I am using shared memory to share some data between my module instances in Apache child processes, and apr_global_mutex_t to achieve mutually-exclusive reads and writes.
In a post_config_hook, I create the mutex using apr_global_mutex_create() and then reopen it inside each child process by calling apr_global_mutex_child_init() inside a child_init hook. However, when I try to grab the lock inside a child, the operation fails with a "permission denied". For the lock file, I am using "/tmp/tmp" which is a file writeable by all. Any clues?
