multithreading - Perl getstore在线程中

Question

在以下脚本中:

use strict;
use warnings;
use LWP::Simple;
use threads;
threads->create(sub { 
    my $url = "http://www.example.com/logo.jpg"; 
    my $file = "/var/www/html/logo.jpg"; 
    getstore($url, $file);
    threads->detach();
});

当我启动它时，它不会保存图像，但是如果我不在线程中启动相同的代码，它将起作用，为什么？

Answer 1

因为“分离”并没有达到您的期望。当程序退出时，分离的线程将终止。 From the docs...

$thr->detach()

Makes the thread unjoinable, and causes any eventual return value to be discarded. When the program exits, any detached threads that are still running are silently terminated.

您应该已经收到了这样的消息。

Perl exited with active threads:
    1 running and unjoined
    0 finished and unjoined
    0 running and detached

而不是分离，您应该等到程序结束时所有线程都完成。

for my $thread (threads->list(threads::running)) {
    $thread->join;
}

如果您只想发出并行HTTP请求，则不需要线程。 LWP::Parallel可能会更有效。