Momentary hang when quitting application using a Service Provider

[rblenkinsopp]

Describe the bug
When quitting a built application, or stopping the editor, when using a Service Provider, the application/editor hangs for approximately 1-2 seconds.

To Reproduce
Steps to reproduce the behaviour:

1. Create a new project
2. Import Ultraleap Tracking 7.3.0 or latest develop
3. Enter Play Mode
4. Stop Play mode

Expected behavior
Application/editor stops back to Editor immediately.

Actual behaviour
The applications/editor hangs for 1-2 seconds (and shows the beachball on macOS).
This only occurs when the Service Provider is in the scene.

Project details

• Unity version: 6.0
• Plugin/package version: 7.3.0/develop
• Installation method: Local Git Checkout
• Packages affected: Tracking

Environment

• OS: macOS

[rblenkinsopp]

I believe I've located the cause of this issue, it's the LeapGetServerStatus call waiting for it's long 1 second timeout internally, Unity can't shut down a native thread that's in-progress (at least not cleanly).

I think this will require a native side/LeapC API change to fix properly.

[rblenkinsopp]

This should be fixed by (Internal PR): https://github.com/WeAreROLI/libtrack/pull/75 and further improved by: https://github.com/WeAreROLI/libtrack/pull/74