Пример #1
0
rtems_status_code rtems_semaphore_release(
  rtems_id   id
)
{
  Semaphore_Control          *the_semaphore;
  Objects_Locations           location;
  CORE_mutex_Status           mutex_status;
  CORE_semaphore_Status       semaphore_status;
  rtems_attribute             attribute_set;
  ISR_lock_Context            lock_context;

  the_semaphore = _Semaphore_Get_interrupt_disable(
    id,
    &location,
    &lock_context
  );
  switch ( location ) {

    case OBJECTS_LOCAL:
      attribute_set = the_semaphore->attribute_set;
#if defined(RTEMS_SMP)
      if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) {
        MRSP_Status mrsp_status;

        mrsp_status = _MRSP_Surrender(
          &the_semaphore->Core_control.mrsp,
          _Thread_Executing,
          &lock_context
        );
        return _Semaphore_Translate_MRSP_status_code( mrsp_status );
      } else
#endif
      if ( !_Attributes_Is_counting_semaphore( attribute_set ) ) {
        mutex_status = _CORE_mutex_Surrender(
          &the_semaphore->Core_control.mutex,
          _Semaphore_Core_mutex_mp_support,
          id,
          &lock_context
        );
        return _Semaphore_Translate_core_mutex_return_code( mutex_status );
      } else {
        semaphore_status = _CORE_semaphore_Surrender(
          &the_semaphore->Core_control.semaphore,
          _Semaphore_Core_mutex_mp_support,
          id,
          &lock_context
        );
        return
          _Semaphore_Translate_core_semaphore_return_code( semaphore_status );
      }

#if defined(RTEMS_MULTIPROCESSING)
    case OBJECTS_REMOTE:
      return _Semaphore_MP_Send_request_packet(
        SEMAPHORE_MP_RELEASE_REQUEST,
        id,
        0,                               /* Not used */
        MPCI_DEFAULT_TIMEOUT
      );
#endif

    case OBJECTS_ERROR:
      break;
  }

  return RTEMS_INVALID_ID;
}
Пример #2
0
rtems_status_code rtems_semaphore_obtain(
  rtems_id        id,
  rtems_option    option_set,
  rtems_interval  timeout
)
{
  Semaphore_Control              *the_semaphore;
  Objects_Locations               location;
  ISR_Level                       level;
  Thread_Control                 *executing;
  rtems_attribute                 attribute_set;
  bool                            wait;

  the_semaphore = _Semaphore_Get_interrupt_disable( id, &location, &level );
  switch ( location ) {

    case OBJECTS_LOCAL:
      executing = _Thread_Executing;
      attribute_set = the_semaphore->attribute_set;
      wait = !_Options_Is_no_wait( option_set );
#if defined(RTEMS_SMP)
      if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) {
        MRSP_Status mrsp_status;

        _ISR_Enable( level );
        mrsp_status = _MRSP_Obtain(
          &the_semaphore->Core_control.mrsp,
          executing,
          wait,
          timeout
        );
        _Objects_Put_for_get_isr_disable( &the_semaphore->Object );
        return _Semaphore_Translate_MRSP_status_code( mrsp_status );
      } else
#endif
      if ( !_Attributes_Is_counting_semaphore( attribute_set ) ) {
        _CORE_mutex_Seize(
          &the_semaphore->Core_control.mutex,
          executing,
          id,
          wait,
          timeout,
          level
        );
        _Objects_Put_for_get_isr_disable( &the_semaphore->Object );
        return _Semaphore_Translate_core_mutex_return_code(
                  executing->Wait.return_code );
      }

      /* must be a counting semaphore */
      _CORE_semaphore_Seize_isr_disable(
        &the_semaphore->Core_control.semaphore,
        executing,
        id,
        wait,
        timeout,
        level
      );
      _Objects_Put_for_get_isr_disable( &the_semaphore->Object );
      return _Semaphore_Translate_core_semaphore_return_code(
                  executing->Wait.return_code );

#if defined(RTEMS_MULTIPROCESSING)
    case OBJECTS_REMOTE:
      return _Semaphore_MP_Send_request_packet(
          SEMAPHORE_MP_OBTAIN_REQUEST,
          id,
          option_set,
          timeout
      );
#endif

    case OBJECTS_ERROR:
      break;

  }

  return RTEMS_INVALID_ID;
}
Пример #3
0
rtems_status_code rtems_semaphore_create(
  rtems_name           name,
  uint32_t             count,
  rtems_attribute      attribute_set,
  rtems_task_priority  priority_ceiling,
  rtems_id            *id
)
{
  Semaphore_Control          *the_semaphore;
  CORE_mutex_Attributes       the_mutex_attr;
  CORE_semaphore_Attributes   the_semaphore_attr;
  CORE_mutex_Status           mutex_status;

  if ( !rtems_is_name_valid( name ) )
    return RTEMS_INVALID_NAME;

  if ( !id )
    return RTEMS_INVALID_ADDRESS;

#if defined(RTEMS_MULTIPROCESSING)
  if ( _Attributes_Is_global( attribute_set ) ) {

    if ( !_System_state_Is_multiprocessing )
      return RTEMS_MP_NOT_CONFIGURED;

    if ( _Attributes_Is_inherit_priority( attribute_set ) ||
         _Attributes_Is_priority_ceiling( attribute_set ) ||
         _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) )
      return RTEMS_NOT_DEFINED;

