Asynchronous write operation (tests needed)

src/com/felhr/usbserial/BLED112SerialDevice.java

@@ -55,6 +55,7 @@ public class BLED112SerialDevice extends UsbSerialDevice
 	{
 		// Restart the working thread if it has been killed before and  get and claim interface
 		restartWorkingThread();
+		restartWriteThread();
 		mInterface = device.getInterface(1); // BLED112 Interface 0: Communications | Interface 1: CDC Data
 
 		if(connection.claimInterface(mInterface, true))
@@ -88,15 +89,15 @@ public class BLED112SerialDevice extends UsbSerialDevice
 		requestIN = new UsbRequest();
 		requestIN.initialize(connection, inEndpoint);
 
-		// Pass reference to the thread
+		// Pass references to the threads
 		workerThread.setUsbRequest(requestIN);
-
+		writeThread.setUsbEndpoint(outEndpoint);
 	}
 
 	@Override
 	public void write(byte[] buffer) 
 	{
-		connection.bulkTransfer(outEndpoint, buffer, buffer.length, USB_TIMEOUT);
+		serialBuffer.putWriteBuffer(buffer);
 	}
 
 	@Override
@@ -112,6 +113,7 @@ public class BLED112SerialDevice extends UsbSerialDevice
 	{
 		setControlCommand(BLED112_SET_CONTROL_LINE_STATE, BLED112_DISCONNECT_CONTROL_LINE , null);
 		killWorkingThread();
+		killWriteThread();
 		connection.close();
 	}
 

src/com/felhr/usbserial/CP2102SerialDevice.java

@@ -59,8 +59,9 @@ public class CP2102SerialDevice extends UsbSerialDevice
 	public void open() 
 	{
 		
-		// Restart the working thread if it has been killed before and  get and claim interface
+		// Restart the working thread and writeThread if it has been killed before and  get and claim interface
 		restartWorkingThread();
+		restartWriteThread();
 		mInterface = device.getInterface(0); // CP2102 has only one interface
 		
 		if(connection.claimInterface(mInterface, true))
@@ -98,14 +99,15 @@ public class CP2102SerialDevice extends UsbSerialDevice
 		requestIN = new UsbRequest();
 		requestIN.initialize(connection, inEndpoint);
 		
-		// Pass references to the thread
+		// Pass references to the threads
 		workerThread.setUsbRequest(requestIN);
+		writeThread.setUsbEndpoint(outEndpoint);
 	}
 
 	@Override
 	public void write(byte[] buffer) 
 	{
-		connection.bulkTransfer(outEndpoint, buffer, buffer.length, USB_TIMEOUT);
+		serialBuffer.putWriteBuffer(buffer);
 	}
 
 	@Override
@@ -121,6 +123,7 @@ public class CP2102SerialDevice extends UsbSerialDevice
 	{
 		setControlCommand(CP210x_IFC_ENABLE, CP210x_UART_DISABLE, null);
 		killWorkingThread();
+		killWriteThread();
 		connection.close();
 	}
 

src/com/felhr/usbserial/SerialBuffer.java

@@ -68,6 +68,11 @@ public class SerialBuffer
 		writeBuffer.put(data);
 	}
 	
+	public void resetWriteBuffer()
+	{
+		writeBuffer.reset();
+	}
+	
 	private class WriteBuffer
 	{
 		private byte[] writeBuffer;
@@ -104,6 +109,11 @@ public class SerialBuffer
 			position = -1;
 			return dst;
 		}
+		
+		public synchronized void reset()
+		{
+			position = -1;
+		}
 	}
 
 }

src/com/felhr/usbserial/UsbSerialDevice.java

@@ -21,6 +21,7 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 	protected SerialBuffer serialBuffer;
 	
 	protected WorkerThread workerThread;
+	protected WriteThread writeThread;
 	
 	public UsbSerialDevice(UsbDevice device, UsbDeviceConnection connection)
 	{
@@ -28,7 +29,9 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 		this.connection = connection;
 		serialBuffer = new SerialBuffer();
 		workerThread = new WorkerThread();
+		writeThread = new WriteThread();
 		workerThread.start();
+		writeThread.start();
 	}
 	
 	// Common Usb Serial Operations (I/O Asynchronous)
@@ -106,6 +109,37 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 		
 	}
 	
+	protected class WriteThread extends Thread
+	{
+		private UsbEndpoint outEndpoint;
+		private AtomicBoolean working;
+		
+		public WriteThread()
+		{
+			working = new AtomicBoolean(true);
+		}
+		
+		@Override
+		public void run()
+		{
+			while(working.get())
+			{
+				byte[] data = serialBuffer.getWriteBuffer();
+				connection.bulkTransfer(outEndpoint, data, data.length, USB_TIMEOUT);
+			}
+		}
+		
+		public void setUsbEndpoint(UsbEndpoint outEndpoint)
+		{
+			this.outEndpoint = outEndpoint;
+		}
+		
+		public void stopWriteThread()
+		{
+			working.set(false);
+		}
+	}
+
 	/*
 	 * Kill workingThread; This must be called when closing a device
 	 */
@@ -129,4 +163,23 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 			workerThread.start();
 		}
 	}
+	
+	protected void killWriteThread()
+	{
+		if(writeThread != null)
+		{
+			writeThread.stopWriteThread();
+			writeThread = null;
+			serialBuffer.resetWriteBuffer();
+		}
+	}
+	
+	protected void restartWriteThread()
+	{
+		if(writeThread == null)
+		{
+			writeThread = new WriteThread();
+			writeThread.start();
+		}
+	}
 }