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/cvs/Coro/Coro/Select.pm
Revision: 1.15
Committed: Mon Sep 29 12:40:50 2008 UTC (15 years, 8 months ago) by root
Branch: MAIN
CVS Tags: rel-4_479
Changes since 1.14: +1 -1 lines
Log Message:
4.479

File Contents

# Content
1 =head1 NAME
2
3 Coro::Select - a (slow but coro-aware) replacement for CORE::select
4
5 =head1 SYNOPSIS
6
7 use Coro::Select; # replace select globally
8 use Core::Select 'select'; # only in this module
9 use Coro::Select (); # use Coro::Select::select
10
11 =head1 DESCRIPTION
12
13 This module tries to create a fully working replacement for perl's
14 C<select> built-in, using C<AnyEvent> watchers to do the job, so other
15 coroutines can run in parallel to any select user. As many libraries that
16 only have a blocking API do not use global variables and often use select
17 (or IO::Select), this effectively makes most such libraries "somewhat"
18 non-blocking w.r.t. other coroutines.
19
20 To be effective globally, this module must be C<use>'d before any other
21 module that uses C<select>, so it should generally be the first module
22 C<use>'d in the main program.
23
24 You can also invoke it from the commandline as C<perl -MCoro::Select>.
25
26 Performance naturally isn't great, but unless you need very high select
27 performance you normally won't notice the difference.
28
29 =over 4
30
31 =cut
32
33 package Coro::Select;
34
35 use strict;
36
37 use Coro;
38 use AnyEvent;
39
40 use base Exporter::;
41
42 our $VERSION = 4.749;
43 our @EXPORT_OK = "select";
44
45 sub import {
46 my $pkg = shift;
47 if (@_) {
48 $pkg->export (scalar caller 0, @_);
49 } else {
50 $pkg->export ("CORE::GLOBAL", "select");
51 }
52 }
53
54 sub select(;*$$$) { # not the correct prototype, but well... :()
55 if (@_ == 0) {
56 return CORE::select
57 } elsif (@_ == 1) {
58 return CORE::select $_[0]
59 } elsif (defined $_[3] && !$_[3]) {
60 return CORE::select $_[0], $_[1], $_[2], $_[3]
61 } else {
62 my $current = $Coro::current;
63 my $nfound = 0;
64 my @w;
65 # AnyEvent does not do 'e', so replace it by 'r'
66 for ([0, 'r', '<'], [1, 'w', '>'], [2, 'r', '<']) {
67 my ($i, $poll, $mode) = @$_;
68 if (defined (my $vec = $_[$i])) {
69 my $rvec = \$_[$i];
70 for my $b (0 .. (8 * length $vec)) {
71 if (vec $vec, $b, 1) {
72 (vec $$rvec, $b, 1) = 0;
73 open my $fh, "$mode&$b"
74 or die "Coro::Select::fd2fh($b): $!";
75 push @w,
76 AnyEvent->io (fh => $fh, poll => $poll, cb => sub {
77 (vec $$rvec, $b, 1) = 1;
78 $nfound++;
79 $current->ready;
80 undef $current;
81 });
82 }
83 }
84 }
85 }
86
87 push @w,
88 AnyEvent->timer (after => $_[3], cb => sub {
89 $current->ready;
90 undef $current;
91 })
92 if defined $_[3];
93
94 # wait here
95 &Coro::schedule;
96 &Coro::schedule while $current;
97
98 return $nfound
99 }
100 }
101
102 1;
103
104 =back
105
106 =head1 SEE ALSO
107
108 L<Coro::LWP>.
109
110 =head1 AUTHOR
111
112 Marc Lehmann <schmorp@schmorp.de>
113 http://home.schmorp.de/
114
115 =cut
116
117