30 lines
878 B
Factor
Executable File
30 lines
878 B
Factor
Executable File
! Copyright (C) 2008 Slava Pestov.
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! See http://factorcode.org/license.txt for BSD license.
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USING: dlists kernel threads math concurrency.conditions
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continuations ;
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IN: concurrency.semaphores
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TUPLE: semaphore count threads ;
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: <semaphore> ( n -- semaphore )
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dup 0 < [ "Cannot have semaphore with negative count" throw ] when
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<dlist> semaphore construct-boa ;
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: wait-to-acquire ( semaphore timeout -- )
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>r semaphore-threads r> "semaphore" wait ;
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: acquire ( semaphore timeout -- )
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dup semaphore-count zero? [
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wait-to-acquire
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] [
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drop
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dup semaphore-count 1- swap set-semaphore-count
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] if ;
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: release ( semaphore -- )
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dup semaphore-count 1+ over set-semaphore-count
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semaphore-threads notify-1 ;
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: with-semaphore ( semaphore quot -- )
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over acquire [ release ] curry [ ] cleanup ; inline
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