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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: tbs.c,v 1.6 2004-01-08 20:10:42 giacomo Exp $

 File:        $File$

 Revision:    $Revision: 1.6 $

 Last update: $Date: 2004-01-08 20:10:42 $

 ------------

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

 Read tbs.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/tbs.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 <tracer.h>

/*+ 4 debug purposes +*/

#undef TBS_TEST

/*+ Status used in the level +*/

#define TBS_WCET_VIOLATED APER_STATUS_BASE+2  /*+ when wcet is finished +*/

#define TBS_WAIT          APER_STATUS_BASE    /*+ waiting the service   +*/

/*+ task flags +*/

#define TBS_SAVE_ARRIVALS 1

/*+ 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's priority

     field.                     */

  int nact[MAX_PROC];    /*+ used to record activations +*/

  BYTE flag[MAX_PROC];

  struct timespec lastdline; /*+ the last deadline assigned to

                                 a TBS task                   +*/

  IQUEUE wait;      /*+ the wait queue of the TBS              +*/

  PID activated;   /*+ the task inserted in another queue     +*/

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

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

  int band_num;

  int band_den;

  LEVEL scheduling_level;

} TBS_level_des;

#ifdef TESTG

#include "drivers/glib.h"

#endif

/* This static function activates the task pointed by lev->activated) */

static __inline__ void TBS_activation(TBS_level_des *lev)

{

    PID p;             /* for readableness    */

    JOB_TASK_MODEL j;  /* the guest model     */

    TIME drel;         /* the relative deadline of the task */

    LEVEL m;           /* the master level... only for readableness */

#ifdef TESTG

    TIME x;

    extern TIME starttime;

#endif

    p = lev->activated;

    /* we compute a suitable deadline for the task */

    drel = (proc_table[p].wcet * lev->band_den) / lev->band_num;

    ADDUSEC2TIMESPEC(drel, &lev->lastdline);

#ifdef TESTG

    if (starttime) {

    x = ((lev->lastdline.tv_sec*1000000+lev->lastdline.tv_nsec/1000)/5000 - starttime) + 20;

    if (x<640)

      grx_plot(x, 15, 7);

    }

#endif

    /* and we insert the task in another level */

    m = lev->scheduling_level;

    job_task_default_model(j,lev->lastdline);

    level_table[m]->private_insert(m,p,(TASK_MODEL *)&j);

    #ifdef TBS_TEST

    kern_printf("TBS_activation: lastdline %ds %dns\n",lev->lastdline.tv_sec,lev->lastdline.tv_nsec);

    #endif

}

/* This static function reclaims the unused time of the task p */

static __inline__ void TBS_bandwidth_reclaiming(TBS_level_des *lev, PID p)

{

    TIME reclaimed;

    struct timespec r, sos;

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

    reclaimed = (proc_table[p].avail_time * lev->band_den) / lev->band_num;

    r.tv_nsec = (reclaimed % 1000000) * 1000;

    r.tv_sec  = reclaimed / 1000000;

    SUBTIMESPEC(&lev->lastdline, &r, &sos);

    TIMESPEC_ASSIGN(&lev->lastdline, &sos);

    #ifdef TBS_TEST

    kern_printf("TBS_bandwidth_reclaiming: lastdline %ds %dns, reclaimed %d, avail %d\n",

              lev->lastdline.tv_sec, lev->lastdline.tv_nsec, reclaimed, proc_table[p].avail_time);

    #endif

}

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

static int TBS_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)

{

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

  if (*freebandwidth >= lev->U) {

    *freebandwidth -= lev->U;

    return 1;

  }

  else

    return 0;

}

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

{

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

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

     valid pclass. */

  SOFT_TASK_MODEL *s;

  if (m->pclass != SOFT_PCLASS) return -1;

  if (m->level != 0 && m->level != l) return -1;

  s = (SOFT_TASK_MODEL *)m;

  if (!(s->wcet && s->periodicity == APERIODIC)) return -1;

  proc_table[p].wcet       = s->wcet;

  /* Enable wcet check */

  if (lev->flags & TBS_ENABLE_WCET_CHECK) {

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

    proc_table[p].control   |= CONTROL_CAP;

  }

  lev->nact[p] = 0;

  if (s->arrivals == SAVE_ARRIVALS)

    lev->flag[p] = TBS_SAVE_ARRIVALS;

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

}

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

{

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

  /* there is at least one task ready inserted in an EDF or similar

     level */

  level_table[ lev->scheduling_level ]->

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

}

static void TBS_public_epilogue(LEVEL l, PID p)

{

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

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

  if ((lev->flags & TBS_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 = TBS_WCET_VIOLATED;

    /* the current task have to die in the scheduling queue, and another

       have to be put in place... this code is identical to the

       TBS_task_end */

    level_table[ lev->scheduling_level ]->

      private_extract(lev->scheduling_level,p);

    /* we reclaim an avail time that can be <0 due to the timer

       approximations -> we have to postpone the deadline a little!

