Show the handle value when logging on Linux

When SafeHandles were implemented, the ToString() method now prints out only the type name, where before it was the actual pointer. Get the pointer value, just for logging purposes only.

Issue: DOTNET-172

code/Native/UnixNativeSerial.cs

@@ -18,6 +18,7 @@ internal class UnixNativeSerial : INativeSerial
     {
         private INativeSerialDll m_Dll;
         private SafeSerialHandle m_Handle;
+        private IntPtr m_HandlePtr;
 
         public UnixNativeSerial()
         {
@@ -26,6 +27,7 @@ public UnixNativeSerial()
             if (m_Handle.IsInvalid) {
                 throw new PlatformNotSupportedException("Can't initialise platform library");
             }
+            m_HandlePtr = m_Handle.DangerousGetHandle();
 
 #if NETSTANDARD15
             // On NetStandard 1.5, we must have proper exception handling
@@ -795,7 +797,7 @@ private unsafe void ReadWriteThread()
                 } else if (Log.SerialTrace(System.Diagnostics.TraceEventType.Verbose)) {
                     Log.Serial.TraceEvent(System.Diagnostics.TraceEventType.Verbose, 0,
                         "{0}: ReadWriteThread: serial_waitforevent({1}, {2}) == {3}",
-                        m_Name, m_Handle, rwevent, result);
+                        m_Name, m_HandlePtr, rwevent, result);
                 }
 
                 if ((result & SerialReadWriteEvent.ReadEvent) != 0) {
@@ -815,7 +817,7 @@ private unsafe void ReadWriteThread()
                             if (Log.SerialTrace(System.Diagnostics.TraceEventType.Verbose))
                                 Log.Serial.TraceEvent(System.Diagnostics.TraceEventType.Verbose, 0,
                                     "{0}: ReadWriteThread: serial_read({1}, {2}, {3}) == {4}",
-                                    m_Name, m_Handle, (IntPtr)bo, length, rresult);
+                                    m_Name, m_HandlePtr, (IntPtr)bo, length, rresult);
                             if (rresult > 0) m_Buffer.Serial.ReadBufferProduce(rresult);
                         }
                     }
@@ -839,7 +841,7 @@ private unsafe void ReadWriteThread()
                             if (Log.SerialTrace(System.Diagnostics.TraceEventType.Verbose))
                                 Log.Serial.TraceEvent(System.Diagnostics.TraceEventType.Verbose, 0,
                                     "{0}: ReadWriteThread: serial_write({1}, {2}, {3}) == {4}",
-                                    m_Name, m_Handle, (IntPtr)bo, length, wresult);
+                                    m_Name, m_HandlePtr, (IntPtr)bo, length, wresult);
                             if (wresult > 0) {
                                 m_Buffer.Serial.WriteBufferConsume (wresult);
                                 m_Buffer.Serial.TxEmptyEvent ();
@@ -876,7 +878,7 @@ private void InterruptReadWriteLoop()
                     if (Log.SerialTrace(System.Diagnostics.TraceEventType.Verbose))
                         Log.Serial.TraceEvent(System.Diagnostics.TraceEventType.Verbose, 0,
                             "{0}: ReadWriteThread: serial_abortwaitforevent({1}) = {2}",
-                            m_Name, m_Handle, result);
+                            m_Name, m_HandlePtr, result);
                 }
             }
         }