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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>
 *   (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: edfact.c,v 1.4 2003-01-07 17:10:15 pj Exp $

 File:        $File$
 Revision:    $Revision: 1.4 $
 Last update: $Date: 2003-01-07 17:10:15 $
 ------------
**/


/*
 * Copyright (C) 2001 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 "edfact.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>

//#define edfact_printf kern_printf
#define edfact_printf printk

/*+ Status used in the level +*/
#define EDFACT_READY         MODULE_STATUS_BASE    /*+ - Ready status        +*/
#define EDFACT_IDLE          MODULE_STATUS_BASE+4  /*+ to wait the deadline  +*/

/*+ flags +*/
#define EDFACT_FLAG_NORAISEEXC  2

/*+ 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               +*/

  struct timespec deadline_timespec[MAX_PROC];

  int dline_miss[MAX_PROC]; /*+ Deadline miss counter +*/
  int wcet_miss[MAX_PROC];  /*+ Wcet miss counter +*/

  int nact[MAX_PROC];       /*+ Wcet miss counter +*/

  int flag[MAX_PROC];
                   /*+ used to manage the JOB_TASK_MODEL and the
                       periodicity                            +*/


  IQUEUE ready;     /*+ the ready queue                        +*/

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

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

} EDFACT_level_des;


static void EDFACT_timer_deadline(void *par);

static void EDFACT_internal_activate(EDFACT_level_des *lev, PID p,
                                     struct timespec *t)
{
  struct timespec *temp;

  temp = iq_query_timespec(p, &lev->ready);

  TIMESPEC_ASSIGN(temp,t);
  ADDUSEC2TIMESPEC(lev->period[p], temp);

  TIMESPEC_ASSIGN(&lev->deadline_timespec[p],
                  temp);

  /* Insert task in the correct position */
  proc_table[p].status = EDFACT_READY;
  iq_timespec_insert(p,&lev->ready);

  /* needed because when there is a wcet miss I disable CONTROL_CAP */
  proc_table[p].control |= CONTROL_CAP;
}

static void EDFACT_timer_deadline(void *par)
{
  PID p = (PID) par;
  EDFACT_level_des *lev;

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

  switch (proc_table[p].status) {
    case EDFACT_IDLE:
      edfact_printf("I%d",p);

      EDFACT_internal_activate(lev,p, &lev->deadline_timespec[p]);

      event_need_reschedule();
      break;

    default:
      edfact_printf("D%d",p);
      /* else, a deadline miss occurred!!! */
      lev->dline_miss[p]++;

      /* the task is into another state */
      lev->nact[p]++;

      /* Set the deadline timer */
      ADDUSEC2TIMESPEC(lev->period[p], &lev->deadline_timespec[p]);
  }

  /* Set the deadline timer */
  lev->deadline_timer[p] = kern_event_post(&lev->deadline_timespec[p],
                                           EDFACT_timer_deadline,
                                           (void *)p);

}

static void EDFACT_timer_guest_deadline(void *par)
{
  PID p = (PID) par;

  edfact_printf("AAARRRGGGHHH!!!");
  kern_raise(XDEADLINE_MISS,p);
}


/* The scheduler only gets the first task in the queue */
static PID EDFACT_public_scheduler(LEVEL l)
{
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  return iq_query_first(&lev->ready);
}

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

  if (lev->flags & EDFACT_FAILED_GUARANTEE) {
    *freebandwidth = 0;
    return 0;
  }
  else
    if (*freebandwidth >= lev->U) {
      *freebandwidth -= lev->U;
      return 1;
    }
    else
      return 0;

}

static int EDFACT_public_create(LEVEL l, PID p, TASK_MODEL *m)
{
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  HARD_TASK_MODEL *h;

  if (m->pclass != HARD_PCLASS) return -1;
  if (m->level != 0 && m->level != l) return -1;
  h = (HARD_TASK_MODEL *)m;
  if (!h->wcet || !h->mit || h->periodicity != PERIODIC) return -1;
  /* now we know that m is a valid model */

  lev->period[p] = h->mit;

  lev->flag[p] = 0;
  lev->deadline_timer[p] = -1;
  lev->dline_miss[p]     = 0;
  lev->wcet_miss[p]      = 0;
  lev->nact[p]           = 0;

  /* Enable wcet check */
  proc_table[p].avail_time = h->wcet;
  proc_table[p].wcet       = h->wcet;
  proc_table[p].control |= CONTROL_CAP;

