int pthread_mutex_unlock(
pthread_mutex_t *mutex
)
{
register POSIX_Mutex_Control *the_mutex;
Objects_Locations location;
CORE_mutex_Status status;
the_mutex = _POSIX_Mutex_Get( mutex, &location );
switch ( location ) {
case OBJECTS_LOCAL:
status = _CORE_mutex_Surrender(
&the_mutex->Mutex,
the_mutex->Object.id,
NULL
);
_Thread_Enable_dispatch();
return _POSIX_Mutex_Translate_core_mutex_return_code( status );
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
int pthread_mutex_getprioceiling(
pthread_mutex_t *mutex,
int *prioceiling
)
{
register POSIX_Mutex_Control *the_mutex;
Objects_Locations location;
if ( !prioceiling )
return EINVAL;
the_mutex = _POSIX_Mutex_Get( mutex, &location );
switch ( location ) {
case OBJECTS_LOCAL:
*prioceiling = _POSIX_Priority_From_core(
the_mutex->Mutex.Attributes.priority_ceiling
);
_Thread_Enable_dispatch();
return 0;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
int pthread_mutex_setprioceiling(
pthread_mutex_t *mutex,
int prioceiling,
int *old_ceiling
)
{
register POSIX_Mutex_Control *the_mutex;
Objects_Locations location;
Priority_Control the_priority;
int status;
if ( !old_ceiling )
return EINVAL;
if ( !_POSIX_Priority_Is_valid( prioceiling ) )
return EINVAL;
the_priority = _POSIX_Priority_To_core( prioceiling );
/*
* Must acquire the mutex before we can change it's ceiling
*/
status = pthread_mutex_lock( mutex );
if ( status )
return status;
the_mutex = _POSIX_Mutex_Get( mutex, &location );
switch ( location ) {
case OBJECTS_REMOTE:
#if defined(RTEMS_MULTIPROCESSING)
/* XXX It feels questionable to set the ceiling on a remote mutex. */
return EINVAL;
#endif
case OBJECTS_ERROR:
return EINVAL; /* impossible to get here */
case OBJECTS_LOCAL:
*old_ceiling = _POSIX_Priority_From_core(
the_mutex->Mutex.Attributes.priority_ceiling
);
the_mutex->Mutex.Attributes.priority_ceiling = the_priority;
_CORE_mutex_Surrender(
&the_mutex->Mutex,
the_mutex->Object.id,
#if defined(RTEMS_MULTIPROCESSING)
_POSIX_Threads_mutex_MP_support
#else
NULL
#endif
);
_Thread_Enable_dispatch();
return 0;
}
return POSIX_BOTTOM_REACHED();
}
int _POSIX_Mutex_Lock_support(
pthread_mutex_t *mutex,
bool wait,
Watchdog_Interval timeout
)
{
POSIX_Mutex_Control *the_mutex;
Thread_queue_Context queue_context;
Thread_Control *executing;
Status_Control status;
the_mutex = _POSIX_Mutex_Get( mutex, &queue_context );
if ( the_mutex == NULL ) {
return EINVAL;
}
executing = _Thread_Executing;
_Thread_queue_Context_set_relative_timeout( &queue_context, timeout );
switch ( the_mutex->protocol ) {
case POSIX_MUTEX_PRIORITY_CEILING:
status = _CORE_ceiling_mutex_Seize(
&the_mutex->Mutex,
executing,
wait,
_POSIX_Mutex_Lock_nested,
&queue_context
);
break;
case POSIX_MUTEX_NO_PROTOCOL:
status = _CORE_recursive_mutex_Seize(
&the_mutex->Mutex.Recursive,
POSIX_MUTEX_NO_PROTOCOL_TQ_OPERATIONS,
executing,
wait,
_POSIX_Mutex_Lock_nested,
&queue_context
);
break;
default:
_Assert( the_mutex->protocol == POSIX_MUTEX_PRIORITY_INHERIT );
status = _CORE_recursive_mutex_Seize(
&the_mutex->Mutex.Recursive,
CORE_MUTEX_TQ_PRIORITY_INHERIT_OPERATIONS,
executing,
wait,
_POSIX_Mutex_Lock_nested,
&queue_context
);
break;
}
return _POSIX_Get_error( status );
}
int pthread_mutex_destroy(
pthread_mutex_t *mutex
)
{
register POSIX_Mutex_Control *the_mutex;
Objects_Locations location;
the_mutex = _POSIX_Mutex_Get( mutex, &location );
switch ( location ) {
case OBJECTS_LOCAL:
/*
* XXX: There is an error for the mutex being locked
* or being in use by a condition variable.
