AssetBundle.CreateFromMemory() actually behaves like synchronous method (?!)

Unity Engine
1

I create AssetBundle from memory (array of bytes):

class Loader
{
  AssetBundleCreateRequest createRequest;
  void enter(byte[] bundleBytes)
  {
    createRequest = AssetBundle.CreateFromMemory(bundleBytes);
  }

  void update()
  {
    if (createRequest != null && createRequest.isDone)
    {
    //do the job
    }
}

As you can see I use polling to check request state and don’t use coroutines/yield. CreateFromMemory() method according to Unity documentation is asynchronous. But according to profiler it behaves exactly like synchronous method: in place when it’s called game literally freezes, frame takes >1 second to complete and 99% of time is taken exactly by AssetBundle.CreateFromMemory() method. I compared this to
CreateFromMemoryImmediate() - time is almost the same.

Please, help!

EDIT1: Read documentation one more time. It seems to be a little bit misleading. Maybe what they mean by “asynchronous” - it’s only decompression on separate thread (when asset bundle is compressed)? Seems like actual asset bundle creation is really synchronous anyway. Will try to use asynchronous delegates w/ CreateFromMemoryImmediate(). I know that Unity API not thread safe but have no other choice.

EDIT2: With async delegate I get error (as expected): “CreateFromMemoryImmediate() can only be called from the main thread.” I’m really frustrated. Seems that asset bundles don’t provide any way to create them asynchronously, it will always result in “stop-the-world” behavior.

2

I tried CreateFromFile() - it creates 30MB bundle in ~5ms (I have HDD). Seems to be rather fast (keeping in mind that this is synchronous method). Probably this is the fastest solution (though not exactly what I wanted).