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fixed a potential hole around lock usage 

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@961272 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Robert Davies 2010-07-07 07:35:31 +00:00
parent 28180b35bd
commit 720ff40ac0
1 changed files with 3 additions and 7 deletions
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10
activemq-core/src/main/java/org/apache/activemq/broker/region/Queue.java
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@ -1677,23 +1677,19 @@ public class Queue extends BaseDestination implements Task, UsageListener {
} }
// Only add new messages, not already pagedIn to avoid multiple // Only add new messages, not already pagedIn to avoid multiple
// dispatch attempts // dispatch attempts
pagedInMessagesLock.readLock().lock(); pagedInMessagesLock.writeLock().lock();
try { try {
resultList = new ArrayList<QueueMessageReference>(result.size()); resultList = new ArrayList<QueueMessageReference>(result.size());
for (QueueMessageReference ref : result) { for (QueueMessageReference ref : result) {
if (!pagedInMessages.containsKey(ref.getMessageId())) { if (!pagedInMessages.containsKey(ref.getMessageId())) {
pagedInMessagesLock.readLock().unlock();
pagedInMessagesLock.writeLock().lock();
pagedInMessages.put(ref.getMessageId(), ref); pagedInMessages.put(ref.getMessageId(), ref);
pagedInMessagesLock.readLock().lock();
pagedInMessagesLock.writeLock().unlock();
resultList.add(ref); resultList.add(ref);
} else { } else {
ref.decrementReferenceCount(); ref.decrementReferenceCount();
} }
} }
} finally { } finally {
pagedInMessagesLock.readLock().unlock(); pagedInMessagesLock.writeLock().unlock();
} }
} else { } else {
// Avoid return null list, if condition is not validated // Avoid return null list, if condition is not validated