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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: cbs.c,v 1.1 2005-02-25 10:53:02 pj Exp $
File: $File$
Revision: $Revision: 1.1 $
Last update: $Date: 2005-02-25 10:53:02 $
------------
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 <cbs/cbs/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 <tracer.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 +*/
/*+ task flags +*/
#define CBS_SAVE_ARRIVALS 1
#define CBS_APERIODIC 2
#define CBS_SLEEP 4
/*+ 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!) */
/* CHANGES by Anton Cervin 2004-06-23:
a) only check: if ( acttime + (avail_time * period) / wcet > cbs_dline )
b) without (long long) in the computation we can have an overflow!! */
TIME t;
struct timespec t2;
t = ((long long)lev->period[p] * (long long)proc_table[p].avail_time)
/ (long long)proc_table[p].wcet;
t2 = *acttime;
ADDUSEC2TIMESPEC(t, &t2);
if (TIMESPEC_A_GT_B(&t2, &lev->cbs_dline[p])) {
/* 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) kern_raise(XUNSPECIFIED_EXCEPTION, exec_shadow);
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 ]->
private_insert(lev->scheduling_level, p, (TASK_MODEL *)&job);
}
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) kern_raise(XUNSPECIFIED_EXCEPTION, exec_shadow);
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 (lev->flag[p] & CBS_SLEEP && proc_table[p].status == CBS_IDLE) {
proc_table[p].status = SLEEP;
proc_table[p].avail_time = proc_table[p].wcet;
NULL_TIMESPEC(&lev->cbs_dline[p]);
return;
}
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 */
TRACER_LOGEVENT(FTrace_EVT_task_timer,(unsigned short int)proc_table[p].context,(unsigned int)proc_table[p].task_level);
}
/*+ 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;
iq_insertfirst(p,&freedesc);
/* and free the allocated bandwidth */
lev->U -= (MAX_BANDWIDTH/lev->period[p]) * proc_table[p].wcet;
}
/* The on-line guarantee is enabled only if the appropriate flag is set... */
static int CBS_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
if (*freebandwidth >= lev->U) {
*freebandwidth -= lev->U;
return 1;
}
else
return 0;
}
static int CBS_public_create(LEVEL l, PID p, TASK_MODEL *m)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
SOFT_TASK_MODEL *soft;
if (m->pclass != SOFT_PCLASS) return -1;
if (m->level != 0 && m->level != l) return -1;
soft = (SOFT_TASK_MODEL *)m;
if (!(soft->met && soft->period)) return -1;
soft = (SOFT_TASK_MODEL *)m;
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
return -1;
}
/* 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;
return 0; /* OK, also if the task cannot be guaranteed... */
}
static void CBS_public_detach(LEVEL l, PID p)
{
/* the CBS level doesn't introduce any dinamic allocated new field.
we have only to decrement the allocated bandwidth */
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
if (lev->flags & CBS_ENABLE_GUARANTEE) {
lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet;
}
}
static int CBS_public_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 ]->
private_extract(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 ]->
private_insert(lev->scheduling_level, p, (TASK_MODEL *)&job);
return -1;
}
return 0;
}
static void CBS_public_dispatch(LEVEL l, PID p, int nostop)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
level_table[ lev->scheduling_level ]->
private_dispatch(lev->scheduling_level,p,nostop);
}
static void CBS_public_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 ]->
private_extract(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 ]->
private_insert(lev->scheduling_level, p, (TASK_MODEL *)&job);
// 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 ]->
private_epilogue(lev->scheduling_level,p);
}
static void CBS_public_activate(LEVEL l, PID p, struct timespec *t)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
if (lev->flag[p] & CBS_SLEEP) {
lev->flag[p] &= ~CBS_SLEEP;
if (proc_table[p].status != SLEEP) return;
}
/* save activation (only if needed... */
if (proc_table[p].status != SLEEP) {
if (lev->flag[p] & CBS_SAVE_ARRIVALS)
lev->nact[p]++;
return;
}
CBS_activation(lev, p, t);
/* 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], t);
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_public_unblock(LEVEL l, PID p)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
struct timespec acttime;
kern_gettime(&acttime);
CBS_activation(lev,p,&acttime);
}
static void CBS_public_block(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 ]->
private_extract(lev->scheduling_level,p);
}
static int CBS_public_message(LEVEL l, PID p, void *m)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
switch((long)(m)) {
case (long)(NULL):
/* check if the wcet is finished... */
CBS_avail_time_check(lev, p);
if (lev->nact[p]) {
/* continue!!!! */
lev->nact[p]--;
level_table[ lev->scheduling_level ]->
private_epilogue(lev->scheduling_level,p);
} else {
level_table[ lev->scheduling_level ]->
private_extract(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;
}
jet_update_endcycle(); /* Update the Jet data... */
TRACER_LOGEVENT(FTrace_EVT_task_end_cycle,(unsigned short int)proc_table[p].context,(unsigned int)l);
break;
case 1:
lev->flag[p] |= CBS_SLEEP;
TRACER_LOGEVENT(FTrace_EVT_task_disable,(unsigned short int)proc_table[p].context,(unsigned int)l);
break;
}
return 0;
}
static void CBS_public_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 ]->
private_extract(lev->scheduling_level,p);
/* we delete the reactivation timer */
if (!(lev->flag[p] & CBS_APERIODIC)) {
kern_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);
}
/* Registration functions */
/*+ Registration function:
int flags the init flags ... see CBS.h +*/
LEVEL 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(sizeof(CBS_level_des));
lev = (CBS_level_des *)level_table[l];
/* fill the standard descriptor */
if (flags & CBS_ENABLE_GUARANTEE)
lev->l.public_guarantee = CBS_public_guarantee;
else
lev->l.public_guarantee = NULL;
lev->l.public_create = CBS_public_create;
lev->l.public_detach = CBS_public_detach;
lev->l.public_end = CBS_public_end;
lev->l.public_eligible = CBS_public_eligible;
lev->l.public_dispatch = CBS_public_dispatch;
lev->l.public_epilogue = CBS_public_epilogue;
lev->l.public_activate = CBS_public_activate;
lev->l.public_unblock = CBS_public_unblock;
lev->l.public_block = CBS_public_block;
lev->l.public_message = CBS_public_message;
/* 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;
return l;
}
bandwidth_t CBS_usedbandwidth(LEVEL l)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
return lev->U;
}
int CBS_get_nact(LEVEL l, PID p)
{
CBS_level_des *lev = (CBS_level_des *)(level_table[l]);
return lev->nact[p];
}