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221 giacomo 1
/*
2
 * Project: S.Ha.R.K.
3
 *
4
 * Coordinators:
5
 *   Giorgio Buttazzo    <giorgio@sssup.it>
6
 *   Paolo Gai           <pj@gandalf.sssup.it>
7
 *
8
 * Authors     :
9
 *   Trimarchi Michael   <trimarchi@gandalf.sssup.it>
10
 *   (see the web pages for full authors list)
11
 *
12
 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
13
 *
14
 * http://www.sssup.it
15
 * http://retis.sssup.it
16
 * http://shark.sssup.it
17
 */
18
 
19
/*
20
 * Copyright (C) 2000 Paolo Gai
21
 *
22
 * This program is free software; you can redistribute it and/or modify
23
 * it under the terms of the GNU General Public License as published by
24
 * the Free Software Foundation; either version 2 of the License, or
25
 * (at your option) any later version.
26
 *
27
 * This program is distributed in the hope that it will be useful,
28
 * but WITHOUT ANY WARR2ANTY; without even the implied waRR2anty of
29
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
30
 * GNU General Public License for more details.
31
 *
32
 * You should have received a copy of the GNU General Public License
33
 * along with this program; if not, write to the Free Software
34
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
35
 *
36
 */
37
 
38
 
39
#include <ll/stdio.h>
40
#include <ll/string.h>
41
#include <kernel/model.h>
42
#include <kernel/descr.h>
43
#include <kernel/var.h>
44
#include <kernel/func.h>
45
#include "posixstar.h"
808 trimarchi 46
#include "fsf_contract.h"
241 giacomo 47
#include "fsf_server.h"
221 giacomo 48
 
822 trimarchi 49
//#define POSIXSTAR_DEBUG
221 giacomo 50
 
51
/*+ Status used in the level +*/
52
#define POSIXSTAR_READY   MODULE_STATUS_BASE
53
 
54
#define POSIXSTAR_CHANGE_LEVEL 1
55
 
815 trimarchi 56
/* flags */
57
#define POSIXSTAR_FLAG_NOPREEMPT   4
58
 
221 giacomo 59
/*+ the level redefinition for the Round Robin level +*/
60
typedef struct {
61
  level_des l;          /*+ the standard level descriptor          +*/
62
 
63
  int nact[MAX_PROC];   /*+ number of pending activations          +*/
64
 
65
  int priority[MAX_PROC]; /*+ priority of each task                +*/
66
 
67
  IQUEUE *ready;        /*+ the ready queue array                  +*/
68
 
69
  int slice;            /*+ the level's time slice                 +*/
70
 
71
  int maxpriority;      /*+ the priority are from 0 to maxpriority
72
                            (i.e 0 to 31)                          +*/
73
 
74
  int yielding;         /*+ equal to 1 when a sched_yield is called +*/
75
 
76
  int budget[MAX_PROC];
77
 
815 trimarchi 78
  int flag[MAX_PROC];
79
 
221 giacomo 80
  PID activated;
81
  int scheduling_level;
296 trimarchi 82
  int cap_lev;
83
  struct timespec cap_lasttime;
221 giacomo 84
 
85
} POSIXSTAR_level_des;
86
 
296 trimarchi 87
static void capacity_handler(void *l)
88
{
89
  POSIXSTAR_level_des *lev = l;
90
  lev->cap_lev = NIL;
91
  event_need_reschedule();
92
}
221 giacomo 93
/* the private scheduler choice a task and insert in cbsstar module */
94
/* This is not efficient but very fair :-)
95
   The need of all this stuff is because if a task execute a long time
96
   due to (shadow!) priority inheritance, then the task shall go to the
97
   tail of the queue many times... */
98
 
99
static void POSIXSTAR_private_scheduler(POSIXSTAR_level_des * lev)
100
{
101
  /* the old posix scheduler select the private job for CBS */
102
  PID p = NIL;
103
 
