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/*

 * 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: edf2.c,v 1.1.1.1 2002-03-29 14:12:52 pj Exp $

 File:        $File$

 Revision:    $Revision: 1.1.1.1 $

 Last update: $Date: 2002-03-29 14:12:52 $

 ------------

 This file contains the scheduling module EDF (Earliest Deadline First)

 Read edf.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/edf.h>

/*+ Status used in the level +*/

#define EDF_READY         MODULE_STATUS_BASE    /*+ - Ready status        +*/

#define EDF_DELAY         MODULE_STATUS_BASE+1  /*+ - Delay status        +*/

#define EDF_WCET_VIOLATED MODULE_STATUS_BASE+2  /*+ when wcet is finished +*/

#define EDF_WAIT          MODULE_STATUS_BASE+3  /*+ to wait the deadline  +*/

#define EDF_IDLE          MODULE_STATUS_BASE+4  /*+ to wait the deadline  +*/

#define EDF_ZOMBIE        MODULE_STATUS_BASE+5  /*+ to wait the free time +*/

/*+ the level redefinition for the Earliest Deadline First level +*/

typedef struct {

  level_des l;     /*+ the standard level descriptor          +*/

  TIME period[MAX_PROC]; /*+ The task periods; the deadlines are

                       stored in the priority field           +*/

  int deadline_timer[MAX_PROC];

                   /*+ The task deadline timers               +*/

  int noraiseexc[MAX_PROC];

                   /*+ used to manage the JOB_TASK_MODEL      +*/

  QUEUE ready;     /*+ the ready queue                        +*/

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

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

} EDF_level_des;

static char *EDF_status_to_a(WORD status)

{

  if (status < MODULE_STATUS_BASE)

    return status_to_a(status);

  switch (status) {

    case EDF_READY        : return "EDF_Ready";

    case EDF_DELAY        : return "EDF_Delay";

    case EDF_WCET_VIOLATED: return "EDF_Wcet_Violated";

    case EDF_WAIT         : return "EDF_Sporadic_Wait";

    case EDF_IDLE         : return "EDF_Idle";

    case EDF_ZOMBIE       : return "EDF_Zombie";

    default               : return "EDF_Unknown";

  }

}

static void EDF_timer_deadline(void *par)

{

  PID p = (PID) par;

  EDF_level_des *lev;

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

  switch (proc_table[p].status) {

    case EDF_ZOMBIE:

      /* 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;

      break;

    case EDF_IDLE:

      /* similar to EDF_task_activate */

      TIMESPEC_ASSIGN(&proc_table[p].request_time,

                      &proc_table[p].timespec_priority);

      ADDUSEC2TIMESPEC(lev->period[p], &proc_table[p].timespec_priority);

      proc_table[p].status = EDF_READY;

      q_timespec_insert(p,&lev->ready);

      lev->deadline_timer[p] = kern_event_post(&proc_table[p].timespec_priority,

                                               EDF_timer_deadline,

                                               (void *)p);

      //printk("(d%d idle priority set to %d)",p,proc_table[p].priority );

      event_need_reschedule();

      printk("el%d|",p);

      break;

    case EDF_WAIT:

      /* Without this, the task cannot be reactivated!!! */

      proc_table[p].status = SLEEP;

      break;

    default:

      /* else, a deadline miss occurred!!! */

      kern_raise(XDEADLINE_MISS,p);

      kern_printf("avail_time %d\n\n",proc_table[p].avail_time);

  }

}

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

static void EDF_timer_delay(void *par)

{

  PID p = (PID) par;

  EDF_level_des *lev;

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

  proc_table[p].status = EDF_READY;

  q_timespec_insert(p,&lev->ready);

  proc_table[p].delay_timer = NIL;  /* Paranoia */

  event_need_reschedule();

}

static int EDF_level_accept_task_model(LEVEL l, TASK_MODEL *m)