  } else
#endif

  if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) &&
       !( _Attributes_Is_binary_semaphore( attribute_set ) &&
         !_Attributes_Is_priority( attribute_set ) ) ) {
    return RTEMS_NOT_DEFINED;
  }

  if ( _Attributes_Is_inherit_priority( attribute_set ) ||
              _Attributes_Is_priority_ceiling( attribute_set ) ) {

    if ( ! (_Attributes_Is_binary_semaphore( attribute_set ) &&
            _Attributes_Is_priority( attribute_set ) ) )
      return RTEMS_NOT_DEFINED;

  }

  if ( !_Attributes_Has_at_most_one_protocol( attribute_set ) )
    return RTEMS_NOT_DEFINED;

  if ( !_Attributes_Is_counting_semaphore( attribute_set ) && ( count > 1 ) )
    return RTEMS_INVALID_NUMBER;

#if !defined(RTEMS_SMP)
  /*
   * On uni-processor configurations the Multiprocessor Resource Sharing
   * Protocol is equivalent to the Priority Ceiling Protocol.
   */
  if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) {
    attribute_set |= RTEMS_PRIORITY_CEILING | RTEMS_PRIORITY;
  }
#endif

  the_semaphore = _Semaphore_Allocate();

  if ( !the_semaphore ) {
    _Objects_Allocator_unlock();
    return RTEMS_TOO_MANY;
  }

#if defined(RTEMS_MULTIPROCESSING)
  if ( _Attributes_Is_global( attribute_set ) &&
       ! ( _Objects_MP_Allocate_and_open( &_Semaphore_Information, name,
                            the_semaphore->Object.id, false ) ) ) {
    _Semaphore_Free( the_semaphore );
    _Objects_Allocator_unlock();
    return RTEMS_TOO_MANY;
  }
#endif

  the_semaphore->attribute_set = attribute_set;

  /*
   *  Initialize it as a counting semaphore.
   */
  if ( _Attributes_Is_counting_semaphore( attribute_set ) ) {
    /*
     *  This effectively disables limit checking.
     */
    the_semaphore_attr.maximum_count = 0xFFFFFFFF;

    if ( _Attributes_Is_priority( attribute_set ) )
      the_semaphore_attr.discipline = CORE_SEMAPHORE_DISCIPLINES_PRIORITY;
    else
      the_semaphore_attr.discipline = CORE_SEMAPHORE_DISCIPLINES_FIFO;

    /*
     *  The following are just to make Purify happy.
     */
    the_mutex_attr.lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES;
    the_mutex_attr.priority_ceiling = PRIORITY_MINIMUM;

    _CORE_semaphore_Initialize(
      &the_semaphore->Core_control.semaphore,
      &the_semaphore_attr,
      count
    );
#if defined(RTEMS_SMP)
  } else if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) {
    MRSP_Status mrsp_status = _MRSP_Initialize(
      &the_semaphore->Core_control.mrsp,
      priority_ceiling,
      _Thread_Get_executing(),
      count != 1
    );

    if ( mrsp_status != MRSP_SUCCESSFUL ) {
      _Semaphore_Free( the_semaphore );
      _Objects_Allocator_unlock();

      return _Semaphore_Translate_MRSP_status_code( mrsp_status );
    }
#endif
  } else {
    /*
     *  It is either simple binary semaphore or a more powerful mutex
     *  style binary semaphore.  This is the mutex style.
     */
    if ( _Attributes_Is_priority( attribute_set ) )
      the_mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY;
    else
      the_mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_FIFO;

    if ( _Attributes_Is_binary_semaphore( attribute_set ) ) {
      the_mutex_attr.priority_ceiling      = _RTEMS_tasks_Priority_to_Core(
                                               priority_ceiling
                                             );
      the_mutex_attr.lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES;
      the_mutex_attr.only_owner_release    = false;

      if ( the_mutex_attr.discipline == CORE_MUTEX_DISCIPLINES_PRIORITY ) {
        if ( _Attributes_Is_inherit_priority( attribute_set ) ) {
          the_mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT;
          the_mutex_attr.only_owner_release = true;
        } else if ( _Attributes_Is_priority_ceiling( attribute_set ) ) {
          the_mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING;
          the_mutex_attr.only_owner_release = true;
        }
      }
    } else /* must be simple binary semaphore */ {
      the_mutex_attr.lock_nesting_behavior = CORE_MUTEX_NESTING_BLOCKS;
      the_mutex_attr.only_owner_release = false;
    }

    mutex_status = _CORE_mutex_Initialize(
      &the_semaphore->Core_control.mutex,
      _Thread_Get_executing(),
      &the_mutex_attr,
      count != 1
    );

    if ( mutex_status == CORE_MUTEX_STATUS_CEILING_VIOLATED ) {
      _Semaphore_Free( the_semaphore );
      _Objects_Allocator_unlock();
      return RTEMS_INVALID_PRIORITY;
    }
  }

  /*
   *  Whether we initialized it as a mutex or counting semaphore, it is
   *  now ready to be "offered" for use as a Classic API Semaphore.
   */
  _Objects_Open(
    &_Semaphore_Information,
    &the_semaphore->Object,
    (Objects_Name) name
  );

  *id = the_semaphore->Object.id;

#if defined(RTEMS_MULTIPROCESSING)
  if ( _Attributes_Is_global( attribute_set ) )
    _Semaphore_MP_Send_process_packet(
      SEMAPHORE_MP_ANNOUNCE_CREATE,
      the_semaphore->Object.id,
      name,
      0                          /* Not used */
    );
#endif
  _Objects_Allocator_unlock();
  return RTEMS_SUCCESSFUL;
}