104
  int prio;
105
 
815 trimarchi 106
 
221 giacomo 107
  prio = lev->maxpriority;
108
 
109
  for (;;) {
110
    p = iq_query_first(&lev->ready[prio]);
111
    if (p == NIL) {
112
      if (prio) {
113
        prio--;
114
        continue;
115
      }
116
      else {
117
        p=NIL;
118
	break;
119
      }
120
    }
121
 
393 giacomo 122
    if (proc_table[p].avail_time <= 0) {
298 giacomo 123
      while (proc_table[p].avail_time<=0)
221 giacomo 124
  	proc_table[p].avail_time += proc_table[p].wcet;
125
      iq_extract(p,&lev->ready[prio]);
126
      iq_insertlast(p,&lev->ready[prio]);
127
    }
128
    else {
129
      break;
130
    }
131
  }
828 trimarchi 132
 
133
  /* check if the task is preempteble or not */
835 trimarchi 134
  if (lev->activated != NIL && (lev->flag[lev->activated] & POSIXSTAR_FLAG_NOPREEMPT)) return;
828 trimarchi 135
 
221 giacomo 136
  if (p!=lev->activated) {
137
    if (lev->activated != NIL )  {
138
     level_table[ lev->scheduling_level ]->
139
       private_extract(lev->scheduling_level, lev->activated);
140
   }
141
   lev->activated = p;
142
 
143
   if (p != NIL) {
144
     BUDGET_TASK_MODEL b;
145
     budget_task_default_model(b, lev->budget[p]);
146
     #ifdef POSIXSTAR_DEBUG
147
       kern_printf("(PS:SchAct:%d:%d)",p,lev->budget[p]);
148
     #endif
149
     level_table[ lev->scheduling_level ]->
150
       private_insert(lev->scheduling_level, p, (TASK_MODEL *)&b);
151
   }
152
 }
153
}
154
 
155
static int POSIXSTAR_public_eligible(LEVEL l, PID p)
156
{
157
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
296 trimarchi 158
  return level_table[ lev->scheduling_level ]->
221 giacomo 159
      private_eligible(lev->scheduling_level,p);
296 trimarchi 160
 
221 giacomo 161
  return 0;
162
}
163
 
296 trimarchi 164
 
165
static void POSIXSTAR_account_capacity(POSIXSTAR_level_des *lev, PID p)
166
{
393 giacomo 167
  struct timespec ty;
168
  TIME tx;
296 trimarchi 169
 
393 giacomo 170
  SUBTIMESPEC(&schedule_time, &lev->cap_lasttime, &ty);
171
  tx = TIMESPEC2USEC(&ty);
296 trimarchi 172
 
393 giacomo 173
  proc_table[p].avail_time -= tx;
296 trimarchi 174
 
175
}
176
 
221 giacomo 177
static int POSIXSTAR_public_create(LEVEL l, PID p, TASK_MODEL *m)
178
{
179
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
180
  NRT_TASK_MODEL *nrt;
181
 
182
  /* DEBUG */
183
  #ifdef POSIXSTAR_DEBUG
184
    kern_printf("(PS:Crt:%d)",p);
185
  #endif
186
 
187
  if (m->pclass != NRT_PCLASS) return -1;
188
  if (m->level != 0 && m->level != l) return -1;
189
 
190
  nrt = (NRT_TASK_MODEL *)m;
191
 
192
  /* the task state is set at SLEEP by the general task_create */
193
 
194
  /* I used the wcet field because using wcet can account if a task
195
     consume more than the timeslice... */
196
 
197
  if (nrt->inherit == NRT_INHERIT_SCHED &&
198
      proc_table[exec_shadow].task_level == l) {
199
    /* We inherit the scheduling properties if the scheduling level
200
       *is* the same */
201
    lev->priority[p] = lev->priority[exec_shadow];
202
 
203
    proc_table[p].avail_time = proc_table[exec_shadow].avail_time;
204
    proc_table[p].wcet       = proc_table[exec_shadow].wcet;
205
 
