[jboss-jira] [JBoss JIRA] (JGRP-2299) LockService does not work correctly if unlock/lock is called in immediate succession

[Bela Ban (Jira)]

    [ https://issues.jboss.org/browse/JGRP-2299?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13773552#comment-13773552 ] 

Bela Ban edited comment on JGRP-2299 at 8/21/19 9:24 AM:
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[~dwhitejazz] Could be because the request handler (req_handler) runner is not stopped on stop(), just on a view change. I added method stop() in master, can you check out master and see if this works for you? The commit is 230766825a7db3d6806539fbe88210bdaa8509fa.

If not, can you describe how to reproduce this?


was (Author: belaban):
Could be because the request handler (req_handler) runner is not stopped on stop(), just on a view change. I added method stop() in master, can you check out master and see if this works for you? The commit is 230766825a7db3d6806539fbe88210bdaa8509fa.

If not, can you describe how to reproduce this?

> LockService does not work correctly if unlock/lock is called in immediate succession
> ------------------------------------------------------------------------------------
>
>                 Key: JGRP-2299
>                 URL: https://issues.jboss.org/browse/JGRP-2299
>             Project: JGroups
>          Issue Type: Bug
>    Affects Versions: 4.0.15
>         Environment: Windows 10 Oracle JDK 1.8 131
> AIX IBM Java 8
>            Reporter: Mirko Streckenbach
>            Assignee: Bela Ban
>            Priority: Major
>             Fix For: 4.1.2
>
>         Attachments: JGroupsExample.java, image.png, udp+lock.xml
>
>
> In our application we have encountered occasional cases of LockService allowing 2 processes to hold the same lock at the same time. I could reproduce this with a simple program (see atttachment) and it happens if for a lock "unlock" is called and immediately afterwards "lock". If there is a small delay (e.g. 1 second) between the two operations everything works as expected.
> This can be produced with the attached program. The program does lock/unlock/lock on a lock and then tries to lock the same lock from a different JChannel and is awarded the lock. If you place a small sleep() after the unlock, everything works as expected and the parallel lock is not awarded.
> If you turn on debugging you'll see no output between unlock and lock, so it looks to me like the lock is awarded without passing GRANT_LOCK messages to the stack. Using a conditional break point you can see that ClientLock.acquired is still true even after the unlock().



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