And one thing to remember is that the main task, in the PAUSE/RESUME or WAIT/POST must "poll" for communications from the subtask. I have not used PAUSE/RELEASE, but it appears that, unlike WAIT/POST, the task doesn't have a way to "poll" to see if something has sent a message. I.e. when the main task does a PAUSE, it stops until something does a RELEASE or a TRANSFER. This may or may not be acceptable.
Being my own weird self, I might consider using UNIX IPC. This could be via UNIX message queues. Or perhaps semaphores. http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/bpxzb1c0/2.104 http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/bpxzb1c0/2.163 The above will work both between tasks in a single address space and tasks in separate address spaces. But you might need to change from ATTACH to POSIX threads. I'm not sure. These options are much more attractive if you are using the C language instead of HLASM. I don't recall if you use C or not. On Wed, Aug 28, 2013 at 8:16 AM, John Gilmore <[email protected]> wrote: > I recommend that you use the PAUSE/RELEASE pair instead of WAIT/POST. > > The WAIT/POST pair is, like GETMAIN/FREEMAIN, lumbered with the > detritus of the ages, much of it ugly. > > Let me also add that another important, in some contexts crucial, use > of subtasks stems from the fact that failures within them are less > catastrophic. Suppose that task A attaches subtask B and that subtask > B in turn attaches its own subtask C. Now if C fails/ABENDs, A and B > survive; and if B fails A survives [B and its subtask(s), C here, are > terminated]. > > The idea of relegating perilous undertakings, those that may fail, to > subtasks that do not bring down the whole shebang when they do in fact > fail is thus a very useful one. (This same recoverability argument > can sometimes make the use of multiple address spaces highly > desirable, but I am not sure you are quite ready for that.) > > > John Gilmore, Ashland, MA 01721 - USA > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > -- As of next week, passwords will be entered in Morse code. Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
