Browse Prior Art Database

Approach for Abnormal Process Termination in Multi-Processor System

IP.com Disclosure Number: IPCOM000118460D
Original Publication Date: 1997-Feb-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Chao, T: AUTHOR [+4]

Abstract

Disclosed is a method for eliminating timing problems associated with stopping the execution of a computer program thread (task or process).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Approach for Abnormal Process Termination in Multi-Processor System

      Disclosed is a method for eliminating timing problems
associated with stopping the execution of a computer program thread
(task or process).

      Coordinating process termination in a threaded environment is
difficult because each thread runs as a separate task.  Depending on
the state of the task (or thread), race conditions can occur if two
threads simultaneously cause the process to exit.  The process could
also get "hung" if one thread fails to exit.

      This disclosure describes a method that eliminates timing
problems associated with stopping a thread while it is executing.
This solution is robust and less likely to hang a process and tie up
system resources.

      The first thread to reach abnormal termination state sets a
shared indicator for process termination pending.  Another task is
created to coordinate the termination.  The new task puts the system
into a pause state to ensure that none of the threads in the process
are actually running.  This pause state is reached by each thread
voluntarily giving up control.  Once the pause state is reached, each
thread is updated to point to exit processing the next time it is
dispatched.  Each thread will give up control within 500ms of
processing.  If the thread does not give up control, the system
forces the thread to exit with an error.  This will ensure that the
process will terminate within a reasonable time.