UNUX^{TM} contains a lot of such queer beasts.
All the textbooks (well, maybe, not all, I've read nothing
except for Stevens 8)8)) explain that nobody knows for what
mandatory locking was invented. Nobody knows useful applications
for SYSV IPC semaphores and message queues.
Unfortunately, linux should comply any standards.
POSIX must be respected. The requirements of SVID are allowed
to be ignored: linux is not UNIX, isn't it?
Alexey Kuznetsov.