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/*
* COPYRIGHT (c) 1989-2009.
* 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 <errno.h>
#include <pthread.h>
#include <rtems/system.h>
#include <rtems/score/coremutex.h>
#include <rtems/score/watchdog.h>
#include <rtems/posix/mutex.h>
#include <rtems/posix/priority.h>
#include <rtems/posix/time.h>
/*PAGE
*
* 11.3.2 Initializing and Destroying a Mutex, P1003.1c/Draft 10, p. 87
*
* NOTE: XXX Could be optimized so all the attribute error checking
* is not performed when attr is NULL.
*/
int pthread_mutex_init(
pthread_mutex_t *mutex,
const pthread_mutexattr_t *attr
)
{
POSIX_Mutex_Control *the_mutex;
CORE_mutex_Attributes *the_mutex_attr;
const pthread_mutexattr_t *the_attr;
CORE_mutex_Disciplines the_discipline;
if ( attr ) the_attr = attr;
else the_attr = &_POSIX_Mutex_Default_attributes;
/* Check for NULL mutex */
if ( !mutex )
return EINVAL;
/*
* This code should eventually be removed.
*
* Although the POSIX specification says:
*
* "Attempting to initialize an already initialized mutex results
* in undefined behavior."
*
* Trying to keep the caller from doing the create when *mutex
* is actually a valid ID causes grief. All it takes is the wrong
* value in an uninitialized variable to make this fail. As best
* I can tell, RTEMS was the only pthread implementation to choose
* this option for "undefined behavior" and doing so has created
* portability problems. In particular, Rosimildo DaSilva
* <rdasilva@connecttel.com> saw seemingly random failures in the
* RTEMS port of omniORB2 when this code was enabled.
*
* Joel Sherrill <joel@OARcorp.com> 14 May 1999
* NOTE: Be careful to avoid infinite recursion on call to this
* routine in _POSIX_Mutex_Get.
*/
#if 0
{
POSIX_Mutex_Control *mutex_in_use;
Objects_Locations location;
if ( *mutex != PTHREAD_MUTEX_INITIALIZER ) {
/* EBUSY if *mutex is a valid id */
mutex_in_use = _POSIX_Mutex_Get( mutex, &location );
switch ( location ) {
case OBJECTS_LOCAL:
_Thread_Enable_dispatch();
return EBUSY;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
}
}
#endif
if ( !the_attr->is_initialized )
return EINVAL;
/*
* We only support process private mutexes.
*/
if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED )
return ENOSYS;
if ( the_attr->process_shared != PTHREAD_PROCESS_PRIVATE )
return EINVAL;
/*
* Determine the discipline of the mutex
*/
switch ( the_attr->protocol ) {
case PTHREAD_PRIO_NONE:
the_discipline = CORE_MUTEX_DISCIPLINES_FIFO;
break;
case PTHREAD_PRIO_INHERIT:
the_discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT;
break;
case PTHREAD_PRIO_PROTECT:
the_discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING;
break;
default:
return EINVAL;
}
/*
* Validate the priority ceiling field -- should always be valid.
*/
if ( !_POSIX_Priority_Is_valid( the_attr->prio_ceiling ) )
return EINVAL;
#if defined(_UNIX98_THREAD_MUTEX_ATTRIBUTES)
/*
* Validate the mutex type and set appropriate SuperCore mutex
* attributes.
*/
switch ( the_attr->type ) {
case PTHREAD_MUTEX_NORMAL:
case PTHREAD_MUTEX_RECURSIVE:
case PTHREAD_MUTEX_ERRORCHECK:
case PTHREAD_MUTEX_DEFAULT:
break;
default:
return EINVAL;
}
#endif
/*
* Enter a dispatching critical section and begin to do the real work.
*/
_Thread_Disable_dispatch();
the_mutex = _POSIX_Mutex_Allocate();
if ( !the_mutex ) {
_Thread_Enable_dispatch();
return EAGAIN;
}
the_mutex->process_shared = the_attr->process_shared;
the_mutex_attr = &the_mutex->Mutex.Attributes;
if ( the_attr->recursive )
the_mutex_attr->lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES;
else
the_mutex_attr->lock_nesting_behavior = CORE_MUTEX_NESTING_IS_ERROR;
the_mutex_attr->only_owner_release = true;
the_mutex_attr->priority_ceiling =
_POSIX_Priority_To_core( the_attr->prio_ceiling );
the_mutex_attr->discipline = the_discipline;
/*
* Must be initialized to unlocked.
*/
_CORE_mutex_Initialize(
&the_mutex->Mutex,
the_mutex_attr,
CORE_MUTEX_UNLOCKED
);
_Objects_Open_u32( &_POSIX_Mutex_Information, &the_mutex->Object, 0 );
*mutex = the_mutex->Object.id;
_Thread_Enable_dispatch();
return 0;
}
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