206
    lev->nact[p] = (lev->nact[exec_shadow] == -1) ? -1 : 0;
207
  }
208
  else {
209
    if (nrt->weight<=lev->maxpriority)
210
      lev->priority[p] = nrt->weight;
211
    else lev->priority[p]=lev->maxpriority;
212
 
213
    if (nrt->slice) {
214
      proc_table[p].avail_time = nrt->slice;
215
      proc_table[p].wcet       = nrt->slice;
216
    }
217
    else {
218
      proc_table[p].avail_time = lev->slice;
219
      proc_table[p].wcet       = lev->slice;
220
    }
815 trimarchi 221
 
392 trimarchi 222
    #if defined POSIXSTAR_DEBUG
223
        kern_printf("(slice %d)", proc_table[p].wcet);
224
    #endif
221 giacomo 225
    if (nrt->arrivals == SAVE_ARRIVALS)
226
      lev->nact[p] = 0;
227
    else
228
      lev->nact[p] = -1;
229
 
230
  }
231
 
834 trimarchi 232
  lev->flag[p] = 0;
393 giacomo 233
  proc_table[p].control = (proc_table[p].control & ~CONTROL_CAP);
234
 
235
  return 0;
236
 
221 giacomo 237
}
238
 
239
static void POSIXSTAR_public_dispatch(LEVEL l, PID p, int nostop)
240
{
241
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
296 trimarchi 242
  struct timespec ty;
221 giacomo 243
  /* the task state is set EXE by the scheduler()
244
     we extract the task from the ready queue
245
     NB: we can't assume that p is the first task in the queue!!! */
246
 
247
  #ifdef POSIXSTAR_DEBUG
296 trimarchi 248
     if( !nostop) kern_printf("(PS:Dsp:%d)",p); else
249
	 kern_printf("(PS:Dsp_shad:%d)",p);
221 giacomo 250
  #endif
383 trimarchi 251
 
384 trimarchi 252
  if (!nostop || proc_table[exec].task_level==l) {
253
    TIMESPEC_ASSIGN(&ty, &schedule_time);
254
    TIMESPEC_ASSIGN(&lev->cap_lasttime, &schedule_time);
383 trimarchi 255
 
256
  /* ...and finally, we have to post a capacity event on exec task because the shadow_task consume
257
   *        capacity on exe task always */
392 trimarchi 258
    ADDUSEC2TIMESPEC(proc_table[exec].avail_time, &ty);
384 trimarchi 259
 
260
    lev->cap_lev = kern_event_post(&ty,capacity_handler, lev);
221 giacomo 261
    level_table[lev->scheduling_level]->private_dispatch(lev->scheduling_level, p, nostop);
296 trimarchi 262
  }
263
  else
384 trimarchi 264
    level_table[proc_table[exec].task_level]->public_dispatch(proc_table[exec].task_level, p, nostop);
265
 
221 giacomo 266
}
267
 
226 giacomo 268
static void POSIXSTAR_public_epilogue(LEVEL l, PID p)
269
{
270
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
402 giacomo 271
 
226 giacomo 272
  #ifdef POSIXSTAR_DEBUG
273
    kern_printf("(PS:Epi:%d)",p);
274
  #endif
275
 
296 trimarchi 276
 if (lev->cap_lev!=NIL) {
393 giacomo 277
   kern_event_delete(lev->cap_lev);
278
   lev->cap_lev=NIL;
296 trimarchi 279
 }
280
 
393 giacomo 281
 if (proc_table[exec].task_level==l ) {
282
 
828 trimarchi 283
   POSIXSTAR_account_capacity(lev,exec);
221 giacomo 284
 
393 giacomo 285
   if (lev->yielding) {
286
     lev->yielding = 0;
287
     iq_extract(p,&lev->ready[lev->priority[exec]]);
288
     iq_insertlast(p,&lev->ready[lev->priority[exec]]);
402 giacomo 289
   } else {
290
 
