This is probably true for any os on which APR favors file locking for global mutexes, in my case it's FreeBSD.
When a global mutex is created with apr_global_mutex_create(), it creates a file owned by root/wheel whose perms are 600. After the server changes uid/gid, it no longer has permissions to the file, and the apr_global_mutex_child_init() will fail with "permission denied". The only similar use of mutexes I could find as an example was in mod_rewrite.c, but alas, it suffers from the same problem (which is a bug AFAICT - try using RewriteLock directive on FreeBSD - if I'm not missing something, you'll get "Configuration Failed" message in the log and the server won't start). I guess my question is - is there some function to set permission on a file to that specified by User/Group, or is that an "excercise left to the reader"? I found unixd_set_global_mutex_perms(), but that's SysV specific.... Any advice/pointers is highly appreciated! Grisha
