[meindnoch]

The render thread is running an infinite loop. You need to manually drain the autorelease pool, otherwise autoreleased objects created during rendering won't be released until the thread exits (there's an implicit top-level pool in each NSThread which is drained on exit). In UIKit/AppKit, the autorelease pool is drained at the end of each NSRunLoop iteration by the framework, so you don't typically drain it yourself. Here they created their own runloop - an infinite `while` loop that calls `onRender()` - so they must drain the pool themselves.