Re^5: forks for running multiple codes at same time

forking, and then calling system to run the command, means he's forking twice for every command. Maybe 3 times depending what's in $command.

You can achieve the goal without threads on win32 like this:

#! perl -slw
use strict;

my @dates = 1 .. 10;
my  @pids;

(my $cmd = <<'CMD' ) =~ s[\s+][ ]g;
    -wle"print qq[task $ARGV[0] starting];
      sleep rand( 10 );
      print qq[task $ARGV[ 0 ] finishing];"
CMD

while( my $date = pop @dates ) {
    push @pids, system 1, 'perl.exe', "$cmd $date";
    if( @pids >= 5 ) {
        my $kid = wait;
        @pids = grep $_ != $kid, @pids;
    }
}

waitpid $_, 0 for @pids;
[download]

Since you need to load a new executable, why not just start it in a new process rather than duplicating the current one first?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

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Re^6: forks for running multiple codes at same time by salva (Canon) on Feb 09, 2009 at 10:45 UTC
Since you need to load a new executable, why not just start it in a new process rather than duplicating the current one first? Well, I was thinking about Unix systems where calling fork & exec is the standard (and sometimes only) way to start a new process. On Windows, you are right, it will be quite inefficient.	[reply]
Re^7: forks for running multiple codes at same time by BrowserUk (Patriarch) on Feb 09, 2009 at 11:21 UTC
I was thinking about Unix systems where calling fork & exec is the standard (and sometimes only) way to start a new process. Sorry. I should have added a smiley. I was taking a gentle dig (back) at *nix :) Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. "Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."	[reply]