291
     if (proc_table[exec].avail_time <= 0) {
292
 
293
       POSIXSTAR_private_scheduler(lev);
294
 
836 trimarchi 295
       if (exec==lev->activated) {
402 giacomo 296
         level_table[lev->scheduling_level]->private_epilogue(lev->scheduling_level,p);
297
       }
298
 
299
     } else  {
300
 
301
       level_table[lev->scheduling_level]->private_epilogue(lev->scheduling_level,p);
302
 
303
     }
304
 
393 giacomo 305
   }
306
 
402 giacomo 307
   proc_table[exec].status = POSIXSTAR_READY;
221 giacomo 308
 
402 giacomo 309
 } else {
310
 
311
   level_table[proc_table[exec].task_level]->public_epilogue(proc_table[exec].task_level,p);
312
 
313
 }
314
 
221 giacomo 315
}
316
 
317
static void POSIXSTAR_internal_activate(POSIXSTAR_level_des *lev, PID p)
318
{
319
 
320
  /* Insert task in the correct position */
321
  proc_table[p].status = POSIXSTAR_READY;
322
  iq_insertlast(p,&lev->ready[lev->priority[p]]);
323
 
324
}
325
 
326
 
783 giacomo 327
static void POSIXSTAR_public_activate(LEVEL l, PID p, struct timespec *t)
221 giacomo 328
{
329
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
330
 
331
  /* Test if we are trying to activate a non sleeping task    */
332
  /* save activation (only if needed...) */
333
  if (proc_table[p].status != SLEEP) {
334
    if (lev->nact[p] != -1)
335
      lev->nact[p]++;
336
    return;
337
  }
338
 
339
  #ifdef POSIXSTAR_DEBUG
340
    kern_printf("(PS:Act:%d)",p);
341
  #endif
342
 
343
  POSIXSTAR_internal_activate(lev, p);
344
  POSIXSTAR_private_scheduler(lev);
345
 
346
}
347
 
348
 
349
static void POSIXSTAR_public_unblock(LEVEL l, PID p)
350
{
351
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
352
 
353
  /* Similar to POSIX_task_activate, but we don't check in what state
354
     the task is */
355
 
356
  #ifdef POSIXSTAR_DEBUG
357
    kern_printf("(PS:UnBlk:%d)",p);
358
  #endif
359
  /* Insert task in the coPOSIXect position */
360
  proc_table[p].status = POSIXSTAR_READY;
361
  iq_insertlast(p,&lev->ready[lev->priority[p]]);
362
  POSIXSTAR_private_scheduler(lev);
363
 
364
}
365
 
366
static void POSIXSTAR_public_block(LEVEL l, PID p)
367
{
368
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
369
 
370
  /* Extract the running task from the level
371
     . we have already extract it from the ready queue at the dispatch time.
372
     . the capacity event have to be removed by the generic kernel
373
     . the wcet don't need modification...
374
     . the state of the task is set by the calling function
375
 
376
     So, we do nothing!!!
377
  */
378
 
379
  #ifdef POSIXSTAR_DEBUG
380
    kern_printf("(PS:Blk:%d)", p);
381
  #endif
382
 
383
  iq_extract(p,&lev->ready[lev->priority[p]]);
384
  POSIXSTAR_private_scheduler(lev);
385
 
386
}
387
 
388
static int POSIXSTAR_public_message(LEVEL l, PID p, void *m)
389
{
390
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
391
 
392
  #ifdef POSIXSTAR_DEBUG
393
    kern_printf("(PS:Msg:%d)",p);
394
  #endif
395
 
396
  switch ((long)(m)) {
397
 
398
    /* Task EndCycle */
399
    case (long)(NULL):
400
 
401
      if (lev->nact[p] > 0) {
402
        /* continue!!!! */
403
        lev->nact[p]--;
404
        iq_extract(p,&lev->ready[lev->priority[p]]);
405
        iq_insertfirst(p,&lev->ready[lev->priority[p]]);
406
        proc_table[p].status = POSIXSTAR_READY;
407
      }
408
      else {
409
        proc_table[p].status = SLEEP;
410
        iq_extract(p,&lev->ready[lev->priority[p]]);
411
      }
412
 
