• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Back To Basics : Databases Active Editing Context
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Back To Basics : Databases Active Editing Context


  • Subject: Re: Back To Basics : Databases Active Editing Context
  • From: Lachlan Deck <email@hidden>
  • Date: Fri, 4 Jul 2008 14:30:54 +1000

On 04/07/2008, at 2:05 PM, Chuck Hill wrote:

On Jul 3, 2008, at 8:00 PM, Lachlan Deck wrote:

On 04/07/2008, at 9:53 AM, Chuck Hill wrote:

If not what does lock() on the EC actually lock ?

It prevents changes in other ECs from affecting what is happening in the locked EC. The changes are queued and processed when the EC is unlocked.



If so, shouldn't rest of EC (waiting to save changes) just hang around and wait instead of trying to access DBcontext and throw exception? In other words, the exception we are seeing implies that rest of ECs have no idea there is ec out there locked the DBcontext.

No, that is just a badly worded exception. What it really means is

Called objectForGlobalID() on the databaseContext's active editingContext, edu.uow.ris.framework.LockErrorScreamerEditingContext@1efaa51, and got back null. The object
: Researcher:(Active_Name=Peter Newnam {rowID=28082;}, is in editing context edu.uow.ris.framework.LockErrorScreamerEditingContext@10c6406.

I've seen this happen when attempting to localize an object into another ec fails... and you find out when attempting to save changes.
e.g., using some context that wasn't properly locked.

I don't think I recall having seen this. How would that happen? localInstance using faulting so I can see it resulting in a dummy fault EO possibly, but not an object in a different EC. Do you have any more details on this?

Perhaps a parent ec? Is there any child ecs involved here?

I don't recall terribly clearly now as it's been a while... but I remember that for some strange reason an object that I had in the shared editing context didn't localize into the ec that I wanted when attempting to set the relationship - but there was no exception until saveChanges. It might have been when said ec didn't have its sharedEc == null, or invalid locking or something.

I recall, when trying to track it down, mucking around with temporarily unlocking shared ec locks and stuff. But I think it turned out to be ensuring that the ec in question didn't properly set its shared ec to null (I think).

Sorry I don't recall much more than that.

with regards,
--

Lachlan Deck

_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden


  • Follow-Ups:
    • Re: Back To Basics : Databases Active Editing Context
      • From: Chuck Hill <email@hidden>
References: 
 >Back To Basics : Databases Active Editing Context (From: Owen McKerrow <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: Chuck Hill <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: Owen McKerrow <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: Chuck Hill <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: "M.Y. Tjoe" <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: Chuck Hill <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: Lachlan Deck <email@hidden>)
 >Re: Back To Basics : Databases Active Editing Context (From: Chuck Hill <email@hidden>)

  • Prev by Date: Re: Back To Basics : Databases Active Editing Context
  • Next by Date: Re: DB uniqueness constraints and dealing with them
  • Previous by thread: Re: Back To Basics : Databases Active Editing Context
  • Next by thread: Re: Back To Basics : Databases Active Editing Context
  • Index(es):
    • Date
    • Thread