AudioUnits v3 OS X: How AU PlugIn may detect that AU Host did close window.

Hello,

In OS X SDK 10.11

AUViewController.viewWillDisappear()

not called when AU Host closes the PlugIn window. It called one time before PlugIn unloading.

How then AudioUnit may know that AU Host did close PlugIn window and AudioUnit view may suspend drawing calls in custom views?

TL;DR

I have a AudioUnit v3 PlugIn with Volume meter. Volume meter draws level of audio signal retrieved from DSP kernel. It refreshes itself in sync with

CVDisplayLink

callbacks.

AudioUnit PlugIn does not own window (

NSWindow

) as it provided by SDK. AudioUnit PlugIn also have no direct access to AU Host PlugIn window (

NSWindow

) and its controller as they on other side of XPC infrastructure. From other side AU Host does not have direct access to AudioUnit PlugIn as it on other side of XPC infrastructure.

I need to know when AU Host did close PlugIn window to stop

CVDisplayLink

on AudioUnit side until AU Host will open PlugIn window again. How to achieve this?

Thanks!