Subversion Repositories shark

/*

 * Project: S.Ha.R.K.

 *

 * Coordinators:

 *   Giorgio Buttazzo    <giorgio@sssup.it>

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *

 * Authors     :

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *   Massimiliano Giorgi <massy@gandalf.sssup.it>

 *   Luca Abeni          <luca@gandalf.sssup.it>

 *   (see the web pages for full authors list)

 *

 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)

 *

 * http://www.sssup.it

 * http://retis.sssup.it

 * http://shark.sssup.it

 */

/**

 ------------

 CVS :        $Id: cbs.c,v 1.2 2002-10-28 07:55:54 pj Exp $

 File:        $File$

 Revision:    $Revision: 1.2 $

 Last update: $Date: 2002-10-28 07:55:54 $

 ------------

 This file contains the aperiodic server CBS (Total Bandwidth Server)

 Read CBS.h for further details.

**/

/*

 * Copyright (C) 2000 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 <modules/cbs.h>

#include <ll/stdio.h>

#include <ll/string.h>

#include <kernel/model.h>

#include <kernel/descr.h>

#include <kernel/var.h>

#include <kernel/func.h>

#include <kernel/trace.h>

/*+ 4 debug purposes +*/

#undef CBS_TEST

#undef CBS_COUNTER

#ifdef TESTG

#include "drivers/glib.h"

TIME x,oldx;

extern TIME starttime;

#endif

/*+ Status used in the level +*/

#define CBS_IDLE          APER_STATUS_BASE   /*+ waiting the activation +*/

#define CBS_ZOMBIE        APER_STATUS_BASE+1 /*+ waiting the period end +*/

#define CBS_DELAY         APER_STATUS_BASE+2 /*+ waiting the delay end  +*/

/*+ task flags +*/

#define CBS_SAVE_ARRIVALS 1

#define CBS_APERIODIC     2

/*+ the level redefinition for the Total Bandwidth Server 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_dline[MAX_PROC]; /*+ CBS deadlines      +*/

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

  struct timespec reactivation_time[MAX_PROC];

        /*+ the time at witch  the reactivation timer is post +*/

  int reactivation_timer[MAX_PROC];

                                   /*+ the recativation timer +*/

  int nact[MAX_PROC]; /*+ number of pending activations       +*/

  BYTE flag[MAX_PROC]; /*+ task flags                         +*/

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

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

  LEVEL scheduling_level;

} CBS_level_des;

#ifdef CBS_COUNTER

int cbs_counter=0;

int cbs_counter2=0;

#endif

static void CBS_activation(CBS_level_des *lev,

                           PID p,

                           struct timespec *acttime)

{

  JOB_TASK_MODEL job;

  /* we have to check if the deadline and the wcet are correct before

     activating a new task or an old task... */

  /* check 1: if the deadline is before than the actual scheduling time */

  /* check 2: if ( avail_time >= (cbs_dline - acttime)* (wcet/period) )

     (rule 7 in the CBS article!) */

  TIME t;

  struct timespec t2,t3;

  t = (lev->period[p] * proc_table[p].avail_time) / proc_table[p].wcet;

  t3.tv_sec = t / 1000000;

  t3.tv_nsec = (t % 1000000) * 1000;

  SUBTIMESPEC(&lev->cbs_dline[p], acttime, &t2);

  if (/* 1 */ TIMESPEC_A_LT_B(&lev->cbs_dline[p], acttime) ||

      /* 2 */ TIMESPEC_A_GT_B(&t3, &t2) ) {

/*    if (TIMESPEC_A_LT_B(&lev->cbs_dline[p], acttime) )

      kern_printf("$");

    else

      kern_printf("(Ûdline%d.%d act%d.%d wcet%d per%d avail%dÛ)",

                  lev->cbs_dline[p].tv_sec,lev->cbs_dline[p].tv_nsec/1000,

                  acttime->tv_sec, acttime->tv_nsec/1000,

                  proc_table[p].wcet, lev->period[p], proc_table[p].avail_time);

*/  /* we modify the deadline ... */

    TIMESPEC_ASSIGN(&lev->cbs_dline[p], acttime);

    ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]);

    /* and the capacity */

    proc_table[p].avail_time = proc_table[p].wcet;

  }

#ifdef TESTG

      if (starttime && p == 3) {

      oldx = x;

      x = ((lev->cbs_dline[p].tv_sec*1000000+lev->cbs_dline[p].tv_nsec/1000)/5000 - starttime) + 20;

