Interactive I/O in real-time Ada applications

Interactive I/O in real-time Ada applications

[dirk]

The following is probably only of interest to users of the Verdix Ada
Development System (VADS) on a Unix system.

We are developing a real-time application in Ada (using tasking).  One
of the tasks implements a low-level interface with the user, and is
basicly a loop with a get_line on standard input.

When standard input is redirected, there are no problems.  When the
input is given interactively, we have the impression that the get_line
operation slows down the other tasks.  This may be unacceptable for some
applications.  (Wasn't Ada developed for programming real-time embedded
systems? :-).

Has anyone encountered the same problem, and found a solution?  If so,
we are very interested if you could mail it to us.  Thanks in advance.

We are using the Verdix Ada Development System (Version 5.1b) on a DEC
MicroVAX II running Ultrix-32m V1.1.  All tasks in an Ada program run
within one Unix process.

+----------------------------------------------------------------------+
| Dirk Craeynest                   | Katholieke Universiteit Leuven    |
| uucp: ...!mcvax!prlb2!kulcs!dirk | Department of Computer Science    |
|       or dirk@kulcs.UUCP         | Celestijnenlaan 200 A             |
| phone:  +(32) 16-200656 x3555    | B-3030 Leuven (Heverlee), Belgium |
+----------------------------------------------------------------------+