Sorry, should have submitted example code, I wasn't being clear: I'm passing objects to the thread through shared variables after it's been created. This code demonstrates what I mean - note that it won't complete successfully as long as the *STDIN line remains uncommented. But I'm looking for the best way of making something like that work!

#!/usr/bin/perl -w

use strict;
use threads;
use threads::shared;

use IO::Handle;
use Thread::Semaphore;

# Here we've a choice - use Storable to freeze and thaw stuff, or
# these two bogus implementations which do nothing.  This illustrates
# (when you use the bogus code) how you cannot simply drop blessed
# objects into shared objects.  If you use Storable, blessed objects
# can be passed across while they're frozen, but file handles (for
# example) still can't.
use Storable qw{freeze thaw};
#sub freeze { ${$_[0]} }
#sub thaw   { \shift }

# Job queue and semaphore; the semaphore gets signalled every time an
# object is pushed onto the queue.
my @queue : shared;
my $queue_ctrl = Thread::Semaphore->new(0);

sub thread {
  while(1) {
    $queue_ctrl->down; # Wait for something to be queued
    lock @queue;
    last unless @queue; # Terminate on empty packet
    my $object = ${ thaw shift @queue };
    # Would normally receive something relatively complex and do some
    # work with it here.
    print "Thread received $object.\n";
  }
}

# Note that I'm creating the thread *first* and *afterwards* passing
# objects across (through the queue) for it to work with..
my $thr = threads->new(\&thread);

# Things we want to try passing through to the thread:
my @stuff = (
# A basic type, works no problem with or without freeze/thaw
  '"hi there"',
# A blessed reference, must be frozen and thawed
  bless({}, 'Foo'),
# We can pass STDIN's file descriptor as an integer
  STDIN->fileno,
# Have to comment this next line out for successful completion - but
# this (or some equivalent) is what I would like to achieve!
  *STDIN,
);

# Queue stuff and see what happens
foreach my $obj ( @stuff ) {
  { # Queue $obj and signal $queue_ctrl
    lock @queue;
    print "\nEnqueueing $obj...\n";
    push @queue, freeze \$obj;
    $queue_ctrl->up;
  }
  sleep 1; # Optional, but gives the thread a chance to grab the queue
}

# Terminate - signal $queue_ctrl without enqueueing anything.
$queue_ctrl->up;
$thr->join;
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.