threadqextractpriority.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 *  Thread Queue Handler
 *
 *
 *  COPYRIGHT (c) 1989-1999.
 *  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: threadqextractpriority.c,v 1.2.6.1 2003/09/04 18:52:48 joel Exp $
 */

#include <rtems/system.h>
#include <rtems/score/chain.h>
#include <rtems/score/isr.h>
#include <rtems/score/object.h>
#include <rtems/score/states.h>
#include <rtems/score/thread.h>
#include <rtems/score/threadq.h>
#include <rtems/score/tqdata.h>

/*PAGE
 *
 *  _Thread_queue_Extract_priority
 *
 *  This routine removes a specific thread from the specified threadq,
 *  deletes any timeout, and unblocks the thread.
 *
 *  Input parameters:
 *    the_thread_queue - pointer to a threadq header
 *    the_thread       - pointer to a thread control block
 *
 *  Output parameters: NONE
 *
 *  INTERRUPT LATENCY:
 *    EXTRACT_PRIORITY
 */

void _Thread_queue_Extract_priority(
  Thread_queue_Control *the_thread_queue,
  Thread_Control       *the_thread
)
{
  ISR_Level              level;
  Chain_Node     *the_node;
  Chain_Node     *next_node;
  Chain_Node     *previous_node;
  Thread_Control *new_first_thread;
  Chain_Node     *new_first_node;
  Chain_Node     *new_second_node;
  Chain_Node     *last_node;

  the_node = (Chain_Node *) the_thread;
  _ISR_Disable( level );
  if ( _States_Is_waiting_on_thread_queue( the_thread->current_state ) ) {
    next_node     = the_node->next;
    previous_node = the_node->previous;

    if ( !_Chain_Is_empty( &the_thread->Wait.Block2n ) ) {
      new_first_node   = the_thread->Wait.Block2n.first;
      new_first_thread = (Thread_Control *) new_first_node;
      last_node        = the_thread->Wait.Block2n.last;
      new_second_node  = new_first_node->next;

      previous_node->next      = new_first_node;
      next_node->previous      = new_first_node;
      new_first_node->next     = next_node;
      new_first_node->previous = previous_node;

      if ( !_Chain_Has_only_one_node( &the_thread->Wait.Block2n ) ) {
                                          /* > two threads on 2-n */
        new_second_node->previous =
                  _Chain_Head( &new_first_thread->Wait.Block2n );
        new_first_thread->Wait.Block2n.first = new_second_node;

        new_first_thread->Wait.Block2n.last = last_node;
        last_node->next = _Chain_Tail( &new_first_thread->Wait.Block2n );
      }
    } else {
      previous_node->next = next_node;
      next_node->previous = previous_node;
    }

    if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
      _ISR_Enable( level );
      _Thread_Unblock( the_thread );
    } else {
      _Watchdog_Deactivate( &the_thread->Timer );
      _ISR_Enable( level );
      (void) _Watchdog_Remove( &the_thread->Timer );
      _Thread_Unblock( the_thread );
    }

#if defined(RTEMS_MULTIPROCESSING)
    if ( !_Objects_Is_local_id( the_thread->Object.id ) )
      _Thread_MP_Free_proxy( the_thread );
#endif
  }
  else
    _ISR_Enable( level );
}