more graceful handling of disconnects

src/Platform.h

@@ -157,10 +157,11 @@ void WriteGBASave(const u8* savedata, u32 savelen, u32 writeoffset, u32 writelen
 bool MP_Init();
 void MP_DeInit();
 int MP_SendPacket(u8* data, int len, u64 timestamp);
-int MP_RecvPacket(u8* data, bool block, u64* timestamp);
+int MP_RecvPacket(u8* data, u64* timestamp);
 int MP_SendCmd(u8* data, int len, u64 timestamp);
 int MP_SendReply(u8* data, int len, u64 timestamp, u16 aid);
 int MP_SendAck(u8* data, int len, u64 timestamp);
+int MP_RecvHostPacket(u8* data, u64* timestamp);
 u16 MP_RecvReplies(u8* data, u64 timestamp, u16 aidmask);
 
 

src/Wifi.cpp

@@ -1150,6 +1150,7 @@ bool CheckRX(int type) // 0=regular 1=MP replies 2=MP host frames
     if (IOPORT(W_RXBufBegin) == IOPORT(W_RXBufEnd))
         return false;
 
+    int rxlen;
     u16 framelen;
     u16 framectl;
     u8 txrate;
@@ -1160,9 +1161,24 @@ bool CheckRX(int type) // 0=regular 1=MP replies 2=MP host frames
     for (;;)
     {
         timestamp = 0;
-        int rxlen = Platform::MP_RecvPacket(RXBuffer, (type != 0), &timestamp);
+
-        if ((rxlen == 0) && (type == 0)) rxlen = WifiAP::RecvPacket(RXBuffer);
+        if (type == 0)
-        if (rxlen == 0) return false;
+        {
+            rxlen = Platform::MP_RecvPacket(RXBuffer, &timestamp);
+            if (rxlen <= 0)
+                rxlen = WifiAP::RecvPacket(RXBuffer);
+        }
+        else
+        {
+            rxlen = Platform::MP_RecvHostPacket(RXBuffer, &timestamp);
+            if (rxlen < 0)
+            {
+                // host is gone
+                IsMPClient = false;
+            }
+        }
+
+        if (rxlen <= 0) return false;
         if (rxlen < 12+24) continue;
 
         framelen = *(u16*)&RXBuffer[10];

src/frontend/qt_sdl/LocalMP.cpp

@@ -81,6 +81,8 @@ const u32 kReplyEnd = kQueueSize;
 
 const int RecvTimeout = 500;
 
+int LastHostID;
+
 
 // we need to come up with our own abstraction layer for named semaphores
 // because QSystemSemaphore doesn't support waiting with a timeout
@@ -220,6 +222,8 @@ bool Init()
     SemInit(InstanceID);
     SemInit(16+InstanceID);
 
+    LastHostID = -1;
+
     printf("MP comm init OK, instance ID %d\n", InstanceID);
 
     return true;
@@ -363,12 +367,7 @@ int SendPacketGeneric(u32 type, u8* packet, int len, u64 timestamp)
     return len;
 }
 
-int SendPacket(u8* packet, int len, u64 timestamp)
+int RecvPacketGeneric(u8* packet, bool block, u64* timestamp)
-{
-    return SendPacketGeneric(0, packet, len, timestamp);
-}
-
-int RecvPacket(u8* packet, bool block, u64* timestamp)
 {
     for (;;)
     {
@@ -402,14 +401,29 @@ int RecvPacket(u8* packet, bool block, u64* timestamp)
         }
 
         if (pktheader.Length)
+        {
             FIFORead(0, packet, pktheader.Length);
 
+            if (pktheader.Type == 1)
+                LastHostID = pktheader.SenderID;
+        }
+
         if (timestamp) *timestamp = pktheader.Timestamp;
         MPQueue->unlock();
         return pktheader.Length;
     }
 }
 
