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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: rm.c,v 1.5 2003-05-05 07:31:44 pj Exp $
File: $File$
Revision: $Revision: 1.5 $
Last update: $Date: 2003-05-05 07:31:44 $
------------
This file contains the scheduling module RM (Rate Monotonic)
Read rm.h for further details.
This file is equal to EDF.c except for:
. EDF changed to RM :-)
. q_timespec_insert changed to q_insert
. proc_table[p].priority is also modified when we modify lev->period[p]
**/
/*
* Copyright (C) 2000,2002 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/rm.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>
/*+ Status used in the level +*/
#define RM_READY MODULE_STATUS_BASE /*+ - Ready status +*/
#define RM_WCET_VIOLATED MODULE_STATUS_BASE+2 /*+ when wcet is finished +*/
#define RM_WAIT MODULE_STATUS_BASE+3 /*+ to wait the deadline +*/
#define RM_IDLE MODULE_STATUS_BASE+4 /*+ to wait the deadline +*/
#define RM_ZOMBIE MODULE_STATUS_BASE+5 /*+ to wait the free time +*/
/*+ flags +*/
#define RM_FLAG_SPORADIC 1
#define RM_FLAG_NORAISEEXC 2
/*+ the level redefinition for the Rate Monotonic +*/
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 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 +*/
} RM_level_des;
static void RM_timer_deadline(void *par)
{
PID p = (PID) par;
RM_level_des *lev;
struct timespec *temp;
lev = (RM_level_des *)level_table[proc_table[p].task_level];
switch (proc_table[p].status) {
case RM_ZOMBIE:
/* 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;
break;
case RM_IDLE:
/* tracer stuff */
trc_logevent(TRC_INTACTIVATION,&p);
/* similar to RM_task_activate */
temp = iq_query_timespec(p, &lev->ready);
ADDUSEC2TIMESPEC(lev->period[p], temp);
proc_table[p].status = RM_READY;
iq_priority_insert(p,&lev->ready);
lev->deadline_timer[p] = kern_event_post(temp,
RM_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 RM_WAIT:
/* Without this, the task cannot be reactivated!!! */
proc_table[p].status = SLEEP;
break;
default:
/* else, a deadline miss occurred!!! */
kern_printf("timer_deadline:AAARRRGGGHHH!!!");
kern_raise(XDEADLINE_MISS,p);
}
}
static void RM_timer_guest_deadline(void *par)
{
PID p = (PID) par;
kern_printf("AAARRRGGGHHH!!!");
kern_raise(XDEADLINE_MISS,p);
}
/* The scheduler only gets the first task in the queue */
static PID RM_public_scheduler(LEVEL l)
{
RM_level_des *lev = (RM_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 RM_public_guarantee(LEVEL l, bandwidth_t *freebandwidth)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
if (*freebandwidth >= lev->U) {
*freebandwidth -= lev->U;
return 1;
}
else
return 0;
}
static int RM_public_create(LEVEL l, PID p, TASK_MODEL *m)
{
RM_level_des *lev = (RM_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) return -1;
/* update the bandwidth... */
if (lev->flags & RM_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
return -1;
}
/* now we know that m is a valid model */
*iq_query_priority(p, &lev->ready) = lev->period[p] = h->mit;
if (h->periodicity == APERIODIC)
lev->flag[p] = RM_FLAG_SPORADIC;
else
lev->flag[p] = 0;
lev->deadline_timer[p] = -1;
/* Enable wcet check */
if (lev->flags & RM_ENABLE_WCET_CHECK) {
proc_table[p].avail_time = h->wcet;
proc_table[p].wcet = h->wcet;
proc_table[p].control |= CONTROL_CAP;
}
return 0; /* OK, also if the task cannot be guaranteed... */
}
static void RM_public_detach(LEVEL l, PID p)
{
/* the RM level doesn't introduce any dinamic allocated new field.
