On Dec 21, 2009, at 11:26 AM, McLaughlin, Michael P. wrote: > Could anyone point me to sample code that shows how to implement a > persistent NSOperation that could be enqueued repeatedly?
You can't. It's a fundamental part of the design of NSOperation. It's not just that support for it was left out of the design. In multi-threaded coding, it is sometimes very important that certain state changes can only go in one direction (not cancelled -> cancelled, not executing or finished -> executing and not finished -> not executing and finished, etc.). It is very likely that NSOperationQueue would break if an NSOperation could change state in the other direction. > Currently, I initialize NSOps just prior to launching but this involves > copying large datasets (to avoid R/W contention) and it would be more > efficient if I could initialize a fixed set of NSOps just once and reuse > them. Make your NSOperations have a relationship to some other object which holds the state that persists. Serially create NSOperations which each have a relationship to this persistent state object, one after the other. Regards, Ken _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
