On Fri, 10 Jun 2005 07:03:58 +0200 Ion Gaztañaga <ion_g_m@terra.es> wrote:
Hi Jody,
Shmem null mutex was just a fast implementation mainly to avoid mutex overhead with shmem machinery when used with non-shared memory buffers, so I if boost::thread, accepts a null mutex, I would happily use that. I haven't checked your patches, but I would expect a zero overhead mutex, regarding its size (eliminated using empty base optimization) and code generation (lock and unlock are empty functions).
I think it satisfies your requirement, but remember when using it with a lock (e.g., scoped_lock), the lock itself is not empty, because it has to preserve the requirements on the lock (e.g., knowing if it is in a locked state). Also, as noted earlier, calling notify_one() and notify_all() on the condition incur overhead (currently), even when used in conjunction with a null_mutex.