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https://issues.apache.org/jira/browse/OOZIE-1922?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15073318#comment-15073318
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Rohini Palaniswamy commented on OOZIE-1922:
-------------------------------------------
Thanks. New logic for memory looks solid now.
{code}
+ InterProcessReadWriteLock readWriteLock = zkLocks.get(resource);
// This shouldn't happen, but if it does, then we should remove entry from map
+ if (readWriteLock == null) {
+ return false;
+ }
{code}
Above code means that it is not in the hashmap already, so trying to remove
from hashmap does not make sense. if (readWriteLock == null) check should be
before and outside of isLockHeld.
> MemoryLocksService fails if lock is acquired multiple times in same thread
> and released
> ---------------------------------------------------------------------------------------
>
> Key: OOZIE-1922
> URL: https://issues.apache.org/jira/browse/OOZIE-1922
> Project: Oozie
> Issue Type: Bug
> Reporter: Purshotam Shah
> Assignee: Purshotam Shah
> Attachments: OOZIE-1922-V1.patch, OOZIE-1922-V2.patch,
> OOZIE-1922.1.patch, OOZIE-1922.2.patch, OOZIE-1922.3.patch
>
>
> ReentrantLock can be acquired multiple times in same thread. For multiple
> acquire call, ReentrantLock hold count is incremented by one.
> So if we acquire lock multiple time from same thread, all will be successful
> and hold count is increased for every call.
> But if we release lock, MemoryLocksService ignore the count and deletes the
> lock. Even if it's held by some command.
> Simple step can reproduce it.
> {code}
> service.getWriteLock("test", 5000); //writeHoldCount = 1
> MemoryLockToken lock = (MemoryLockToken)service.getWriteLock("test",
> 5000); //writeHoldCount = 2
> lock.release(); //writeHoldCount = 1
> lock = (MemoryLockToken)service.getWriteLock("test", 5000);
> //writeHoldCount = 1, it should be 2.
> {code}
> {code}
> @Override
> public void release() {
> int val = rwLock.getQueueLength();
> if (val == 0) {
> synchronized (locks) {
> locks.remove(resource);
> }
> }
> lock.unlock();
> }
> }
> {code}
> MemoryLocks should check hold count before removing lock.
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