fix: adding ping/pong support to avoid error on receive

James-Frowen · James-Frowen · commit 0828049f4c33 · 2025-04-27T17:07:21.000+01:00
diff --git a/source/Runtime/Common/Connection.cs b/source/Runtime/Common/Connection.cs
@@ -34,6 +34,7 @@ internal sealed class Connection : IDisposable
 
         public ManualResetEventSlim sendPending = new ManualResetEventSlim(false);
         public ConcurrentQueue<ArrayBuffer> sendQueue = new ConcurrentQueue<ArrayBuffer>();
+        public bool needsPong;
 
         public Action<Connection> onDispose;
         private volatile bool hasDisposed;
diff --git a/source/Runtime/Common/MessageProcessor.cs b/source/Runtime/Common/MessageProcessor.cs
@@ -10,6 +10,8 @@ public enum OpCode : byte
         text = 1,
         binary = 2,
         close = 8,
+        ping = 9,
+        pong = 10,
     }
 
     public static class MessageProcessor
@@ -165,8 +167,8 @@ static void ThrowIfBadOpCode(OpCode opcode, bool finished, bool opCodeContinuati
             }
             else
             {
-                // Normal message, should be binary, text, or close
-                if (opcode == OpCode.binary || opcode == OpCode.close)
+                // Normal message, should be binary, text, close, or ping
+                if (opcode == OpCode.binary || opcode == OpCode.close || opcode == OpCode.ping || opcode == OpCode.pong)
                     return;
 
                 throw new InvalidDataException($"Unexpected opcode {opcode}");
diff --git a/source/Runtime/Common/ReceiveLoop.cs b/source/Runtime/Common/ReceiveLoop.cs
@@ -130,6 +130,14 @@ static void ReadOneMessage(Config config, byte[] buffer)
                     case OpCode.close:
                         HandleCloseMessage(config, buffer, msgOffset, header.payloadLength);
                         break;
+                    case OpCode.ping:
+                        // Set flag to send pong response
+                        conn.needsPong = true;
+                        conn.sendPending.Set();
+                        break;
+                    case OpCode.pong:
+                        // nothing
+                        break;
                 }
             }
             else
diff --git a/source/Runtime/Common/SendLoop.cs b/source/Runtime/Common/SendLoop.cs
@@ -14,6 +14,8 @@ public static class SendLoopConfig
     }
     internal static class SendLoop
     {
+        private static readonly byte[] PongResponse = new byte[] { 0b1000_0000 | 10, 0 }; // FIN bit + PONG opcode, Length 0
+
         public struct Config
         {
             public readonly Connection conn;
@@ -57,6 +59,10 @@ public static void Loop(Config config)
                 {
                     // wait for message
                     conn.sendPending.Wait();
+
+                    if (conn.needsPong)
+                        SendPongResponse(conn);
+
                     // wait for 1ms for mirror to send other messages
                     if (SendLoopConfig.sleepBeforeSend)
                     {
@@ -130,6 +136,13 @@ public static void Loop(Config config)
             }
         }
 
+
+        static void SendPongResponse(Connection conn)
+        {
+            conn.stream.Write(PongResponse, 0, PongResponse.Length);
+            conn.needsPong = false;
+        }
+
         /// <returns>new offset in buffer</returns>
         static int SendMessage(byte[] buffer, int startOffset, ArrayBuffer msg, bool setMask, MaskHelper maskHelper)
         {

Original file line number	Diff line number	Diff line change
`@@ -10,6 +10,8 @@ public enum OpCode : byte`
`10`	`10`	`text = 1,`
`11`	`11`	`binary = 2,`
`12`	`12`	`close = 8,`
	`13`	`+ ping = 9,`
	`14`	`+ pong = 10,`
`13`	`15`	`}`
`14`	`16`
`15`	`17`	`public static class MessageProcessor`
`@@ -165,8 +167,8 @@ static void ThrowIfBadOpCode(OpCode opcode, bool finished, bool opCodeContinuati`
`165`	`167`	`}`
`166`	`168`	`else`
`167`	`169`	`{`
`168`		`- // Normal message, should be binary, text, or close`
`169`		`- if (opcode == OpCode.binary \|\| opcode == OpCode.close)`
	`170`	`+ // Normal message, should be binary, text, close, or ping`
	`171`	`+ if (opcode == OpCode.binary \|\| opcode == OpCode.close \|\| opcode == OpCode.ping \|\| opcode == OpCode.pong)`
`170`	`172`	`return;`
`171`	`173`
`172`	`174`	`throw new InvalidDataException($"Unexpected opcode {opcode}");`
Original file line number	Diff line number	Diff line change
`@@ -14,6 +14,8 @@ public static class SendLoopConfig`
`14`	`14`	`}`
`15`	`15`	`internal static class SendLoop`
`16`	`16`	`{`
	`17`	`+ private static readonly byte[] PongResponse = new byte[] { 0b1000_0000 \| 10, 0 }; // FIN bit + PONG opcode, Length 0`
	`18`	`+`
`17`	`19`	`public struct Config`
`18`	`20`	`{`
`19`	`21`	`public readonly Connection conn;`
`@@ -57,6 +59,10 @@ public static void Loop(Config config)`
`57`	`59`	`{`
`58`	`60`	`// wait for message`
`59`	`61`	`conn.sendPending.Wait();`
	`62`	`+`
	`63`	`+ if (conn.needsPong)`
	`64`	`+ SendPongResponse(conn);`
	`65`	`+`
`60`	`66`	`// wait for 1ms for mirror to send other messages`
`61`	`67`	`if (SendLoopConfig.sleepBeforeSend)`
`62`	`68`	`{`
`@@ -130,6 +136,13 @@ public static void Loop(Config config)`
`130`	`136`	`}`
`131`	`137`	`}`
`132`	`138`
	`139`	`+`
	`140`	`+ static void SendPongResponse(Connection conn)`
	`141`	`+ {`
	`142`	`+ conn.stream.Write(PongResponse, 0, PongResponse.Length);`
	`143`	`+ conn.needsPong = false;`
	`144`	`+ }`
	`145`	`+`
`133`	`146`	`/// <returns>new offset in buffer</returns>`
`134`	`147`	`static int SendMessage(byte[] buffer, int startOffset, ArrayBuffer msg, bool setMask, MaskHelper maskHelper)`
`135`	`148`	`{`