public void run() {
while (true) {
IResponse resp = responseQueue.removeResponse();
Integer respId = (Integer) resp.getId();
SPFSession session = sessions.remove(respId);
FutureSPFResult result = results.remove(respId);
DNSLookupContinuation cont =
(DNSLookupContinuation) session.getAttribute(ATTRIBUTE_STAGED_EXECUTOR_CONTINUATION);
DNSResponse response;
if (resp.getException() != null) {
response = new DNSResponse((TimeoutException) resp.getException());
} else {
response = new DNSResponse(resp.getValue());
}
try {
cont = cont.getListener().onDNSResponse(response, session);
if (cont != null) {
invokeAsynchService(session, result, cont, false);
} else {
execute(session, result, false);
}
} catch (Exception e) {
SPFChecker checker = null;
while (e != null) {
while (checker == null || !(checker instanceof SPFCheckerExceptionCatcher)) {
checker = session.popChecker();
}
try {
((SPFCheckerExceptionCatcher) checker).onException(e, session);
e = null;
} catch (SPFResultException ex) {
e = ex;
} finally {
checker = null;
}
}
execute(session, result, false);
}
}
}
/**
* throttle should be true only when the caller thread is the client and not the worker thread. We
* could even remove the throttle parameter and check the currentThread. This way the worker is
* never "blocked" while outside callers will be blocked if our queue is too big (so this is not
* fully "asynchronous").
*/
private synchronized void invokeAsynchService(
SPFSession session, FutureSPFResult result, DNSLookupContinuation cont, boolean throttle) {
while (throttle && results.size() > 50) {
try {
this.wait(100);
} catch (InterruptedException e) {
}
}
int nextId = nextId();
sessions.put(new Integer(nextId), session);
results.put(new Integer(nextId), result);
session.setAttribute(ATTRIBUTE_STAGED_EXECUTOR_CONTINUATION, cont);
dnsProbe.getRecordsAsynch(cont.getRequest(), nextId, responseQueue);
}