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/*

 *  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.OARcorp.com/rtems/license.html.

 *

 *  $Id: threadqenqueuefifo.c,v 1.2 2001-09-27 11:59:34 chris 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_Enqueue_fifo

 *

 *  This routine blocks a thread, places it on a thread, and optionally

 *  starts a timeout timer.

 *

 *  Input parameters:

 *    the_thread_queue - pointer to threadq

 *    the_thread       - pointer to the thread to block

 *    timeout          - interval to wait

 *

 *  Output parameters: NONE

 *

 *  INTERRUPT LATENCY:

 *    only case

 */

void _Thread_queue_Enqueue_fifo (

  Thread_queue_Control *the_thread_queue,

  Thread_Control       *the_thread,

  Watchdog_Interval    timeout

)

{

  ISR_Level            level;

  Thread_queue_States  sync_state;

  _ISR_Disable( level );

  sync_state = the_thread_queue->sync_state;

  the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED;

  switch ( sync_state ) {

    case THREAD_QUEUE_SYNCHRONIZED:

      /*

       *  This should never happen.  It indicates that someone did not

       *  enter a thread queue critical section.

       */

      break;

    case THREAD_QUEUE_NOTHING_HAPPENED:

      _Chain_Append_unprotected(

        &the_thread_queue->Queues.Fifo,

        &the_thread->Object.Node

      );

      _ISR_Enable( level );

      return;

    case THREAD_QUEUE_TIMEOUT:

      the_thread->Wait.return_code = the_thread->Wait.queue->timeout_status;

      _ISR_Enable( level );

      break;

    case THREAD_QUEUE_SATISFIED:

      if ( _Watchdog_Is_active( &the_thread->Timer ) ) {

        _Watchdog_Deactivate( &the_thread->Timer );

        _ISR_Enable( level );

        (void) _Watchdog_Remove( &the_thread->Timer );

      } else

        _ISR_Enable( level );

      break;

  }

  /*

   *  Global objects with thread queue's should not be operated on from an

   *  ISR.  But the sync code still must allow short timeouts to be processed

   *  correctly.

   */

  _Thread_Unblock( the_thread );

#if defined(RTEMS_MULTIPROCESSING)

  if ( !_Objects_Is_local_id( the_thread->Object.id ) )

    _Thread_MP_Free_proxy( the_thread );

#endif

}