46918065: Network time synchronization causes audio overloads

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Description

I've been having random audio overloads on my new 2018 MacBook Air. After browsing several logs, I noticed that IOAudioEngine::pauseAudioEngine() was called immediately after the 'timed' process attempted to synchronize the local time to a network time server.

This issue is 100% reproducible and persists across reboots. While audio was playing, I opened up Date & Time preferences and repeatably toggled the "Set date and time automatically" check box. Each time I turned this setting on, I saw a log entry for IOAudioEngine::pauseAudioEngine(). These pauses are often long enough to cause an audio overload.

Steps to Reproduce: 1) Have a MacBook Air 2018 and an audio device whose "Clock Source" isn't "Default". I used both an Apogee Groove and a Focusrite iTrack Solo. 2) Turn on "Set date and time automatically"

Expected Results: No audio overloads, glitchless playback

Actual Results: Whenever "Set date and time automatically" is first turned on, or once per hour when 'timed' runs, audio glitches due to something calling IOAudioEngine::pauseAudioEngine() at the kernel layer.

Version/Build: 10.14.2 (18C54)

Configuration: 2018 MacBook Air + Apogee Groove

Test matrix: 2015 MacBook Pro + Built-in Output = ok 2015 MacBook Pro + Audioengine D3 = ok 2015 MacBook Pro + Groove = ok 2015 MacBook Pro + iTrack Solo = ok

2017 iMac Pro + Built-in Output = ok 2017 iMac Pro + Audioengine D3 = ok 2017 iMac Pro + Groove = ok 2017 iMac Pro + iTrack Solo = ok

2018 MacBook Air + Built-in Output = ok 2018 MacBook Air + Audioengine D3 = ok 2018 MacBook Air + Groove = FAILED 2018 MacBook Air + iTrack Solo = FAILED

- Product Version: Created: 2018-12-22T10:27:00.695573 Originated: 2019-02-07T00:00:00 Open Radar Link: http://www.openradar.me/46918065

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Modified: 2019-02-07T00:11:53.440121

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Modified: 2019-02-07T00:11:53.440121