*/
if ( _CORE_mutex_Is_locked( &the_mutex->Mutex ) ) {
_Thread_Enable_dispatch();
return EBUSY;
}
_Objects_Close( &_POSIX_Mutex_Information, &the_mutex->Object );
_CORE_mutex_Flush( &the_mutex->Mutex, NULL, EINVAL );
_POSIX_Mutex_Free( the_mutex );
_Thread_Enable_dispatch();
return 0;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
int _POSIX_Condition_variables_Wait_support(
pthread_cond_t *cond,
pthread_mutex_t *mutex,
Watchdog_Interval timeout,
bool already_timedout
)
{
POSIX_Condition_variables_Control *the_cond;
POSIX_Mutex_Control *the_mutex;
Objects_Locations location;
int status;
int mutex_status;
Thread_Control *executing;
the_mutex = _POSIX_Mutex_Get( mutex, &location );
if ( !the_mutex ) {
return EINVAL;
}
_Objects_Put_without_thread_dispatch( &the_mutex->Object );
the_cond = _POSIX_Condition_variables_Get( cond, &location );
switch ( location ) {
case OBJECTS_LOCAL:
if ( the_cond->Mutex && ( the_cond->Mutex != *mutex ) ) {
_Objects_Put( &the_cond->Object );
return EINVAL;
}
mutex_status = pthread_mutex_unlock( mutex );
/*
* Historically, we ignored the return code since the behavior
* is undefined by POSIX. But GNU/Linux returns EPERM in this
* case, so we follow their lead.
*/
if ( mutex_status ) {
_Objects_Put( &the_cond->Object );
return EPERM;
}
if ( !already_timedout ) {
the_cond->Mutex = *mutex;
executing = _Thread_Executing;
executing->Wait.return_code = 0;
executing->Wait.id = *cond;
_Thread_queue_Enqueue(
&the_cond->Wait_queue,
executing,
STATES_WAITING_FOR_CONDITION_VARIABLE
| STATES_INTERRUPTIBLE_BY_SIGNAL,
timeout,
ETIMEDOUT
);
_Objects_Put( &the_cond->Object );
/*
* Switch ourself out because we blocked as a result of the
* _Thread_queue_Enqueue.
*/
/*
* If the thread is interrupted, while in the thread queue, by
* a POSIX signal, then pthread_cond_wait returns spuriously,
* according to the POSIX standard. It means that pthread_cond_wait
* returns a success status, except for the fact that it was not
* woken up a pthread_cond_signal or a pthread_cond_broadcast.
*/
status = executing->Wait.return_code;
if ( status == EINTR )
status = 0;
} else {
_Objects_Put( &the_cond->Object );
status = ETIMEDOUT;
}
/*
* When we get here the dispatch disable level is 0.
