0,0 → 1,574 |
/* |
* 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> |
* Giacomo Guidi <giacomo@gandalf.sssup.it> |
* [Hard Reservation] |
* |
* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy) |
* |
* http://www.sssup.it |
* http://retis.sssup.it |
* http://shark.sssup.it |
*/ |
|
/* |
* 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/hardcbs.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 HCBS_IDLE APER_STATUS_BASE /*+ waiting the activation +*/ |
#define HCBS_ZOMBIE APER_STATUS_BASE+1 /*+ waiting the period end +*/ |
|
/*+ task flags +*/ |
#define HCBS_SAVE_ARRIVALS 1 |
#define HCBS_APERIODIC 2 |
#define HCBS_SLEEP 4 |
#define HCBS_OVERLOAD 8 |
|
/*+ 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; |
|
} HCBS_level_des; |
|
static void HCBS_activation(HCBS_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!) */ |
TIME t; |
struct timespec t2,t3; |
|
t = (lev->period[p] * proc_table[p].avail_time) / proc_table[p].wcet; |
t3.tv_sec = t / 1000000; |
t3.tv_nsec = (t % 1000000) * 1000; |
|
SUBTIMESPEC(&lev->cbs_dline[p], acttime, &t2); |
|
if (/* 1 */ TIMESPEC_A_LT_B(&lev->cbs_dline[p], acttime) || |
/* 2 */ TIMESPEC_A_GT_B(&t3, &t2) ) { |
|
/* 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; |
|
} |
|
/* 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 HCBS_avail_time_check(HCBS_level_des *lev, PID p) |
{ |
|
if (proc_table[p].avail_time < 0) { |
ADDUSEC2TIMESPEC(lev->period[p], &lev->cbs_dline[p]); |
proc_table[p].avail_time += proc_table[p].wcet; |
} |
|
} |
|
|
/* this is the periodic reactivation of the task... it is posted only |
if the task is a periodic task */ |
static void HCBS_timer_reactivate(void *par) |
{ |
PID p = (PID) par; |
HCBS_level_des *lev; |
|
lev = (HCBS_level_des *)level_table[proc_table[p].task_level]; |
|
if (lev->flag[p] & HCBS_SLEEP && proc_table[p].status == HCBS_IDLE) { |
proc_table[p].status = SLEEP; |
return; |
} |
|
if (proc_table[p].status == HCBS_IDLE) { |
/* the task has finished the current activation and must be |
reactivated */ |
HCBS_activation(lev,p,&lev->reactivation_time[p]); |
|
event_need_reschedule(); |
|
} |
else if (lev->flag[p] & HCBS_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... |
For bandwidth hard reservation, an aperiodic |
task is forced to generate a reactivate event */ |
if (!(lev->flag[p] & HCBS_APERIODIC)) { |
ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]); |
lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p], |
HCBS_timer_reactivate, |
(void *)p); |
} |
|
/* tracer stuff */ |
trc_logevent(TRC_INTACTIVATION,&p); |
|
} |
|
/*+ this function is called when a killed or ended task reach the |
period end +*/ |
static void HCBS_timer_zombie(void *par) |
{ |
PID p = (PID) par; |
|
/* we finally put the task in the free queue */ |
proc_table[p].status = FREE; |
iq_insertfirst(p,&freedesc); |
|
} |
|
/* The on-line guarantee is enabled only if the appropriate flag is set... */ |
static int HCBS_public_guarantee(LEVEL l, bandwidth_t *freebandwidth) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
if (*freebandwidth >= lev->U) { |
*freebandwidth -= lev->U; |
return 1; |
} |
else |
return 0; |
} |
|
static int HCBS_public_create(LEVEL l, PID p, TASK_MODEL *m) |
{ |
HCBS_level_des *lev = (HCBS_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 & HCBS_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] = HCBS_APERIODIC; |
else |
lev->flag[p] = 0; |
|
if (soft->arrivals == SAVE_ARRIVALS) |
lev->flag[p] |= HCBS_SAVE_ARRIVALS; |
|
return 0; /* OK, also if the task cannot be guaranteed... */ |
} |
|
static void HCBS_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 */ |
|
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
if (lev->flags & HCBS_ENABLE_GUARANTEE) { |
lev->U -= (MAX_BANDWIDTH / lev->period[p]) * proc_table[p].wcet; |
} |
} |
|
static int HCBS_public_eligible(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_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 HCBS_public_dispatch(LEVEL l, PID p, int nostop) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
level_table[ lev->scheduling_level ]-> |
private_dispatch(lev->scheduling_level,p,nostop); |
} |
|
static void HCBS_public_epilogue(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
/* check if the wcet is finished... */ |
if ( proc_table[p].avail_time <= 0) { |
|
lev->flag[p] |= HCBS_OVERLOAD; |
|
/* we kill the current activation */ |
level_table[ lev->scheduling_level ]-> |
private_extract(lev->scheduling_level, p); |
|
/* Hard Reservation: The avail_time will be reloaded in the |
next reactivation event. The task is suspended */ |
proc_table[p].status = HCBS_IDLE; |
if (lev->flag[p] & HCBS_APERIODIC) { |
|
