Continuing my research, I thought that I should check how GET PROCESS VARIABLE interacts with workers. Fear not, my hatred of this command and its brethren remains fierce, hot and pure. I took a look at Laurent Esnault's lucid presentation on mutli-threaded code from the Portland Summit and nothing seems to have changed since then. I can only add a few details not found in there. Here's a summary:
* GET PROCESS VARIABLE works normally when you have a cooperative worker. * GET PROCESS VARIABLE returns nothing from a preemptive worker. That all makes sense. It would be a bit nuts to make preemptive threads have to spend a lot of time checking for inbound requests for data. (You need an interrupt.) It makes sense to avoid all of that and restrict preemptive workers to discrete tasks. I'm so much in favor of this idea, I even asked for it as a feature request: Protect process variables inside of workers http://forums.4d.fr/Post/EN/19111663/1/19111664 Yeah, well, I got no love from other developers there. John DeSoi also privately explained a case he has where it makes a lot of sense to use GET PROCESS VARIABLE. It tastes like bitter ash in my mouth, but I had to agree that the existing feature set didn't give him a better option. Anyway, I never use those commands so I don't care much about how they work, but I did want to check that a GET PROCESS VARIABLE call to a preemptive worker wouldn't blow it up the way a bit of cooperative code executed remotely via CALL WORKER does. That would really suck. But it doesn't work that way, 4D thought this through. But as a heads up to those of you who do use The Evil Commands, I figured you might want to know that they *fail silently* with a call to preemptive process. So. Now you know. ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: http://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
