如何让所有的 fork(ing) 子进程同时执行？

Question

我有一个进程，我希望主线程运行一个循环并生成 n 个子线程，所有子线程都应休眠 j 秒，然后（或多或少）同时醒来并执行其操作。

我的代码看起来像这样 [根据 Dre 的请求编辑]：

 #THE IDEA HERE IS SOMETIMES I WANT TO HOLD THE 
SMS DELIVERY FOR $smsDelay number of seconds 
    if($smsDelay){
            my $forkPid = fork();
            if($forkPid){
                next;
            }
            elsif($forkPid == 0){
                                #db connection disappears while children wait, so, need to reconnect (probably not the best way to handle THIS either! :)
                $myDbC = DBI->connect([DBLOGIN STUFF]) or myDie("can not connect to db");
                &logData("WAITING $smsDelay SECONDS TO SEND SMS");
                sleep($smsDelay * 1);
                $t = time();
                print "sending SMS";
                &send_sms_message($userPN, $smsText , $smsCampaignId);
                print "SMS sent";       
                my $smsVerification = &getDeliveryStatus($userPN, '.smslog');       
                &logData("SMS delivery for $userPN, filename:$filename. Status = $smsVerification");
                #save mms, sms, response code in db
                &runSQL([SQL HERE]);
                exit; #this should only exit the fork, not the entire process!
            }
        }else{
            #HERE I WOULD SEND SMS IMMEDIATELY WITHOUT DELAY

        }

我看到的是每个子进程都连续执行，但每个子进程在下一个子进程之间等待 j 秒！这不是我想要的（坦率地说，完全令人困惑）。我做错了什么？

TIA

Answer 1

他们应该同时醒来，我测试时他们也这样做了。我的代码：

print "parent: ".localtime."\n";
for (1..3) {
    my $pid = fork();
    if ($pid == 0){
       sleep(3);
       print "$: ".localtime."\n";
       exit(0);
    }
}

1 while wait != -1;

Unix:

parent: Wed Mar  9 22:21:27 2011
29757: Wed Mar  9 22:21:30 2011
29755: Wed Mar  9 22:21:30 2011
29756: Wed Mar  9 22:21:30 2011

Windows (fork emulation):

parent: Thu Mar 10 01:19:39 2011
-3836: Thu Mar 10 01:19:42 2011
-4600: Thu Mar 10 01:19:42 2011
-4400: Thu Mar 10 01:19:42 2011

我怀疑问题出在你没有显示的代码中。