{

  if (m->pclass == PERIODIC_PCLASS || m->pclass == (PERIODIC_PCLASS | l) ||

      m->pclass == SPORADIC_PCLASS || m->pclass == (SPORADIC_PCLASS | l))

    return 0;

  else

    return -1;

}

static int EDF_level_accept_guest_model(LEVEL l, TASK_MODEL *m)

{

  if (m->pclass == JOB_PCLASS || m->pclass == (JOB_PCLASS | l) )

    return 0;

  else

    return -1;

}

static char *onoff(int i)

{

  if (i)

    return "On ";

  else

    return "Off";

}

static void EDF_level_status(LEVEL l)

{

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

  PID p = lev->ready;

  kern_printf("Wcet     Check    : %s\n",

            onoff(lev->flags & EDF_ENABLE_WCET_CHECK));

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

            onoff(lev->flags & EDF_ENABLE_GUARANTEE));

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

            lev->U, MAX_BANDWIDTH);

  while (p != NIL) {

    if ((proc_table[p].pclass & 0xFF00) == JOB_PCLASS)

      kern_printf("Pid: %2d (GUEST)\n", p);

    else

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

              p,

              proc_table[p].name,

              (proc_table[p].pclass == PERIODIC_PCLASS) ? "Period  " : "MinITime",

              lev->period[p],

              proc_table[p].timespec_priority.tv_sec,

              proc_table[p].timespec_priority.tv_nsec/1000,

              EDF_status_to_a(proc_table[p].status));

    p = proc_table[p].next;

  }

  for (p=0; p<MAX_PROC; p++)

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

        && proc_table[p].status != FREE )

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

                p,

                proc_table[p].name,

                (proc_table[p].pclass == PERIODIC_PCLASS) ? "Period  " : "MinITime",

                lev->period[p],

                proc_table[p].timespec_priority.tv_sec,

                proc_table[p].timespec_priority.tv_nsec/1000,

                EDF_status_to_a(proc_table[p].status));

}

/* The scheduler only gets the first task in the queue */

static PID EDF_level_scheduler(LEVEL l)

{

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

/*  {  // print 4 dbg the ready queue

    PID p= lev->ready;

    kern_printf("(s");

    while (p != NIL) {

      kern_printf("%d ",p);

      p = proc_table[p].next;

    }

    kern_printf(") ");

  }

  */

  return (PID)lev->ready;

}

/* The on-line guarantee is enabled only if the appropriate flag is set... */

static int EDF_level_guarantee(LEVEL l, bandwidth_t *freebandwidth)

{

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

  if (lev->flags & EDF_FAILED_GUARANTEE) {

    *freebandwidth = 0;

    return 0;

  }

  else

    if (*freebandwidth >= lev->U) {

      *freebandwidth -= lev->U;

      return 1;

    }

    else

      return 0;

}

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

{

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

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

     valid pclass.

     Warning!! PERIODIC_PCLASS and SPORADIC_PCLASS have the same fields

     so the code is the same...

     ... In fact, if the sporadic model will change in the future,

     we have to check this code!!!... */

  /* PERIODIC_TASK_MODEL handling; SPORADIC_TASK_MODEL works with the same

     code... */

  PERIODIC_TASK_MODEL *per = (PERIODIC_TASK_MODEL *)m;

  lev->period[p] = per->period;

  lev->noraiseexc[p] = 0;

  lev->deadline_timer[p] = -1;

  /* Enable wcet check */

  if (lev->flags & EDF_ENABLE_WCET_CHECK) {

    proc_table[p].avail_time = per->wcet;

    proc_table[p].wcet       = per->wcet;

    proc_table[p].control |= CONTROL_CAP;

  }

  /* update the bandwidth... */

  if (lev->flags & EDF_ENABLE_GUARANTEE) {

    bandwidth_t b;

    b = (MAX_BANDWIDTH / per->period) * per->wcet;

    /* 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)...

         in this case, we don't raise an exception... in fact, after the

         EDF_task_create the task_create will call level_guarantee that return

         -1... return -1 in EDF_task_create isn't correct, because:

           . generally, the guarantee must be done when also the resources

             are registered

           . returning -1 will cause the task_create to return with an errno

             ETASK_CREATE instead of ENO_GUARANTEE!!!

