Subversion Repositories shark

Rev

Blame | Last modification | View Log | RSS feed

/*
 * Project: S.Ha.R.K.
 *
 * Coordinators: Giorgio Buttazzo <giorgio@sssup.it>
 *               Paolo Gai <pj@hartik.sssup.it>
 *
 * Authors     : Marco Caccamo and Paolo Gai
 *
 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
 *
 * http://www.sssup.it
 * http://retis.sssup.it
 * http://shark.sssup.it
 */


/**
 ------------
 CVS :        $Id: cbs_ft.c,v 1.1 2004-06-01 11:42:41 giacomo Exp $

 File:        $File$
 Revision:    $Revision: 1.1 $
 Last update: $Date: 2004-06-01 11:42:41 $
 ------------

 This file contains the server CBS_FT

 Read CBS_FT.h for further details.

**/


/*
 * Copyright (C) 2000 Marco Caccamo and Paolo Gai
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */



#include "cbs_ft.h"

/*+ Status used in the level +*/
#define CBS_FT_IDLE          APER_STATUS_BASE   /*+ waiting the activation +*/
#define CBS_FT_ZOMBIE        APER_STATUS_BASE+1 /*+ waiting the period end +*/

/* structure of an element of the capacity queue */  
struct cap_queue {
  int              cap;
  struct timespec  dead;
  struct cap_queue *next;
};  

/*+ the level redefinition for the CBS_FT level +*/
typedef struct {
  level_des l;     /*+ the standard level descriptor          +*/

  /* The wcet are stored in the task descriptor, but we need
     an array for the deadlines. We can't use the timespec_priority
     field because it is used by the master level!!!...
     Notice that however the use of the timespec_priority field
     does not cause any problem...                     */


  struct timespec cbs_ft_dline[MAX_PROC]; /*+ CBS_FT deadlines      +*/
 

  TIME period[MAX_PROC]; /*+ CBS_FT activation period            +*/


  int maxcap[MAX_PROC]; /* amount of capacity reserved to a primary+backup
                        couple */

 
  PID backup[MAX_PROC];  /* Backup task pointers, defined for primary tasks  */

  char CP[MAX_PROC];      /* checkpoint flag */
 
  char P_or_B[MAX_PROC];  /*  Type of task: PRIMARY or BACKUP */

 
  struct timespec reactivation_time[MAX_PROC];
        /*+ the time at witch  the reactivation timer is post +*/

  int reactivation_timer[MAX_PROC];  /*+ the recativation timer +*/

  struct cap_queue *queue;         /* pointer to the spare capacity queue */

  int flags;       /*+ the init flags...                      +*/

  bandwidth_t U;   /*+ the used bandwidth by the server       +*/

  int idle;         /* the idle flag...  */
 
  struct timespec start_idle; /*gives the start time of the last idle period */
 
  LEVEL scheduling_level;

} CBS_FT_level_des;



/* insert a capacity in the queue capacity ordering by deadline */

static int c_insert(struct timespec dead, int cap, struct cap_queue **que,
                     PID p)
{
  struct cap_queue *prev, *n, *new;

    prev = NULL;
    n = *que;

    while ((n != NULL) &&
           !TIMESPEC_A_LT_B(&dead, &n->dead)) {
        prev = n;
        n = n->next;
    }

   
    new = (struct cap_queue *)kern_alloc(sizeof(struct cap_queue));
    if (new == NULL) {
      kern_printf("\nNew cash_queue element failed\n");
      kern_raise(XINVALID_TASK, p);
      return -1;
    }
    new->next = NULL;
    new->cap = cap;
    new->dead = dead;
   
    if (prev != NULL)
      prev->next = new;
    else
      *que = new;

    if (n != NULL)
      new->next = n;
    return 0;

}

/* extract the first element from the capacity queue */

int c_extractfirst(struct cap_queue **que)
{
    struct cap_queue *p = *que;


    if (*que == NULL) return(-1);
   
    *que = (*que)->next;
   
    kern_free(p, sizeof(struct cap_queue));
    return(1);
}

/* read data of the first element from the capacity queue */

static void c_readfirst(struct timespec *d, int *c, struct cap_queue *que)
{
    *d = que->dead;
    *c = que->cap;
}

