fix for AMQ-575 to avoid the deadlock when removing consumers, which can sometimes cause messages to be redispatched when another consumer is ack-ing a message. a good lesson this one - keep locks for as short a time as possible

git-svn-id: https://svn.apache.org/repos/asf/incubator/activemq/trunk@378268 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
James Strachan 2006-02-16 15:06:00 +00:00
parent e82d0fb470
commit dba97b77c5
1 changed files with 21 additions and 14 deletions

View File

@ -187,12 +187,14 @@ public class Queue implements Destination {
ConsumerId consumerId = sub.getConsumerInfo().getConsumerId();
MessageGroupSet ownedGroups = getMessageGroupOwners().removeConsumer(consumerId);
synchronized (messages) {
if (!sub.getConsumerInfo().isBrowser()) {
MessageEvaluationContext msgContext = context.getMessageEvaluationContext();
try {
msgContext.setDestination(destination);
if (!sub.getConsumerInfo().isBrowser()) {
MessageEvaluationContext msgContext = context.getMessageEvaluationContext();
try {
msgContext.setDestination(destination);
// lets copy the messages to dispatch to avoid deadlock
List messagesToDispatch = new ArrayList();
synchronized (messages) {
for (Iterator iter = messages.iterator(); iter.hasNext();) {
IndirectMessageReference node = (IndirectMessageReference) iter.next();
if (node.isDropped()) {
@ -202,20 +204,25 @@ public class Queue implements Destination {
String groupID = node.getGroupID();
// Re-deliver all messages that the sub locked
if (node.getLockOwner() == sub || wasExclusiveOwner
|| (groupID != null && ownedGroups.contains(groupID))) {
node.incrementRedeliveryCounter();
node.unlock();
msgContext.setMessageReference(node);
dispatchPolicy.dispatch(context, node, msgContext, consumers);
if (node.getLockOwner() == sub || wasExclusiveOwner || (groupID != null && ownedGroups.contains(groupID))) {
messagesToDispatch.add(node);
}
}
} finally {
msgContext.clear();
}
// now lets dispatch from the copy of the collection to avoid deadlocks
for (Iterator iter = messagesToDispatch.iterator(); iter.hasNext();) {
IndirectMessageReference node = (IndirectMessageReference) iter.next();
node.incrementRedeliveryCounter();
node.unlock();
msgContext.setMessageReference(node);
dispatchPolicy.dispatch(context, node, msgContext, consumers);
}
}
finally {
msgContext.clear();
}
}
} finally {
dispatchValve.turnOn();
}