       we can use the ADDUSEC2TIMESPEC because the time postponed is

       less than 55ms */

    ADDUSEC2TIMESPEC((-proc_table[p].avail_time * lev->band_den)

                     / lev->band_num, &lev->lastdline);

    #ifdef TBS_TEST

    kern_printf("TBS_task_epilogue: Deadline posponed to %ds %dns\n",

              lev->lastdline.tv_sec, lev->lastdline.tv_nsec);

    #endif

    lev->activated = iq_getfirst(&lev->wait);

    if (lev->activated != NIL)

      TBS_activation(lev);

  }

  else

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

       calling the guest_epilogue... */

    level_table[ lev->scheduling_level ]->

      private_epilogue(lev->scheduling_level,p);

}

static void TBS_public_activate(LEVEL l, PID p)

{

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

  struct timespec t;

  if (proc_table[p].status == SLEEP ||

       proc_table[p].status == TBS_WCET_VIOLATED) {

    kern_gettime(&t);

    if (TIMESPEC_A_GT_B(&t, &lev->lastdline))

      TIMESPEC_ASSIGN(&lev->lastdline, &t );

    if (lev->activated == NIL) {

      /* This is the first task in the level, so we activate it immediately */

      lev->activated = p;

      TBS_activation(lev);

    }

    else {

      proc_table[p].status = TBS_WAIT;

      iq_insertlast(p, &lev->wait);

    }

  }

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

    lev->nact[p]++;

/*  else

    kern_printf("TBSREJ!!!");*/

}

static void TBS_public_unblock(LEVEL l, PID p)

{

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

  JOB_TASK_MODEL j;

  job_task_default_model(j,lev->lastdline);

  level_table[lev->scheduling_level]->

    private_insert(lev->scheduling_level,p,(TASK_MODEL *)&j);

}

static void TBS_public_block(LEVEL l, PID p)

{

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

  level_table[ lev->scheduling_level ]->

    private_extract(lev->scheduling_level,p);

}

static int TBS_public_message(LEVEL l, PID p, void *m)

{

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

  /* 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 ]->

    private_extract(lev->scheduling_level,p);

  TBS_bandwidth_reclaiming(lev,p);

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

  if (lev->flags & TBS_ENABLE_WCET_CHECK)

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

  if (lev->nact[p]) {

    // lev->nact[p] can be >0 only if the SAVE_ARRIVALS bit is set

    lev->nact[p]--;

    proc_table[p].status = TBS_WAIT;

    iq_insertlast(p, &lev->wait);

  }

  else

    proc_table[p].status = SLEEP;

  lev->activated = iq_getfirst(&lev->wait);

  if (lev->activated != NIL)

    TBS_activation(lev);

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

  TRACER_LOGEVENT(FTrace_EVT_task_end_cycle,3,proc_table[p].context,l);

  return 0;

}

static void TBS_public_end(LEVEL l, PID p)

{

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

  level_table[ lev->scheduling_level ]->

    private_extract(lev->scheduling_level,p);

  TBS_bandwidth_reclaiming(lev,p);

  proc_table[p].status = FREE;

  iq_insertfirst(p,&freedesc);

  lev->activated = iq_getfirst(&lev->wait);

  if (lev->activated != NIL)

    TBS_activation(lev);

}

/* Registration functions */

/*+ Registration function:

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

void TBS_register_level(int flags, LEVEL master, int num, int den)

{

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

  TBS_level_des *lev;  /* for readableness only */

  PID i;              /* a counter */

  printk("TBS_register_level\n");

  /* request an entry in the level_table */

  l = level_alloc_descriptor(sizeof(TBS_level_des));

  lev = (TBS_level_des *)level_table[l];

  /* fill the standard descriptor */

  if (flags & TBS_ENABLE_GUARANTEE)

    lev->l.public_guarantee = TBS_public_guarantee;

  else

    lev->l.public_guarantee = NULL;

  lev->l.public_guarantee = TBS_public_guarantee;

  lev->l.public_create    = TBS_public_create;

  lev->l.public_end       = TBS_public_end;

  lev->l.public_dispatch  = TBS_public_dispatch;

  lev->l.public_epilogue  = TBS_public_epilogue;

  lev->l.public_activate  = TBS_public_activate;

  lev->l.public_unblock   = TBS_public_unblock;

  lev->l.public_block     = TBS_public_block;

  lev->l.public_message   = TBS_public_message;

  /* fill the TBS descriptor part */

  for (i = 0; i < MAX_PROC; i++) {

    lev->nact[i] = 0;

    lev->flag[i] = 0;

  }

  NULL_TIMESPEC(&lev->lastdline);

  iq_init(&lev->wait, &freedesc, 0);

  lev->activated = NIL;

  lev->U = (MAX_BANDWIDTH / den) * num;

  lev->band_num = num;

  lev->band_den = den;

  lev->scheduling_level = master;

  lev->flags = flags & 0x07;

}

bandwidth_t TBS_usedbandwidth(LEVEL l)

{

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

  return lev->U;

}

int TBS_get_nact(LEVEL l, PID p)

{

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

  return lev->nact[p];

}