) offset)", fParams.fName, cycle_offset);
+                
+                if (fCycleOffset != 0)
+                    jack_info("'%s' can't run in fast network mode, data received too late (%d cycle(s) offset)", fParams.fName, fCycleOffset);
                 break;
         }
 
@@ -507,8 +517,9 @@ namespace Jack
                         // SL: 25/01/09
                         // if ( !IsNextPacket() )
                         //    jack_error ( "Packet(s) missing from '%s'...", fParams.fName );
-                        if (recvd_audio_pckt++ != rx_head->fSubCycle)
-                            jack_error ( "Packet(s) missing from '%s'...", fParams.fName );
+                        if (recvd_audio_pckt++ != rx_head->fSubCycle) {
+                            jack_error("Packet(s) missing from '%s'...", fParams.fSlaveNetName);
+                        }
                         fRxHeader.fCycle = rx_head->fCycle;
                         fRxHeader.fSubCycle = rx_head->fSubCycle;
                         fRxHeader.fIsLastPckt = rx_head->fIsLastPckt;
@@ -752,8 +763,9 @@ namespace Jack
                         //SL: 25/01/09
                         // if ( !IsNextPacket() )
                         //    jack_error ( "Packet(s) missing..." );
-                        if (recvd_audio_pckt++ != rx_head->fSubCycle)
-                            jack_error ( "Packet(s) missing from '%s'...", fParams.fName );
+                        if (recvd_audio_pckt++ != rx_head->fSubCycle) {
+                            jack_error("Packet(s) missing from '%s'...", fParams.fMasterNetName);
+                        }
                         fRxHeader.fCycle = rx_head->fCycle;
                         fRxHeader.fSubCycle = rx_head->fSubCycle;
                         fRxHeader.fIsLastPckt = rx_head->fIsLastPckt;

common/JackNetInterface.h

@@ -100,6 +100,7 @@ namespace Jack
     {
         protected:
             bool fRunning;
+            int fCycleOffset;
 
             bool Init();
             int SetRxTimeout();
@@ -112,9 +113,11 @@ namespace Jack
 
             int Send ( size_t size, int flags );
             int Recv ( size_t size, int flags );
+            
+            bool IsSynched();
 
         public:
-            JackNetMasterInterface() : JackNetInterface(), fRunning ( false )
+            JackNetMasterInterface() : JackNetInterface(), fRunning(false), fCycleOffset(0)
             {}
             JackNetMasterInterface ( session_params_t& params, JackNetSocket& socket, const char* multicast_ip )
                     : JackNetInterface ( params, socket, multicast_ip )

common/JackNetManager.cpp

@@ -414,25 +414,31 @@ namespace Jack
             fNetAudioPlaybackBuffer->SetBuffer ( port_index, static_cast<sample_t*> ( jack_port_get_buffer ( fAudioPlaybackPorts[port_index],
                                                  fParams.fPeriodSize ) ) );
 
-        //encode the first packet
-        if ( EncodeSyncPacket() < 0 )
-            return 0;
-
-        //send sync
-        if ( SyncSend() == SOCKET_ERROR )
-            return SOCKET_ERROR;
-
-#ifdef JACK_MONITOR
-        fNetTimeMon->Add ( ( ( ( float ) ( jack_get_time() - begin_time ) ) / ( float ) fPeriodUsecs ) * 100.f );
-#endif
-
-        //send data
-        if ( DataSend() == SOCKET_ERROR )
-            return SOCKET_ERROR;
-
-#ifdef JACK_MONITOR
-        fNetTimeMon->Add ( ( ( ( float ) ( jack_get_time() - begin_time ) ) / ( float ) fPeriodUsecs ) * 100.f );
-#endif
+        if (IsSynched()) {  // only send if connection is "synched"
+        
+            //encode the first packet
+            if ( EncodeSyncPacket() < 0 )
+                return 0;
+
+            //send sync
+            if ( SyncSend() == SOCKET_ERROR )
+                return SOCKET_ERROR;
+
+    #ifdef JACK_MONITOR
+            fNetTimeMon->Add ( ( ( ( float ) ( jack_get_time() - begin_time ) ) / ( float ) fPeriodUsecs ) * 100.f );
+    #endif
+
+            //send data
+            if ( DataSend() == SOCKET_ERROR )
+                return SOCKET_ERROR;
+
+    #ifdef JACK_MONITOR
+            fNetTimeMon->Add ( ( ( ( float ) ( jack_get_time() - begin_time ) ) / ( float ) fPeriodUsecs ) * 100.f );
+    #endif
+    
+        } else {
+            jack_error("Connection is not synched, skip cycle...\n");
+        }
 
         //receive sync
         res = SyncRecv();