multithreading - 如何将 perl 子例程排队到线程队列而不是数据？

Question

背景 :
在阅读如何对我的 perl 脚本进行多线程处理时，我阅读了(来自 http://perldoc.perl.org/threads.html#BUGS-AND-LIMITATIONS)

On most systems, frequent and continual creation and destruction of threads can lead to ever-increasing growth in the memory footprint of the Perl interpreter. While it is simple to just launch threads and then ->join() or ->detach() them, for long-lived applications, it is better to maintain a pool of threads, and to reuse them for the work needed, using queues to notify threads of pending work.

我的剧本将是长期存在的；它是一个始终运行的 PKI LDAP 目录监视守护程序。如果企业监控解决方案因任何原因停止运行，则会生成警报。我的脚本将检查我是否可以访问另一个 PKI LDAP 目录，并验证两者上的吊销列表。

问题 :我在谷歌上能找到的所有内容都显示将变量(例如标量)传递给线程队列而不是子例程本身......我想我只是不明白如何与实现线程的方式(没有队列)。

问题 1 : 我怎样才能“维护一个线程池”来避免 perl 解释器慢慢地吃掉越来越多的内存？
问题 2 :(无关，但虽然我发布了此代码)在主程序结束时是否有安全的 sleep 量，以便我不会在一分钟内多次启动线程？ 60 似乎很明显，但是如果循环很快，或者由于处理时间或其他原因可能会错过一分钟，这是否会导致它运行多次？
提前致谢!

#!/usr/bin/perl

use feature ":5.10";
use warnings;
use strict;
use threads;
use Proc::Daemon;
#

### Global Variables
use constant false => 0;
use constant true  => 1;
my $app = $0;
my $continue = true;
$SIG{TERM} = sub { $continue = false };

# Directory Server Agent (DSA) info
my @ListOfDSAs = (
    { name => "Myself (inbound)",
      host => "ldap.myco.ca",
      base => "ou=mydir,o=myco,c=ca",
    },
    { name => "Company 2",
      host => "ldap.comp2.ca",
      base => "ou=their-dir,o=comp2,c=ca",
    }
);    
#

### Subroutines

sub checkConnections
{   # runs every 5 minutes
    my (@DSAs, $logfile) = @_;
    # Code to ldapsearch
    threads->detach();
}

sub validateRevocationLists
{   # runs every hour on minute xx:55
    my (@DSAs, $logfile) = @_;
    # Code to validate CRLs haven't expired, etc
    threads->detach();
}

#

### Main program
Proc::Daemon::Init;

while ($continue)
{
    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);

    # Question 1: Queues??

    if ($min % 5 == 0 || $min == 0)
        { threads->create(&checkConnections, @ListOfDSAs, "/var/connect.log"); }

    if ($min % 55 == 0)
        { threads->create(&validateRevocationLists, @ListOfDSAs, "/var/RLs.log"); }

    sleep 60; # Question 2: Safer/better way to prevent multiple threads being started for same check in one matching minute?
}

# TERM RECEIVED
exit 0;
__END__

Answer 1

use threads;
use Thread::Queue 3.01 qw( );

my $check_conn_q      = Thread::Queue->new();
my $validate_revoke_q = Thread::Queue->new();

my @threads;
push @threads, async {
   while (my $job = $check_conn_q->dequeue()) {
      check_conn(@$job);
   }
};
push @threads, async {
   while (my $job = $validate_revoke_q->dequeue()) {
      validate_revoke(@$job);
   }
};

while ($continue) {
   my ($S,$M,$H,$m,$d,$Y) = localtime; $m+=1; $Y+=1900;

   $check_conn_q->enqueue([ @ListOfDSAs, "/var/connect.log" ])
      if $M % 5 == 0;

   $validate_revoke_q->enqueue([ @ListOfDSAs, "/var/RLs.log" ])
      if $M == 55;

   sleep 30;
}

$check_conn_q->end();
$validate_revoke_q->end();
$_->join for @threads;

我不确定这里是否需要并行化。如果不是，你可以简单地使用

use List::Util qw( min );

sub sleep_until {
   my ($until) = @_;
   my $time = time;
   return if $time >= $until;
   sleep($until - $time);
}

my $next_check_conn = my $next_validate_revoke = time;
while ($continue) {
   sleep_until min $next_check_conn, $next_validate_revoke;
   last if !$continue;

   my $time = time;
   if ($time >= $next_check_conn) {
      check_conn(@ListOfDSAs, "/var/connect.log");
      $next_check_conn = time + 5*60;
   }

   if ($time >= $next_validate_revoke) {
      validate_revoke(@ListOfDSAs, "/var/RLs.log");
      $next_validate_revoke = time + 60*60;
   }
}