//      kern_printf("(a%d)",lev->cbs_dline[p].tv_sec*1000000+lev->cbs_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_dline[p]);

  job_task_def_noexc(job);

  level_table[ lev->scheduling_level ]->

    guest_create(lev->scheduling_level, p, (TASK_MODEL *)&job);

  level_table[ lev->scheduling_level ]->

    guest_activate(lev->scheduling_level, p);

}

static char *CBS_status_to_a(WORD status)

{

  if (status < MODULE_STATUS_BASE)

    return status_to_a(status);

  switch (status) {

    case CBS_IDLE   : return "CBS_Idle";

    case CBS_ZOMBIE : return "CBS_Zombie";

    case CBS_DELAY  : return "CBS_Delay";

    default         : return "CBS_Unknown";

  }

}

static void CBS_avail_time_check(CBS_level_des *lev, PID p)

{

  /* 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) {

    ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]);

    proc_table[p].avail_time += proc_table[p].wcet;

#ifdef TESTG

    if (starttime && p == 3) {

    oldx = x;

    x = ((lev->cbs_dline[p].tv_sec*1000000+lev->cbs_dline[p].tv_nsec/1000)/5000 - starttime) + 20;

//      kern_printf("(e%d avail%d)",lev->cbs_dline[p].tv_sec*1000000+lev->cbs_dline[p].tv_nsec/1000,proc_table[p].avail_time);

    if (oldx > x) sys_end();

    if (x<640)

      grx_plot(x, 15, 2);

    }

#endif

  }

}

/* this is the periodic reactivation of the task... it is posted only

   if the task is a periodic task */

static void CBS_timer_reactivate(void *par)

{

  PID p = (PID) par;

  CBS_level_des *lev;

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

  #ifdef CBS_COUNTER

    if (p==5) cbs_counter++;

  #endif

  if (proc_table[p].status == CBS_IDLE) {

    /* the task has finished the current activation and must be

       reactivated */

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

    event_need_reschedule();

  }

  else if (lev->flag[p] & CBS_SAVE_ARRIVALS)

    /* the task has not completed the current activation, so we save

       the activation incrementing nact... */

    lev->nact[p]++;

  /* repost the event at the next period end... */

  ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]);

  lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],

                                               CBS_timer_reactivate,

                                               (void *)p);

  #ifdef CBS_COUNTER

    if (p==5) cbs_counter2++;

  #endif

  /* tracer stuff */

  trc_logevent(TRC_INTACTIVATION,&p);

}

/*+ this function is called when a task finish his delay +*/

static void CBS_timer_delay(void *par)

{

  PID p = (PID) par;

  CBS_level_des *lev;

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

  CBS_activation(lev,p,&proc_table[p].timespec_priority);

  event_need_reschedule();

}

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

    period end +*/

static void CBS_timer_zombie(void *par)

{

  PID p = (PID) par;

  CBS_level_des *lev;

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

  /* we finally put the task in the ready queue */

  proc_table[p].status = FREE;

  q_insertfirst(p,&freedesc);

  /* and free the allocated bandwidth */

  lev->U -= (MAX_BANDWIDTH/lev->period[p]) * proc_table[p].wcet;

}

static int CBS_level_accept_task_model(LEVEL l, TASK_MODEL *m)

{

  if (m->pclass == SOFT_PCLASS || m->pclass == (SOFT_PCLASS | l)) {

    SOFT_TASK_MODEL *s = (SOFT_TASK_MODEL *)m;

    if (s->met && s->period)

      return 0;

  }

  return -1;

}

static int CBS_level_accept_guest_model(LEVEL l, TASK_MODEL *m)

{

  return -1;

}

static char *onoff(int i)

{

  if (i)

    return "On ";

  else

    return "Off";

}

static void CBS_level_status(LEVEL l)

{

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

  PID p;

  kern_printf("On-line guarantee : %s\n",

            onoff(lev->flags & CBS_ENABLE_GUARANTEE));

  kern_printf("Used Bandwidth    : %u/%u\n",

            lev->U, MAX_BANDWIDTH);

  for (p=0; p<MAX_PROC; p++)

    if (proc_table[p].task_level == l && proc_table[p].status != FREE )

      kern_printf("Pid: %2d Name: %10s Period: %9ld Dline: %9ld.%6ld Stat: %s\n",

                p,

                proc_table[p].name,

                lev->period[p],

                lev->cbs_dline[p].tv_sec,

                lev->cbs_dline[p].tv_nsec/1000,

                CBS_status_to_a(proc_table[p].status));

}

static PID CBS_level_scheduler(LEVEL l)

{

  /* the CBS 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_level_guarantee(LEVEL l, bandwidth_t *freebandwidth)

