schwernbot
commented
10 years ago From: @schwern Date: Tuesday Nov 22, 2011 at 06:36 GMT Orig: https://github.com/Test-More/test-more/issues/232#issuecomment-2831021
I have a solution. It's not too bad. http://stackoverflow.com/q/8222822/14660
Two tricks remain. The first is turning that into something which can be applied multiple times to a class (ie. to output_fh and error_fh). That should be a matter of some Mouse->meta->add_attribute.
The second is, ideally, this would only take effect if a thread is created. That involves using the CLONE class method which is nasty work.
Halfway there would be to make it only take effect if threads are enabled.
From: @schwern Date: Sunday Nov 20, 2011 at 09:35 GMT Orig: https://github.com/Test-More/test-more/issues/232
Perl threads do not support sharing filehandles. All the elements of a shared data structure must be shared. This presents a problem: if we're going to share the TestState and everything in it that includes the Formatter which includes the Streamer which contains a filehandle.
Either Streamer::Print has to put that filehandle outside of itself in a non-shared structure, as suggested here: http://stackoverflow.com/questions/8200159/how-to-share-an-object-which-contains-a-filehandle/8200275#8200275
Or somehow the Streamer is not part of the Formatter. One possibility is to make the Streamer an inside-out object, then all its data can be in unshared structures. http://stackoverflow.com/questions/8200159/how-to-share-an-object-which-contains-a-filehandle/8200621#8200621
Unfortunately thread-safe inside-out objects are difficult in 5.8, but this article about using
CLONEmight help. http://perlmonks.org/index.pl?node_id=483162It's ok if changes to the Streamer are not reflected across threads. We can just document not to do that. It doesn't work in stable either.