NSManagedObjectContext and GCD

Question

From Apple's Core Data Programming Guide:

You should give each thread its own entirely private managed object context and keep their associated object graphs separated on a per-thread basis.

How does that scale to Grand Central Dispatch, where you have absolutely no control over threads, which are created automagically on your behalf?

The way I do it now is to have one NSManagedObjectContext for each dispatch queue, but that's the thing: a dispatch queue doesn't necessarily use the same thread every time, right?

possible duplicate of What does Apple mean when they say that a NSManagedObjectContext is owned by the thread or queue that created it? — Brad Larson
As Nick points out, the other question has a few pretty good explanations for this (particularly Ben's). Also, without breaking NDA, you may wish to read about what's changed in Lion for Core Data (which I assume will find its way to iOS 5.0). — Brad Larson

Nick Weaver Nick Weaver · Accepted Answer · 2011-04-03T20:11:16

I think "What does Apple mean when they say that a NSManagedObjectContext is owned by the thread or queue that created it?" on SO will answer your question.

NSManagedObjectContext and GCD

2 Answers