we have only to reset the NO_GUARANTEE FIELD and decrement the allocated
bandwidth */
RM_level_des *lev = (RM_level_des *)(level_table[l]);
if (lev->flags & RM_ENABLE_GUARANTEE) {
lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet;
}
}
static void RM_public_dispatch(LEVEL l, PID p, int nostop)
{
RM_level_des *lev = (RM_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!!! */
iq_extract(p, &lev->ready);
}
static void RM_public_epilogue(LEVEL l, PID p)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
// kern_printf("(epil %d)",p);
/* check if the wcet is finished... */
if ((lev->flags & RM_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 = RM_WCET_VIOLATED;
}
else {
/* the task has been preempted. it returns into the ready queue... */
iq_priority_insert(p,&lev->ready);
proc_table[p].status = RM_READY;
}
}
static void RM_public_activate(LEVEL l, PID p)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
struct timespec *temp;
if (proc_table[p].status == RM_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 != RM_WCET_VIOLATED)
return;
/* see also RM_timer_deadline */
temp = iq_query_timespec(p, &lev->ready);
kern_gettime(temp);
ADDUSEC2TIMESPEC(lev->period[p], temp);
/* Insert task in the correct position */
proc_table[p].status = RM_READY;
iq_priority_insert(p,&lev->ready);
/* Set the deadline timer */
lev->deadline_timer[p] = kern_event_post(temp,
RM_timer_deadline,
(void *)p);
}
static void RM_public_unblock(LEVEL l, PID p)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
/* Similar to RM_task_activate,
but we don't check in what state the task is */
/* Insert task in the correct position */
proc_table[p].status = RM_READY;
iq_priority_insert(p,&lev->ready);
}
static void RM_public_block(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 int RM_public_message(LEVEL l, PID p, void *m)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
/* the task has terminated his job before it consume the wcet. All OK! */
if (lev->flag[p] & RM_FLAG_SPORADIC)
proc_table[p].status = RM_WAIT;
else /* pclass = sporadic_pclass */
proc_table[p].status = RM_IDLE;
/* we reset the capacity counters... */
if (lev->flags & RM_ENABLE_WCET_CHECK)
proc_table[p].avail_time = proc_table[p].wcet;
jet_update_endcycle(); /* Update the Jet data... */
trc_logevent(TRC_ENDCYCLE,&exec_shadow); /* tracer stuff */
/* when the deadline timer fire, it recognize the situation and set
correctly all the stuffs (like reactivation, sleep, etc... ) */
return 0;
}
static void RM_public_end(LEVEL l, PID p)
{
proc_table[p].status = RM_ZOMBIE;
/* When the deadline timer fire, it put the task descriptor in
the free queue, and free the allocated bandwidth... */
}
static void RM_private_insert(LEVEL l, PID p, TASK_MODEL *m)
{
RM_level_des *lev = (RM_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;
*iq_query_timespec(p,&lev->ready) = job->deadline;
*iq_query_priority(p, &lev->ready) = lev->period[p] = job->period;
lev->deadline_timer[p] = -1;
/* Insert task in the correct position */
iq_priority_insert(p,&lev->ready);
proc_table[p].status = RM_READY;
if (job->noraiseexc)
lev->flag[p] = RM_FLAG_NORAISEEXC;
else {
lev->flag[p] = 0;
lev->deadline_timer[p] = kern_event_post(iq_query_timespec(p, &lev->ready),
RM_timer_guest_deadline,
(void *)p);
}
}
static void RM_private_dispatch(LEVEL l, PID p, int nostop)
{
RM_level_des *lev = (RM_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 RM_private_epilogue(LEVEL l, PID p)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
/* the task has been preempted. it returns into the ready queue... */
iq_priority_insert(p,&lev->ready);
proc_table[p].status = RM_READY;
}
static void RM_private_extract(LEVEL l, PID p)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
//kern_printf("RM_guest_end: dline timer %d\n",lev->deadline_timer[p]);
if (proc_table[p].status == RM_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("RM_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 rm.h +*/
LEVEL RM_register_level(int flags)
{
LEVEL l; /* the level that we register */
RM_level_des *lev; /* for readableness only */
PID i; /* a counter */
printk("RM_register_level\n");
/* request an entry in the level_table */
l = level_alloc_descriptor(sizeof(RM_level_des));
lev = (RM_level_des *)level_table[l];
printk(" lev=%d\n",(int)lev);
/* fill the standard descriptor */
lev->l.private_insert = RM_private_insert;
lev->l.private_extract = RM_private_extract;
lev->l.private_dispatch = RM_private_dispatch;
lev->l.private_epilogue = RM_private_epilogue;
lev->l.public_scheduler = RM_public_scheduler;
if (flags & RM_ENABLE_GUARANTEE)
lev->l.public_guarantee = RM_public_guarantee;
else
lev->l.public_guarantee = NULL;
lev->l.public_create = RM_public_create;
lev->l.public_detach = RM_public_detach;
lev->l.public_end = RM_public_end;
lev->l.public_dispatch = RM_public_dispatch;
lev->l.public_epilogue = RM_public_epilogue;
lev->l.public_activate = RM_public_activate;
lev->l.public_unblock = RM_public_unblock;
lev->l.public_block = RM_public_block;
lev->l.public_message = RM_public_message;
/* fill the RM descriptor part */
for(i=0; i<MAX_PROC; i++) {
lev->period[i] = 0;
lev->deadline_timer[i] = -1;
lev->flag[i] = 0;
}
iq_init(&lev->ready, &freedesc, 0);
lev->flags = flags;
lev->U = 0;
return l;
}
bandwidth_t RM_usedbandwidth(LEVEL l)
{
RM_level_des *lev = (RM_level_des *)(level_table[l]);
return lev->U;
}