fix: prevent QUIC heartbeat stalls and isolate TCP retransmission counters [CI] [SKIP TESTS]

backend/tests/MoShiro.Backend.Analysis.Tests/OpTests.cs

@@ -211,6 +211,55 @@ public sealed class OpTests
         Assert.Equal(100UL, retrans.Denominator);
     }
 
+    [Fact]
+    public void Retrans_InterleavedConnections_DoNotCreateFalseRetransmissions()
+    {
+        long ts = ChunkFactory.ProbeUs(0);
+        var builder = new StreamBuilder(Kinds.TcpEcho.FindStream("tcp_info")!);
+        builder.Add(ts, 0, 40_000, 0, 10, 10, 1000, 0, 1);
+        builder.Add(ts + 1_000_000, 0, 40_000, 0, 10, 20, 1100, 0, 2);
+        builder.Add(ts + 2_000_000, 0, 40_000, 0, 10, 11, 1100, 0, 1);
+        builder.Add(ts + 3_000_000, 0, 40_000, 0, 10, 21, 1200, 0, 2);
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+            _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [builder.Build()]);
+        var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
+        Assert.Equal(2UL, retrans.Numerator);
+        Assert.Equal(200UL, retrans.Denominator);
+    }
+
+    [Fact]
+    public void Retrans_OutOfOrderSamples_DoNotMoveTheBaselineBackwards()
+    {
+        long ts = ChunkFactory.ProbeUs(0);
+        RawStream info = ChunkFactory.TcpInfo([
+            (ts, 0, 40_000u, 0u, 100u),
+            (ts + 2_000_000, 0, 40_000u, 2u, 300u),
+            (ts + 1_000_000, 0, 40_000u, 1u, 200u),
+            (ts + 3_000_000, 0, 40_000u, 3u, 400u),
+        ]);
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+            _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [info]);
+        var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
+        Assert.Equal(3UL, retrans.Numerator);
+        Assert.Equal(300UL, retrans.Denominator);
+    }
+
+    [Fact]
+    public void Retrans_EqualConnectionIdsOnDifferentSides_AreIndependent()
+    {
+        long ts = ChunkFactory.ProbeUs(0);
+        var builder = new StreamBuilder(Kinds.TcpEcho.FindStream("tcp_info")!);
+        builder.Add(ts, 0, 40_000, 0, 10, 10, 1000, 0, 1);
+        builder.Add(ts, 1, 40_000, 0, 10, 100, 2000, 0, 1);
+        builder.Add(ts + 1_000_000, 0, 40_000, 0, 10, 11, 1100, 0, 1);
+        builder.Add(ts + 1_000_000, 1, 40_000, 0, 10, 102, 2200, 0, 1);
+        RawChunk chunk = ChunkFactory.Echo(s_agent, "tcp_echo", T0, 10, 100,
+            _ => new EchoPacket(false, false, 20_000, 20_000), extraStreams: [builder.Build()]);
+        var retrans = (RatioAcc)EvaluateOneBucket(chunk, "tcp.retrans").Items["tcp.retrans"];
+        Assert.Equal(3UL, retrans.Numerator);
+        Assert.Equal(300UL, retrans.Denominator);
+    }
+
     [Fact]
     public void Connect_Outcomes_AreCountedByClass()
     {

backend/tests/MoShiro.TestSupport/AgentSimulator.cs

@@ -274,6 +274,11 @@ public sealed class AgentSimulator : IAsyncDisposable
             {
                 // 已经断开
             }
+            catch (OperationCanceledException) when (_stop.IsCancellationRequested)
+            {
+                // Canceling the receive loop may abort/dispose the transport
+                // between the State check and CloseOutputAsync.
+            }
         }
 
         if (_loop is not null)

backend/tests/MoShiro.TestSupport/ChunkFactory.cs

@@ -79,7 +79,7 @@ public static class ChunkFactory
         var builder = new StreamBuilder(Kinds.TcpEcho.FindStream("tcp_info")!);
         foreach ((long ts, byte side, uint srtt, uint retrans, uint segs) in samples)
         {
-            builder.Add(ts, side, srtt, srtt / 4, 10, retrans, segs, segs * 100L);
+            builder.Add(ts, side, srtt, srtt / 4, 10, retrans, segs, segs * 100L, null);
         }
 
         return builder.Build();