[Pdx-pm] to fork or thread...

[Chris Dawson]

Hello,

I am trying to write a SOAP client/server program.  I want to start 
another program inside my start() method, and then stop that program 
using the stop() method.  I am unsure as to how I should execute the 
child program, and then what I should do to stop it.  I have been 
experimenting with fork, but I don't know the proper way to kill the 
child process.  I am happy to use perl 5.8 and the threads module if 
necessary, but I am not clear on whether I should signal the external 
application, kill it using it's pid, or what.  Any suggestions?  This is 
all happening in a linux environment, so that should simplify things.  I 
have tried writing a script which upon the stop() method, runs a 
'killall program_name' but this appears to leave a bunch of zombie 
processes, which is not optimal.  They don't get cleaned/reaped until 
the program is shutdown completely, and I want to have this running 
non-stop for a while.  I don't think the zombies are an issue and are 
not consuming resources, but I think there must be a limit to the number 
of child processes associated with an application, correct?

So, briefly this is pseudo-code for what I want to do

sub start {
    $pid = ( exec | fork | new thread | async start ) "program name"
    return true
}

sub stop
{
    kill $pid
    return true
}

Thanks,
Chris