FTDI read() now waits until timeout

previously returned after periodic FTDI status response (default 16 msec)

usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java

@@ -1101,9 +1101,6 @@ public class DeviceTest {
 
     @Test
     public void writeAsync() throws Exception {
-        if (usb.serialDriver instanceof FtdiSerialDriver)
-            return; // periodically sends status messages, so does not block here
-
         byte[] data, buf = new byte[]{1};
 
         // w/o timeout: write delayed until something is read
@@ -1134,20 +1131,18 @@ public class DeviceTest {
 
     @Test
     public void readTimeout() throws Exception {
-        if (usb.serialDriver instanceof FtdiSerialDriver)
-            return; // periodically sends status messages, so does not block here
         final Boolean[] closed = {Boolean.FALSE};
 
         Runnable closeThread = new Runnable() {
             @Override
             public void run() {
-                try {
+            try {
-                    Thread.sleep(100);
+                Thread.sleep(100);
-                } catch (InterruptedException e) {
+            } catch (InterruptedException e) {
-                    e.printStackTrace();
+                e.printStackTrace();
-                }
+            }
-                usb.close();
+            usb.close();
-                closed[0] = true;
+            closed[0] = true;
             }
         };
 
@@ -1155,19 +1150,22 @@ public class DeviceTest {
         usb.setParameters(19200, 8, 1, UsbSerialPort.PARITY_NONE);
         telnet.setParameters(19200, 8, 1, UsbSerialPort.PARITY_NONE);
 
-        byte[] buf = new byte[]{1};
+        byte[] writeBuf = new byte[]{1};
+        byte[] readBuf = new byte[1];
+        if (usb.serialDriver instanceof FtdiSerialDriver)
+            readBuf = new byte[3]; // include space for 2 header bytes
         int len,i,j;
         long time;
 
         // w/o timeout
-        telnet.write(buf);
+        telnet.write(writeBuf);
-        len = usb.serialPort.read(buf, 0); // not blocking because data is available
+        len = usb.serialPort.read(readBuf, 0); // not blocking because data is available
         assertEquals(1, len);
 
         time = System.currentTimeMillis();
         closed[0] = false;
         Executors.newSingleThreadExecutor().submit(closeThread);
-        len = usb.serialPort.read(buf, 0); // blocking until close()
+        len = usb.serialPort.read(readBuf, 0); // blocking until close()
         assertEquals(0, len);
         assertTrue(System.currentTimeMillis()-time >= 100);
         // wait for usbClose
@@ -1185,7 +1183,7 @@ public class DeviceTest {
         int longTimeout = 1000;
         int shortTimeout = 10;
         time = System.currentTimeMillis();
-        len = usb.serialPort.read(buf, shortTimeout);
+        len = usb.serialPort.read(readBuf, shortTimeout);
         assertEquals(0, len);
         assertTrue(System.currentTimeMillis()-time < 100);
 
@@ -1193,9 +1191,10 @@ public class DeviceTest {
         time = System.currentTimeMillis();
         for(i=0; i<50; i++) {
             Thread.sleep(10);
-            telnet.write(buf);
+            telnet.write(writeBuf);
+            Log.d(TAG,"telnet write 1");
             for(j=0; j<20; j++) {
-                len = usb.serialPort.read(buf, shortTimeout);
+                len = usb.serialPort.read(readBuf, shortTimeout);
                 if (len > 0)
                     break;
             }

usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/CommonUsbSerialPort.java

@@ -158,15 +158,12 @@ public abstract class CommonUsbSerialPort implements UsbSerialPort {
             }
             nread = buf.position();
         }
-        if (nread > 0) {
+        if (nread > 0)
-            return readFilter(dest, nread);
+            return nread;
-        } else {
+        else
             return 0;
-        }
     }
 
-    protected int readFilter(final byte[] buffer, int len) throws IOException { return len; }
-
     @Override
     public int write(final byte[] src, final int timeout) throws IOException {
         int offset = 0;

usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/FtdiSerialDriver.java

@@ -136,7 +136,22 @@ public class FtdiSerialDriver implements UsbSerialDriver {
         }
 
         @Override
-        protected int readFilter(byte[] buffer, int totalBytesRead) throws IOException {
+        public int read(final byte[] dest, final int timeout) throws IOException {
+            int nread;
+            if (timeout != 0) {
+                long endTime = System.currentTimeMillis() + timeout;
+                do {
+                    nread = super.read(dest, Math.max(1, (int)(endTime - System.currentTimeMillis())));
+                } while (nread == READ_HEADER_LENGTH && System.currentTimeMillis() < endTime);
+            } else {
+                do {
+                    nread = super.read(dest, timeout);
+                } while (nread == READ_HEADER_LENGTH);
+            }
+            return readFilter(dest, nread);
+        }
+
+        private int readFilter(byte[] buffer, int totalBytesRead) throws IOException {
             final int maxPacketSize = mReadEndpoint.getMaxPacketSize();
             int destPos = 0;
             for(int srcPos = 0; srcPos < totalBytesRead; srcPos += maxPacketSize) {
@@ -146,6 +161,7 @@ public class FtdiSerialDriver implements UsbSerialDriver {
                 System.arraycopy(buffer, srcPos + READ_HEADER_LENGTH, buffer, destPos, length);
                 destPos += length;
             }
+            //Log.d(TAG, "read filter " + totalBytesRead + " -> " + destPos);
             return destPos;
         }