Question

我正在使用threads和threads::shared模块编写perl脚本，其中父进程可以在子执行过程中检索子线程的结果。

例如。我需要在以下脚本

中的flag = 1时获取子线程的输出

#!/usr/bin/perl
use strict;
use warnings;
use threads;
use threads::shared;

my $flag : shared = 0;
my $num : shared = 0;

my $thr = new threads(\&sub1);

my @res = $thr->join();

print "@res" if ($flag != 0);

sub sub1
{

  for( $num=0;$num<1000;$num++)
  {
    print "$num\t";
  }

  print "\n";
  $flag = 1;
  sleep(5);

  for( $num=50;$num<100;$num++)`enter code here`
  {
    print "$num\t";
  }

  print "\n";
}

Answer 1

您希望在线程内外等待设置/取消设置标志。请参阅代码中的注释：

#!/usr/bin/perl
use strict;
use warnings;
use threads;
use threads::shared;

my $flag : shared = 0;
my $num : shared = 0;

my $thr = new threads(\&sub1);

# do some things here

#wait for thread to set the flag
while( $flag == 0) {}
print "Outside thread: num=$num\n";
#unset flag so thread can continue
$flag = 0;

# do some things here

#block until thread finishes
my @res = $thr->join();

print "Outside thread: num=$num\n";
print @res;

sub sub1
{
  #do initial calculations in thread
  for( $num=0;$num<1000;$num++)
  {
    print "$num\t";
  }

  print "\n";
  #set flag to parent can read value
  $flag = 1;
  #wait for parent to unset the flag
  while($flag==1) {}

  #continue with rest of thread
  for( $num=50;$num<100;$num++)
  {
    print "$num\t";
  }

  print "\n";
  return "I'm done\n";
}

在子线程执行期间检索子线程输出

1 个答案: