Linas Vepstas <linasveps...@gmail.com> writes:
> Well, once you identify the section that needs locking,
> you'll want to use an rwlock instead of a mutex. The
> rwlock (pthread_rwlock_rdlock) allows multiple
> simultaneous readers. The writers, however, get
> exclusive access. (pthread_rwlock_wrlock)
I forgot to comment on this before...
In my view the important case to optimize is the one with only a
single thread - i.e. I don't want to add any significant performance
penalty in that case. And for that case, IIUC, there is no difference
between a mutex and an rwlock.
Also I would guess that we would hit more portability issues in future
with a rwlock than with a mutex. Of course, we could look at
configure time for rwlock support, and fall back to a mutex - but that
has a cost too, in code complexity.
On balance, therefore, I don't think using a rwlock rather than a
mutex is worthwhile.
Regards,
Neil
