map@honda.siemens.com (Michael Platoff) (01/03/91)
I remember reading about an IEEE POSIX standard for a real-time OS interface. Does anyone know the progress of that effort? Has anything been drafted yet? Does anyone have an estimate of when real-time execs will begin to have a standardized interface? Since I don't read this newsgroup very often, e-mail is the best way to reach me. I'll summarize and post any responses, if requested. Thanks, Michael Platoff Michael Platoff email: map@cadillac.siemens.com Siemens Corporate Research phone: (609) 734-3354 755 College Road East Princeton, NJ 08540-6668
bog@lynx.uucp (Bill O. Gallmeister) (01/04/91)
map@honda.siemens.com (Michael Platoff) writes: >I remember reading about an IEEE POSIX standard for a real-time >OS interface. Does anyone know the progress of that effort? Has >anything been drafted yet? Does anyone have an estimate of >when real-time execs will begin to have a standardized interface? Michael said to send mail, so I did. But I also thought this would be of general interest, so I'm posting it. POSIX 1003.4 is the real-time standards group, and Posix 1003.4 is the proposed standard. Draft 9 of this proposal went out to ballot about a year ago, with chapters on: priority scheduling binary semaphores memory locking shared memory asynchronous event notification clocks and timers IPC message passing synchronized I/O asynchronous I/O realtime files We are planning on wrapping up the ballot resolution in New Orleans next week (1/7/90 - 1/11/90). After that, the draft will be sent out (draft 10, now) for recirculation. And the whole process will begin again. Once we hit a certain threashold of acceptances (I don't remember the figure), the draft will become a standard. I'm anticipating another six months at least before that time. Another proposed standard that just went to first ballot is the threads draft (IEEE POSIX 1003.4a draft 5). POSIX threads provide multiple threads of control within a single UNIX (actually POSIX) process. The draft has chapters for thread management (create, exit, join, etc) thread scheduling thread synchronization (currently mutexes and condition variables) thread cancellation thread-specific data process behavior in the presence of threads signals and asynchronous events reentrant functions Threads provide hope for reasonable Ada compilers under UNIX. They're also a much better way of dealing with asynchrony than are signals, select, and all that nonsense. In my humble opinion. Threads just went to ballot (sent off the week before Christmas) and will be a while in getting out as a draft standard. Meanwhile, at least one company is already putting out a system that supplies the functions found in Draft 9. That's us; our release 2.0 will have every chapter of POSIX.4 covered. We don't anticipate a big deal in going from draft 9 to draft 10. We are also providing all the functions of Posix 1003.4a drafts 3 and 4. And we have two Ada compilers running using threads, Alsys and DDC-I. OSF also recently made threads-like noises, and DEC anounced plans for at least P1003.1 support under VMS (!). As far as I know, we are the only ones out with POSIX.4. For copies of the draft, you should write to the IEEE: IEEE Service Center 445 Hoes Lane Piscataway, NJ 08855-1331 (800) 678-IEEE (201) 981-0060 Regards, - bog -- Bill O. Gallmeister Lynx Real-Time Systems bog@lynx.com Trendy Los Gatos, CA