osf1 man page for sem_getvalue

sem_getvalue(3) 					     Library Functions Manual						   sem_getvalue(3)

NAME
       sem_getvalue - Gets the value of a specified semaphore (P1003.1b)

LIBRARY
       Realtime Library (librt.so, librt.a)

SYNOPSIS
       #include <semaphore.h>

       int sem_getvalue (
       sem_t *sem,
       int *sval);

PARAMETERS
       sem	 Specifies a pointer to the semaphore for which a value is to be returned.

       sval	 References a location to be updated with the value of the semaphore indicated by the sem argument.

DESCRIPTION
       The sem_getvalue function updates a location referenced by the sval argument with the value of semaphore sem.  The updated value represents
       an actual semaphore value that occurred during the call, but may not be the actual value of the semaphore at the time  that  the  value	is
       returned to the calling process.

       If  the semaphore is locked, the value returned will either be zero or a negative number indicating the number of processes waiting for the
       semaphore at some time during the call.

RETURN VALUES
       On a successful call, a value of 0 (zero) is returned. Otherwise, a value of -1 is returned and errno is set  to  indicate  that  an  error
       occurred.

ERRORS
       The  sem_getvalue function fails under the following condition:

       [EINVAL]       The sem argument does not refer to a valid semaphore.

RELATED INFORMATION
       Functions: sem_post(3), sem_trywait(3), sem_wait(3)

       Guide to Realtime Programming delim off

																   sem_getvalue(3)