When DB- open() is called, is File I/O blocked?

Question

Hello experts,
Our customer is asking whether file I/O is blocked or not when multi tasks call
DB->open() simultaneously.
Best regards,
Yuki

Answer 1

BobHarris,
shlock looks very much like this logic that I found via google:
if ( set -o noclobber; echo "$$" > "$lockfile") 2> /dev/null;
then
trap 'rm -f "$lockfile"; exit $?' INT TERM EXIT
critical-section
rm -f "$lockfile"
trap - INT TERM EXIT
else
echo "Failed to acquire lockfile: $lockfile."
echo "Held by $(cat $lockfile)"
fi
However, the above code handles abnormal script terminations, whereas the man page mentions abnormal terminations not being handled by shlock. I'm using the above now... which seems to be holding up under stress.