/* write data of the first element from the capacity queue */

static void c_writefirst(struct timespec dead, int cap, struct cap_queue *que)
{
    que->dead = dead;
    que->cap = cap;
}


static void CBS_FT_activation(CBS_FT_level_des *lev,
                             PID p,
                             struct timespec *acttime)
{
  JOB_TASK_MODEL job;
  int capacity;  
 
  /* This rule is used when we recharge the budget at initial task activation
     and each time a new task instance must be activated  */

 
  if (TIMESPEC_A_GT_B(acttime, &lev->cbs_ft_dline[p])) {
    /* we modify the deadline ... */
    TIMESPEC_ASSIGN(&lev->cbs_ft_dline[p], acttime);
  }

   
  if (proc_table[p].avail_time > 0)
    proc_table[p].avail_time = 0;


 
  /* A spare capacity is inserted in the capacity queue!! */
  ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_ft_dline[p]);
  capacity = lev->maxcap[p] - proc_table[ lev->backup[p] ].wcet;
  c_insert(lev->cbs_ft_dline[p], capacity, &lev->queue, p);
 
 
  /* it exploits available capacities from the capacity queue */
  while (proc_table[p].avail_time < proc_table[p].wcet &&
         lev->queue != NULL) {
    struct timespec dead;
    int             cap, delta;
    delta = proc_table[p].wcet - proc_table[p].avail_time;
    c_readfirst(&dead, &cap, lev->queue);
    if (!TIMESPEC_A_GT_B(&dead, &lev->cbs_ft_dline[p])) {
      if (cap > delta) {
        proc_table[p].avail_time += delta;
        c_writefirst(dead, cap - delta, lev->queue);
      }
      else {
        proc_table[p].avail_time += cap;
        c_extractfirst(&lev->queue);
      }
    }
    else
      break;
  }
 
  /* If the budget is still less than 0, an exception is raised */
  if (proc_table[p].avail_time <= 0) {
    kern_printf("\nnegative value for the budget!\n");
    kern_raise(XINVALID_TASK, p);
    return;
  }


 
  /*if (p==6)
    kern_printf("(act_time:%d  dead:%d av_time:%d)\n",
                acttime->tv_sec*1000000+
                acttime->tv_nsec/1000,
                lev->cbs_ft_dline[p].tv_sec*1000000+
                lev->cbs_ft_dline[p].tv_nsec/1000,
                proc_table[p].avail_time);  */





 

#ifdef TESTG
  if (starttime && p == 3) {
    oldx = x;
    x = ((lev->cbs_ft_dline[p].tv_sec*1000000+lev->cbs_ft_dline[p].tv_nsec/1000)/5000 - starttime) + 20;
    //      kern_printf("(a%d)",lev->cbs_ft_dline[p].tv_sec*1000000+lev->cbs_ft_dline[p].tv_nsec/1000);
    if (oldx > x) sys_end();
    if (x<640)
      grx_plot(x, 15, 8);
  }
#endif

  /* and, finally, we reinsert the task in the master level */
  job_task_default_model(job, lev->cbs_ft_dline[p]);
  job_task_def_yesexc(job);
  level_table[ lev->scheduling_level ]->
    private_insert(lev->scheduling_level, p, (TASK_MODEL *)&job);
}


/* this is the periodic reactivation of the task... */
static void CBS_FT_timer_reactivate(void *par)
{
  PID p = (PID) par;
  CBS_FT_level_des *lev;
  struct timespec t;

  lev = (CBS_FT_level_des *)level_table[proc_table[p].task_level];

  if (proc_table[p].status == CBS_FT_IDLE) {
    /* the task has finished the current activation and must be
       reactivated */

   
    /* request_time represents the time of the last instance release!! */
    TIMESPEC_ASSIGN(&t, &lev->reactivation_time[p]);
 
