Guys - I'm digging this out right now, but I'm having trouble keeping up with your dialog ;-) Be aware we are talking about win32 which doesn't fork, so it doesn't have the same apr_global_mutex_t in the child worker process as in the parent process.
File mutex modes aren't really win32 files - they are simply named mutexes. Elsewhere in apr we've translated slash and backslash to underbars so that the name is a legal object name (as long as it's 255 characters or shorter.) However, this means two servers with "logs/mymutex" end up being the very same name. It almost seems like we need to abspath this name, e.g. "c:/apache/logs/mymutex" and then translate the reserved chars, so you get c__apache_logs_mymutex. Then you can have c__apache_logs_mymutex happily coexisting with c__apache21_logs_mymutex.
