Spawn benchmark problems

[Darksonn]

The spawning benchmarks in benches/spawn.rs seem to be rather poor:

1. The spawned tasks are not awaited, so spawns from one iteration may still be consuming resources during the next benchmark iteration.
2. The threaded_scheduler_local_spawn benchmark uses a basic scheduler and is identical to the basic_scheduler_local_spawn benchmark.
3. The basic_scheduler_remote_spawn benchmark doesn't use block_on, so the spawned tasks do not run, whereas they do run in other benchmarks.

[Wizdave97]

@Darksonn I would love to help with this, any pointers on where to start?

[Darksonn]

Well, come up with some better ways to test them, then modify the files as appropriate. You should be able to run them by running cargo bench from the benches/ directory.

If you have more questions on how to approach this, I would encourage you to join the Tokio discord where I would be happy to give you some pointers in the right direction.

[xudong963]

Hi @Wizdave97, how's this going? If you are busy with other things, I want to try it! /cc @Darksonn

[Wizdave97]

Hi @Wizdave97, how's this going? If you are busy with other things, I want to try it! /cc @Darksonn

Yeah you can take a stab at it.