Question

如何在Perl中实现Javascript setTimeout功能？这是我要在Perl中编写的javascript代码。使用线程有可能吗？

alert("Event 1 occured");
setTimeout(function(){ alert("3 seconds elapsed"); }, 3000);
alert("Event 2 occured");

输出为：

 Event 1 occured
 Event 2 occured
 3 seconds elapsed

我有perl 5.18.2，并且在Mac OSX上

Answer 1

不需要线程，它们是not great anyway in Perl。您可以像JavaScript一样使用事件循环，Perl核心中没有任何事件循环。 IO::Async和Mojo::IOLoop（Mojolicious Web框架背后的事件循环）是两个流行且得到良好支持的事件循环生态系统。主要区别在于，与JavaScript不同，事件循环在某些东西启动之前不会运行。

use strict;
use warnings;
use IO::Async::Loop;
print "Event 1 occurred\n";
my $future = IO::Async::Loop->new->delay_future(after => 3)->on_done(sub { print "3 seconds elapsed\n" });
print "Event 2 occurred\n";
$future->await; # run event loop until Future has been resolved

use strict;
use warnings;
use Mojo::IOLoop;
print "Event 1 occurred\n";
Mojo::IOLoop->timer(3 => sub { print "3 seconds elapsed\n" });
print "Event 2 occurred\n";
Mojo::IOLoop->start; # run event loop until no more events to wait for

请查看Mojolicious cookbook，以获取有关事件循环和非阻塞代码的高级概述。

Answer 2

请参见alarm功能。否则，请考虑查看threads.pm或，如果要使用Javascript获得功能奇偶校验，则事件循环之一，例如AnyEvent或Mojo::IOLoop或IO::Async。

使用threads，您的示例将是：

use strict;
use threads;
print("Event 1 occured\n");
async {
    sleep 3;
    print "3 seconds elapsed\n";
};
print("Event 2 occured\n");
$_->join for threads->list; # to wait until all threads have finished

在perl中实现js setTimeout功能

2 个答案: