perl中的简单并行处理

Question

我有一些代码块,在一些对象的函数内,可以并行运行并为我加速.

我尝试使用subs::parallel以下方式(所有这些都在函数体中):

my $is_a_done = parallelize { 
                              # block a, do some work
                              return 1;
                             };
my $is_b_done = parallelize { 
                              # block b, do some work
                              return 1;
                             };
my $is_c_done = parallelize { 
                              # block c depends on a so let's wait (block)
                              if ($is_a_done) {
                               # do some work
                              };
                              return 1;
                             };
my $is_d_done = parallelize { 
                              # block d, do some work
                              return 1;
                             };

if ($is_a_done && $is_b_done && $is_c_done && $is_d_done) {
 # just wait for all to finish before the function returns
}

首先,注意我if用来等待线程阻塞并等待前一个线程在需要时完成(更好的想法？这if很难看......).

其次,我收到一个错误:

Thread already joined at /usr/local/share/perl/5.10.1/subs/parallel.pm line 259.
Perl exited with active threads:
    1 running and unjoined
    -1 finished and unjoined
    3 running and detached

Answer 1

我以前没见过subs::parallel,但鉴于它正在为你做所有的线程处理,而且它似乎做错了,根据错误信息,我认为这有点可疑.

通常我不会只是建议把它扔出去这样,但你在做什么真的是没有任何困难与普通螺纹接口,所以为什么不给这一个镜头,并简化问题一点？与此同时,我会回答你问题的其他部分.

use threads;
my @jobs;
push @jobs, threads->create(sub {
  # do some work
});

push @jobs, threads->create(sub {
  # do some other work
});

# Repeat as necessary :)

$_->join for @jobs; # Wait for everything to finish.

如果你使用那些sub的返回值,你需要一些更复杂的东西(简单地切换到一个散列会有很大帮助)但是在你提供的代码示例中,你忽略了它们,这使事情变得容易.