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

[Allon Mureinik]

----- Original Message -----
> From: "Roy Golan" <rgolan at redhat.com>
> To: "Yair Zaslavsky" <yzaslavs at redhat.com>
> Cc: "engine-devel" <engine-devel at ovirt.org>
> Sent: Sunday, August 11, 2013 5:16:47 PM
> Subject: Re: [Engine-devel] LockManager maybe not be really taking locks in your flows...
> 
> On Sun 11 Aug 2013 05:14:04 PM IDT, Roy Golan wrote:
> > 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
> >> _______________________________________________
> >> Engine-devel mailing list
> >> Engine-devel at ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >
> > 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.
> >
> more info from the bug:
> see the list of commands that overrrides getExcelusiveLocks but *don't*
> have the @LockIdNameAttribute annotation:
> 
> bll/src/main/java/org/ovirt/engine/core/bll/AddDiskCommand.java
Manually calls acquireLockInternal() - disgusting, but works (on my todo list for some future version, don't worry).

> bll/src/main/java/org/ovirt/engine/core/bll/MoveOrCopyDiskCommand.java
Same.

> bll/src/main/java/org/ovirt/engine/core/bll/AddVdsCommand.java
> bll/src/main/java/org/ovirt/engine/core/bll/UpdateVmTemplateCommand.java
> bll/src/main/java/org/ovirt/engine/core/bll/ExportRepoImageCommand.java
> 
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