  /* update the bandwidth... */
  if (lev->flags & EDFACT_ENABLE_GUARANTEE) {
    bandwidth_t b;
    b = (MAX_BANDWIDTH / h->mit) * h->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
         EDFACT_task_create the task_create will call level_guarantee that return
         -1... return -1 in EDFACT_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 |= EDFACT_FAILED_GUARANTEE;
  }

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

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


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

  if (lev->flags & EDFACT_FAILED_GUARANTEE)
    lev->flags &= ~EDFACT_FAILED_GUARANTEE;
  else
    lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet;
}

static void EDFACT_public_dispatch(LEVEL l, PID p, int nostop)
{
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  /* 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!!! */

  iq_extract(p, &lev->ready);
}

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

  /* check if the wcet is finished... */
  if (proc_table[p].avail_time <= 0 && proc_table[p].control&CONTROL_CAP) {
    /* wcet finished: disable wcet event and count wcet miss */
    edfact_printf("W%d",p);
    proc_table[p].control &= ~CONTROL_CAP;
    lev->wcet_miss[p]++;
  }

  /* the task it returns into the ready queue... */
  iq_timespec_insert(p,&lev->ready);
  proc_table[p].status = EDFACT_READY;
}

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

  /* Test if we are trying to activate a non sleeping task    */
  /* save activation (only if needed... */
  if (proc_table[p].status != SLEEP) {
    /* a periodic task cannot be activated when it is already active */
    kern_raise(XACTIVATION,p);
    return;
  }

  kern_gettime(&t);
  EDFACT_internal_activate(lev,p, &t);

  /* Set the deadline timer */
  lev->deadline_timer[p] = kern_event_post(&lev->deadline_timespec[p],
                                           EDFACT_timer_deadline,
                                           (void *)p);

}

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

  /* Insert task in the coEDFect position */
  proc_table[p].status = EDFACT_READY;
  iq_timespec_insert(p,&lev->ready);
}

static void EDFACT_public_block(LEVEL l, PID p)
{
}

static int EDFACT_public_message(LEVEL l, PID p, void *m)
{
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);
  struct timespec t;

  /* we reset the capacity counters... */
  proc_table[p].avail_time = proc_table[p].wcet;

  if (lev->nact[p] > 0) {
    edfact_printf("E%d",p);

    /* Pending activation: reactivate the thread!!! */
    lev->nact[p]--;

    /* see also EDFACT_timer_deadline */
    kern_gettime(&t);
    EDFACT_internal_activate(lev,p, &t);

    /* check if the deadline has already expired */
    if (TIMESPEC_A_LT_B(iq_query_timespec(p, &lev->ready), &schedule_time)) {
      /* count the deadline miss */
      lev->dline_miss[p]++;
      kern_event_delete(lev->deadline_timer[p]);
    }

  }
  else {
    edfact_printf("e%d",p);

    /* the task has terminated his job before it consume the wcet. All OK! */
    proc_table[p].status = EDFACT_IDLE;

    /* when the deadline timer fire, it recognize the situation and set
       correctly all the stuffs (like reactivation, etc... ) */

  }

  jet_update_endcycle(); /* Update the Jet data... */
  trc_logevent(TRC_ENDCYCLE,&exec_shadow); /* tracer stuff */

  return 0;
}

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

  edfact_printf("Û%d",p);

  /* we finally put the task in the ready queue */
  proc_table[p].status = FREE;
  iq_insertfirst(p,&freedesc);
  /* and free the allocated bandwidth */
  lev->U -= (MAX_BANDWIDTH/lev->period[p]) * proc_table[p].wcet;

  if (lev->deadline_timer[p] != -1) {
    edfact_printf("²%d",p);
    kern_event_delete(lev->deadline_timer[p]);
  }
}


/* Guest Functions
   These functions manages a JOB_TASK_MODEL, that is used to put
   a guest task in the EDFACT ready queue. */


static void EDFACT_private_insert(LEVEL l, PID p, TASK_MODEL *m)
{
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  JOB_TASK_MODEL *job;

  if (m->pclass != JOB_PCLASS || (m->level != 0 && m->level != l) ) {
    kern_raise(XINVALID_TASK, p);
    return;
  }

  job = (JOB_TASK_MODEL *)m;

  TIMESPEC_ASSIGN(iq_query_timespec(p, &lev->ready), &job->deadline);
 
  lev->deadline_timer[p] = -1;
  lev->dline_miss[p]     = 0;
  lev->wcet_miss[p]      = 0;
  lev->nact[p]           = 0;

  if (job->noraiseexc)
    lev->flag[p] = EDFACT_FLAG_NORAISEEXC;
  else {
    lev->flag[p] = 0;
    lev->deadline_timer[p] = kern_event_post(iq_query_timespec(p, &lev->ready),
                                             EDFACT_timer_guest_deadline,
                                             (void *)p);
  }

  lev->period[p] = job->period;

