🚀 go-pugleaf

Does anybody know how to get XtAppAddInput() to work under DECwindows/Motif 1.0
on VMS 5.5? The only documentation DEC supplies (that I can find) specifically
says that the source and condition arguments are OS specific and then tells what
they look like on Posix systems. 

I went back to the old DECwindows (XUI) docs and tried doing it that way, with
an event flag and IOSB, and that isn't working. I've tried different event
flags, and I've tried having the first QIO done immediately, or later via a work
procedure. 

I'm trying to do I/O to VMS mailbox devices. I'm using QIO (not QIOW), and I'm
not using IO$M_NOW, so the I/O request will actually wait until the other
process reads or writes to the mailbox (I have one of each on different
mailboxes), but the program doesn't wait for the I/O request. When the other
process does do its read or write, the event flag should be set and the IOSB
filled in, causing Xt to call the procedure specified in the XtAppAddInput()
call.

That all seems to be happening as far as I can tell, except the processing
routine isn't being called. I know the I/O's are working and the IOSB's are
being filled in, because right now I'm simulating the XtAppAddInput() processing
with a work procedure that checks the IOSB's and calls the procedure that Xt
should have called when the IOSB was filled in (i.e. the I/O completed). This
works fine, with the nasty little side effect that it consumes all available CPU
time polling the IOSB's.

Has anyone gotten this to work? What's the trick?

[PS. Dear DEC, of you are out there, please document aspects (such as this) of
DECwindows that aren't in the industry standard documentation that you
provide.]
--
Terry Poot <tp@mccall.com>                   The McCall Pattern Company
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(800)255-2762, in KS (913)776-4041           Manhattan, KS 66502, USA