    /* If idle=1, then we have to discharge the capacities stored in
       the capacity queue up to the length of the idle interval */

    if (lev->idle == 1) {
      TIME interval;
      struct timespec delta;
      lev->idle = 0;
      SUBTIMESPEC(&t, &lev->start_idle, &delta);
      /* length of the idle interval expressed in usec! */
      interval = TIMESPEC2NANOSEC(&delta) / 1000;

      /* it discharges the available capacities from the capacity queue */
      while (interval > 0 && lev->queue != NULL) {
        struct timespec dead;
        int             cap;
        c_readfirst(&dead, &cap, lev->queue);
        if (cap > interval) {
          c_writefirst(dead, cap - interval, lev->queue);
          interval = 0;
        }
        else {
          interval -= cap;
          c_extractfirst(&lev->queue);
        }      
      }
    }

    CBS_FT_activation(lev,p,&lev->reactivation_time[p]);

 
    /* Set the reactivation timer */
    TIMESPEC_ASSIGN(&lev->reactivation_time[p], &lev->cbs_ft_dline[p]);
    lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],
                                                 CBS_FT_timer_reactivate,
                                                 (void *)p);
    event_need_reschedule();
  }
  else {
    /* this situation cannot occur */
    kern_printf("\nTrying to reactivate a primary task which is not IDLE!\n");
    kern_raise(XINVALID_TASK,p);
  }
}



static void CBS_FT_avail_time_check(CBS_FT_level_des *lev, PID p)
{
 
  /*+ if the capacity became negative the remaining computation time
    is diminuished.... +*/

  /* if (p==4)
    kern_printf("(old dead:%d av_time:%d)\n",
                lev->cbs_ft_dline[p].tv_sec*1000000+
                lev->cbs_ft_dline[p].tv_nsec/1000,
                proc_table[p].avail_time);  */



  int newcap = proc_table[p].wcet / 100 * 30;
  if (newcap <= 0)
    newcap = proc_table[p].wcet;
  /* it exploits available capacities from the capacity queue */
  while (proc_table[p].avail_time < newcap
         && lev->queue != NULL) {
    struct timespec dead;
    int             cap, delta;
    delta = newcap - proc_table[p].avail_time;
    c_readfirst(&dead, &cap, lev->queue);
    if (!TIMESPEC_A_GT_B(&dead, &lev->cbs_ft_dline[p])) {
      if (cap > delta) {
        proc_table[p].avail_time += delta;
        c_writefirst(dead, cap - delta, lev->queue);
      }
      else {
        proc_table[p].avail_time += cap;
        c_extractfirst(&lev->queue);
      }
    }
    else
      break;
  }



 /*if (p==6)
    kern_printf("(ATC dead:%d av_time:%d)\n",
                lev->cbs_ft_dline[p].tv_sec*1000000+
                lev->cbs_ft_dline[p].tv_nsec/1000,
                proc_table[p].avail_time);  */



 
  /* if the budget is still empty, the backup task must be woken up.
     Remind that a short chunk of primary will go ahead executing
     before the task switch occurs                                */

  if (proc_table[p].avail_time <= 0) {
    lev->CP[p] = 1;
    proc_table[p].avail_time += proc_table[ lev->backup[p] ].wcet;
  }


 /*if (p==6)
    kern_printf("(ATC1 dead:%d av_time:%d)\n",
                lev->cbs_ft_dline[p].tv_sec*1000000+
                lev->cbs_ft_dline[p].tv_nsec/1000,
                proc_table[p].avail_time);  */



 
}


/*+ this function is called when a killed or ended task reach the
  period end +*/

static void CBS_FT_timer_zombie(void *par)
{
  PID p = (PID) par;
  CBS_FT_level_des *lev;

  lev = (CBS_FT_level_des *)level_table[proc_table[p].task_level];

  /* we finally put the task in the FREE status */
  proc_table[p].status = FREE;
  iq_insertfirst(p,&freedesc);


  /* and free the allocated bandwidth */
  lev->U -= (MAX_BANDWIDTH / lev->period[p]) * (TIME)lev->maxcap[p];
}

static PID CBS_FT_public_scheduler(LEVEL l)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);
 
  /* it stores the actual time and set the IDLE flag in order to handle
     the capacity queue discharging!!! */

  lev->idle = 1;
  kern_gettime(&lev->start_idle);

