awaitNoFibers

Block the current Thread until there are no fibers that can run. If nothing outside the VM is actively creating and running new fibers, this is a permanent state. After this method returns, there will be no more AvailTasks added to the executor.

Note (MvG, 2021-07-23): This mechanism will have to be revisited if we rework the L2Chunk optimizer to queue optimization tasks, which may run even after the last fiber has ended. Wrapping those tasks in their own fibers would be a sufficient solution.