Bug 534286. Made read(byte[],int,int) blocking

Added a loop in read(byte[], int, int) to block until any input is
available. Or until the port is closed, or an exception occurs.

Change-Id: I1ead6f465571274e77e74de685b8185c8cdde108
Signed-off-by: Waqas Ilyas <waqas.ilyas@gmail.com>

native/org.eclipse.cdt.native.serial/src/org/eclipse/cdt/serial/SerialPort.java

@@ -103,21 +103,38 @@ public class SerialPort {
 					rpos += n;
 					return n;
 				} else {
-					n = read1(handle, b, off, len);
+					while (isOpen()) {
-					if (n <= 0 && isPaused) {
+						n = read1(handle, b, off, len);
-						synchronized (pauseMutex) {
+						if (n <= 0 ) {
-							while (isPaused) {
+							if (isPaused) {
-								try {
+								synchronized (pauseMutex) {
-									pauseMutex.wait();
+									while (isPaused) {
-								} catch (InterruptedException e) {
+										try {
-									return -1;
+											pauseMutex.wait();
+										} catch (InterruptedException e) {
+											return -1;
+										}
+									}
 								}
 							}
+							else if (n < 0) {
+								// End of stream, connection closed?
+								return n;
+							}
+							else {
+								// Nothing available yet, keep blocking
+								try {
+									Thread.sleep(500);
+								} catch (InterruptedException e) {
+									// ignore
+								}
+							}
+						} else {
+							return n;
 						}
-						return read1(handle, b, off, len);
-					} else {
-						return n;
 					}
+					
+					return -1;
 				}
 			} else {
 				return -1;