# Workgroup Management Coordinate the activity of custom real-time audio threads with those of the system and other processes. ## Discussion Real-time audio rendering often requires coordination between the threads of an app, the system, and the threads of any active Audio Unit plug-ins. Workgroups provide the mechanism to coordinate the efforts of these different processes, and ensure that they execute on the same schedule. In an Audio Unit, use a render context observer to retrieve the workgroup that the host app uses for real-time audio rendering. In an app, fetch the workgroup for a Core Audio device directly from the device or from your [`AUAudioUnit`](/documentation/AudioToolbox/AUAudioUnit) object. If your app has real-time rendering threads that operate on their own deadlines, create your own workgroup using the [`AudioWorkIntervalCreate`](/documentation/AudioToolbox/AudioWorkIntervalCreate) function. Use your custom workgroup to set and update the rendering schedule for your threads. ## Topics ### Essentials [Understanding Audio Workgroups](/documentation/AudioToolbox/understanding-audio-workgroups) Learn how to optimize real-time rendering performance with the Audio Workgroups API. [Adding Parallel Real-Time Threads to Audio Workgroups](/documentation/AudioToolbox/adding-parallel-real-time-threads-to-audio-workgroups) Optimize the performance of real-time audio threads that run in sync with the I/O thread by adding them to the audio device workgroup. [Adding Asynchronous Real-Time Threads to Audio Workgroups](/documentation/AudioToolbox/adding-asynchronous-real-time-threads-to-audio-workgroups) Optimize system performance by adding real-time audio threads that run asynchronously to the I/O thread to custom audio workgroups. [Adding Audio Unit Auxiliary Real-Time Threads to Audio Workgroups](/documentation/AudioToolbox/adding-audio-unit-auxiliary-real-time-threads-to-audio-workgroups) If your Audio Unit plug-in creates auxiliary real-time rendering threads, add them to the host app’s audio workgroup so the system can schedule them appropriately. ### Host App Workgroup [`kAudioUnitProperty_RenderContextObserver`](/documentation/AudioToolbox/kAudioUnitProperty_RenderContextObserver) The block that the system calls when the rendering context changes. [`AURenderContextObserver`](/documentation/AudioToolbox/AURenderContextObserver) A custom block that tells the audio unit which thread context to use for the next render cycle. [`AudioUnitRenderContext`](/documentation/AudioToolbox/AudioUnitRenderContext) A structure that contains thread context information for a real-time rendering operation. ### Device Workgroup [`kAudioOutputUnitProperty_OSWorkgroup`](/documentation/AudioToolbox/kAudioOutputUnitProperty_OSWorkgroup) The workgroup associated with the audio device underlying this Audio Unit. ### Custom Workgroups [`AudioWorkIntervalCreate`](/documentation/AudioToolbox/AudioWorkIntervalCreate) Creates a new interval workgroup for managing real-time audio threads. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)