413
      jet_update_endcycle(); /* Update the Jet data... */
414
      POSIXSTAR_private_scheduler(lev);
415
 
416
      break;
417
 
418
    /* Task Disable */
419
    case (long)(1):
420
 
421
      break;
422
 
423
    default:
424
 
241 giacomo 425
      break;
221 giacomo 426
 
427
  }
428
 
429
  return 0;
430
 
431
}
432
 
433
static void POSIXSTAR_public_end(LEVEL l, PID p)
434
{
435
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
436
 
437
  #ifdef POSIXSTAR_DEBUG
438
    kern_printf("(PS:End:%d)", p);
439
  #endif
440
 
441
  lev->nact[p] = -1;
348 trimarchi 442
  /* extract task from the queue */
443
  iq_extract(p,&lev->ready[lev->priority[p]]);
221 giacomo 444
 
445
  /* then, we insert the task in the free queue */
446
  proc_table[p].status = FREE;
447
  iq_priority_insert(p,NULL);
448
  POSIXSTAR_private_scheduler(lev);
449
 
450
}
451
 
452
/* Registration functions */
453
 
454
/*+ Registration function:
455
    TIME slice                the slice for the Round Robin queue +*/
456
LEVEL POSIXSTAR_register_level(int master, TIME slice,
457
                       int prioritylevels)
458
{
459
  LEVEL l;            /* the level that we register */
460
  POSIXSTAR_level_des *lev;  /* for readableness only */
461
  PID i;              /* a counter */
462
  int x;              /* a counter */
463
 
464
  #ifdef POSIXSTRA_DEBUG
465
    kern_printf("POSIXSTAR_register_level\n");
466
  #endif
467
 
468
  l = level_alloc_descriptor(sizeof(POSIXSTAR_level_des));
469
 
470
  lev = (POSIXSTAR_level_des *)level_table[l];
471
 
270 giacomo 472
  lev->l.public_guarantee = NULL;
221 giacomo 473
  lev->l.public_create    = POSIXSTAR_public_create;
474
  lev->l.public_end       = POSIXSTAR_public_end;
475
  lev->l.public_dispatch  = POSIXSTAR_public_dispatch;
476
  lev->l.public_epilogue  = POSIXSTAR_public_epilogue;
477
  lev->l.public_activate  = POSIXSTAR_public_activate;
478
  lev->l.public_unblock   = POSIXSTAR_public_unblock;
479
  lev->l.public_block     = POSIXSTAR_public_block;
480
  lev->l.public_message   = POSIXSTAR_public_message;
481
  lev->l.public_eligible  = POSIXSTAR_public_eligible;
482
 
483
  /* fill the POSIX descriptor part */
484
  for (i = 0; i < MAX_PROC; i++) {
485
    lev->nact[i] = -1;
486
    lev->budget[i] = -1;
487
  }
488
 
489
  lev->maxpriority = prioritylevels - 1;
490
 
491
  lev->ready = (IQUEUE *)kern_alloc(sizeof(IQUEUE) * prioritylevels);
492
 
493
  for (x = 0; x < prioritylevels; x++)
494
    iq_init(&lev->ready[x], NULL, 0);
495
 
496
  if (slice < POSIXSTAR_MINIMUM_SLICE) slice = POSIXSTAR_MINIMUM_SLICE;
497
  if (slice > POSIXSTAR_MAXIMUM_SLICE) slice = POSIXSTAR_MAXIMUM_SLICE;
498
  lev->slice = slice;
499
  lev->activated = NIL;
500
  lev->scheduling_level = master;
298 giacomo 501
  lev->cap_lev = NIL;
296 trimarchi 502
  NULL_TIMESPEC(&lev->cap_lasttime);
503
 
