From ac5e9d84f0798853f88ffb3687fb5a3bce07cfe7 Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Tue, 10 Nov 2026 10:37:52 -0500
Subject: [PATCH] fix: propagate SDK request cancellation to historian calls

---
 .../OtOpcUaNodeManager.cs                     | 33 ++++++++++---------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
index 57b1929a..9c7f539c 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
@@ -5577,7 +5577,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
         nodesToProcess = AuthorizeHistoryRead(context, nodesToProcess, results, errors);
         WithHistoryReadBatchLimiter(nodesToProcess, results, errors, () =>
         {
-            using var deadline = CreateDeadline();
+            using var deadline = CreateDeadline(context);
             var ct = deadline?.Token ?? CancellationToken.None;
             var work = new List<Func<Task>>(nodesToProcess.Count);
             foreach (var handle in nodesToProcess)
@@ -5632,7 +5632,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
         var served = AdvertisedAggregateFunctions.ServedBy(HistorianDataSource);
         WithHistoryReadBatchLimiter(nodesToProcess, results, errors, () =>
         {
-            using var deadline = CreateDeadline();
+            using var deadline = CreateDeadline(context);
             var ct = deadline?.Token ?? CancellationToken.None;
             var work = new List<Func<Task>>(nodesToProcess.Count);
             foreach (var handle in nodesToProcess)
@@ -5691,7 +5691,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
         nodesToProcess = AuthorizeHistoryRead(context, nodesToProcess, results, errors);
         WithHistoryReadBatchLimiter(nodesToProcess, results, errors, () =>
         {
-            using var deadline = CreateDeadline();
+            using var deadline = CreateDeadline(context);
             var ct = deadline?.Token ?? CancellationToken.None;
             var work = new List<Func<Task>>(nodesToProcess.Count);
             foreach (var handle in nodesToProcess)
@@ -5781,7 +5781,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
         nodesToProcess = AuthorizeHistoryRead(context, nodesToProcess, results, errors);
         WithHistoryReadBatchLimiter(nodesToProcess, results, errors, () =>
         {
-            using var deadline = CreateDeadline();
+            using var deadline = CreateDeadline(context);
             var ct = deadline?.Token ?? CancellationToken.None;
             var work = new List<Func<Task>>(nodesToProcess.Count);
             foreach (var handle in nodesToProcess)
@@ -6381,7 +6381,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
 
         WithHistoryReadBatchLimiter(planned.Select(p => p.Handle).ToList(), results, errors, () =>
         {
-            using var deadline = CreateDeadline();
+            using var deadline = CreateDeadline(context);
             var ct = deadline?.Token ?? CancellationToken.None;
             var work = new List<Func<Task>>(planned.Count);
             foreach (var (handle, tagname, operation) in planned)
@@ -6753,16 +6753,19 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
         }
     }
 
-    /// <summary>
-    ///     Create the per-request deadline source for a HistoryRead arm (arch-review 03/S3): a
-    ///     <see cref="CancellationTokenSource"/> that fires after <see cref="HistoryReadDeadline"/>, so a
-    ///     single request can never hold an SDK request thread longer than the deadline regardless of node
-    ///     count. Returns <c>null</c> when the deadline is non-positive (unbounded — the arm then passes
-    ///     <see cref="CancellationToken.None"/>), matching the <c>ServerHistorianOptions</c> warning.
-    /// </summary>
-    /// <returns>The deadline source, or <c>null</c> for an unbounded (non-positive) deadline.</returns>
-    private CancellationTokenSource? CreateDeadline() =>
-        HistoryReadDeadline > TimeSpan.Zero ? new CancellationTokenSource(HistoryReadDeadline) : null;
+    /// <summary>Link the SDK request lifetime to the application's per-batch history deadline.</summary>
+    /// <param name="context">The request's server context.</param>
+    /// <returns>The linked deadline source, or null when neither request nor application can cancel.</returns>
+    private CancellationTokenSource? CreateDeadline(ServerSystemContext context)
+    {
+        var request = context.OperationContext?.CancellationToken ?? CancellationToken.None;
+        if (!request.CanBeCanceled && HistoryReadDeadline <= TimeSpan.Zero) return null;
+        var deadline = request.CanBeCanceled
+            ? CancellationTokenSource.CreateLinkedTokenSource(request)
+            : new CancellationTokenSource();
+        if (HistoryReadDeadline > TimeSpan.Zero) deadline.CancelAfter(HistoryReadDeadline);
+        return deadline;
+    }
 
     /// <summary>Awaits one work item under a semaphore permit, releasing it when the item completes.</summary>
     /// <param name="gate">The concurrency-limiting semaphore.</param>