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=head1 NAME |
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Coro::Select - a (slow but coro-aware) replacement for CORE::select |
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|
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=head1 SYNOPSIS |
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|
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use Coro::Select; # replace select globally |
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use Core::Select 'select'; # only in this module |
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use Coro::Select (); # use Coro::Select::select |
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|
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=head1 DESCRIPTION |
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|
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This module tries to create a fully working replacement for perl's |
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C<select> built-in, using C<AnyEvent> watchers to do the job, so other |
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coroutines can run in parallel to any select user. As many libraries that |
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only have a blocking API do not use global variables and often use select |
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(or IO::Select), this effectively makes most such libraries "somewhat" |
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non-blocking w.r.t. other coroutines. |
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|
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To be effective globally, this module must be C<use>'d before any other |
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module that uses C<select>, so it should generally be the first module |
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C<use>'d in the main program. |
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|
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You can also invoke it from the commandline as C<perl -MCoro::Select>. |
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|
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Performance naturally isn't great, but unless you need very high select |
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performance you normally won't notice the difference. |
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|
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=over 4 |
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|
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=cut |
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|
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package Coro::Select; |
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|
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use strict; |
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|
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use Coro (); |
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use AnyEvent (); |
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use Coro::AnyEvent (); |
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|
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use base Exporter::; |
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|
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our $VERSION = 5.1; |
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our @EXPORT_OK = "select"; |
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|
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sub import { |
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my $pkg = shift; |
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if (@_) { |
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$pkg->export (scalar caller 0, @_); |
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} else { |
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$pkg->export ("CORE::GLOBAL", "select"); |
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} |
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} |
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|
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sub select(;*$$$) { # not the correct prototype, but well... :() |
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if (@_ == 0) { |
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return CORE::select |
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} elsif (@_ == 1) { |
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return CORE::select $_[0] |
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} elsif (defined $_[3] && !$_[3]) { |
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return CORE::select $_[0], $_[1], $_[2], $_[3] |
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} else { |
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my $nfound = 0; |
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my @w; |
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my $wakeup = Coro::rouse_cb; |
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|
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# AnyEvent does not do 'e', so replace it by 'r' |
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for ([0, 'r', '<'], [1, 'w', '>'], [2, 'r', '<']) { |
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my ($i, $poll, $mode) = @$_; |
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if (defined (my $vec = $_[$i])) { |
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my $rvec = \$_[$i]; |
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for my $b (0 .. (8 * length $vec)) { |
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if (vec $vec, $b, 1) { |
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(vec $$rvec, $b, 1) = 0; |
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open my $fh, "$mode&=$b" |
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or die "Coro::Select::fd2fh($b): $!"; |
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push @w, |
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AnyEvent->io (fh => $fh, poll => $poll, cb => sub { |
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(vec $$rvec, $b, 1) = 1; |
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$nfound++; |
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$wakeup->(); |
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}); |
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} |
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} |
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} |
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} |
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|
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push @w, |
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AnyEvent->timer (after => $_[3], cb => $wakeup) |
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if defined $_[3]; |
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|
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Coro::rouse_wait; |
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|
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return $nfound |
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} |
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} |
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|
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1; |
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|
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=back |
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|
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=head1 SEE ALSO |
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|
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L<Coro::LWP>. |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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|
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=cut |
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