ADDUSEC2TIMESPEC(lev->period[p], &lev->reactivation_time[p]); |
lev->reactivation_timer[p] = kern_event_post(&lev->reactivation_time[p], |
HCBS_timer_reactivate, |
(void *)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 HCBS_public_activate(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
struct timespec t; |
|
if (lev->flag[p] & HCBS_SLEEP) { |
/* disable HCBS_SLEEP flag */ |
lev->flag[p] &= ~HCBS_SLEEP; |
if (proc_table[p].status != SLEEP) return; |
} |
|
/* save activation (only if needed... */ |
if (proc_table[p].status != SLEEP) { |
if (lev->flag[p] & HCBS_SAVE_ARRIVALS) |
lev->nact[p]++; |
return; |
} |
|
kern_gettime(&t); |
|
HCBS_activation(lev, p, &t); |
|
/* Set the reactivation timer */ |
if (!(lev->flag[p] & HCBS_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], |
HCBS_timer_reactivate, |
(void *)p); |
} |
} |
|
static void HCBS_public_unblock(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
struct timespec acttime; |
|
kern_gettime(&acttime); |
|
HCBS_activation(lev,p,&acttime); |
} |
|
static void HCBS_public_block(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
/* check if the wcet is finished... */ |
HCBS_avail_time_check(lev, p); |
|
level_table[ lev->scheduling_level ]-> |
private_extract(lev->scheduling_level,p); |
} |
|
static int HCBS_public_message(LEVEL l, PID p, void *m) |
{ |
|
HCBS_command_message *msg; |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
switch((long)(m)) { |
|
/* task_endcycle */ |
case (long)(NULL): |
|
if (!(lev->flag[p] & HCBS_APERIODIC) && lev->flag[p] & HCBS_OVERLOAD) { |
lev->flag[p] &= ~HCBS_OVERLOAD; |
lev->nact[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] & HCBS_APERIODIC) |
proc_table[p].status = SLEEP; |
else /* the task is soft_periodic */ |
proc_table[p].status = HCBS_IDLE; |
} |
|
jet_update_endcycle(); /* Update the Jet data... */ |
trc_logevent(TRC_ENDCYCLE,&exec_shadow); /* tracer stuff */ |
|
break; |
|
/* task_disable */ |
case (1): |
|
lev->flag[p] |= HCBS_SLEEP; |
|
break; |
|
/* Set/Get Met/Period */ |
default: |
|
msg = (HCBS_command_message *)(m); |
|
switch (msg->command) { |
case HCBS_SET_PERIOD: |
lev->U -= (bandwidth_t)(MAX_BANDWIDTH / lev->period[p] |
* proc_table[p].wcet); |
lev->period[p] = msg->param; |
lev->U += (bandwidth_t)(MAX_BANDWIDTH / lev->period[p] |
* proc_table[p].wcet); |
break; |
case HCBS_GET_PERIOD: |
msg->param = lev->period[p]; |
break; |
case HCBS_SET_MET: |
lev->U -= (bandwidth_t)(MAX_BANDWIDTH / lev->period[p] |
* proc_table[p].wcet); |
proc_table[p].wcet = msg->param; |
lev->U += (bandwidth_t)(MAX_BANDWIDTH / lev->period[p] |
* proc_table[p].wcet); |
break; |
case HCBS_GET_MET: |
msg->param = proc_table[p].wcet; |
break; |
} |
|
break; |
|
} |
|
return 0; |
|
} |
|
static void HCBS_public_end(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
/* check if the wcet is finished... */ |
HCBS_avail_time_check(lev, p); |
|
level_table[ lev->scheduling_level ]-> |
private_extract(lev->scheduling_level,p); |
|
/* free the allocated bandwidth */ |
lev->U -= (MAX_BANDWIDTH/lev->period[p]) * proc_table[p].wcet; |
|
/* we delete the reactivation timer */ |
if (!(lev->flag[p] & HCBS_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 = HCBS_ZOMBIE; |
lev->reactivation_timer[p] = kern_event_post(&lev->cbs_dline[p], |
HCBS_timer_zombie, |
(void *)p); |
} |
|
/* Registration functions */ |
|
/*+ Registration function: |
int flags the init flags ... see CBS.h +*/ |
LEVEL HCBS_register_level(int flags, LEVEL master) |
{ |
LEVEL l; /* the level that we register */ |
HCBS_level_des *lev; /* for readableness only */ |
PID i; /* a counter */ |
|
printk("HCBS_register_level\n"); |
|
/* request an entry in the level_table */ |
l = level_alloc_descriptor(sizeof(HCBS_level_des)); |
|
lev = (HCBS_level_des *)level_table[l]; |
|
printk(" lev=%d\n",(int)lev); |
|
/* fill the standard descriptor */ |
if (flags & HCBS_ENABLE_GUARANTEE) |
lev->l.public_guarantee = HCBS_public_guarantee; |
else |
lev->l.public_guarantee = NULL; |
lev->l.public_create = HCBS_public_create; |
lev->l.public_detach = HCBS_public_detach; |
lev->l.public_end = HCBS_public_end; |
lev->l.public_eligible = HCBS_public_eligible; |
lev->l.public_dispatch = HCBS_public_dispatch; |
lev->l.public_epilogue = HCBS_public_epilogue; |
lev->l.public_activate = HCBS_public_activate; |
lev->l.public_unblock = HCBS_public_unblock; |
lev->l.public_block = HCBS_public_block; |
lev->l.public_message = HCBS_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 HCBS_usedbandwidth(LEVEL l) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
return lev->U; |
} |
|
int HCBS_get_nact(LEVEL l, PID p) |
{ |
HCBS_level_des *lev = (HCBS_level_des *)(level_table[l]); |
|
return lev->nact[p]; |
} |
|