{

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

  if (lev->flags & CBS_FAILED_GUARANTEE) {

    *freebandwidth = 0;

    return 0;

  }

  else

    if (*freebandwidth >= lev->U) {

      *freebandwidth -= lev->U;

      return 1;

    }

    else

      return 0;

}

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

{

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

  /* if the CBS_task_create is called, then the pclass must be a

     valid pclass. */

  SOFT_TASK_MODEL *soft = (SOFT_TASK_MODEL *)m;

  /* Enable wcet check */

  proc_table[p].avail_time = soft->met;

  proc_table[p].wcet       = soft->met;

  proc_table[p].control   |= CONTROL_CAP;

  lev->nact[p] = 0;

  lev->period[p] = soft->period;

  NULL_TIMESPEC(&lev->cbs_dline[p]);

  if (soft->periodicity == APERIODIC)

    lev->flag[p] = CBS_APERIODIC;

  else

    lev->flag[p] = 0;

  if (soft->arrivals == SAVE_ARRIVALS)

    lev->flag[p] |= CBS_SAVE_ARRIVALS;

  /* update the bandwidth... */

  if (lev->flags & CBS_ENABLE_GUARANTEE) {

    bandwidth_t b;

    b = (MAX_BANDWIDTH / soft->period) * soft->met;

    /* 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_FAILED_GUARANTEE;

  }

  return 0; /* OK, also if the task cannot be guaranteed... */

}

static void CBS_task_detach(LEVEL l, PID p)

{

  /* the CBS level doesn't introduce any dinamic allocated new field.

     we have only to reset the NO_GUARANTEE FIELD and decrement the allocated

     bandwidth */

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

  if (lev->flags & CBS_FAILED_GUARANTEE)

    lev->flags &= ~CBS_FAILED_GUARANTEE;

  else

    lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet;

}

static int CBS_task_eligible(LEVEL l, PID p)

{

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

  JOB_TASK_MODEL job;

  /* we have to check if the deadline and the wcet are correct...

     if the CBS level schedules in background with respect to others

     levels, there can be the case in witch a task is scheduled by

     schedule_time > CBS_deadline; in this case (not covered in the

     article because if there is only the standard scheduling policy

     this never apply) we reassign the deadline */

  if ( TIMESPEC_A_LT_B(&lev->cbs_dline[p], &schedule_time) ) {

    /* we kill the current activation */

    level_table[ lev->scheduling_level ]->

      guest_end(lev->scheduling_level, p);

    /* we modify the deadline ... */

    TIMESPEC_ASSIGN(&lev->cbs_dline[p], &schedule_time);

    ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]);

    /* and the capacity */

    proc_table[p].avail_time = proc_table[p].wcet;

    /* and, finally, we reinsert the task in the master level */

    job_task_default_model(job, lev->cbs_dline[p]);

    job_task_def_noexc(job);

    level_table[ lev->scheduling_level ]->

      guest_create(lev->scheduling_level, p, (TASK_MODEL *)&job);

    level_table[ lev->scheduling_level ]->

      guest_activate(lev->scheduling_level, p);

    return -1;

  }

  return 0;

}

#ifdef __TEST1__

extern int testactive;

extern struct timespec s_stime[];

extern TIME s_curr[];

extern TIME s_PID[];

extern int useds;

#endif

static void CBS_task_dispatch(LEVEL l, PID p, int nostop)

{

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

  level_table[ lev->scheduling_level ]->

    guest_dispatch(lev->scheduling_level,p,nostop);

  #ifdef __TEST1__

  if (testactive)

  {

    TIMESPEC_ASSIGN(&s_stime[useds], &schedule_time);

    s_curr[useds] = proc_table[p].avail_time;

    s_PID[useds]  = p;

    useds++;

  }

  #endif

}

static void CBS_task_epilogue(LEVEL l, PID p)

{

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

  JOB_TASK_MODEL job;

  /* check if the wcet is finished... */

  if ( proc_table[p].avail_time <= 0) {

    /* we kill the current activation */

    level_table[ lev->scheduling_level ]->

      guest_end(lev->scheduling_level, p);

    /* we modify the deadline according to rule 4 ... */

    CBS_avail_time_check(lev, p);

    /* and, finally, we reinsert the task in the master level */

    job_task_default_model(job, lev->cbs_dline[p]);

    job_task_def_noexc(job);

    level_table[ lev->scheduling_level ]->

      guest_create(lev->scheduling_level, p, (TASK_MODEL *)&job);

    level_table[ lev->scheduling_level ]->

      guest_activate(lev->scheduling_level, p);

