[Engine-devel] LockManager maybe not be really taking locks in your flows...

Roy Golan rgolan at redhat.com
Sun Aug 11 14:14:04 UTC 2013


On Sun 11 Aug 2013 05:03:05 PM IDT, Yair Zaslavsky wrote:
> Hi all,
> Thanks to Alon Bar Lev's efforts for preventing to concurrent host installation for the same host entity + Roy Golan's check of the code, we saw that for commands that override
>
> getExclusiveLocks() or getSharedLocks() the locking mechanism does not work (lock is not being acquired) if there is no annotation of @LockIdNameAttribute on the class.
> A bug was filed for removing this annotation (leftover from some historical code ) , but until it is fixed - bare in mind you need to add this annotation in current commands you are working on
> in order to utilize the mechanism.
> See RemoveVmCommand (has the annotation) vs AddDiskCommand (which doesn't have the annotation)
>
>
> Cheers,
> Yair
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just to make it clear, the storage commands are calling explicitly 
aquireLockInternal in the canDoAction. since there is no contract (no 
interface) we are open to mistakes and misuse. this should be rectified.




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