Hi!
Somewhere I read that it would be no problem to add read-locks that
can be upgraded to write-locks. I'd like to have such locks. I'd
also like to use the other direction.
In an interrupt, I have the following situation:
a) read a register, possibly decide to leave interrupt, if not,
b) write some registers, and then
c) some lengthy reading and checking of some registers.
Currently, I use spin-locks and only lock part b), because a) is
atomic and cannot be disturbed by another write. But c) might not
like writing, I have to think about that thouroughly. However, it is
quiet a lengthy checking procedure in an interrupt that occurs
periodically every 1.333ms (on a sound card). I'd really like to
unlock as early as possible. Using a write->read lock demotion would
be perfect.
So the thing that would be nice is a read-lock that can be promoted to
be a write-lock and then demoted again to be a read-lock before
unlocking completely.
Bye,
Henrik
[-- theiling@cs.uni-sb.de -- http://www.cs.uni-sb.de/~theiling/ --]
[-- Saarland University -- Bau 45 R 429 -- +49 681 8318304 --]
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