         Why I use the flag??? because if the lev->U overflows, if i.e. I set

         it to MAX_BANDWIDTH, I lose the correct allocated bandwidth...

      */

      lev->flags |= EDF_FAILED_GUARANTEE;

  }

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

}

static void EDF_task_detach(LEVEL l, PID p)

{

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

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

     bandwidth */

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

  if (lev->flags & EDF_FAILED_GUARANTEE)

    lev->flags &= ~EDF_FAILED_GUARANTEE;

  else

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

}

static int EDF_task_eligible(LEVEL l, PID p)

{

  return 0; /* if the task p is chosen, it is always eligible */

}

#ifdef __TEST1__

extern int testactive;

extern struct timespec s_stime[];

extern TIME s_curr[];

extern TIME s_PID[];

extern int useds;

#endif

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

{

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

//  kern_printf("(disp %d)",p);

  /* the task state is set EXE by the scheduler()

     we extract the task from the ready queue

     NB: we can't assume that p is the first task in the queue!!! */

  q_extract(p, &lev->ready);

  #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 EDF_task_epilogue(LEVEL l, PID p)

{

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

//  kern_printf("(epil %d)",p);

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

  if ((lev->flags & EDF_ENABLE_WCET_CHECK) && proc_table[p].avail_time <= 0) {

    /* if it is, raise a XWCET_VIOLATION exception */

    kern_raise(XWCET_VIOLATION,p);

    proc_table[p].status = EDF_WCET_VIOLATED;

  }

  else {

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

    q_timespec_insert(p,&lev->ready);

    proc_table[p].status = EDF_READY;

  }

}

static void EDF_task_activate(LEVEL l, PID p)

{

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

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

    kern_raise(XACTIVATION,p);

    return;

  }

  /* Test if we are trying to activate a non sleeping task    */

  /* Ignore this; the task is already active                  */

  if (proc_table[p].status != SLEEP &&

      proc_table[p].status != EDF_WCET_VIOLATED)

    return;

  /* see also EDF_timer_deadline */

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

  TIMESPEC_ASSIGN(&proc_table[p].timespec_priority,

                  &proc_table[p].request_time);

  ADDUSEC2TIMESPEC(lev->period[p], &proc_table[p].timespec_priority);

  /* Insert task in the correct position */

  proc_table[p].status = EDF_READY;

  q_timespec_insert(p,&lev->ready);

  /* Set the deadline timer */

  lev->deadline_timer[p] = kern_event_post(&proc_table[p].timespec_priority,

                                           EDF_timer_deadline,

                                           (void *)p);

}

static void EDF_task_insert(LEVEL l, PID p)

{

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

  /* Similar to EDF_task_activate, but we don't check in what state

     the task is and we don't set the request_time*/

  /* Insert task in the coEDFect position */

  proc_table[p].status = EDF_READY;

  q_timespec_insert(p,&lev->ready);

}

static void EDF_task_extract(LEVEL l, PID p)

{

  /* Extract the running task from the level

     . we have already extract it from the ready queue at the dispatch time.

     . the capacity event have to be removed by the generic kernel

     . the wcet don't need modification...

     . the state of the task is set by the calling function

     . the deadline must remain...

     So, we do nothing!!!

