1 ! Copyright (C) 2004, 2008 Slava Pestov.
2 ! See https://factorcode.org/license.txt for BSD license.
3 USING: accessors alien.data assocs bit-arrays io.backend.unix
4 io.backend.unix.multiplexers kernel layouts math math.order
5 sequences unix.ffi unix.time ;
6 IN: io.backend.unix.multiplexers.select
8 TUPLE: select-mx < mx read-fdset write-fdset ;
10 ! Factor's bit-arrays are an array of bytes, OS X expects
11 ! FD_SET to be an array of cells, so we have to account for
12 ! byte order differences on big endian platforms
15 cell 4 = 0b11000 0b111000 ? bitxor
18 : <select-mx> ( -- mx )
20 FD_SETSIZE 8 * <bit-array> >>read-fdset
21 FD_SETSIZE 8 * <bit-array> >>write-fdset ;
23 : clear-nth ( n seq -- ? )
24 [ nth ] [ [ f ] 2dip set-nth ] 2bi ;
26 :: check-fd ( fd fdset mx quot -- )
27 fd munge fdset clear-nth [ fd mx quot call ] when ; inline
29 : check-fdset ( fds fdset mx quot -- )
30 [ check-fd ] 3curry each ; inline
32 : init-fdset ( fds fdset -- )
33 '[ t swap munge _ set-nth ] each ;
35 : read-fdset/tasks ( mx -- seq fdset )
36 [ reads>> keys ] [ read-fdset>> ] bi ;
38 : write-fdset/tasks ( mx -- seq fdset )
39 [ writes>> keys ] [ write-fdset>> ] bi ;
41 : max-fd ( assoc -- n )
42 dup assoc-empty? [ drop 0 ] [ keys maximum ] if ;
45 [ reads>> max-fd ] [ writes>> max-fd ] bi max 1 + ;
47 : init-fdsets ( mx -- nfds read write except )
49 [ read-fdset/tasks [ init-fdset ] keep ]
50 [ write-fdset/tasks [ init-fdset ] keep ] tri
53 M:: select-mx wait-for-events ( nanos mx -- )
55 [ init-fdsets nanos dup [ 1000 /i make-timeval ] when select multiplexer-error drop ]
56 [ [ read-fdset/tasks ] keep [ input-available ] check-fdset ]
57 [ [ write-fdset/tasks ] keep [ output-available ] check-fdset ]