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/*

 *  Watchdog 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: watchdoginsert.c,v 1.2 2001-09-27 11:59:34 chris Exp $

 */

#include <rtems/system.h>

#include <rtems/score/isr.h>

#include <rtems/score/watchdog.h>

/*PAGE

 *

 *  _Watchdog_Insert

 *

 *  This routine inserts a watchdog timer on to the appropriate delta

 *  chain while updating the delta interval counters.

 */

void _Watchdog_Insert(

  Chain_Control         *header,

  Watchdog_Control      *the_watchdog

)

{

  ISR_Level          level;

  Watchdog_Control  *after;

  unsigned32         insert_isr_nest_level;

  Watchdog_Interval  delta_interval;

  insert_isr_nest_level   = _ISR_Nest_level;

  the_watchdog->state = WATCHDOG_BEING_INSERTED;

  _Watchdog_Sync_count++;

restart:

  delta_interval = the_watchdog->initial;

  _ISR_Disable( level );

  for ( after = _Watchdog_First( header ) ;

        ;

        after = _Watchdog_Next( after ) ) {

     if ( delta_interval == 0 || !_Watchdog_Next( after ) )

       break;

     if ( delta_interval < after->delta_interval ) {

       after->delta_interval -= delta_interval;

       break;

     }

     delta_interval -= after->delta_interval;

     /*

      *  If you experience problems comment out the _ISR_Flash line.

      *  3.2.0 was the first release with this critical section redesigned.

      *  Under certain circumstances, the PREVIOUS critical section algorithm

      *  used around this flash point allowed interrupts to execute

      *  which violated the design assumptions.  The critical section

      *  mechanism used here WAS redesigned to address this.

      */

     _ISR_Flash( level );

     if ( the_watchdog->state != WATCHDOG_BEING_INSERTED ) {

       goto exit_insert;

     }

     if ( _Watchdog_Sync_level > insert_isr_nest_level ) {

       _Watchdog_Sync_level = insert_isr_nest_level;

       _ISR_Enable( level );

       goto restart;

     }

  }

  _Watchdog_Activate( the_watchdog );

  the_watchdog->delta_interval = delta_interval;

  _Chain_Insert_unprotected( after->Node.previous, &the_watchdog->Node );

  the_watchdog->start_time = _Watchdog_Ticks_since_boot;

exit_insert:

  _Watchdog_Sync_level = insert_isr_nest_level;

  _Watchdog_Sync_count--;

  _ISR_Enable( level );

}