  */

}

static void EDF_task_endcycle(LEVEL l, PID p)

{

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

  /* the task has terminated his job before it consume the wcet. All OK! */

  if (proc_table[p].pclass = PERIODIC_PCLASS)

    proc_table[p].status = EDF_IDLE;

  else /* pclass = sporadic_pclass */

    proc_table[p].status = EDF_WAIT;

  /* we reset the capacity counters... */

  if (lev->flags & EDF_ENABLE_WCET_CHECK)

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

  /* when the deadline timer fire, it recognize the situation and set

     correctly all the stuffs (like reactivation, request_time, etc... ) */

}

static void EDF_task_end(LEVEL l, PID p)

{

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

  if (proc_table[p].status == EDF_READY)

    q_extract(p, &lev->ready);

  else if (proc_table[p].status == EDF_DELAY) {

    event_delete(proc_table[p].delay_timer);

    proc_table[p].delay_timer = NIL;    /* paranoia */

  }

  proc_table[p].status = EDF_ZOMBIE;

  /* When the deadline timer fire, it put the task descriptor in

     the free queue, and free the allocated bandwidth... */

}

static void EDF_task_sleep(LEVEL l, PID p)

{

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

  /* the task has terminated his job before it consume the wcet. All OK! */

  proc_table[p].status = EDF_WAIT;

  /* we reset the capacity counters... */

  if (lev->flags & EDF_ENABLE_WCET_CHECK)

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

  /* when the deadline timer fire, it recognize the situation and set

     correctly the task state to sleep... */

}

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

{

  struct timespec wakeuptime;

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

  /* equal to EDF_task_endcycle */

  proc_table[p].status = EDF_DELAY;

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

  ll_gettime(TIME_EXACT, &wakeuptime);

  ADDUSEC2TIMESPEC(usdelay, &wakeuptime);

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

                                              EDF_timer_delay,

                                              (void *)p);

}

/* Guest Functions

   These functions manages a JOB_TASK_MODEL, that is used to put

   a guest task in the EDF ready queue. */

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

{

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

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

     valid pclass. */

  JOB_TASK_MODEL *job = (JOB_TASK_MODEL *)m;

  proc_table[p].guest_pclass = m->pclass;

  TIMESPEC_ASSIGN(&proc_table[p].timespec_priority, &job->deadline);

  lev->deadline_timer[p] = -1;

  lev->noraiseexc[p] = job->noraiseexc;

  /* there is no bandwidth guarantee at this level, it is performed

     by the level that inserts guest tasks... */

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

}

static void EDF_guest_detach(LEVEL l, PID p)

{

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

     No guarantee is performed on guest tasks... so we don't have to reset

     the NO_GUARANTEE FIELD */

}

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

{

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

  /* the task state is set to EXE by the scheduler()

     we extract the task from the ready queue

     NB: we can't assume that p is the first task in the queue!!! */

  q_extract(p, &lev->ready);

}

static void EDF_guest_epilogue(LEVEL l, PID p)

{

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

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

  q_timespec_insert(p,&lev->ready);

  proc_table[p].status = EDF_READY;

}

static void EDF_guest_activate(LEVEL l, PID p)

{

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

  /* Insert task in the correct position */

  q_timespec_insert(p,&lev->ready);

  proc_table[p].status = EDF_READY;

  /* Set the deadline timer */

  if (!lev->noraiseexc[p])

    lev->deadline_timer[p] = kern_event_post(&proc_table[p].timespec_priority,

                                             EDF_timer_deadline,

                                             (void *)p);

}

static void EDF_guest_insert(LEVEL l, PID p)

{

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

  /* Insert task in the correct position */

  q_timespec_insert(p,&lev->ready);

  proc_table[p].status = EDF_READY;

}

static void EDF_guest_extract(LEVEL l, PID p)

{

  /* Extract the running task from the level

     . we have already extract it from the ready queue at the dispatch time.

     . the state of the task is set by the calling function

     . the deadline must remain...

     So, we do nothing!!!

