feat(twincat): BOOL-within-word writes via driver-level parent-word RMW

2026-06-17 11:55:44 -04:00
parent 5c6b7cd6f9
commit a73e20fb28
3 changed files with 127 additions and 5 deletions
@@ -266,4 +266,86 @@ public sealed class TwinCATReadWriteTests

        factory.Clients[0].DisposeCount.ShouldBe(1);
    }
+
+    // ---- BOOL-within-word RMW writes ----
+
+    /// <summary>A BOOL-within-word set reads the parent word, ORs the bit, writes it back as UDInt.</summary>
+    [Fact]
+    public async Task Bit_set_RMWs_parent_word_as_UDInt()
+    {
+        var (drv, factory) = NewDriver(
+            new TwinCATTagDefinition("Flag", "ads://5.23.91.23.1.1:851", "MAIN.Flags.3", TwinCATDataType.Bool));
+        factory.Customise = () => new FakeTwinCATClient { Values = { ["MAIN.Flags"] = 0b0001u } };
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        var results = await drv.WriteAsync([new WriteRequest("Flag", true)], CancellationToken.None);
+
+        results.Single().StatusCode.ShouldBe(TwinCATStatusMapper.Good);
+        factory.Clients[0].Values["MAIN.Flags"].ShouldBe(0b1001u);
+        factory.Clients[0].WriteLog.ShouldContain(e =>
+            e.symbol == "MAIN.Flags" && e.type == TwinCATDataType.UDInt && e.bit == null);
+    }
+
+    /// <summary>A BOOL-within-word clear preserves the other bits in the parent word.</summary>
+    [Fact]
+    public async Task Bit_clear_preserves_other_bits()
+    {
+        var (drv, factory) = NewDriver(
+            new TwinCATTagDefinition("Flag", "ads://5.23.91.23.1.1:851", "MAIN.Flags.3", TwinCATDataType.Bool));
+        factory.Customise = () => new FakeTwinCATClient { Values = { ["MAIN.Flags"] = 0xFFFFu } };
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        await drv.WriteAsync([new WriteRequest("Flag", false)], CancellationToken.None);
+
+        factory.Clients[0].Values["MAIN.Flags"].ShouldBe(0xFFF7u);
+    }
+
+    /// <summary>RMW works on a DWORD parent (bit 20 set above the 16-bit boundary).</summary>
+    [Fact]
+    public async Task Bit_set_on_DWORD_parent_sets_high_bit()
+    {
+        var (drv, factory) = NewDriver(
+            new TwinCATTagDefinition("Hi", "ads://5.23.91.23.1.1:851", "GVL.Status.20", TwinCATDataType.Bool));
+        factory.Customise = () => new FakeTwinCATClient { Values = { ["GVL.Status"] = 0u } };
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        await drv.WriteAsync([new WriteRequest("Hi", true)], CancellationToken.None);
+
+        factory.Clients[0].Values["GVL.Status"].ShouldBe(1u << 20);
+    }
+
+    /// <summary>A failed parent read short-circuits the RMW and surfaces the read status.</summary>
+    [Fact]
+    public async Task Bit_write_surfaces_parent_read_failure()
+    {
+        var (drv, factory) = NewDriver(
+            new TwinCATTagDefinition("Flag", "ads://5.23.91.23.1.1:851", "MAIN.Flags.3", TwinCATDataType.Bool));
+        factory.Customise = () => new FakeTwinCATClient
+        {
+            ReadStatuses = { ["MAIN.Flags"] = TwinCATStatusMapper.BadNodeIdUnknown },
+        };
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        var results = await drv.WriteAsync([new WriteRequest("Flag", true)], CancellationToken.None);
+
+        results.Single().StatusCode.ShouldBe(TwinCATStatusMapper.BadNodeIdUnknown);
+        factory.Clients[0].WriteLog.ShouldBeEmpty();
+    }
+
+    /// <summary>Concurrent bit writes to the same word compose correctly (per-parent lock).</summary>
+    [Fact]
+    public async Task Concurrent_bit_writes_to_same_word_compose_correctly()
+    {
+        var tags = Enumerable.Range(0, 8)
+            .Select(b => new TwinCATTagDefinition($"Bit{b}", "ads://5.23.91.23.1.1:851", $"MAIN.Flags.{b}", TwinCATDataType.Bool))
+            .ToArray();
+        var (drv, factory) = NewDriver(tags);
+        factory.Customise = () => new FakeTwinCATClient { Values = { ["MAIN.Flags"] = 0u } };
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        await Task.WhenAll(Enumerable.Range(0, 8).Select(b =>
+            drv.WriteAsync([new WriteRequest($"Bit{b}", true)], CancellationToken.None)));
+
+        Convert.ToUInt32(factory.Clients[0].Values["MAIN.Flags"]).ShouldBe(0xFFu);
+    }
 }