Use multi-task definition in pull-based execution loop

[Dandandan]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
Currently, the pull based event loop only can retrieve a single tasks.
That means a higher overhead.

Describe the solution you'd like
Add a poll_work_multi_task to allow getting multiple tasks at once, given the available task slots.

Describe alternatives you've considered

Additional context