180593 2017-12-08 11:37:52 -0800 Web Inspector: Canvas recordings use a lot of memory and are never released 2017-12-08 16:02:56 -0800 1 1 1 Unclassified WebKit Web Inspector WebKit Nightly Build All All NEW InRadar P2 Normal --- 173807 1 bburg webkit-unassigned bburg hi inspector-bugzilla-changes webkit-bug-importer oldest_to_newest 1379678 0 bburg 2017-12-08 11:37:52 -0800 via Nelson Thachuk: * SUMMARY - Canvas Tab: high resource usage when recording/after completing recording * STEPS TO REPRODUCE 1. Launch Safari 2. Navigate to https://www.google.com/maps/place/Apple+Infinite+Loop/@37.3316756,-122.0323777,17z/data=!3m1!4b1!4m5!3m4!1s0x808fb5b6c4951d0f:0xb651414deb31e9fb!8m2!3d37.3316756!4d-122.030189 3. Show Web Inspector (⌥⌘I) 4. Click New Tab button 5. Select Canvas tab 6. Launch Activity Monitor 7. Filter by “Safari” 8. Return to Safari and record the Canvas 9. Interact with Google Maps (NOTE: the Web Content processes’ CPU usage spikes) 10. Wait for recording to finish (NOTE: the Web Content processes’ CPU usage returns to normal and Web Inspector’s processes’ Memory usage spikes) 11. Dismiss the recording or close the Canvas tab and wait 30 seconds * EXPECTED RESULTS - Memory should be released * ACTUAL RESULTS - Memory is not released until the Web Inspector process is killed 1379683 1 bburg 2017-12-08 11:39:14 -0800 <rdar://problem/35893620> 1379690 2 bburg 2017-12-08 11:41:34 -0800 The resource usage is somewhat expected, though we should have some way to clear recordings from memory if we don't expect to ever see them again. I don't know in what cases this would make sense. After navigating, clear if: - User never opened the recording - Canvas Tab is closed - Web Inspector is closed Preserve recording if: - User has opened it at least once - It is imported from file - Relevant canvas has been deleted from DOM but page hasn't navigated