Re: forked process exiting before output read

["Jeffrey Ratcliffe" <jeffrey ratcliffe gmail com>]

On 31/07/07, muppet <scott asofyet org> wrote:
> Is it the handling in the parent that takes a while, or in the
> child?  I notice you have a sleep(2) in the loop in the gui,
> presumably to simulate the gui taking al ong time...

A bit of both. It seems to depend on what the rest of the system is
doing, but 25% of the time, I definitely had the problem that the GUI
in the parent wasn't keeping up with the child.

> With some very minor changes, i get this example to work just fine.
> (No need to go dorking around with the insanity of threads... ;-)

Thanks!

> If small lines of text are what you have, you might actually want to
> use datagram sockets, because you'll get guaranteed delivery of
> entire messages.

Never heard of those before, but google is my friend. So to do this, I change:

  socketpair($reader, $writer,  AF_UNIX, SOCK_STREAM, PF_UNSPEC);
[..]
    $line = <$reader>;
[..]
   $writer->write($i/$n."Running $i of $n\n");
   $writer->flush;

to

  socketpair($reader, $writer,  AF_UNIX, SOCK_DGRAM, PF_UNSPEC);
[..]
    recv($reader, $line, 1000, 0);
[..]
   send($writer, $i/$n."Running $i of $n\n", 0);

Seems to work fine. Thanks.

Do I need to worry about the flags in send and recv?

Jeff