sleep-time ( -- nanos/f )

Vocabulary

threads

Inputs

None

Outputs

nanos/f

a non-negative integer or f

Word description

Returns the time until the next sleeping thread is scheduled to wake up, which could be zero if there are threads in the run queue, or threads which need to wake up right now. If there are no runnable or sleeping threads, returns f.

Definition

USING: alien.private assocs combinators deques heaps kernel
math.order system ;

IN: threads

: sleep-time ( -- nanos/f )
    {
        { [ current-callback waiting-callbacks key? ] [ 0 ] }
        { [ run-queue deque-empty? not ] [ 0 ] }
        { [ sleep-queue heap-empty? ] [ f ] }
        [ sleep-queue heap-peek nip nano-count [-] ]
    } cond ;