factor/core/alien/alien.factor

88 lines
2.0 KiB
Factor

! Copyright (C) 2004, 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors assocs kernel math namespaces sequences system
kernel.private byte-arrays arrays init ;
IN: alien
! Some predicate classes used by the compiler for optimization
! purposes
PREDICATE: simple-alien < alien underlying>> not ;
UNION: simple-c-ptr
simple-alien POSTPONE: f byte-array ;
DEFER: pinned-c-ptr?
PREDICATE: pinned-alien < alien underlying>> pinned-c-ptr? ;
UNION: pinned-c-ptr
pinned-alien POSTPONE: f ;
GENERIC: >c-ptr ( obj -- c-ptr )
M: c-ptr >c-ptr ;
SLOT: underlying
M: object >c-ptr underlying>> ;
GENERIC: expired? ( c-ptr -- ? ) flushable
M: alien expired? expired>> ;
M: f expired? drop t ;
: <alien> ( address -- alien )
f <displaced-alien> { simple-c-ptr } declare ; inline
: <bad-alien> ( -- alien )
-1 <alien> t >>expired ; inline
M: alien equal?
over alien? [
2dup [ expired? ] either? [
[ expired? ] both?
] [
[ alien-address ] bi@ =
] if
] [
2drop f
] if ;
M: simple-alien hashcode* nip dup expired>> [ drop 1234 ] [ alien-address ] if ;
ERROR: alien-callback-error ;
: alien-callback ( return parameters abi quot -- alien )
alien-callback-error ;
ERROR: alien-indirect-error ;
: alien-indirect ( ... funcptr return parameters abi -- )
alien-indirect-error ;
ERROR: alien-invoke-error library symbol ;
: alien-invoke ( ... return library function parameters -- ... )
2over alien-invoke-error ;
! Callbacks are registered in a global hashtable. If you clear
! this hashtable, they will all be blown away by code GC, beware.
SYMBOL: callbacks
[ H{ } clone callbacks set-global ] "alien" add-init-hook
<PRIVATE
TUPLE: expiry-check object alien ;
: recompute-value? ( check -- ? )
dup [ alien>> expired? ] [ drop t ] if ;
PRIVATE>
: initialize-alien ( symbol quot -- )
swap dup get-global dup recompute-value?
[ drop [ call dup 31337 <alien> expiry-check boa ] dip set-global ]
[ 2nip object>> ] if ; inline