Hi Chad,
I think your error lay in the place where Jenda pointed for you. Going posix
way is the right way if you intend to do a lot of low level stuff your self.
Mark
----- Original Message -----
From: "chad kellerman" <[EMAIL PROTECTED]>
To: "beginners" <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 1:58 PM
Subject: counting fork process, again
>
> Helloe everyone,
> I was wondering is someone can help me out with an issue with forking.
I
> am trying to fork 8 process at a time.
>
> Here is what I have:
>
> <code snippet>
>
> #!/usr/bin/perl
> use strict;
> use warnings;
> use lib ".";
> use BACKUP; #my own module
> use POSIX ":sys_wait_h";
>
> my( $MAX_CHILDREN ) = "8";
> my( $CHILD_PIDS ) = "0";
> my( $maxtries ) = "7";
> my( $failure ) = "0";
>
> # there are actually 100 hostIds. but you should get the point..
> my( @hostIds ) = "10.10.10.1, 10.10.10.2, 10.10.10.3 ,10.10.10.4";
>
> $SIG{CHLD} = \&CHILD_COUNT($CHILD_PIDS);
>
> FORK:
> {
>
> HOSTID: foreach my $hostId ( @hostIds ) {
>
> redo HOSTID if $CHILD_PIDS >= $MAX_CHILDREN;
>
> if( my $pid = fork ) {
> $CHILD_PIDS++; #Add the children up until we hit the max
> next;
> }elsif (defined $pid) {
> # In here I do some stuff with each $hostID.
> # To make the code easier to read, I made a module
that
> # has a bunch of subroutines in it.
> #There are basically 2 subroutines that I call for
each
> # hostID. 1 grabs the quota for each user on the
hostId,
> #The other tars and copies the user where the script
> # is. I eval my connection and if some fails I
> # go on to the next. ex.
> until ( (BACKUP->QuotaIt( $hostId ) or ( $failures ==
> $maxtries ) ) ) {
> $failures++;
> if ( $failures == $maxtries ) {
> my( $subject ) = "Hey, WTF is up with
$hosId";
> my( $message ) = "$0 failed to connect to $hostID.";
> BACKUP->MailIt( $subject, $message, $daily );
> #go to the next hostid
> next HOSTID2;
> } #if statememt
> } #until statement
>
> }elsif($! =~ /No more process/){
> sleep 15;
> redo; #do over.
> }else{
> # this is just a mail routine that mails be that I
> #can't fork
> my( $subject ) = "Failed to fork any children";
> my( $message ) = "$0 failed to fork anymore children.
> BACKUP->MailIt( $subject, $message, $daily );
> die;
> }
>
> } # foreach loop ends
>
> } # this is the FORK
>
>
> sub CHILD_COUNT {
> my $child_pids = @_;
> my $child = waitpid(-1,WNOHANG);
> while ($child != -1 && ($child_pids > 0 )) {
> $child_pids--;
> $child = waitpid(-1,WNOHANG);
> }
> }
>
> <end of code snippet>
>
> Just typing this I realized that if I can't fork then I probably won't
be
> able to mail myself a notification. So I gotta change that else statement
> with the mail notification.
>
> Anyways, the issues I am having are two fold. The first I get this
> warning:
> Not a subroutine reference at ./script.pl line 331 which is:
> " redo HOSTID2 if $CHILD_PIDS >= $MAX_CHILDREN;"
>
> The second is a bigger issue. I also fork in the "home made" perl
module
> for each user of the HostId I am doing.
> nothing crazy, just.........
>
> #----------------------------------------------------------#
> foreach $user (@users) {
> my( $pid ) = fork ();
> die "Cannot fork: $!" unless defined( $pid );
> if ( $pid == 0 ) {
> #do tarring of user
> exit 0;
> }
> waitpid($pid,0);
> }
> #-----------------------------------------------------------#
>
> Here I get the error:
> Not a subroutine reference at BACKUP.pm line 195.
> which is: " waitpid($pid,0);"
>
> I know this is very confusing. And I might not even be posting to the
right
> list. But I am so frustrated with trying to get this thing to work. It
> seems as if I have searched everywhere for examples of limiting the number
of
> forked processes, then being able to fork with in a fork.
> I originally was using Parallel::ForkManager. But I found that if I
set
> the max_processes to 8 it will start eight but will not contiue until all
> eight were done, then only do one at a time.
>
> That's when I decided to go the POSIX route and use fork.. But just
can't
> get it working. I think setting the SIG{CHLD} is messing things up. BUt
I
> am not sure.
>
> Sorry for being so drawn out. Please feel free to tear me/my code up.
I am
> new and would really like to know how to do this. Don't worry I can take
> criticism pretty well... lol
>
> Thanks in advance,
>
> Chad
>
>
>
>
>
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>
>
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