PTHREAD_BARRIERATTR_GETPSHARED(3C) Standard C Library Functions

NAME

pthread_barrierattr_getpshared, pthread_barrierattr_setpshared - get and
set process-shared attribute of barrier attributes object

SYNOPSIS

cc -mt [ flag... ] file... [ library... ]
#include <pthread.h>

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


int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr,
int pshared);

DESCRIPTION

The pthread_barrierattr_getpshared() function obtains the value of the
process-shared attribute from the attributes object referenced by attr.
The pthread_barrierattr_setpshared() function sets the process-shared
attribute in an initialized attributes object referenced by attr.


The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit a
barrier to be operated upon by any thread that has access to the memory
where the barrier is allocated. If the process-shared attribute is
PTHREAD_PROCESS_PRIVATE, the barrier will only be operated upon by
threads created within the same process as the thread that initialized
the barrier. If threads of different processes attempt to operate on such
a barrier, the behavior is undefined.


The default value of the attribute is PTHREAD_PROCESS_PRIVATE. Both
constants PTHREAD_PROCESS_SHARED and PTHREAD_PROCESS_PRIVATE are defined
in <pthread.h>.


No barrier attributes other than the process-shared attribute are
provided.

RETURN VALUES

Upon successful completion, the pthread_barrierattr_getpshared() function
returns 0 and stores the value of the process-shared attribute of attr
into the object referenced by the pshared parameter. Otherwise, an error
number is returned to indicate the error.


Upon successful completion, the pthread_barrierattr_setpshared() function
returns 0. Otherwise, an error number is returned to indicate the error.

ERRORS

These functions may fail if:

EINVAL
The value specified by attr is invalid.


The pthread_barrierattr_setpshared() function may fail if:

EINVAL
The new value specified for the process-shared attribute is not
one of the legal values PTHREAD_PROCESS_SHARED or
PTHREAD_PROCESS_PRIVATE.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

pthread_barrier_init(3C), pthread_barrierattr_destroy(3C), attributes(7),
standards(7)


January 30, 2004
PTHREAD_BARRIERATTR_GETPSHARED(3C)