 
  /* the CBS_FT don't schedule anything...
     it's an EDF level or similar that do it! */

  return NIL;
}


/* The on-line guarantee is enabled only if the appropriate flag is set... */
static int CBS_FT_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);

  if (lev->flags & CBS_FT_FAILED_GUARANTEE) {
    *freebandwidth = 0;
    kern_printf("guarantee :garanzia fallita!!!!!!\n");
    return 0;
  }
  else if (*freebandwidth >= lev->U) {
    *freebandwidth -= lev->U;
    return 1;
  }
  else {
    kern_printf("guarantee :garanzia fallita per mancanza di banda!!!!!!\n");
    kern_printf("freeband: %d request band: %d", *freebandwidth, lev->U);
    return 0;
  }
}


static int CBS_FT_public_create(LEVEL l, PID p, TASK_MODEL *m)

{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);
  FT_TASK_MODEL *s;

  if (m->pclass != FT_PCLASS) return -1;
  if (m->level != 0 && m->level != l) return -1;
  s = (FT_TASK_MODEL *) m;
  //kern_printf("accept :FAULT TOLERANT TASK found!!!!!!\n"); */
  if (!(s->type == PRIMARY && s->execP > 0 && s->budget < (int)s->period
      && s->backup != NIL)) return -1;
  if (!(s->type == BACKUP && s->wcetB > 0))
    return -1;
  /* now we know that m is a valid model */
 
  /* Enable budget check */
  proc_table[p].control |= CONTROL_CAP;  

  proc_table[p].avail_time = 0;
  NULL_TIMESPEC(&lev->cbs_ft_dline[p]);


  if (s->type == PRIMARY) {
    proc_table[p].wcet = (int)s->execP;
    lev->period[p] = s->period;
    lev->maxcap[p] = s->budget;
    lev->backup[p] = s->backup;
    lev->CP[p] = 0;
    lev->P_or_B[p] = PRIMARY;

    /* update the bandwidth... */
    if (lev->flags & CBS_FT_ENABLE_GUARANTEE) {
      bandwidth_t b;
      b = (MAX_BANDWIDTH / lev->period[p]) * (TIME)lev->maxcap[p];
     
      /* really update lev->U, checking an overflow... */
      if (MAX_BANDWIDTH - lev->U > b)
        lev->U += b;
      else
        /* The task can NOT be guaranteed (U>MAX_BANDWIDTH)...
           (see EDF.c) */

        lev->flags |= CBS_FT_FAILED_GUARANTEE;
    }
  }
  else {
    proc_table[p].wcet = (int)s->wcetB;
    lev->P_or_B[p] = BACKUP;

    /* Backup tasks are unkillable tasks! */
    proc_table[p].control |= NO_KILL;
  }
 
  return 0; /* OK, also if the task cannot be guaranteed... */
}


static void CBS_FT_public_detach(LEVEL l, PID p)
{
  /* the CBS_FT level doesn't introduce any dynamic allocated new field.
     we have only to reset the NO_GUARANTEE FIELD and decrement the allocated
     bandwidth */


  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);

  if (lev->flags & CBS_FT_FAILED_GUARANTEE)
    lev->flags &= ~CBS_FT_FAILED_GUARANTEE;
  else
    lev->U -= (MAX_BANDWIDTH / lev->period[p]) * (TIME)lev->maxcap[p];
}


static void CBS_FT_public_dispatch(LEVEL l, PID p, int nostop)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);
  level_table[ lev->scheduling_level ]->
    private_dispatch(lev->scheduling_level,p,nostop);
}

static void CBS_FT_public_epilogue(LEVEL l, PID p)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);

  /* check if the budget is finished... */
  if (proc_table[p].avail_time <= 0) {

    /* A backup task cannot ever exhaust its budget! */
    if (lev->P_or_B[p] == BACKUP) {
      kern_printf("\nBACKUP wcet violation!\n");
      kern_raise(XWCET_VIOLATION,p);
      /* we kill the current activation */
      level_table[ lev->scheduling_level ]->
        private_extract(lev->scheduling_level, p);
      return;
    }

