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我想维护一个我已经分叉的孩子的 pidlist 数组，然后在它们退出时将它们删除（以限制我在任何给定时间有多少个分叉进程）。我想我可能很聪明，可以通过在删除或拼接中使用@main::pid_list 来做到这一点，但没有乐趣。我可以成功弹出一个元素，但显然它不会删除正确的 pid。有什么想法如何处理这个问题，或者我会以完全不同的方式更好地做到这一点？

#!/usr/bin/perl -w
use POSIX ":sys_wait_h";
use Data::Dumper;

# Only allow 5 processes running at a time

sub REAPER {
    my $child = shift;
    while (($child = waitpid(-1, WNOHANG)) > 0) {
        # Need to remove child from pidlist here
        #pop(@main::pid_list);                     #This works
        #delete($main::pid_list[$child]);          #This does not

    }
    $SIG{CHLD} = \&REAPER;
}

@pid_list = ();
@files = (1 .. 20);

foreach my $file (@files) {
    my $processed = 'false';
    while ($processed eq 'false') {

        print "Working on file: $file\n";
        $SIG{CHLD} = \&REAPER;
        if (scalar(@pid_list) < 5) {
            $pid = fork();
            if ( $pid == 0 ) {
                print "$$: Child Processing file #" . $file . "\n";
                sleep(10);
                print "$$: Child done processing file #" . $file . "\n";
                exit(0);
            }
            push(@pid_list, $pid);
            print Dumper(@pid_list);
            $processed = 'true';
        }
        sleep(1);
    }
}

# Since we are at the end we need to wait for the last process to end
print "PID: $$ End of parent program\n";

exit 0;
4

2 回答 2

5

使用哈希表而不是数组。

sub REAPER {
    my $child = shift;
    while (($child = waitpid(-1, WNOHANG)) > 0) {
        # Need to remove child from pidlist here
        delete $main::pid_list{$child};
    }
    $SIG{CHLD} = \&REAPER;
}

...

if ((scalar keys %main::pid_list) < 5) {
    ...
    if ($pid != 0) {
        ...
       exit(0);
    }
    $main::pid_list{$pid}++;
}
于 2011-03-08T05:40:27.323 回答
0

尝试@main::pid_list = grep $_ != $child, @main::pid_list;

于 2011-03-08T05:23:13.233 回答