221 giacomo 504
  return l;
505
 
506
}
507
 
508
int POSIXSTAR_setbudget(LEVEL l, PID p, int budget)
509
{
510
 
511
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
512
 
513
  lev->budget[p] = budget;
514
 
515
  return 0;
516
 
517
}
518
 
519
int POSIXSTAR_getbudget(LEVEL l, PID p)
520
{
521
 
522
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
523
 
524
  return lev->budget[p];
525
 
526
}
527
 
528
int POSIXSTAR_budget_has_thread(LEVEL l, int budget)
529
{
530
 
531
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
532
  int i;
533
 
534
  for(i = 0; i< MAX_PROC; i++)
535
    if (lev->budget[i] == budget) return 1;
536
 
537
  return 0;
538
 
539
}
540
 
541
/*+ this function forces the running task to go to his queue tail;
542
    (it works only on the POSIX level) +*/
543
int POSIXSTAR_sched_yield(LEVEL l)
544
{
545
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
546
 
547
  if (proc_table[exec_shadow].task_level != l)
548
    return -1;
549
 
550
  proc_table[exec_shadow].context = kern_context_save();
551
  lev->yielding = 1;
552
  scheduler();
553
  kern_context_load(proc_table[exec_shadow].context);
554
  return 0;
555
}
556
 
557
/*+ this function returns the maximum level allowed for the POSIX level +*/
558
int POSIXSTAR_get_priority_max(LEVEL l)
559
{
560
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
561
  return lev->maxpriority;
562
}
563
 
564
/*+ this function returns the default timeslice for the POSIX level +*/
565
int POSIXSTAR_rr_get_interval(LEVEL l)
566
{
567
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
568
  return lev->slice;
569
}
570
 
571
/*+ this functions returns some paramaters of a task;
572
    policy must be NRT_RR_POLICY or NRT_FIFO_POLICY;
573
    priority must be in the range [0..prioritylevels]
574
    returns ENOSYS or ESRCH if there are problems +*/
575
int POSIXSTAR_getschedparam(LEVEL l, PID p, int *policy, int *priority)
576
{
577
  if (p<0 || p>= MAX_PROC || proc_table[p].status == FREE)
578
    return ESRCH;
579
 
580
  if (proc_table[p].task_level != l)
581
    return ENOSYS;
582
 
393 giacomo 583
  *policy = NRT_RR_POLICY;
221 giacomo 584
  *priority = ((POSIXSTAR_level_des *)(level_table[l]))->priority[p];
585
 
586
  return 0;
587
}
588
 
589
/*+ this functions sets paramaters of a task +*/
590
int POSIXSTAR_setschedparam(LEVEL l, PID p, int policy, int priority)
591
{
592
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
593
 
594
  if (p<0 || p>= MAX_PROC || proc_table[p].status == FREE)
595
    return ESRCH;
596
 
597
  if (proc_table[p].task_level != l)
598
    return ENOSYS;
599
  if (lev->priority[p] != priority) {
600
    if (proc_table[p].status == POSIXSTAR_READY) {
601
      iq_extract(p,&lev->ready[lev->priority[p]]);
602
      lev->priority[p] = priority;
603
      iq_insertlast(p,&lev->ready[priority]);
604
    }
605
    else
606
      lev->priority[p] = priority;
607
  }
608
 
609
  return 0;
610
}
611
 
815 trimarchi 612
 
613
void POSIXSTAR_set_nopreemtive_current(LEVEL l) {
614
 
615
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
616
 
617
  lev->flag[lev->activated]|=POSIXSTAR_FLAG_NOPREEMPT;
618
}
619
 
620
void POSIXSTAR_unset_nopreemtive_current(LEVEL l) {
621
 
622
  POSIXSTAR_level_des *lev = (POSIXSTAR_level_des *)(level_table[l]);
623
 
624
  lev->flag[lev->activated]&=~POSIXSTAR_FLAG_NOPREEMPT;
625
}