Fixed PlatformNotSupportedException on close

Nefarius.Peripherals.SerialPort/SerialPort.cs

@@ -30,6 +30,7 @@ public partial class SerialPort : IDisposable
     private Exception _rxException;
     private bool _rxExceptionReported;
     private Thread _rxThread;
+    private CancellationTokenSource _cts;
     private int _stateBrk = 2;
     private int _stateDtr = 2;
     private int _stateRts = 2;
@@ -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
@@ -186,10 +188,12 @@ public partial class SerialPort : IDisposable
 
     private void InternalClose()
     {
+        _cts.Cancel();
         PInvoke.CancelIo(_hPort);
+
         if (_rxThread != null)
         {
-            _rxThread.Abort();
+            _rxThread.Join();
             _rxThread = null;
         }
 
@@ -461,7 +465,7 @@ public partial class SerialPort : IDisposable
 
         try
         {
-            while (true)
+            while (!_cts.IsCancellationRequested)
             {
                 COMM_EVENT_MASK eventMask = 0;