I’ve encountered a strange problem during iOS AUv3 Instrument development which I’m having trouble finding information on. I’ve spent a couple weeks now attempting to debug this, and I was wondering if anyone else has encountered it. It feels more like an "OS killed the app" than a crash, so I use the term crash loosely. Here are the symptoms:
It doesn't seem to ever happen on initial instantiation; it's when a project is reloaded. But, you can comment out setFullState and it'll still occur.
The “crash” is inconsistent. Like a lot of slippery bugs, it’ll start happening consistently and then it’ll stop happening completely. When it does happen, it initially appears to load fine: the view loads and looks correct, and it produces audio. But, after a couple seconds, the plugin view disappears and it stops producing audio. I see this in the console log: viewServiceDidTerminateWithError:: Error Domain=_UIViewServiceInterfaceErrorDomain Code=3 "(null)" UserInfo={Message=Service Connection Interrupted}
You don’t have to generate any MIDI events to crash it. It would crash even after I commented out the processing block.
If anyone has any ideas, including how to get some useful debugging info out of this situation, let me know!
I tried to look at crash logs, but there are no crash logs generated
didReceiveMemoryWarning is not tripped. In fact, I did an experiment where I allocated 100 megs and memset’d it on startup, and it didn’t crash it.
I tried attaching a debugger, but it goes from “no debug session” to “waiting to attach” after it crashes-- at no point does it actually attach. It will attach if I then reload the plugin, but then it won’t crash. The Zombies and Leaks tools didn't reveal anything, nor did the memory sanitizers.
Using a Storyboard instead of a XIB didn't change the behavior (not sure why it would, but it was one of the last few differences between this and Apple's example).
I created a very tiny example project which exhibits the problem (unfortunately, I cannot post any code which shows the problem because I cannot find where exactly the problem code is-- maybe it's even a project setting?). It has a minimal GUI, no setFullState, and generates white noise: https://drive.google.com/open?id=1dw3xTHn3qY411eXLaIb_9_S5PAtrr5Nk
Expected: It doesn't crash or disappear randomly
Actual results: After reloading a project file which uses this AUv3, the plugin will disappear after a few seconds. It initially produces audio normally and the GUI looks OK, but then vanishes.
