On 12/29/2011 8:57 AM, Peter Relson wrote:
z/OS itself does not provide support for TRAP2/TRAP4. But some (authorized) program products do this on their own (a bad decision not to have this provided by the operating system).
...
The long and short of it is that you can't use TRAP2/TRAP4 "on your own" if you are not privileged.
These are the two instructions I love to hate. Life would be a lot simpler had they be implemented as No-Ops unless trapping was enabled. Some years ago I was assigned to debug an LPA resident program that had mysterious, intermittent failures, but always worked while being tested. Because the failure modes differed (e.g., bad data rather than an interrupt), SLIP was of limited utility. Had there been a benign form of TRAP (ignored by other tasks) it would have been a lot easier to track this (turned out to be an uninitialized variable).
Gerhard Postpischil Bradford, VT ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
