Fixed receiver thread cancellation

Fixed blocking endlessly on port close

Nefarius.Peripherals.SerialPort/SerialPort.cs

@@ -22,6 +22,7 @@ public partial class SerialPort : IDisposable
     private readonly ManualResetEvent _writeEvent = new(false);
     private bool _auto;
     private bool _checkSends = true;
+    private CancellationTokenSource _cts;
 
     private Handshake _handShake;
     private SafeFileHandle _hPort;
@@ -151,6 +152,7 @@ public partial class SerialPort : IDisposable
         _rxException = null;
         _rxExceptionReported = false;
 
+        _cts = new CancellationTokenSource();
         _rxThread = new Thread(ReceiveThread)
         {
             Name = "CommBaseRx", Priority = ThreadPriority.AboveNormal, IsBackground = true
@@ -175,21 +177,25 @@ public partial class SerialPort : IDisposable
     /// </summary>
     public void Close()
     {
-        if (_online)
+        if (!_online)
         {
-            _auto = false;
+            return;
-            BeforeClose(false);
-            InternalClose();
-            _rxException = null;
         }
+
+        _auto = false;
+        BeforeClose(false);
+        InternalClose();
+        _rxException = null;
     }
 
     private void InternalClose()
     {
         PInvoke.CancelIo(_hPort);
+
         if (_rxThread != null)
         {
-            _rxThread.Abort();
+            _cts.Cancel();
+            _rxThread.Join();
             _rxThread = null;
         }
 
@@ -403,6 +409,9 @@ public partial class SerialPort : IDisposable
     {
     }
 
+    /// <summary>
+    ///     Invoked when a single character has been received.
+    /// </summary>
     public event Action<byte> DataReceived;
 
     /// <summary>
@@ -461,7 +470,7 @@ public partial class SerialPort : IDisposable
 
         try
         {
-            while (true)
+            while (!_cts.IsCancellationRequested)
             {
                 COMM_EVENT_MASK eventMask = 0;
 
@@ -478,7 +487,7 @@ public partial class SerialPort : IDisposable
                 {
                     if (Marshal.GetLastWin32Error() == (int)WIN32_ERROR.ERROR_IO_PENDING)
                     {
-                        sg.WaitOne();
+                        WaitHandle.WaitAny(new[] { sg, _cts.Token.WaitHandle });
                     }
                     else
                     {

PInvokeSerialPort.Sample/Program.cs

@@ -20,5 +20,7 @@ internal class Program
         serialPort.Write("START\r\n");
 
         Console.ReadKey();
+
+        serialPort.Close();
     }
 }