//    kern_printf("epil : dl %d per %d p %d |\n",

//              lev->cbs_dline[p].tv_nsec/1000,lev->period[p],p);

  }

  else

    /* the task has been preempted. it returns into the ready queue by

       calling the guest_epilogue... */

    level_table[ lev->scheduling_level ]->

      guest_epilogue(lev->scheduling_level,p);

}

static void CBS_task_activate(LEVEL l, PID p)

{

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

  /* save activation (only if needed... */

  if (proc_table[p].status != SLEEP) {

    if (lev->flag[p] & CBS_SAVE_ARRIVALS)

      lev->nact[p]++;

    return;

  }

  ll_gettime(TIME_EXACT, &proc_table[p].request_time);

  CBS_activation(lev, p, &proc_table[p].request_time);

  /* Set the reactivation timer */

  if (!(lev->flag[p] & CBS_APERIODIC))

  {

    /* we cannot use the deadline computed by CBS_activation because

       the deadline may be != from actual_time + period

       (if we call the task_activate after a task_sleep, and the

       deadline was postponed a lot...) */

    TIMESPEC_ASSIGN(&lev->reactivation_time[p], &proc_table[p].request_time);

    ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]);

//    TIMESPEC_ASSIGN(&lev->reactivation_time[p], &lev->cbs_dline[p]);

    lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p],

                                                 CBS_timer_reactivate,

                                                 (void *)p);

    #ifdef CBS_COUNTER

      if (p==5) cbs_counter2++;

    #endif

  }

//  kern_printf("act : %d %d |",lev->cbs_dline[p].tv_nsec/1000,p);

}

static void CBS_task_insert(LEVEL l, PID p)

{

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

  struct timespec acttime;

  ll_gettime(TIME_EXACT, &acttime);

  CBS_activation(lev,p,&acttime);

}

static void CBS_task_extract(LEVEL l, PID p)

{

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

  /* check if the wcet is finished... */

  CBS_avail_time_check(lev, p);

  level_table[ lev->scheduling_level ]->

    guest_end(lev->scheduling_level,p);

}

static void CBS_task_endcycle(LEVEL l, PID p)

{

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

  /* check if the wcet is finished... */

  CBS_avail_time_check(lev, p);

  if (lev->nact[p]) {

    /* continue!!!! */

    ll_gettime(TIME_EXACT, &proc_table[p].request_time);

    lev->nact[p]--;

    level_table[ lev->scheduling_level ]->

      guest_epilogue(lev->scheduling_level,p);

  }

  else {

    level_table[ lev->scheduling_level ]->

      guest_end(lev->scheduling_level,p);

    if (lev->flag[p] & CBS_APERIODIC)

      proc_table[p].status = SLEEP;

    else  /* the task is soft_periodic */

      proc_table[p].status = CBS_IDLE;

  }

}

static void CBS_task_end(LEVEL l, PID p)

{

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

  /* check if the wcet is finished... */

  CBS_avail_time_check(lev, p);

  level_table[ lev->scheduling_level ]->

    guest_end(lev->scheduling_level,p);

  /* we delete the reactivation timer */

  if (!(lev->flag[p] & CBS_APERIODIC)) {

    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_ZOMBIE;

  lev->reactivation_timer[p] = kern_event_post(&lev->cbs_dline[p],

                                               CBS_timer_zombie,

                                               (void *)p);

}

static void CBS_task_sleep(LEVEL l, PID p)

{

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

  /* check if the wcet is finished... */

  CBS_avail_time_check(lev, p);

  /* a task activation is finished, but we are using a JOB_TASK_MODEL

     that implements a single activation, so we have to call

     the guest_end, that representsa single activation... */

  level_table[ lev->scheduling_level ]->

    guest_end(lev->scheduling_level,p);

  /* we delete the reactivation timer */

  if (!(lev->flag[p] & CBS_APERIODIC)) {

    event_delete(lev->reactivation_timer[p]);

    lev->reactivation_timer[p] = -1;

  }

  proc_table[p].status = SLEEP;

  /* the sleep forgets pending activations... */

  lev->nact[p] = 0;

}

static void CBS_task_delay(LEVEL l, PID p, TIME usdelay)

{

  struct timespec wakeuptime;

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

  /* check if the wcet is finished... */

  CBS_avail_time_check(lev, p);

  level_table[ lev->scheduling_level ]->

    guest_end(lev->scheduling_level,p);

  proc_table[p].status = CBS_DELAY;

  /* we need to delete this event if we kill the task while it is sleeping */

  ll_gettime(TIME_EXACT, &wakeuptime);

