sharing complex data structures

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I'm using threads and threads::shared to spawn a few new instances of my $mech object. The trouble I'm having is that I'm unable to successfully share my response object from $mech.

Here is what I'm doing:

my $data :shared = shared_clone({});
bless($data);
...
my $res = $mech->get("$url");

$data->{'current_info'} = $res;
...
[download]

The problem is that the $res object contains a few methods like $res->decoded_content, $res->is_success, etc.
Do I need to somehow share the $res object as well?

Comment on sharing complex data structures Download Code

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Re: sharing complex data structures by Joost (Canon) on Jul 07, 2008 at 19:36 UTC
You can more or less forget about successfully sharing objects using threads::shared unless their documentation explictly states that you can. Also, because of the way WWW::Mechanize (I'm assuming that's what you mean by "$mech") works - it has a concept of "the current page I'm looking at", for one - sharing the same mechanize object is probably not going to be very useful. Is there any reason you're not using a separate mechanize instance per thread? "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]
Re: sharing complex data structures by jettero (Monsignor) on Jul 07, 2008 at 19:35 UTC
Every time I try to use threads on perl I'm disappointed in some way. I'd recommend either use forks; or flattening the response object with Storable or YAML or something. The problem appears to be though, that although your hash is shared, the ref you put under the key 'current_info' is not shared. Maybe you want the page contents shared? `$data->{key} = $mech->content;` [download] -Paul	[reply] [d/l]
Re: sharing complex data structures by renodino (Curate) on Jul 08, 2008 at 03:13 UTC
What version of Perl are you using ? What version of threads are you using ? What version of threads::shared are you using ? And yes, you need to share the $res object. Every reference stored in a shared object must also be shared. And I don't know if a $res object can be shared. If it contains file handles or coderefs, or uses tie()s, than no. If its just an object with scalar members, then probably. Anything in-between will require the new shared_clone() capability (as you've used on $data above, for reasons that escape me, since you're just creating a hashref). I suspect your app will need some refactoring to be able to use threads effectively, but as you've not posted any significant code, its a challenge to decipher your intent. Perl Contrarian & SQL fanboy	[reply]
Re^2: sharing complex data structures by Anonymous Monk on Jul 08, 2008 at 14:04 UTC
Perl: 5.10 (1003) threads: 1.71 threads::shared: 1.23 my asumption was correct, I need to somehow share my $res object. It's a http::response object so I'm sure of the best way to share it.	[reply]
Re^3: sharing complex data structures by renodino (Curate) on Jul 08, 2008 at 14:42 UTC
Looks like you're running the latest stuff. IIRC, there's no file handles, coderefs, or ties in an HTTP::Response, so it may be as simple as share_clone($res). Perl Contrarian & SQL fanboy	[reply]