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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];
}