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961 pj 1
/*
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 * Project: S.Ha.R.K.
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 *
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 * Coordinators:
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 *   Giorgio Buttazzo    <giorgio@sssup.it>
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 *   Paolo Gai           <pj@gandalf.sssup.it>
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 *
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 * Authors     :
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 *   Paolo Gai           <pj@gandalf.sssup.it>
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 *   Massimiliano Giorgi <massy@gandalf.sssup.it>
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 *   Luca Abeni          <luca@gandalf.sssup.it>
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 *   (see the web pages for full authors list)
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 *
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 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
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 *
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 * http://www.sssup.it
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 * http://retis.sssup.it
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 * http://shark.sssup.it
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 */
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/**
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 ------------
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 CVS :        $Id: rr2.c,v 1.1 2005-02-25 10:40:58 pj Exp $
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 File:        $File$
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 Revision:    $Revision: 1.1 $
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 Last update: $Date: 2005-02-25 10:40:58 $
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 ------------
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 This file contains the scheduling module RR2 (Round Robin) version 2
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 Read rr2.h for further details.
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**/
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/*
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 * Copyright (C) 2000 Paolo Gai
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARR2ANTY; without even the implied waRR2anty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 *
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 */
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#include <rr2/rr2/rr2.h>
1621 fabio 57
#include <arch/stdio.h>
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#include <arch/string.h>
961 pj 59
#include <kernel/model.h>
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#include <kernel/descr.h>
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#include <kernel/var.h>
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#include <kernel/func.h>
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64
#include <tracer.h>
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/*+ Status used in the level +*/
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#define RR2_READY   MODULE_STATUS_BASE
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69
/*+ the level redefinition for the Round Robin level +*/
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typedef struct {
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  level_des l;     /*+ the standard level descriptor          +*/
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73
  int nact[MAX_PROC]; /*+ number of pending activations       +*/
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75
  IQUEUE ready;    /*+ the ready queue                        +*/
76
 
77
  int slice;       /*+ the level's time slice                 +*/
78
 
79
  struct multiboot_info *multiboot; /*+ used if the level have to insert
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                                        the main task +*/
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} RR2_level_des;
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83
 
84
/* This is not efficient but very fair :-)
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   The need of all this stuff is because if a task execute a long time
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   due to (shadow!) priority inheritance, then the task shall go to the
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   tail of the queue many times... */
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static PID RR2_public_scheduler(LEVEL l)
89
{
90
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
91
 
92
  PID p;
93
 
94
  for (;;) {
95
    p = iq_query_first(&lev->ready);
96
    if (p == -1)
97
      return p;
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99
    if (proc_table[p].avail_time <= 0) {
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      proc_table[p].avail_time += proc_table[p].wcet;
101
      iq_extract(p,&lev->ready);
102
      iq_insertlast(p,&lev->ready);
103
    }
104
    else
105
      return p;
106
  }
107
}
108
 
109
static int RR2_public_create(LEVEL l, PID p, TASK_MODEL *m)
110
{
111
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
112
  NRT_TASK_MODEL *nrt;
113
 
114
  if (m->pclass != NRT_PCLASS) return -1;
115
  if (m->level != 0 && m->level != l) return -1;
116
  nrt = (NRT_TASK_MODEL *)m;
117
 
118
  /* the task state is set at SLEEP by the general task_create
119
     the only thing to set remains the capacity stuffs that are set
120
     to the values passed in the model... */
121
 
122
  /* I used the wcet field because using wcet can account if a task
123
     consume more than the timeslice... */
124
 
125
  if (nrt->slice) {
126
    proc_table[p].avail_time = nrt->slice;
127
    proc_table[p].wcet       = nrt->slice;
128
  }
129
  else {
130
    proc_table[p].avail_time = lev->slice;
131
    proc_table[p].wcet       = lev->slice;
132
  }
133
  proc_table[p].control   |= CONTROL_CAP;
134
 
135
  if (nrt->arrivals == SAVE_ARRIVALS)
136
    lev->nact[p] = 0;
137
  else
138
    lev->nact[p] = -1;
139
 
140
  return 0; /* OK */
141
}
142
 
143
static void RR2_public_dispatch(LEVEL l, PID p, int nostop)
144
{
145
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
146
 
147
  /* the task state is set EXE by the scheduler()
148
     we extract the task from the ready queue
149
     NB: we can't assume that p is the first task in the queue!!! */
150
  iq_extract(p, &lev->ready);
151
}
152
 
153
static void RR2_public_epilogue(LEVEL l, PID p)
154
{
155
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
156
 
157
  /* check if the slice is finished and insert the task in the coRR2ect
158
     qqueue position */
159
  if (proc_table[p].avail_time <= 0) {
160
    proc_table[p].avail_time += proc_table[p].wcet;
161
    iq_insertlast(p,&lev->ready);
162
  }
163
  else
164
    /* cuRR2 is >0, so the running task have to run for another cuRR2 usec */
165
    iq_insertfirst(p,&lev->ready);
166
 
167
  proc_table[p].status = RR2_READY;
168
}
169
 
170
static void RR2_public_activate(LEVEL l, PID p, struct timespec *t)
171
{
172
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
173
 