*/
mutex_status = pthread_mutex_lock( mutex );
if ( mutex_status )
return EINVAL;
return status;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
int _POSIX_Condition_variables_Wait_support(
pthread_cond_t *cond,
pthread_mutex_t *mutex,
Watchdog_Interval timeout,
bool already_timedout
)
{
register POSIX_Condition_variables_Control *the_cond;
Objects_Locations location;
int status;
int mutex_status;
if ( !_POSIX_Mutex_Get( mutex, &location ) ) {
return EINVAL;
}
_Thread_Unnest_dispatch();
the_cond = _POSIX_Condition_variables_Get( cond, &location );
switch ( location ) {
case OBJECTS_LOCAL:
if ( the_cond->Mutex && ( the_cond->Mutex != *mutex ) ) {
_Thread_Enable_dispatch();
return EINVAL;
}
(void) pthread_mutex_unlock( mutex );
/* XXX ignore this for now since behavior is undefined
if ( mutex_status ) {
_Thread_Enable_dispatch();
return EINVAL;
}
*/
if ( !already_timedout ) {
the_cond->Mutex = *mutex;
_Thread_queue_Enter_critical_section( &the_cond->Wait_queue );
_Thread_Executing->Wait.return_code = 0;
_Thread_Executing->Wait.queue = &the_cond->Wait_queue;
_Thread_Executing->Wait.id = *cond;
_Thread_queue_Enqueue( &the_cond->Wait_queue, timeout );
_Thread_Enable_dispatch();
/*
* Switch ourself out because we blocked as a result of the
* _Thread_queue_Enqueue.
*/
/*
* If the thread is interrupted, while in the thread queue, by
* a POSIX signal, then pthread_cond_wait returns spuriously,
* according to the POSIX standard. It means that pthread_cond_wait
* returns a success status, except for the fact that it was not
* woken up a pthread_cond_signal or a pthread_cond_broadcast.
*/
status = _Thread_Executing->Wait.return_code;
if ( status == EINTR )
status = 0;
} else {
_Thread_Enable_dispatch();
status = ETIMEDOUT;
}
/*
* When we get here the dispatch disable level is 0.
*/
mutex_status = pthread_mutex_lock( mutex );
if ( mutex_status )
return EINVAL;
return status;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
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
* <*****@*****.**> saw seemingly random failures in the
* RTEMS port of omniORB2 when this code was enabled.
*
* Joel Sherrill <*****@*****.**> 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:
_Objects_Put( &mutex_in_use->Object );
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
the_mutex = _POSIX_Mutex_Allocate();
if ( !the_mutex ) {
_Objects_Allocator_unlock();
return EAGAIN;
}
the_mutex->process_shared = the_attr->process_shared;
the_mutex_attr = &the_mutex->Mutex.Attributes;
if ( the_attr->type == PTHREAD_MUTEX_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, NULL, the_mutex_attr, false );
_Objects_Open_u32( &_POSIX_Mutex_Information, &the_mutex->Object, 0 );
*mutex = the_mutex->Object.id;
_Objects_Allocator_unlock();
return 0;
}
int pthread_mutex_setprioceiling(
pthread_mutex_t *mutex,
int prioceiling,
int *old_ceiling
)
{
register POSIX_Mutex_Control *the_mutex;
Objects_Locations location;
Priority_Control the_priority;
if ( !old_ceiling )
return EINVAL;
if ( !_POSIX_Priority_Is_valid( prioceiling ) )
return EINVAL;
the_priority = _POSIX_Priority_To_core( prioceiling );
/*
* Must acquire the mutex before we can change it's ceiling.
* POSIX says block until we acquire it.
*/
(void) pthread_mutex_lock( mutex );
/*
* Do not worry about the return code from this. The Get operation
* will also fail if it is a bad id or was deleted between the two
* operations.
*
* NOTE: This makes it easier to get 100% binary coverage since the
* bad Id case is handled by the switch.
*/
the_mutex = _POSIX_Mutex_Get( mutex, &location );
switch ( location ) {
case OBJECTS_LOCAL:
*old_ceiling = _POSIX_Priority_From_core(
the_mutex->Mutex.Attributes.priority_ceiling
);
the_mutex->Mutex.Attributes.priority_ceiling = the_priority;
/*
* We are required to unlock the mutex before we return.
*/
_CORE_mutex_Surrender(
&the_mutex->Mutex,
the_mutex->Object.id,
NULL
);
_Thread_Enable_dispatch();
return 0;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE: /* impossible to get here */
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
