On Fri, 4 Jun 2004, Joe Orton wrote:
> On Fri, Jun 04, 2004 at 02:31:48AM -0700, Justin Erenkrantz wrote: > > I took a look at the locking problem, and I think it can be fixed > > rather trivially. This is a minor problem in that it only affects the > > case where the child doesn't share memory addresses - such as when > > happens by using apr_proc_create. Hence, adding an 'apr_*_mutex_join' > > could solve the problem. > > But that model only works for fcntl and flock mutexes: the other three > mechanisms on Unix (as currently implemented) simply cannot be used for > synchronisation between processes which did not inherit a particular > apr_proc_t structure. > > I think that we're looking for solutions to a non-problem here: the > apr_proc_mutex interface is only useful on platforms with fork(). So > let's surround the header with #if APR_HAS_FORK and be done with it? > > If you want to do portable synchronisation between two independent > processes, you can use files and apr_file_lock(), right? No. We have names locks on _all_ platforms, which allow you to do synchronisation between two independent processes just fine. The only problem is that our API doesn't know how to open the locks in the child process. This isn't hard to fix, but APR needs to understand which locking types can be used proc_exec and which can't. Once APR learns that, this becomes almost trivial to actually fix. Ryan
