fix(saf): publish _sweepTask only on CAS win so StopAsync drains the real in-flight sweep (plan R2-02 T8)

2026-07-13 10:09:40 -04:00
parent 6e1ab62d27
commit 61442b5f81
2 changed files with 96 additions and 4 deletions
@@ -821,4 +821,67 @@ public class StoreAndForwardServiceTests : IAsyncLifetime, IDisposable
        }
        finally { await service.StopAsync(); }
    }
+
+    // ── R2 T8: _sweepTask clobber (N3) ──
+
+    [Fact]
+    public async Task TriggerSweep_WhileSweepInFlight_DoesNotClobberTheDrainHandle()
+    {
+        var service = CreateService(retryTimerInterval: TimeSpan.FromHours(1));
+        var entered = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+        var release = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+        service.RegisterDeliveryHandler(StoreAndForwardCategory.ExternalSystem, async _ =>
+        {
+            entered.TrySetResult();
+            await release.Task;
+            return true;
+        });
+        await service.StartAsync();
+        try
+        {
+            await service.EnqueueAsync(StoreAndForwardCategory.ExternalSystem, "t", "{}",
+                attemptImmediateDelivery: false, retryInterval: TimeSpan.Zero);
+
+            service.TriggerSweep();                       // real sweep, blocked in the handler
+            await entered.Task.WaitAsync(TimeSpan.FromSeconds(5));
+            service.TriggerSweep();                       // redundant kick — pre-fix clobbers _sweepTask
+
+            var handle = service.CurrentSweepTaskForTest;
+            Assert.NotNull(handle);
+            Assert.False(handle!.IsCompleted);            // pre-fix: true (a completed no-op replaced the real sweep)
+        }
+        finally
+        {
+            release.TrySetResult();
+            await service.StopAsync();
+        }
+    }
+
+    [Fact]
+    public async Task StopAsync_WaitsForTheRealInFlightSweep_EvenAfterARedundantTrigger()
+    {
+        var service = CreateService(retryTimerInterval: TimeSpan.FromHours(1));
+        var entered = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+        var release = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+        service.RegisterDeliveryHandler(StoreAndForwardCategory.ExternalSystem, async _ =>
+        {
+            entered.TrySetResult();
+            await release.Task;
+            return true;
+        });
+        await service.StartAsync();
+        await service.EnqueueAsync(StoreAndForwardCategory.ExternalSystem, "t", "{}",
+            attemptImmediateDelivery: false, retryInterval: TimeSpan.Zero);
+
+        service.TriggerSweep();
+        await entered.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        service.TriggerSweep(); // the clobbering kick
+
+        var stop = service.StopAsync();
+        await Task.Delay(300);
+        Assert.False(stop.IsCompleted); // pre-fix: StopAsync already returned (awaited the no-op)
+
+        release.TrySetResult();
+        await stop.WaitAsync(TimeSpan.FromSeconds(5)); // drains the real sweep promptly once released
+    }
 }