SYS$SETEF (OpenVMS) SYS$SETEF (OpenVMS)
NAME
semop - perform semaphore operations
SYS$SETEF - Set event flag
EXPLAINATION
The Digital UNIX semop system call is similar to the OpenVMS SYS$SETEF
system service in that they can both set the value of a process syn‐
chronization variable. The semop function can be called with the
sem_op field of the sembuf structure set to either decrement or incre‐
ment the semaphore. If the operation is decrement and the resulting
value would bring the semaphore to a value of less than zero, the
process waits until the semaphore value is will be at least zero after
the pending semaphore operation is completed. It is possible to make
this operation non-blocking by specifiying the IPC_NOWAIT value for
sem_flg, but it is suggested that the semctl function be used to
explicitly set semaphore values.
RELATED INFORMATION
Digital UNIX Functions:
semop(2), semget(2), semctl(2) delim off
SYS$SETEF (OpenVMS)
