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Annotation of src/lib/librt/sem_getvalue.3, Revision 1.4

1.4     ! wiz         1: .\" $NetBSD: sem_getvalue.3,v 1.3 2012/03/08 21:59:29 joerg Exp $
1.1       thorpej     2: .\"
                      3: .\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>.
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1.3       joerg      30: .Dd February 29, 2012
1.1       thorpej    31: .Dt SEM_GETVALUE 3
                     32: .Os
                     33: .Sh NAME
                     34: .Nm sem_getvalue
                     35: .Nd get the value of a semaphore
                     36: .Sh LIBRARY
                     37: .Lb librt
                     38: .Sh SYNOPSIS
                     39: .In semaphore.h
                     40: .Ft int
1.2       kleink     41: .Fn sem_getvalue "sem_t * restrict sem" "int * restrict sval"
1.1       thorpej    42: .Sh DESCRIPTION
                     43: The
                     44: .Fn sem_getvalue
                     45: function sets the variable pointed to by
                     46: .Fa sval
                     47: to the current value of the semaphore pointed to by
                     48: .Fa sem ,
                     49: as of the time that the call to
                     50: .Fn sem_getvalue
                     51: is actually run.
                     52: .Sh RETURN VALUES
                     53: .Rv -std sem_getvalue
                     54: .Sh ERRORS
                     55: .Fn sem_getvalue
                     56: will fail if:
                     57: .Bl -tag -width Er
                     58: .It Bq Er EINVAL
                     59: .Fa sem
                     60: points to an invalid semaphore.
                     61: .El
                     62: .Sh SEE ALSO
                     63: .Xr sem_post 3 ,
1.4     ! wiz        64: .Xr sem_timedwait 3 ,
1.1       thorpej    65: .Xr sem_trywait 3 ,
                     66: .Xr sem_wait 3
                     67: .Sh STANDARDS
                     68: .Fn sem_getvalue
                     69: conforms to
                     70: .St -p1003.1-96 .
                     71: .Pp
                     72: The value of the semaphore is never negative, even if there are threads blocked
                     73: on the semaphore.
                     74: POSIX is somewhat ambiguous in its wording with regard to
                     75: what the value of the semaphore should be if there are blocked waiting threads,
                     76: but this behavior is conformant, given the wording of the specification.

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