> I've just been learning to use threads.pm and > threads::shared.pm. > I spent ages trying to get my script to work until I realised > that > use threads; > must come before > use threads:shared; > This probably should have been obvious from the documentation > in threads.pm which says > preferably enable threads...as early as possible > > I was wondering: > - if threads could work with a simple use threads; or use > threads::shared;? > Looking at the code, it appears that they have been modified > so > that they don't do this. No doubt for some very technical > reason beyond me (though I'd be grateful if someone could try > to explain), so if its not feasible, then fair enough.
Yes this is deliberate design decision. The reason is that if a module is using threads::shared to share a variable if running in a threaded enviroment, and the caller doesn't want threads we don't want to impose the overhead of shared variables. > - if threads.pm and threads::shared.pm could have their > documentation amended to explicitly mention the order of the > 'use's? > Given this is Perl (i.e. 'fix what you find if you can'), I'd > be happy to do this. Most welcome. > - should threads::shared.pm silently fail when there has been no > use threads;? > Again looking at the code, this appears to have been > deliberately designed, so if there's a good reason, then > ok, though this did give me a lot of grief. Yes, it should just disable itself. However a good fix would be that threads::shared raises a flag and threads.pm emites a mandatory warning if it is loaded after threads::shared. Warning, threads::shared has already been loaded by modules '...', to enable shared variables for these modules 'use threads' must be called before any of those modules are loaded' > Any thoughts? > > Andy Bussey > Arthur
