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/*
* POSIX Barrier Manager -- Initialize a Barrier Instance
*
* COPYRIGHT (c) 1989-2006.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <pthread.h>
#include <errno.h>
#include <rtems/system.h>
#include <rtems/posix/barrier.h>
/*
* pthread_barrier_init
*
* This directive creates a barrier. A barrier id is returned.
*
* Input parameters:
* barrier - pointer to barrier id
* attr - barrier attributes
* count - number of threads before automatic release
*
* Output parameters:
* barrier - barrier id
* 0 - if successful
* error code - if unsuccessful
*/
int pthread_barrier_init(
pthread_barrier_t *barrier,
const pthread_barrierattr_t *attr,
unsigned int count
)
{
POSIX_Barrier_Control *the_barrier;
CORE_barrier_Attributes the_attributes;
pthread_barrierattr_t my_attr;
const pthread_barrierattr_t *the_attr;
/*
* Error check parameters
*/
if ( !barrier )
return EINVAL;
if ( count == 0 )
return EINVAL;
/*
* If the user passed in NULL, use the default attributes
*/
if ( attr ) {
the_attr = attr;
} else {
(void) pthread_barrierattr_init( &my_attr );
the_attr = &my_attr;
}
/*
* Now start error checking the attributes that we are going to use
*/
if ( !the_attr->is_initialized )
return EINVAL;
switch ( the_attr->process_shared ) {
case PTHREAD_PROCESS_PRIVATE: /* only supported values */
break;
case PTHREAD_PROCESS_SHARED:
default:
return EINVAL;
}
/*
* Convert from POSIX attributes to Core Barrier attributes
*/
the_attributes.discipline = CORE_BARRIER_AUTOMATIC_RELEASE;
the_attributes.maximum_count = count;
/*
* Enter dispatching critical section to allocate and initialize barrier
*/
_Thread_Disable_dispatch(); /* prevents deletion */
the_barrier = _POSIX_Barrier_Allocate();
if ( !the_barrier ) {
_Thread_Enable_dispatch();
return EAGAIN;
}
_CORE_barrier_Initialize( &the_barrier->Barrier, &the_attributes );
_Objects_Open_u32(
&_POSIX_Barrier_Information,
&the_barrier->Object,
0
);
/*
* Exit the critical section and return the user an operational barrier
*/
*barrier = the_barrier->Object.id;
_Thread_Enable_dispatch();
return 0;
}
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