#include <semaphore.h> int
sem_getvalue (sem_t * restrict sem int * restrict sval);
DESCRIPTION
The
sem_getvalue ();
function sets the variable pointed to by
Fa sval
to the current value of the semaphore pointed to by
Fa sem ,
as of the time that the call to
sem_getvalue ();
is actually run.
RETURN VALUES
Rv -std sem_getvalue
ERRORS
The
sem_getvalue ();
function will fail if:
Bq Er EINVAL
The
Fa sem
argument
points to an invalid semaphore.
The
sem_getvalue ();
function conforms to
St -p1003.1-96 .
The value of the semaphore is never negative, even if there are threads blocked
on the semaphore.
POSIX
is somewhat ambiguous in its wording with regard to
what the value of the semaphore should be if there are blocked waiting threads,
but this behavior is conformant, given the wording of the specification.
