Re: [ecf-dev] Small problem with RegistrySharedObject#handleAddRegistrat

[Scott Lewis <slewis@xxxxxxxxxxxxx>]

Hi Pavel,

Yes, this is a bug...thanks for finding.  If you could open a bug report 
and attach code for fix (in patch or in comment given that it's so 
small), I'll apply.

There are one or two other handle* methods in the RegistrySharedObject 
class that should probably also be adjusted similarly...just to avoid 
spurious NPEs reported to console because of thread race.

Thanks,

Scott


Samolisov Pavel wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Hello folks,
>
> I find a potential bug in the method
> RegistrySharedObject#handleAddRegistration:
>
> in this code:
> if (remoteContainerID == null || 		
>     getLocalContainerID().equals(remoteContainerID)) {				  return;
> }
>  XMPPRemoteServiceAdapterFactory#XMPPRegistrySharedObject#getLocalContainerID()
> returns container ID as connected ID:
>
> protected ID getLocalContainerID() {
> 	// For XMPP, the local container ID is its connected ID.
> 	return getContext().getConnectedID();
> }
>
> this code returns XMPPContainer.remoteServerID
>
> But! If we will invoke method XMPPContainer.disconnect() then we will
> set remoteServerID to null and getLocalContainerID will return null. In
> RegistrySharedObject#handleAddRegistration we will have NPE.
>
> This situation can occur because we receive/handle packet in another
> (not main) thread.
>
> We can receive message in thread A, close connection in thread Main and
>  begin handle received message in thread A. Therefore we can got NPE.
>
> May be we should change code in the
> RegistrySharedObject#handleAddRegistration to:
>
> ID localContainerID = getLocalContainerID();
> if (remoteContainerID == null || localContainerID == null ||
>     localContainerID.equals(remoteContainerID)) {				  return;
> }
>
> Any ideas?
>
>
> - --
> Pavel Samolisov
>
> Meet me at:
> Vkontakte.ru: http://vkontakte.ru/id3178981
> Blog: http://samolisov.blogspot.com
> Twitter: http://twitter.com/samolisov
> XMPP/Jabber: samolisov@xxxxxxxxx
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