    /* we try to recharge the budget */
    CBS_FT_avail_time_check(lev, p);

    /* The budget must be greater than 0! */
    if (proc_table[p].avail_time <= 0) {
      kern_printf("\nBackup task starting with exhausted budget\n");
      kern_raise(XINVALID_TASK, p);
      lev->CP[p] = 0;
      /* we kill the current activation */
      level_table[ lev->scheduling_level ]->
        private_extract(lev->scheduling_level, p);
      return;
    }
  }
 
    /* the task returns into the ready queue by
       calling the guest_epilogue... */

    level_table[ lev->scheduling_level ]->
      private_epilogue(lev->scheduling_level,p);
}


static void CBS_FT_public_activate(LEVEL l, PID p)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);
  struct timespec t;

  kern_gettime(&t);

  if (lev->P_or_B[p] == BACKUP) {
    kern_printf("\nTrying to activate a BACKUP task!\n");
    kern_raise(XINVALID_TASK, p);
  }
  else {
 
    /* If idle=1, then we have to discharge the capacities stored in
       the capacity queue up to the length of the idle interval */

    if (lev->idle == 1) {
      TIME interval;
      struct timespec delta;
      lev->idle = 0;
      SUBTIMESPEC(&t, &lev->start_idle, &delta);
      /* length of the idle interval expressed in usec! */
      interval = TIMESPEC2NANOSEC(&delta) / 1000;
     
      /* it discharge the available capacities from the capacity queue */
      while (interval > 0 && lev->queue != NULL) {
        struct timespec dead;
        int             cap;
        c_readfirst(&dead, &cap, lev->queue);
        if (cap > interval) {
          c_writefirst(dead, cap - interval, lev->queue);
          interval = 0;
        }
        else {
          interval -= cap;
          c_extractfirst(&lev->queue);
        }      
      }
    }
   
    CBS_FT_activation(lev, p, &t);
   
 
    /* Set the reactivation timer */
    TIMESPEC_ASSIGN(&lev->reactivation_time[p], &lev->cbs_ft_dline[p]);
    lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],
                                                 CBS_FT_timer_reactivate,
                                                 (void *)p);
   
    //  kern_printf("act : %d %d |",lev->cbs_ft_dline[p].tv_nsec/1000,p);
  }
}

static int CBS_FT_public_message(LEVEL l, PID p, void *m)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);

 
  level_table[ lev->scheduling_level ]->
    private_extract(lev->scheduling_level,p);

 
  proc_table[p].status = CBS_FT_IDLE;

 
  if (lev->P_or_B[p] == PRIMARY) {
    if (lev->CP[p]) {
      JOB_TASK_MODEL job;
     
      /* We have to start the backup task  */
      TIMESPEC_ASSIGN(&lev->cbs_ft_dline[ lev->backup[p] ],
                      &lev->cbs_ft_dline[p]);
      proc_table[ lev->backup[p] ].avail_time = proc_table[p].avail_time;
      lev->CP[p] = 0;

      /* and, finally, we insert the backup task in the master level */
      job_task_default_model(job, lev->cbs_ft_dline[p]);
      job_task_def_yesexc(job);
      level_table[ lev->scheduling_level ]->
        private_insert(lev->scheduling_level, lev->backup[p],
                     (TASK_MODEL *)&job);
    }
    else {
      /* A spare capacity is inserted in the capacity queue!! */
      proc_table[p].avail_time += proc_table[ lev->backup[p] ].wcet;    
      if (proc_table[p].avail_time > 0) {
        c_insert(lev->cbs_ft_dline[p], proc_table[p].avail_time,
                 &lev->queue, p);
        proc_table[p].avail_time = 0;
      }
    }
  }
  else {
    /* this branch is for backup tasks:
       A spare capacity is inserted in the capacity queue!! */

    if (proc_table[p].avail_time > 0) {
      c_insert(lev->cbs_ft_dline[p], proc_table[p].avail_time,
               &lev->queue, p);
      proc_table[p].avail_time = 0;
    }
  }  

  jet_update_endcycle(); /* Update the Jet data... */

  return 0;
}


static void CBS_FT_public_end(LEVEL l, PID p)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);