  ADDUSEC2TIMESPEC(usdelay, &wakeuptime);

  /* the timespec_priority field is used to store the time at witch the delay

     timer raises */

  TIMESPEC_ASSIGN(&proc_table[p].timespec_priority, &wakeuptime);

  proc_table[p].delay_timer = kern_event_post(&wakeuptime,

                                              CBS_timer_delay,

                                              (void *)p);

}

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

{ kern_raise(XINVALID_GUEST,exec_shadow); return 0; }

static void CBS_guest_detach(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_dispatch(LEVEL l, PID p, int nostop)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_epilogue(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_activate(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_insert(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_extract(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_endcycle(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_end(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_sleep(LEVEL l, PID p)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

static void CBS_guest_delay(LEVEL l, PID p,DWORD tickdelay)

{ kern_raise(XINVALID_GUEST,exec_shadow); }

/* Registration functions */

/*+ Registration function:

    int flags                 the init flags ... see CBS.h +*/

void CBS_register_level(int flags, LEVEL master)

{

  LEVEL l;            /* the level that we register */

  CBS_level_des *lev;  /* for readableness only */

  PID i;              /* a counter */

  printk("CBS_register_level\n");

  /* request an entry in the level_table */

  l = level_alloc_descriptor();

  printk("    alloco descrittore %d %d\n",l,(int)sizeof(CBS_level_des));

  /* alloc the space needed for the CBS_level_des */

  lev = (CBS_level_des *)kern_alloc(sizeof(CBS_level_des));

  printk("    lev=%d\n",(int)lev);

  /* update the level_table with the new entry */

  level_table[l] = (level_des *)lev;

  /* fill the standard descriptor */

  strncpy(lev->l.level_name,  CBS_LEVELNAME, MAX_LEVELNAME);

  lev->l.level_code               = CBS_LEVEL_CODE;

  lev->l.level_version            = CBS_LEVEL_VERSION;

  lev->l.level_accept_task_model  = CBS_level_accept_task_model;

  lev->l.level_accept_guest_model = CBS_level_accept_guest_model;

  lev->l.level_status             = CBS_level_status;

  lev->l.level_scheduler          = CBS_level_scheduler;

  if (flags & CBS_ENABLE_GUARANTEE)

    lev->l.level_guarantee        = CBS_level_guarantee;

  else

    lev->l.level_guarantee        = NULL;

  lev->l.task_create              = CBS_task_create;

  lev->l.task_detach              = CBS_task_detach;

  lev->l.task_eligible            = CBS_task_eligible;

  lev->l.task_dispatch            = CBS_task_dispatch;

  lev->l.task_epilogue            = CBS_task_epilogue;

  lev->l.task_activate            = CBS_task_activate;

  lev->l.task_insert              = CBS_task_insert;

  lev->l.task_extract             = CBS_task_extract;

  lev->l.task_endcycle            = CBS_task_endcycle;

  lev->l.task_end                 = CBS_task_end;

  lev->l.task_sleep               = CBS_task_sleep;

  lev->l.task_delay               = CBS_task_delay;

  lev->l.guest_create             = CBS_guest_create;

  lev->l.guest_detach             = CBS_guest_detach;

  lev->l.guest_dispatch           = CBS_guest_dispatch;

  lev->l.guest_epilogue           = CBS_guest_epilogue;

  lev->l.guest_activate           = CBS_guest_activate;

  lev->l.guest_insert             = CBS_guest_insert;

  lev->l.guest_extract            = CBS_guest_extract;

  lev->l.guest_endcycle           = CBS_guest_endcycle;

  lev->l.guest_end                = CBS_guest_end;

  lev->l.guest_sleep              = CBS_guest_sleep;

  lev->l.guest_delay              = CBS_guest_delay;

  /* fill the CBS descriptor part */

  for (i=0; i<MAX_PROC; i++) {

     NULL_TIMESPEC(&lev->cbs_dline[i]);

     lev->period[i] = 0;

     NULL_TIMESPEC(&lev->reactivation_time[i]);

     lev->reactivation_timer[i] = -1;

     lev->nact[i] = 0;

     lev->flag[i] = 0;

  }

  lev->U = 0;

  lev->scheduling_level = master;

  lev->flags = flags & 0x01;

}

bandwidth_t CBS_usedbandwidth(LEVEL l)

{

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

  if (lev->l.level_code    == CBS_LEVEL_CODE &&

      lev->l.level_version == CBS_LEVEL_VERSION)

    return lev->U;

  else

    return 0;

}

int CBS_get_nact(LEVEL l, PID p)

{

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