IO ::选择并将标记添加到句柄 [英] IO::Select and adding a tag to the handle
问题描述
我想知道使用IO::Select
时向句柄添加其他数据的最佳方法是什么?
I'm wondering what's the best way to add additional data to a handle when I'm using IO::Select
?
基本上,我想向IO::Select
添加一个句柄,但还附加了该句柄的其他信息,以后可以检索.
Basically I'd like to add a handle to IO::Select
but also have additional info attached to that handle that I could retrieve later.
注意:我知道我可以保留一个单独的数据结构,该结构包含一个句柄和其他数据,但是这需要协调两个数据结构,这可能会引起更多的问题,而不是有价值的问题.
Note: I know I could keep a separate data structure which holds a handle and additional data but that would require coordinating two data structures and that's probably going to cause more problems than its worth.
推荐答案
IO :: Select 文档用于add
方法
每个句柄可以是IO :: Handle对象,整数或数组引用,其中第一个元素是IO :: Handle或整数.
Each handle can be an IO::Handle object, an integer or an array reference where the first element is an IO::Handle or an integer.
因此,这里可以使用数组引用".
So there, there's "an array reference" that one may use.
一个例子:
use warnings;
use strict;
use feature 'say';
use Time::HiRes qw(sleep);
use POSIX qw(:sys_wait);
use IO::Select;
my $sel = IO::Select->new;
my @procs;
for my $job (1..3) {
pipe my ($reader, $writer);
$sel->add( [$reader, "job-$job"] ); # add a tag to the handle
my $pid = fork // die "Can't fork: $!";
if ($pid == 0) {
close $reader;
sleep rand 4;
say $writer "\tkid $$ (job $job)";
close $writer;
exit;
}
close $writer;
push @procs, $pid;
}
say "Started processes @procs\n";
# Read from pipes when ready, print piped messages
while ( my @ready = $sel->can_read ) {
foreach my $p (@ready) {
my ($handle, $tag) = @$p;
say "Reading from fileno ", $handle->fileno, ", tag: ", $tag;
print while <$handle>;
$sel->remove($p); # *this* order: remove then close
close $handle;
}
}
# Reap
my $msg = "\nExited (with status): ";
my $kid = 0; # poll to reap
while (($kid = waitpid -1, WNOHANG) > -1) {
$msg .= "$kid ($?) " if $kid > 0;
sleep 0.1;
}
say $msg;
打印
Started processes 15679 15680 15681
Reading from fileno 5, tag: job-2
kid 15680 (job 2)
Reading from fileno 4, tag: job-1
kid 15679 (job 1)
Reading from fileno 6, tag: job-3
kid 15681 (job 3)
Exited (with status): 15680 (0) 15679 (0) 15681 (0)
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