операции управления семафором System V (System V semaphore control operations)
Стандарты (Conforming to)
POSIX.1-2001, POSIX.1-2008, SVr4.
POSIX.1 specifies the sem_nsems field of the semid_ds structure
as having the type unsigned short, and the field is so defined on
most other systems. It was also so defined on Linux 2.2 and
earlier, but, since Linux 2.4, the field has the type
unsigned long.