  */

}

static void EDF_guest_endcycle(LEVEL l, PID p)

{ kern_raise(XUNVALID_GUEST,exec_shadow); }

static void EDF_guest_end(LEVEL l, PID p)

{

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

  //kern_printf("EDF_guest_end: dline timer %d\n",lev->deadline_timer[p]);

  if (proc_table[p].status == EDF_READY)

    q_extract(p, &lev->ready);

  else if (proc_table[p].status == EDF_DELAY) {

    event_delete(proc_table[p].delay_timer);

    proc_table[p].delay_timer = NIL;    /* paranoia */

  }

  /* we remove the deadline timer, because the slice is finished */

  if (lev->deadline_timer[p] != NIL) {

    event_delete(lev->deadline_timer[p]);

    lev->deadline_timer[p] = NIL;

  }

}

static void EDF_guest_sleep(LEVEL l, PID p)

{ kern_raise(XUNVALID_GUEST,exec_shadow); }

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

{

  struct timespec wakeuptime;

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

  /* equal to EDF_task_endcycle */

  proc_table[p].status = EDF_DELAY;

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

  ll_gettime(TIME_EXACT, &wakeuptime);

  ADDUSEC2TIMESPEC(usdelay, &wakeuptime);

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

                                              EDF_timer_delay,

                                              (void *)p);

}

/* Registration functions */

/*+ Registration function:

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

void EDF_register_level(int flags)

{

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

  EDF_level_des *lev;  /* for readableness only */

  PID i;              /* a counter */

  printk("EDF_register_level\n");

  /* request an entry in the level_table */

  l = level_alloc_descriptor();

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

  /* alloc the space needed for the EDF_level_des */

  lev = (EDF_level_des *)kern_alloc(sizeof(EDF_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,  EDF_LEVELNAME, MAX_LEVELNAME);

  lev->l.level_code               = EDF_LEVEL_CODE;

  lev->l.level_version            = EDF_LEVEL_VERSION;

  lev->l.level_accept_task_model  = EDF_level_accept_task_model;

  lev->l.level_accept_guest_model = EDF_level_accept_guest_model;

  lev->l.level_status             = EDF_level_status;

  lev->l.level_scheduler          = EDF_level_scheduler;

  if (flags & EDF_ENABLE_GUARANTEE)

    lev->l.level_guarantee        = EDF_level_guarantee;

  else

    lev->l.level_guarantee        = NULL;

  lev->l.task_create              = EDF_task_create;

  lev->l.task_detach              = EDF_task_detach;

  lev->l.task_eligible            = EDF_task_eligible;

  lev->l.task_dispatch            = EDF_task_dispatch;

  lev->l.task_epilogue            = EDF_task_epilogue;

  lev->l.task_activate            = EDF_task_activate;

  lev->l.task_insert              = EDF_task_insert;

  lev->l.task_extract             = EDF_task_extract;

  lev->l.task_endcycle            = EDF_task_endcycle;

  lev->l.task_end                 = EDF_task_end;

  lev->l.task_sleep               = EDF_task_sleep;

  lev->l.task_delay               = EDF_task_delay;

  lev->l.guest_create             = EDF_guest_create;

  lev->l.guest_detach             = EDF_guest_detach;

  lev->l.guest_dispatch           = EDF_guest_dispatch;

  lev->l.guest_epilogue           = EDF_guest_epilogue;

  lev->l.guest_activate           = EDF_guest_activate;

  lev->l.guest_insert             = EDF_guest_insert;

  lev->l.guest_extract            = EDF_guest_extract;

  lev->l.guest_endcycle           = EDF_guest_endcycle;

  lev->l.guest_end                = EDF_guest_end;

  lev->l.guest_sleep              = EDF_guest_sleep;

  lev->l.guest_delay              = EDF_guest_delay;

  /* fill the EDF descriptor part */

  for(i=0; i<MAX_PROC; i++) {

    lev->period[i]         = 0;

    lev->deadline_timer[i] = -1;

  }

  lev->ready = NIL;

  lev->flags = flags & 0x07;

  lev->U     = 0;

}

bandwidth_t EDF_usedbandwidth(LEVEL l)

{

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

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

      lev->l.level_version == EDF_LEVEL_VERSION)

    return lev->U;

  else

    return 0;

}