count-down ( count-down -- )
Count-down latches

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Vocabulary
concurrency.count-downs

Inputs

count-down

a count-down

Outputs
None

Word description
Decrements a count-down latch. If it reaches zero, all threads blocking on await are notified.

Errors
Throws an error if an attempt is made to decrement the count lower than zero.

Definition

USING: accessors kernel math ;

IN: concurrency.count-downs

: count-down ( count-down -- )
    dup n>> dup zero?
    [ count-down-already-done ] [ 1 - >>n count-down-check ] if
    ;