fix(ablegacy): prune per-key gates when an indirect index moves

Review 07 L7: each index value an indirect tag (N7:[N7:0]) swept through left a per-runtime and a creation SemaphoreSlim in the device's gate tables until shutdown. A moved index now drops the stale resolution's gates along with its handle, and sweeps any other stale resolution of the same tag a concurrent reader cached, so the tables stay bounded by the authored set. Refs #738 Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
2026-10-22 14:17:16 -04:00
parent 92171a01ec
commit 7377daa9b0
2 changed files with 56 additions and 2 deletions
@@ -128,4 +128,32 @@ public sealed class AbLegacyIndirectAddressingTests
        w.StatusCode.ShouldBe(AbLegacyStatusMapper.BadOutOfRange);
        f.Tags.Values.ShouldAllBe(t => t.WriteCount == 0);
    }
+
+    /// <summary>
+    ///     Review 07 L7: every index value an indirect tag sweeps through used to leave one per-runtime semaphore and
+    ///     one creation semaphore behind until shutdown. They are pruned with the stale resolution's handle, so the
+    ///     per-key gate tables stay bounded by the authored set however far the index sweeps.
+    /// </summary>
+    [Fact]
+    public async Task Sweeping_index_does_not_accumulate_per_key_gates()
+    {
+        var (drv, f) = await NewDriverAsync(new AbLegacyTagDefinition("Ind", Host, "N7:[N7:0]", AbLegacyDataType.Int));
+        Seed(f, ("N7:0", (short)10));
+        (await drv.ReadAsync(["Ind"], CancellationToken.None)).Single().StatusCode.ShouldBe(AbLegacyStatusMapper.Good);
+        var state = drv.GetDeviceState(Host)!;
+        var baseline = state.GateCount;
+
+        for (short i = 11; i < 60; i++)
+        {
+            f.Tags["N7:0"].Value = i;
+            f.Customise = p => new FakeAbLegacyTag(p) { Value = (short)(p.TagName == "N7:0" ? i : 1000 + i) };
+            var r = (await drv.ReadAsync(["Ind"], CancellationToken.None)).Single();
+            r.StatusCode.ShouldBe(AbLegacyStatusMapper.Good); // positive control: every resolution really read
+            r.Value.ShouldBe((short)(1000 + i));
+        }
+
+        state.GateCount.ShouldBe(baseline);
+        // Only the live resolution's handle (plus the index word's parent runtime) remains cached.
+        state.Runtimes.Keys.Count(k => k.StartsWith("Ind=>", StringComparison.Ordinal)).ShouldBe(1);
+    }
 }