  /* Insert task in the correct position */
  iq_timespec_insert(p,&lev->ready);
  proc_table[p].status = EDFACT_READY;

  /* there is no bandwidth guarantee at this level, it is performed
     by the level that inserts guest tasks... */

}

static void EDFACT_private_dispatch(LEVEL l, PID p, int nostop)
{
  EDFACT_level_des *lev = (EDFACT_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!!! */

  iq_extract(p, &lev->ready);
}

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

  /* the task has been preempted. it returns into the ready queue... */
  iq_timespec_insert(p,&lev->ready);
  proc_table[p].status = EDFACT_READY;
}

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

  //kern_printf("EDFACT_guest_end: dline timer %d\n",lev->deadline_timer[p]);
  if (proc_table[p].status == EDFACT_READY)
  {
    iq_extract(p, &lev->ready);
    //kern_printf("(g_end rdy extr)");
  }

  /* we remove the deadline timer, because the slice is finished */
  if (lev->deadline_timer[p] != NIL) {
//    kern_printf("EDFACT_guest_end: dline timer %d\n",lev->deadline_timer[p]);
    kern_event_delete(lev->deadline_timer[p]);
    lev->deadline_timer[p] = NIL;
  }

}

/* Registration functions */

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

LEVEL EDFACT_register_level(int flags)
{
  LEVEL l;            /* the level that we register */
  EDFACT_level_des *lev;  /* for readableness only */
  PID i;              /* a counter */

  printk("EDFACT_register_level\n");

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

  lev = (EDFACT_level_des *)level_table[l];

  printk("    lev=%d\n",(int)lev);

  /* fill the standard descriptor */
  lev->l.private_insert   = EDFACT_private_insert;
  lev->l.private_extract  = EDFACT_private_extract;
  lev->l.private_dispatch = EDFACT_private_dispatch;
  lev->l.private_epilogue = EDFACT_private_epilogue;

  lev->l.public_scheduler = EDFACT_public_scheduler;
  if (flags & EDFACT_ENABLE_GUARANTEE)
    lev->l.public_guarantee = EDFACT_public_guarantee;
  else
    lev->l.public_guarantee = NULL;
  lev->l.public_create    = EDFACT_public_create;
  lev->l.public_detach    = EDFACT_public_detach;
  lev->l.public_end       = EDFACT_public_end;
  lev->l.public_dispatch  = EDFACT_public_dispatch;
  lev->l.public_epilogue  = EDFACT_public_epilogue;
  lev->l.public_activate  = EDFACT_public_activate;
  lev->l.public_unblock   = EDFACT_public_unblock;
  lev->l.public_block     = EDFACT_public_block;
  lev->l.public_message   = EDFACT_public_message;

  /* fill the EDFACT descriptor part */
  for(i=0; i<MAX_PROC; i++) {
    lev->period[i]         = 0;
    lev->deadline_timer[i] = -1;
    lev->flag[i]           = 0;
    lev->dline_miss[i]     = 0;
    lev->wcet_miss[i]      = 0;
    lev->nact[i]           = 0;
  }

  iq_init(&lev->ready,&freedesc, 0);
  lev->flags = flags & 0x07;
  lev->U     = 0;

  return l;
}

bandwidth_t EDFACT_usedbandwidth(LEVEL l)
{
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);
 
  return lev->U;
}

int EDFACT_get_dline_miss(PID p)
{
  LEVEL l = proc_table[p].task_level;
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  return lev->dline_miss[p];
}

int EDFACT_get_wcet_miss(PID p)
{
  LEVEL l = proc_table[p].task_level;
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  return lev->wcet_miss[p];
}

int EDFACT_get_nact(PID p)
{
  LEVEL l = proc_table[p].task_level;
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);
 
  return lev->nact[p];
}

int EDFACT_reset_dline_miss(PID p)
{
  LEVEL l = proc_table[p].task_level;
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  lev->dline_miss[p] = 0;
  return 0;
}

int EDFACT_reset_wcet_miss(PID p)
{
  LEVEL l = proc_table[p].task_level;
  EDFACT_level_des *lev = (EDFACT_level_des *)(level_table[l]);

  lev->wcet_miss[p] = 0;
  return 0;
}