A new instance of CMMotionManager results in a Thread Checker warning
Originator: | futuretap | ||
Number: | rdar://46210367 | Date Originated: | 22-Nov-2018 10:46 AM |
Status: | Duplicate/31658500/Closed | Resolved: | |
Product: | iOS + SDK | Product Version: | 12.1 |
Classification: | Serious Bug | Reproducible: | Always |
Summary: This is a duplicate of radar #45003816. We encounter the same issue when using UIInterpolatingMotionEffect. The Main Thread Checker kicks in on an iPhone XS@12.1. iPhone X@12.1.1, iPhone 6s@11.4.1, iPhone 6s Plus@11.4.1 all work fine so it seems to depend on the new hardware. Creating a new instance of CMMotionManager always results in a Thread Checker exception Steps to Reproduce: Instantiate a new CMMotionManager in the main thread: let motion = CMMotionManager() Expected Results: No exception is raised Actual Results: The thread checker kicks in: ``` Main Thread Checker: UI API called on a background thread: -[UIApplication applicationState] PID: 9123, TID: 1958556, Thread name: com.apple.CoreMotion.MotionThread, Queue name: com.apple.root.default-qos.overcommit, QoS: 0 Backtrace: 4 libobjc.A.dylib 0x00000002079d7894 <redacted> + 56 5 CoreMotion 0x000000020e2387a4 CoreMotion + 305060 6 CoreMotion 0x000000020e238cd8 CoreMotion + 306392 7 CoreMotion 0x000000020e238be8 CoreMotion + 306152 8 CoreMotion 0x000000020e26a3cc CoreMotion + 508876 9 CoreMotion 0x000000020e26a42c CoreMotion + 508972 10 CoreFoundation 0x0000000208770888 <redacted> + 28 11 CoreFoundation 0x000000020877016c <redacted> + 276 12 CoreFoundation 0x000000020876af54 <redacted> + 1016 13 CoreFoundation 0x000000020876a844 CFRunLoopRunSpecific + 452 14 CoreFoundation 0x000000020876b5a8 CFRunLoopRun + 84 15 CoreMotion 0x000000020e269d64 CoreMotion + 507236 16 libsystem_pthread.dylib 0x00000002083e5a04 <redacted> + 132 17 libsystem_pthread.dylib 0x00000002083e5960 _pthread_start + 52 18 libsystem_pthread.dylib 0x00000002083eddf4 thread_start + 4 2018-10-04 12:09:35.737994+0200 test[9123:1958556] [reports] Main Thread Checker: UI API called on a background thread: -[UIApplication applicationState] PID: 9123, TID: 1958556, Thread name: com.apple.CoreMotion.MotionThread, Queue name: com.apple.root.default-qos.overcommit, QoS: 0 ``` Version/Build: iOS 12 Xcode Version 10.0 (10A255) Version: 12.1 Notes:
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Happening for me as well, lot of things getting impacted, and yeah only happens on XS, XS Max, and XR
This issue still happens. Should I file yet another bug report with Apple?
Any update on this issue, seems like this is massively impacting a lot of projects