On Aug 8, 2016, at 1:48 PM, Jens Alfke <j...@mooseyard.com> wrote: > On Aug 8, 2016, at 12:46 PM, Aaron Tuller <mandelb...@mac.com > <mailto:mandelb...@mac.com>> wrote: >> >> Search for NSImage here: >> >> https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Multithreading/ThreadSafetySummary/ThreadSafetySummary.html#//apple_ref/doc/uid/10000057i-CH12-126728 >> >> <https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Multithreading/ThreadSafetySummary/ThreadSafetySummary.html#//apple_ref/doc/uid/10000057i-CH12-126728> >> > > All it says about NSImage is: "One thread can create an NSImage object, draw > to the image buffer, and pass it off to the main thread for drawing. The > underlying image cache is shared among all threads.” > > So it sounds like the problem isn’t the new NSImage but the existing one > being drawn into it. It might help to get the NSImage’s imageRep on the main > thread and then pass that to the background thread. > > (I’ve got some similar code in one of my apps that creates NSImages on a > parallel dispatch queue and draws into them, but it only draws text, not any > pre-existing images. This code works fine even with dozens of tasks at a > time.)
Well it also says: "The following classes and functions are generally not thread-safe. In most cases, you can use these classes from any thread as long as you use them from only one thread at a time." and then lists NSImage. That's why a serial queue would probably work...or using something else like passing around an image rep as Jens suggests and drawing it to a local NSGraphicsContext backed by a NSBitmapImageRep. -aaron _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
