PTHREAD_BARRIERATTR(3)					   BSD Library Functions Manual 				    PTHREAD_BARRIERATTR(3)

NAME

     pthread_barrierattr_destroy, pthread_barrierattr_getpshared, pthread_barrierattr_init, pthread_barrierattr_setpshared -- manipulate a barrier
     attribute object

LIBRARY

     POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

     #include <pthread.h>

     int
     pthread_barrierattr_destroy(pthread_barrierattr_t *attr);

     int
     pthread_barrierattr_getpshared(const pthread_barrierattr_t *attr, int *pshared);

     int
     pthread_barrierattr_init(pthread_barrierattr_t *attr);

     int
     pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared);

DESCRIPTION

     The pthread_barrierattr_init() function will initialize attr with default attributes.  The pthread_barrierattr_destroy() function will
     destroy attr and release any resources that may have been allocated on its behalf.

     The pthread_barrierattr_getpshared() function will put the value of the process-shared attribute from attr into the memory area pointed to by
     pshared.  The pthread_barrierattr_setpshared() function will set the process-shared attribute of attr to the value specified in pshared.  The
     argument pshared may have one of the following values:

     PTHREAD_PROCESS_PRIVATE  The barrier object it is attached to may only be accessed by threads in the same process as the one that created the
			      object.

     PTHREAD_PROCESS_SHARED   The barrier object it is attached to may be accessed by threads in processes other than the one that created the
			      object.

RETURN VALUES

     If successful, all these functions will return zero.  Otherwise, an error number will be returned to indicate the error.

     None of these functions will return EINTR.

ERRORS

     The pthread_barrierattr_destroy(), pthread_barrierattr_getpshared() and pthread_barrierattr_setpshared() functions may fail if:

     [EINVAL]		The value specified by attr is invalid.

     The pthread_barrierattr_init() function will fail if:

     [ENOMEM]		Insufficient memory to initialize the barrier attribute object attr.

     The pthread_barrierattr_setpshared() function will fail if:

     [EINVAL]		The value specified in pshared is not one of the allowed values.

SEE ALSO

     pthread_barrier_destroy(3), pthread_barrier_init(3), pthread_barrier_wait(3)

HISTORY

     The pthread_barrierattr_*() functions first appeared in N:M Threading Library (libkse, -lkse) in FreeBSD 5.2, and in 1:1 Threading Library
     (libthr, -lthr) in FreeBSD 5.3.

BUGS

     The implementation of barriers does not fully conform to IEEE Std 1003.2 (``POSIX.2'') because the process-shared attribute is ignored in 1:1
     Threading Library (libthr, -lthr), and in N:M Threading Library (libkse, -lkse); if any value other than PTHREAD_PROCESSES_PRIVATE is speci-
     fied in a call to pthread_barrierattr_setpshared(), it will return EINVAL.

BSD
								 February 19, 2004							       BSD