public void run() {
DatagramPacket packet;
byte receive_buf[] = new byte[65535];
int len;
byte[] tmp, data;
// moved out of loop to avoid excessive object creations (bela March 8 2001)
packet = new DatagramPacket(receive_buf, receive_buf.length);
while (mcast_receiver != null && mcast_sock != null) {
try {
packet.setData(receive_buf, 0, receive_buf.length);
mcast_sock.receive(packet);
len = packet.getLength();
data = packet.getData();
if (len == 1 && data[0] == 0) {
if (Trace.debug) {
Trace.info("UDP.run()", "received dummy packet");
}
continue;
}
if (len == 4) { // received a diagnostics probe
if (data[0] == 'd' && data[1] == 'i' && data[2] == 'a' && data[3] == 'g') {
handleDiagnosticProbe(packet.getAddress(), packet.getPort());
continue;
}
}
if (Trace.debug) {
Trace.info(
"UDP.receive()",
"received (mcast) "
+ packet.getLength()
+ " bytes from "
+ packet.getAddress()
+ ":"
+ packet.getPort()
+ " (size="
+ len
+ " bytes)");
}
if (len > receive_buf.length) {
Trace.error(
"UDP.run()",
"size of the received packet ("
+ len
+ ") is bigger than "
+ "allocated buffer ("
+ receive_buf.length
+ "): will not be able to handle packet. "
+ "Use the FRAG protocol and make its frag_size lower than "
+ receive_buf.length);
}
if (Version.compareTo(data) == false) {
Trace.warn(
"UDP.run()",
"packet from "
+ packet.getAddress()
+ ":"
+ packet.getPort()
+ " has different version ("
+ Version.printVersionId(data, Version.version_id.length)
+ ") from ours ("
+ Version.printVersionId(Version.version_id)
+ "). This may cause problems");
}
if (use_incoming_packet_handler) {
tmp = new byte[len];
System.arraycopy(data, 0, tmp, 0, len);
incoming_queue.add(tmp);
} else {
handleIncomingUdpPacket(data);
}
} catch (SocketException sock_ex) {
if (Trace.trace) {
Trace.info("UDP.run()", "multicast socket is closed, exception=" + sock_ex);
}
break;
} catch (InterruptedIOException io_ex) { // thread was interrupted
; // go back to top of loop, where we will terminate loop
} catch (Throwable ex) {
Trace.error("UDP.run()", "exception=" + ex + ", stack trace=" + Util.printStackTrace(ex));
Util.sleep(300); // so we don't get into 100% cpu spinning (should NEVER happen !)
}
}
if (Trace.trace) {
Trace.info("UDP.run()", "multicast thread terminated");
}
}
