Browse Prior Art Database

Triggering Scheme to Trap Trace Data

IP.com Disclosure Number: IPCOM000120466D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 55K

Publishing Venue

IBM

Related People

Brabec, N: AUTHOR [+4]

Abstract

Many operating systems include facilities for tracing data which can be started and stopped under manual control. A better technique is to embed the capability to automatically halt the trace when specified conditions occur, assuring that the right trace information will be captured.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 66% of the total text.

Triggering Scheme to Trap Trace Data

      Many operating systems include facilities for tracing data
which can be started and stopped under manual control.  A better
technique is to embed the capability to automatically halt the trace
when specified conditions occur, assuring that the right trace
information will be captured.

      When problems occur in the microcode used to operate a hardware
device, such as a communications controller, the end results
frequently indicate that a specific failure has occurred.  However,
it is difficult to trace the events leading up to this failure.
Manual attempts to stop a program trace at precisely the correct time
often result in overflowed buffers, or truncated buffers with only
partial information.

      For example, it may be known that a task becomes suspended at a
certain point.  It may be known what the task's control block looks
like when it becomes suspended. The desired trace would contain task
activity up to and including the time when the task's control block
indicates that it has been suspended.  It is impossible to reliably
use a manual method to stop the trace when the condition occurs.

      A breakpoint facility has been designed which stops all tracing
when a particular string of data occurs at a specific offset within
the data block being traced.  The facility also permits the criterion
that the data string will appear in a specific kind of trace data.
This function may be optionally selected...