Re: Using a stack with fork()

Thanks to both of you, neither idea hit me. I'm not concerned with the output from the child, as it does its own error checking and checks in its status to a mysql database. The parent is going to take care of the errors after the last child reports in.

Thanks a lot from a wannabe monk with 0 reputation :)

Comment on Re: Using a stack with fork()

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Re: Re: Using a stack with fork() by $code or die (Deacon) on Jan 06, 2001 at 07:32 UTC
Hi, My idea is that the parent pop's the stack right after the fork, so that the value the child process got is no longer in the stack. Is this the right thing to do, or is there a "right thing to do"? I'm not all that familiar with `fork()` (I spend most my time on Win32). But wasn't Fastolfe's suggestion basically what you asked for? except more efficient. The `while (host = pop array_of_hosts)`does the pop before the child is created, all the child needs to know is the value of $host, it doesn't need to pop, because the parent has already taken care of it. Update: I've just read up a bit on fork. If I were you, I would develop Merlyn's snippet. It's a little less pseudocode than Fastolfe's but basically the same. You could add a `sleep()` in there for the parent so you don't spawn too many children and overload the CPU which concerned geektron. To just explain Merlyn's a bit further (and alter it a bit to utilise pop): while (my $host = pop @arrayofhosts) { # $host is no longer in the +array defined (my $pid = fork) or die "Cannot fork: $!"; # self-explanato +ry unless ($pid) { # only the child will execute this code from here ... # do some things with $host exit 0; # very important!!! don't let it get past here # to here. At this point, the child process will terminate ... } # The parent continues here after forking the child # here it can do what it wants. # you can rest here a while so you don't have too many zombies sleep (10); # now do some more things before forking the next child process } [download]	[reply] [d/l]

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Re: Re: Using a stack with fork()
by $code or die (Deacon) on Jan 06, 2001 at 07:32 UTC

My idea is that the parent pop's the stack right after the fork, so that the value the child process got is no longer in the stack. Is this the right thing to do, or is there a "right thing to do"?

fork()

Fastolfe

while (host = pop array_of_hosts)

Update:

a bit

sleep()

while (my $host = pop @arrayofhosts) {    # $host is no longer in the 
+array
  defined (my $pid = fork) or die "Cannot fork: $!";  # self-explanato
+ry
  unless ($pid) {         
    # only the child will execute this code from here ...
         # do some things with $host
    exit 0; # very important!!! don't let it get past here
    # to here. At this point, the child process will terminate ...
  }

    # The parent continues here after forking the child
    # here it can do what it wants. 
    # you can rest here a while so you don't have too many zombies

    sleep (10);
    # now do some more things before forking the next child process

}
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