factor/extra/concurrency/flags/flags.factor

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2008-02-25 20:37:43 -05:00
! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: boxes kernel threads ;
IN: concurrency.flags
TUPLE: flag value? thread ;
: <flag> ( -- flag ) f <box> flag construct-boa ;
: raise-flag ( flag -- )
dup flag-value? [
dup flag-thread ?box
[ resume ] [ drop t over set-flag-value? ] if
] unless drop ;
: lower-flag ( flag -- )
dup flag-value? [
f swap set-flag-value?
] [
[ flag-thread >box ] curry "flag" suspend drop
] if ;