Yes, I’ve seen it happen. 4D language is multi-threaded already - it’s cooperative instead of pre-emptive prior to v16. A method looping through an interprocess array can easily be paused while another method updates that same array.
------------------------------------------------ Richard Wright DataDomain [email protected] ------------------------------------------------ > Date: Mon, 31 Oct 2016 22:43:48 -0700 > From: Kirk Brooks <[email protected]> > > > David, > Great points - but, respectfully, does it ever actually happen? Can you > write an example db that does this? > > And bear in mind I'm talking about conditions on a client - not the server. > And I'm not talking about situations where an external client might be > attempting to set variables either. Just plain old accessing IP vars from > multiple processes. > > On Mon, Oct 31, 2016 at 10:12 PM, David Adams <[email protected]> wrote: > >> Sure, it's absolutely possible to encounter a race condition if you write >> to a shared resource (IP arrays in your case) without a locking mechanism. >> It's likelihood increases in compiled mode and as you add more >> participants. Even if you can't predict how often you'll encounter a race >> condition, you already know that the chance is greater than zero. >> ... >> >> >> * Hoping that it won't happen isn't a sound strategy. Maybe it won't, maybe >> it will. It definitely might. >> > > -- > Kirk Brooks > San Francisco, CA > ======================= ********************************************************************** 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] **********************************************************************
