[comp.sys.apollo] Tasks, etc

agq@itd0.dsto.oz (Ashley Quick) (07/14/90)

Re-Post as out news doesnt always send out (so post from a real
UNIX box, not a VMS one......)



A few days ago, I posted an item requesting information about print
servers, and HP LaserJet in particular. I omitted to mention that
I am using a DN4500 running SR10.1.

Also:
  - Has anybody noticed that the print servers have more features
    (not just "extensible options") under SR10.2 and later? (More
    filters, etc)

  - I have recently been writing / modifying device drivers using
    GPIO (the PBU_$ calls). Has anybody else noticed that when using
    PBU_$ calls, inside a TASK (Tasks only came out in SR10), that
    occasionally a call to PBU_$WAIT will return with a QUIT FAULT
    status, when in fact a quit fault had not ocurred!. This causes
    terrible problems as the call side of the driver thinks the
    interrupt side has finished whatever it was doing (OR that there
    really was a quit fault depending on how you handle it). You can
    get incomplete data transfers, etc. YUK! This has been observed to
    happen VERY RARELY (about 0.001% of transfers) - but it means that
    data will get lost! This has been observed on a DN3000 and a DN4500
    both running SR10.1. (The release notes for 10.2 don't indicate that
    this is a known [corrected] problem).  In my case the work-around
    involved major changes, and the use of event counts so that I dont
    need to use the multi-threading offered by TASKs.    IF THIS IS NOT
    A BUG IT SHOULD BE HIGHLIGHTED IN LETTERS OF FIRE IN THE GPIO MANUAL!

  - Has anybody else noticed that prsvr uses TASKs???? Beware of them,
    they can be nasty! Make sure you shut down all tasks in an orderly
    fashion when you write code which uses them! I have also noticed that
    when developing a print server, it is a good idea to run it in a
    window - this make it easy to shut down. If your server FAULTs for
    any reason, make sure you quit it (control-Q or whatever) - not
    doing so means you may have to re-boot the node........

  - Does anybody know the E-Mail address for Apollo for APR's? I sent one
    off over two weeks ago and have not heard anything yet?



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Ashleigh Quick                                  | AGQ@dstos3.dsto.oz.au
Defence Science and Technology Organisation     |
PO Box 1600                                     |
Salisbury 5108                                  |
Australia                                       |
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