@Override
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
super.readExternal(in);
byte[] serReq = new byte[in.readInt()];
in.readFully(serReq);
request = TOMMessage.bytesToMessage(serReq);
request.serializedMessage = serReq;
boolean signed = in.readBoolean();
if (signed) {
byte[] serReqSign = new byte[in.readInt()];
in.readFully(serReqSign);
request.serializedMessageSignature = serReqSign;
}
}
/**
* This is the method invoked by the client side communication system.
*
* @param reply The reply delivered by the client side communication system
*/
@Override
public void replyReceived(TOMMessage reply) {
canReceiveLock.lock();
if (reqId == -1) { // no message being expected
Logger.println(
"throwing out request: sender=" + reply.getSender() + " reqId=" + reply.getSequence());
canReceiveLock.unlock();
return;
}
int pos = getViewManager().getCurrentViewPos(reply.getSender());
if (pos < 0) { // ignore messages that don't come from replicas
canReceiveLock.unlock();
return;
}
if (reply.getSequence() == reqId && reply.getReqType() == requestType) {
if (replyListener != null) {
replyListener.replyReceived(reply);
canReceiveLock.unlock();
return;
}
Logger.println(
"Receiving reply from "
+ reply.getSender()
+ " with reqId:"
+ reply.getSequence()
+ ". Putting on pos="
+ pos);
if (replies[pos] == null) {
receivedReplies++;
}
replies[pos] = reply;
// Compare the reply just received, to the others
int sameContent = 1;
for (int i = 0; i < replies.length; i++) {
if (i != pos
&& replies[i] != null
&& (comparator.compare(replies[i].getContent(), reply.getContent()) == 0)) {
sameContent++;
if (sameContent >= replyQuorum) {
response = extractor.extractResponse(replies, sameContent, pos);
reqId = -1;
this.sm.release(); // resumes the thread that is executing the "invoke" method
break;
}
}
}
if (response == null) {
if (requestType.equals(TOMMessageType.ORDERED_REQUEST)) {
if (receivedReplies == getViewManager().getCurrentViewN()) {
reqId = -1;
this.sm.release(); // resumes the thread that is executing the "invoke" method
}
} else { // UNORDERED
if (receivedReplies != sameContent) {
reqId = -1;
this.sm.release(); // resumes the thread that is executing the "invoke" method
}
}
}
}
// Critical section ends here. The semaphore can be released
canReceiveLock.unlock();
}
/**
* This method sends a request to the replicas, and returns the related reply. If the servers take
* more than invokeTimeout seconds the method returns null. This method is thread-safe.
*
* @param request Request to be sent
* @param reqType TOM_NORMAL_REQUESTS for service requests, and other for reconfig requests.
* @return The reply from the replicas related to request
*/
public byte[] invoke(byte[] request, TOMMessageType reqType) {
canSendLock.lock();
// Clean all statefull data to prepare for receiving next replies
Arrays.fill(replies, null);
receivedReplies = 0;
response = null;
replyListener = null;
replyQuorum =
(int)
Math.ceil(
(getViewManager().getCurrentViewN() + getViewManager().getCurrentViewF()) / 2)
+ 1;
// Send the request to the replicas, and get its ID
reqId = generateRequestId(reqType);
requestType = reqType;
TOMulticast(request, reqId, reqType);
Logger.println("Sending request (" + reqType + ") with reqId=" + reqId);
Logger.println("Expected number of matching replies: " + replyQuorum);
// This instruction blocks the thread, until a response is obtained.
// The thread will be unblocked when the method replyReceived is invoked
// by the client side communication system
try {
if (!this.sm.tryAcquire(invokeTimeout, TimeUnit.SECONDS)) {
Logger.println("###################TIMEOUT#######################");
Logger.println("Reply timeout for reqId=" + reqId);
canSendLock.unlock();
System.out.print(getProcessId() + " // " + reqId + " // TIMEOUT // ");
System.out.println("Replies received: " + receivedReplies);
return null;
}
} catch (InterruptedException ex) {
}
Logger.println("Response extracted = " + response);
byte[] ret = null;
if (response == null) {
// the response can be null if n-f replies are received but there isn't
// a replyQuorum of matching replies
Logger.println("Received n-f replies and no response could be extracted.");
canSendLock.unlock();
if (reqType == TOMMessageType.UNORDERED_REQUEST) {
// invoke the operation again, whitout the read-only flag
Logger.println("###################RETRY#######################");
return invokeOrdered(request);
} else {
throw new RuntimeException("Received n-f replies without f+1 of them matching.");
}
} else {
// normal operation
// ******* EDUARDO BEGIN **************//
if (reqType == TOMMessageType.ORDERED_REQUEST) {
// Reply to a normal request!
if (response.getViewID() == getViewManager().getCurrentViewId()) {
ret = response.getContent(); // return the response
} else { // if(response.getViewID() > getViewManager().getCurrentViewId())
// updated view received
reconfigureTo((View) TOMUtil.getObject(response.getContent()));
canSendLock.unlock();
return invoke(request, reqType);
}
} else {
if (response.getViewID() > getViewManager().getCurrentViewId()) {
// Reply to a reconfigure request!
Logger.println("Reconfiguration request' reply received!");
Object r = TOMUtil.getObject(response.getContent());
if (r
instanceof
View) { // did not executed the request because it is using an outdated view
reconfigureTo((View) r);
canSendLock.unlock();
return invoke(request, reqType);
} else { // reconfiguration executed!
reconfigureTo(((ReconfigureReply) r).getView());
ret = response.getContent();
}
} else {
// Reply to readonly request
ret = response.getContent();
}
}
}
// ******* EDUARDO END **************//
canSendLock.unlock();
return ret;
}
