...You cant share a blessed object though, since whenever you share something, its contents get clobbered...

Actually, sharing a simple scalar does keep its value: 

use threads;
use threads::shared;
my $foo = "foo\n";
share( $foo );
print $foo;
__END__
foo

[download]

Internally, share() is basically a tie on the reference of what is specified. This is the same approach I use with forks: oddly enough, forks doesn't have that problem, e.g. with a hash: 

use forks;
use forks::shared;
my %foo = (bar => "foo\n");
share( %foo );
print %foo;
__END
barfoo

[download]
I think I'll keep this "inconsistency" in forks, but will add a little note in the pod about this. I agree this is a bug in threads::shared that should be fixed. As always, patches are welcome ;-)

...These and other things might have been useful to put the threads::shared docs...

Please feel free to supply a documentation patch to p5p, or a proposal for (additional) text here (in which case I'll turn it into a documentation patch and submit it to p5p on your behalf).

...it seems I can cheat a little, use freeze/thaw, and actually share objects...

FWIW, that's the approach that Thread::Queue::Any, Thread::Conveyor and Thread::Tie use under the hood (which is actually externalized into its own module: Thread::Serialize).

...Anyone know how, what, why and WTF?

Look at shared.xs in your Perl distribution. I think most of the problem comes from the fact that there is internally only 1 subclass for the tieing: threads::shared::tie. Whereas in forks, I have taken the approach of creating a seperate subclass for each data type.

Hope this helps.

Liz

In reply to Re: ithreads, shared variables.. by liz
in thread ithreads, shared variables.. by castaway

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