sleep and Timer

[Peter Hansen]

Rob Hall wrote:
> 
> If I alter it to do a join() on each thread before going on to kill the next
> thread, it takes over 300 seconds - clearly unacceptable.

Definitely, when killing a large batch of threads, it's much much
better to iterate over them and issue the "kill" (i.e. the "please
be so good as to commit suicide" request), and only then iterate
over the list again and join() each one.  That gives the snappier
ones time to kill themselves while you are telling others to die,
so it's faster than the serialized approach.

-Peter