  /* A backup task cannot be killed, this behaviour can be modified
     in a new release */

  if (lev->P_or_B[p] == BACKUP) {
    kern_printf("\nKilling a BACKUP task!\n");
    kern_raise(XINVALID_TASK, p);
    return;
  }

  /* check if the capacity becomes negative... */
  /* there is a while because if the wcet is << than the system tick
     we need to postpone the deadline many times */

  while (proc_table[p].avail_time < 0) {
    /* the CBS_FT rule for recharging the capacity */
    proc_table[p].avail_time += lev->maxcap[p];
    ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_ft_dline[p]);
  }
 
  level_table[ lev->scheduling_level ]->
    private_extract(lev->scheduling_level,p);


  /* we delete the reactivation timer */
  kern_event_delete(lev->reactivation_timer[p]);
  lev->reactivation_timer[p] = -1;
 

  /* Finally, we post the zombie event. when the end period is reached,
     the task descriptor and banwidth are freed */

  proc_table[p].status = CBS_FT_ZOMBIE;
  lev->reactivation_timer[p] = kern_event_post(&lev->cbs_ft_dline[p],
                                               CBS_FT_timer_zombie,
                                               (void *)p);
}

/* Registration functions */

/*+ Registration function:
    int flags                 the init flags ... see CBS.h +*/

LEVEL CBS_FT_register_level(int flags, LEVEL master)
{
  LEVEL l;            /* the level that we register */
  CBS_FT_level_des *lev;  /* for readableness only */
  PID i;              /* a counter */

  printk("CBS_FT_register_level\n");

  /* request an entry in the level_table */
  l = level_alloc_descriptor(sizeof(CBS_FT_level_des));

  lev = (CBS_FT_level_des *)level_table[l];

  printk("    lev=%d\n",(int)lev);

  /* fill the standard descriptor */
  lev->l.public_scheduler = CBS_FT_public_scheduler;

  if (flags & CBS_FT_ENABLE_GUARANTEE)
    lev->l.public_guarantee = CBS_FT_public_guarantee;
  else
    lev->l.public_guarantee = NULL;

  lev->l.public_create    = CBS_FT_public_create;
  lev->l.public_detach    = CBS_FT_public_detach;
  lev->l.public_end       = CBS_FT_public_end;
  lev->l.public_dispatch  = CBS_FT_public_dispatch;
  lev->l.public_epilogue  = CBS_FT_public_epilogue;
  lev->l.public_activate  = CBS_FT_public_activate;
  lev->l.public_message   = CBS_FT_public_message;

  /* fill the CBS_FT descriptor part */
  for (i=0; i<MAX_PROC; i++) {
     NULL_TIMESPEC(&lev->cbs_ft_dline[i]);
     lev->period[i] = 0;
     NULL_TIMESPEC(&lev->reactivation_time[i]);
     lev->reactivation_timer[i] = -1;
     lev->maxcap[i] = 0;
     lev->backup[i] = NIL;
     lev->CP[i] = 0;
     lev->P_or_B[i] = PRIMARY;
  }

  lev->U = 0;
  lev->idle = 0;
  lev->queue = NULL;
 
  lev->scheduling_level = master;

  lev->flags = flags & 0x07;

  return l;
}



bandwidth_t CBS_FT_usedbandwidth(LEVEL l)
{
  CBS_FT_level_des *lev = (CBS_FT_level_des *)(level_table[l]);

  return lev->U;
}



void CBS_FT_Primary_Abort()
{
  PID p;
  CBS_FT_level_des *lev;

  kern_cli();
  p = exec_shadow;
  lev = (CBS_FT_level_des *)level_table[proc_table[p].task_level];
  lev->CP[p] = 1;
  kern_sti();
}


char CBS_FT_Checkpoint()
{
  char f;
  PID p;
  CBS_FT_level_des *lev;
 
  kern_cli();
  p = exec_shadow;
  lev = (CBS_FT_level_des *)level_table[proc_table[p].task_level];
  f = lev->CP[p];
  kern_sti();
  return f;
}