From 339d51f573d7b6e944c940c861f6b737667a0495 Mon Sep 17 00:00:00 2001
From: Clive Galway <clive.galway@ecs-digital.com>
Date: Fri, 21 Jan 2022 19:57:53 +0000
Subject: [PATCH] Fix WorkerThread hanging on dispose

---
 .../DeviceHandlers/DeviceHandler.cs           |  3 +-
 .../DeviceHandlers/MouseHandler.cs            |  3 --
 C#/AutoHotInterception/WorkerThread.cs        | 39 +++++++------------
 3 files changed, 15 insertions(+), 30 deletions(-)

diff --git a/C#/AutoHotInterception/DeviceHandlers/DeviceHandler.cs b/C#/AutoHotInterception/DeviceHandlers/DeviceHandler.cs
index ece90a3..c48f97f 100644
--- a/C#/AutoHotInterception/DeviceHandlers/DeviceHandler.cs
+++ b/C#/AutoHotInterception/DeviceHandlers/DeviceHandler.cs
@@ -38,7 +38,6 @@ namespace AutoHotInterception.DeviceHandlers
             if (!mappingOptions.Concurrent && !WorkerThreads.ContainsKey(code))
             {
                 WorkerThreads.TryAdd(code, new WorkerThread());
-                WorkerThreads[code].Start();
             }
             _isFiltered = true;
         }
@@ -69,7 +68,6 @@ namespace AutoHotInterception.DeviceHandlers
             if (!mappingOptions.Concurrent && DeviceWorkerThread == null)
             {
                 DeviceWorkerThread = new WorkerThread();
-                DeviceWorkerThread.Start();
             }
             _isFiltered = true;
         }
@@ -84,6 +82,7 @@ namespace AutoHotInterception.DeviceHandlers
             if (!AllButtonsMapping.Concurrent && DeviceWorkerThread != null)
             {
                 DeviceWorkerThread.Dispose();
+                DeviceWorkerThread = null;
             }
             AllButtonsMapping = null;
             DisableFilterIfNeeded();
diff --git a/C#/AutoHotInterception/DeviceHandlers/MouseHandler.cs b/C#/AutoHotInterception/DeviceHandlers/MouseHandler.cs
index d34a846..63a3120 100644
--- a/C#/AutoHotInterception/DeviceHandlers/MouseHandler.cs
+++ b/C#/AutoHotInterception/DeviceHandlers/MouseHandler.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Threading;
 using AutoHotInterception.Helpers;
@@ -46,7 +45,6 @@ namespace AutoHotInterception.DeviceHandlers
             if (!mappingOptions.Concurrent && !WorkerThreads.ContainsKey(7))
             {
                 WorkerThreads.TryAdd(7, new WorkerThread());
-                WorkerThreads[7].Start();
             }
             _isFiltered = true;
         }
@@ -76,7 +74,6 @@ namespace AutoHotInterception.DeviceHandlers
             if (!mappingOptions.Concurrent && !WorkerThreads.ContainsKey(8))
             {
                 WorkerThreads.TryAdd(8, new WorkerThread());
-                WorkerThreads[8].Start();
             }
             _isFiltered = true;
         }
diff --git a/C#/AutoHotInterception/WorkerThread.cs b/C#/AutoHotInterception/WorkerThread.cs
index d073aed..473a318 100644
--- a/C#/AutoHotInterception/WorkerThread.cs
+++ b/C#/AutoHotInterception/WorkerThread.cs
@@ -1,8 +1,5 @@
 using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -10,40 +7,32 @@ namespace AutoHotInterception
 {
     class WorkerThread : IDisposable
     {
-        private readonly Thread _worker;
-        private volatile bool _running;
+        private Task _worker;
+        private CancellationTokenSource _cancellationToken;
+        public BlockingCollection<Action> Actions { get; }
 
         public WorkerThread()
         {
             Actions = new BlockingCollection<Action>();
-            _worker = new Thread(Run);
-            _running = false;
-        }
-
-        public BlockingCollection<Action> Actions { get; }
-
-        public void Dispose()
-        {
-            if (!_running) return;
-            _running = false;
-            _worker.Abort();
-            _worker.Join();
-        }
-
-        public void Start()
-        {
-            if (_running) return;
-            _running = true;
+            _cancellationToken = new CancellationTokenSource();
+            _worker = new Task(Run, _cancellationToken.Token);
             _worker.Start();
         }
 
-        private void Run()
+        private void Run(Object obj)
         {
-            while (_running)
+            var token = (CancellationToken)obj;
+            while (!token.IsCancellationRequested)
             {
                 var action = Actions.Take();
                 action.Invoke();
             }
         }
+
+        public void Dispose()
+        {
+            _cancellationToken.Cancel();
+            _cancellationToken.Dispose();
+        }
     }
 }