+int SendPacket(u8* packet, int len, u64 timestamp)
+{
+    return SendPacketGeneric(0, packet, len, timestamp);
+}
+
+int RecvPacket(u8* packet, u64* timestamp)
+{
+    return RecvPacketGeneric(packet, false, timestamp);
+}
+
 
 int SendCmd(u8* packet, int len, u64 timestamp)
 {
@@ -426,10 +440,42 @@ int SendAck(u8* packet, int len, u64 timestamp)
     return SendPacketGeneric(3, packet, len, timestamp);
 }
 
+int RecvHostPacket(u8* packet, u64* timestamp)
+{
+    if (LastHostID != -1)
+    {
+        // check if the host is still connected
+
+        MPQueue->lock();
+        u8* data = (u8*)MPQueue->data();
+        MPQueueHeader* header = (MPQueueHeader*)&data[0];
+        u16 curinstmask = header->InstanceBitmask;
+        MPQueue->unlock();
+
+        if (!(curinstmask & (1 << LastHostID)))
+            return -1;
+    }
+
+    return RecvPacketGeneric(packet, true, timestamp);
+}
+
 u16 RecvReplies(u8* packets, u64 timestamp, u16 aidmask)
 {
     u16 ret = 0;
-    u16 instmask = (1 << InstanceID);
+    u16 myinstmask = (1 << InstanceID);
+    u16 curinstmask;
+
+    {
+        MPQueue->lock();
+        u8* data = (u8*)MPQueue->data();
+        MPQueueHeader* header = (MPQueueHeader*)&data[0];
+        curinstmask = header->InstanceBitmask;
+        MPQueue->unlock();
+    }
+
+    // if all clients have left: return early
+    if ((myinstmask & curinstmask) == curinstmask)
+        return 0;
 
     for (;;)
     {
@@ -472,8 +518,8 @@ u16 RecvReplies(u8* packets, u64 timestamp, u16 aidmask)
             ret |= (1 << aid);
         }
 
-        instmask |= (1 << pktheader.SenderID);
+        myinstmask |= (1 << pktheader.SenderID);
-        if ((instmask & header->InstanceBitmask) == header->InstanceBitmask)
+        if ((myinstmask & curinstmask) == curinstmask)
         {
             // all the clients have sent their reply
 

src/frontend/qt_sdl/LocalMP.h

@@ -27,10 +27,11 @@ namespace LocalMP
 bool Init();
 void DeInit();
 int SendPacket(u8* data, int len, u64 timestamp);
-int RecvPacket(u8* data, bool block, u64* timestamp);
+int RecvPacket(u8* data, u64* timestamp);
 int SendCmd(u8* data, int len, u64 timestamp);
 int SendReply(u8* data, int len, u64 timestamp, u16 aid);
 int SendAck(u8* data, int len, u64 timestamp);
+int RecvHostPacket(u8* data, u64* timestamp);
 u16 RecvReplies(u8* data, u64 timestamp, u16 aidmask);
 
 }

src/frontend/qt_sdl/Platform.cpp

@@ -374,9 +374,9 @@ int MP_SendPacket(u8* data, int len, u64 timestamp)
     return LocalMP::SendPacket(data, len, timestamp);
 }
 
-int MP_RecvPacket(u8* data, bool block, u64* timestamp)
+int MP_RecvPacket(u8* data, u64* timestamp)
 {
-    return LocalMP::RecvPacket(data, block, timestamp);
+    return LocalMP::RecvPacket(data, timestamp);
 }
 
 int MP_SendCmd(u8* data, int len, u64 timestamp)
@@ -394,6 +394,11 @@ int MP_SendAck(u8* data, int len, u64 timestamp)
     return LocalMP::SendAck(data, len, timestamp);
 }
 
+int MP_RecvHostPacket(u8* data, u64* timestamp)
+{
+    return LocalMP::RecvHostPacket(data, timestamp);
+}
+
 u16 MP_RecvReplies(u8* data, u64 timestamp, u16 aidmask)
 {
     return LocalMP::RecvReplies(data, timestamp, aidmask);