KVO performance degradation; single observer, many objects
| Originator: | kimtsi | ||
| Number: | rdar://16179751 | Date Originated: | 02/26/2014 |
| Status: | Open | Resolved: | |
| Product: | OS X | Product Version: | 10.9.2 (13C64) |
| Classification: | Performance | Reproducible: | Always |
Summary: KVO performance degrades when a single observer observes many objects. Steps to Reproduce: 1. Create a single observer object. 2. Observe a number of different objects. 3. Unobserve. 4. Repeat steps #2 and #3. Expected Results: No performance degradation when adding observers. Unobservation performed in Step 3 to have helped mitigate. Actual Results: Each observation takes longer and longer. From the sample project attached. 2014-02-26 16:21:41.578 KVOSlowDown[14766:1303] Trial 1 dt:0.046364 2014-02-26 16:21:41.725 KVOSlowDown[14766:1303] Trial 2 dt:0.120685 2014-02-26 16:21:42.021 KVOSlowDown[14766:1303] Trial 3 dt:0.217752 2014-02-26 16:21:42.424 KVOSlowDown[14766:1303] Trial 4 dt:0.275786 2014-02-26 16:21:42.938 KVOSlowDown[14766:1303] Trial 5 dt:0.358562 2014-02-26 16:21:43.635 KVOSlowDown[14766:1303] Trial 6 dt:0.469945 2014-02-26 16:21:44.455 KVOSlowDown[14766:1303] Trial 7 dt:0.558854 2014-02-26 16:21:45.366 KVOSlowDown[14766:1303] Trial 8 dt:0.627054 2014-02-26 16:21:46.423 KVOSlowDown[14766:1303] Trial 9 dt:0.658799 2014-02-26 16:21:47.589 KVOSlowDown[14766:1303] Trial 10 dt:0.766691 Version: OS X 10.9.2/Build 13C64 Notes: Configuration: MacBookPro11,3, Intel Core i7, 2.6 GHz, 16 GB Attachments: 'MacBook Pro.spx' and 'KVOSlowDown.zip' were successfully uploaded. Attachment URL: https://dl.dropboxusercontent.com/u/1898287/rdar/16179751/KVOSlowDown.zip
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