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/**
* @file
*
* @brief Allocate resources to use the read-write lock and Initialize it
* @ingroup POSIXAPI
*/
/*
* POSIX RWLock Manager -- Destroy a RWLock 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.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <pthread.h>
#include <errno.h>
#include <rtems/posix/rwlockimpl.h>
#include <rtems/score/apimutex.h>
static bool _POSIX_RWLock_Check_id_and_auto_init(
pthread_mutex_t *rwlock,
Objects_Locations *location
)
{
if ( rwlock == NULL ) {
*location = OBJECTS_ERROR;
return false;
}
if ( *rwlock == PTHREAD_RWLOCK_INITIALIZER ) {
int eno;
_Once_Lock();
if ( *rwlock == PTHREAD_RWLOCK_INITIALIZER ) {
eno = pthread_rwlock_init( rwlock, NULL );
} else {
eno = 0;
}
_Once_Unlock();
if ( eno != 0 ) {
*location = OBJECTS_ERROR;
return false;
}
}
return true;
}
POSIX_RWLock_Control *_POSIX_RWLock_Get(
pthread_rwlock_t *rwlock,
Objects_Locations *location
)
{
if ( !_POSIX_RWLock_Check_id_and_auto_init( rwlock, location ) ) {
return NULL;
}
return (POSIX_RWLock_Control *) _Objects_Get(
&_POSIX_RWLock_Information,
*rwlock,
location
);
}
/*
* pthread_rwlock_init
*
* This directive creates a rwlock. A rwlock id is returned.
*
* Input parameters:
* rwlock - pointer to rwlock id
* attr - rwlock attributes
*
* Output parameters:
* rwlock - rwlock id
* 0 - if successful
* error code - if unsuccessful
*/
int pthread_rwlock_init(
pthread_rwlock_t *rwlock,
const pthread_rwlockattr_t *attr
)
{
POSIX_RWLock_Control *the_rwlock;
CORE_RWLock_Attributes the_attributes;
pthread_rwlockattr_t default_attr;
const pthread_rwlockattr_t *the_attr;
/*
* Error check parameters
*/
if ( !rwlock )
return EINVAL;
/*
* If the user passed in NULL, use the default attributes
*/
if ( attr ) {
the_attr = attr;
} else {
(void) pthread_rwlockattr_init( &default_attr );
the_attr = &default_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 RWLock attributes
*
* NOTE: Currently there are no core rwlock attributes
*/
_CORE_RWLock_Initialize_attributes( &the_attributes );
the_rwlock = _POSIX_RWLock_Allocate();
if ( !the_rwlock ) {
_Objects_Allocator_unlock();
return EAGAIN;
}
_CORE_RWLock_Initialize( &the_rwlock->RWLock, &the_attributes );
_Objects_Open_u32(
&_POSIX_RWLock_Information,
&the_rwlock->Object,
0
);
*rwlock = the_rwlock->Object.id;
_Objects_Allocator_unlock();
return 0;
}
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