private void handleApplicationShutdown(ChannelHandlerContext ctx, MessageEvent me) {
synchronized (monitor) {
this.shutdown = true;
emptyAcknowledgementSchedule.clear();
ongoingMessageExchanges.clear();
}
ctx.sendDownstream(me);
}
/**
* If the message to be written is a {@link CoapResponse} this method decides whether the message
* type is {@link MessageType.Name#ACK} (if there wasn't an empty acknowledgement sent yet) or
* {@link MessageType.Name#CON} (if there was already an empty acknowledgement sent). In the
* latter case it additionally cancels the sending of an empty acknowledgement (which was
* scheduled by the <code>messageReceived</code> method when the request was received).
*
* @param ctx The {@link ChannelHandlerContext} connecting relating this class (which implements
* the {@link ChannelUpstreamHandler} interface) to the datagramChannel that received the
* message.
* @param me the {@link MessageEvent} containing the actual message
* @throws Exception if an error occurred
*/
@Override
public void writeRequested(ChannelHandlerContext ctx, MessageEvent me) throws Exception {
if (isShutdown()) return;
if (me.getMessage() instanceof CoapResponse) handleOutgoingCoapResponse(ctx, me);
else if (me.getMessage() instanceof InternalApplicationShutdownMessage)
handleApplicationShutdown(ctx, me);
else ctx.sendDownstream(me);
}
private void handleOutgoingCoapResponse(ChannelHandlerContext ctx, MessageEvent me) {
CoapResponse coapResponse = (CoapResponse) me.getMessage();
InetSocketAddress remoteEndpoint = (InetSocketAddress) me.getRemoteAddress();
IncomingMessageExchange messageExchange;
synchronized (monitor) {
messageExchange = ongoingMessageExchanges.remove(remoteEndpoint, coapResponse.getMessageID());
}
if (messageExchange instanceof IncomingReliableMessageExchange) {
// if the ongoing message exchange is reliable and the empty ACK was not yet sent make
// response piggy-
// backed and suppress scheduled empty ACK
if (!((IncomingReliableMessageExchange) messageExchange).isAcknowledgementSent()) {
coapResponse.setMessageType(MessageType.Name.ACK.getNumber());
((IncomingReliableMessageExchange) messageExchange).setAcknowledgementSent();
}
}
ctx.sendDownstream(me);
}