174
  /* Test if we are trying to activate a non sleeping task    */
175
  /* save activation (only if needed... */
176
  if (proc_table[p].status != SLEEP) {
177
    if (lev->nact[p] != -1)
178
      lev->nact[p]++;
179
    return;
180
  }
181
 
182
  /* Insert task in the coRR2ect position */
183
  proc_table[p].status = RR2_READY;
184
  iq_insertlast(p,&lev->ready);
185
}
186
 
187
static void RR2_public_unblock(LEVEL l, PID p)
188
{
189
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
190
 
191
  /* Similar to RR2_task_activate,
192
     but we don't check in what state the task is */
193
 
194
  /* Insert task in the coRR2ect position */
195
  proc_table[p].status = RR2_READY;
196
  iq_insertlast(p,&lev->ready);
197
}
198
 
199
static void RR2_public_block(LEVEL l, PID p)
200
{
201
  /* Extract the running task from the level
202
     . we have already extract it from the ready queue at the dispatch time.
203
     . the capacity event have to be removed by the generic kernel
204
     . the wcet don't need modification...
205
     . the state of the task is set by the calling function
206
 
207
     So, we do nothing!!!
208
  */
209
}
210
 
211
static int RR2_public_message(LEVEL l, PID p, void *m)
212
{
213
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
214
 
215
  if (lev->nact[p] > 0) {
216
    /* continue!!!! */
217
    lev->nact[p]--;
218
    iq_insertfirst(p,&lev->ready);
219
    proc_table[p].status = RR2_READY;
220
  }
221
  else
222
    proc_table[p].status = SLEEP;
223
 
224
  jet_update_endcycle(); /* Update the Jet data... */
225
  TRACER_LOGEVENT(FTrace_EVT_task_end_cycle,(unsigned short int)proc_table[p].context,(unsigned int)l);
226
 
227
  return 0;
228
}
229
 
230
static void RR2_public_end(LEVEL l, PID p)
231
{
232
  RR2_level_des *lev = (RR2_level_des *)(level_table[l]);
233
 
234
  lev->nact[p] = -1;
235
 
236
  /* then, we insert the task in the free queue */
237
  proc_table[p].status = FREE;
238
  iq_insertlast(p,&freedesc);
239
}
240
 
241
/* Registration functions */
242
 
243
/*+ This init function install the "main" task +*/
244
static void RR2_call_main(void *l)
245
{
246
  LEVEL lev;
247
  PID p;
248
  NRT_TASK_MODEL m;
249
  void *mb;
250
 
251
  lev = (LEVEL)l;
252
 
253
  nrt_task_default_model(m);
254
  nrt_task_def_level(m,lev); /* with this we are sure that the task aRR2ives
255
                                to the coRR2ect level */
256
 
257
  mb = ((RR2_level_des *)level_table[lev])->multiboot;
258
  nrt_task_def_arg(m,mb);
259
  nrt_task_def_usemath(m);
260
  nrt_task_def_nokill(m);
261
  nrt_task_def_ctrl_jet(m);
262
 
263
  p = task_create("Main", __init__, (TASK_MODEL *)&m, NULL);
264
 
265
  if (p == NIL)
266
    printk("\nPanic!!! can't create main task...\n");
267
 
268
  RR2_public_activate(lev,p,NULL);
269
}
270
 
271
 
272
/*+ Registration function:
273
    TIME slice                the slice for the Round Robin queue
274
    int createmain            1 if the level creates the main task 0 otherwise
275
    struct multiboot_info *mb used if createmain specified   +*/
276
LEVEL RR2_register_level(TIME slice,
277
                       int createmain,
278
                       struct multiboot_info *mb)
279
{
280
  LEVEL l;             /* the level that we register */
281
  RR2_level_des *lev;  /* for readableness only */
282
  PID i;
283
 
284
  printk("RR2_register_level\n");
285
 
286
  /* request an entry in the level_table */
287
  l = level_alloc_descriptor(sizeof(RR2_level_des));
288
 
289
  lev = (RR2_level_des *)level_table[l];
290
 
291
  /* fill the standard descriptor */
292
  lev->l.public_scheduler = RR2_public_scheduler;
293
  lev->l.public_create    = RR2_public_create;
294
  lev->l.public_end       = RR2_public_end;
295
  lev->l.public_dispatch  = RR2_public_dispatch;
296
  lev->l.public_epilogue  = RR2_public_epilogue;
297
  lev->l.public_activate  = RR2_public_activate;
298
  lev->l.public_unblock   = RR2_public_unblock;
299
  lev->l.public_block     = RR2_public_block;
300
  lev->l.public_message   = RR2_public_message;
301
 
302
  /* fill the RR2 descriptor part */
303
  for (i = 0; i < MAX_PROC; i++)
304
    lev->nact[i] = -1;
305
 
306
  iq_init(&lev->ready, &freedesc, 0);
307
 
308
  if (slice < RR2_MINIMUM_SLICE) slice = RR2_MINIMUM_SLICE;
309
  if (slice > RR2_MAXIMUM_SLICE) slice = RR2_MAXIMUM_SLICE;
310
  lev->slice      = slice;
311
 
312
  lev->multiboot  = mb;
313
 
314
  if (createmain)
315
    sys_atrunlevel(RR2_call_main,(void *) l, RUNLEVEL_INIT);
316
 
317
  return l;
318
}
319
 
320