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8baf2c95 MD |
1 | /* |
2 | * mem.spin: Promela code to validate memory barriers with OOO memory. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (c) 2009 Mathieu Desnoyers | |
19 | */ | |
20 | ||
21 | /* Promela validation variables. */ | |
22 | ||
23 | /* specific defines "included" here */ | |
24 | /* DEFINES file "included" here */ | |
25 | ||
26 | /* All signal readers have same PID and uses same reader variable */ | |
27 | #ifdef TEST_SIGNAL_ON_WRITE | |
28 | ||
29 | #define NR_READERS 1 /* the writer is also a signal reader */ | |
30 | #define NR_WRITERS 1 | |
31 | ||
32 | #define NR_PROCS 1 | |
33 | ||
34 | #define get_pid() (0) | |
35 | ||
36 | #elif defined(TEST_SIGNAL_ON_READ) | |
37 | ||
38 | #define get_pid() ((_pid < 2) -> 0 : 1) | |
39 | ||
40 | #define NR_READERS 1 | |
41 | #define NR_WRITERS 1 | |
42 | ||
43 | #define NR_PROCS 2 | |
44 | ||
45 | #else | |
46 | ||
47 | #define get_pid() (_pid) | |
48 | ||
49 | #define NR_READERS 1 | |
50 | #define NR_WRITERS 1 | |
51 | ||
52 | #define NR_PROCS 2 | |
53 | ||
54 | #endif | |
55 | ||
56 | #define get_readerid() (get_pid()) | |
57 | ||
58 | /* | |
59 | * Each process have its own data in cache. Caches are randomly updated. | |
60 | * smp_wmb and smp_rmb forces cache updates (write and read), smp_mb forces | |
61 | * both. | |
62 | */ | |
63 | ||
64 | typedef per_proc_byte { | |
65 | byte val[NR_PROCS]; | |
66 | }; | |
67 | ||
68 | /* Bitfield has a maximum of 8 procs */ | |
69 | typedef per_proc_bit { | |
70 | byte bitfield; | |
71 | }; | |
72 | ||
73 | #define DECLARE_CACHED_VAR(type, x) \ | |
74 | type mem_##x; \ | |
75 | per_proc_##type cached_##x; \ | |
76 | per_proc_bit cache_dirty_##x; | |
77 | ||
78 | #define INIT_CACHED_VAR(x, v, j) \ | |
79 | mem_##x = v; \ | |
80 | cache_dirty_##x.bitfield = 0; \ | |
81 | j = 0; \ | |
82 | do \ | |
83 | :: j < NR_PROCS -> \ | |
84 | cached_##x.val[j] = v; \ | |
85 | j++ \ | |
86 | :: j >= NR_PROCS -> break \ | |
87 | od; | |
88 | ||
89 | #define IS_CACHE_DIRTY(x, id) (cache_dirty_##x.bitfield & (1 << id)) | |
90 | ||
91 | #define READ_CACHED_VAR(x) (cached_##x.val[get_pid()]) | |
92 | ||
93 | #define WRITE_CACHED_VAR(x, v) \ | |
94 | atomic { \ | |
95 | cached_##x.val[get_pid()] = v; \ | |
96 | cache_dirty_##x.bitfield = \ | |
97 | cache_dirty_##x.bitfield | (1 << get_pid()); \ | |
98 | } | |
99 | ||
100 | #define CACHE_WRITE_TO_MEM(x, id) \ | |
101 | if \ | |
102 | :: IS_CACHE_DIRTY(x, id) -> \ | |
103 | mem_##x = cached_##x.val[id]; \ | |
104 | cache_dirty_##x.bitfield = \ | |
105 | cache_dirty_##x.bitfield & (~(1 << id)); \ | |
106 | :: else -> \ | |
107 | skip \ | |
108 | fi; | |
109 | ||
110 | #define CACHE_READ_FROM_MEM(x, id) \ | |
111 | if \ | |
112 | :: !IS_CACHE_DIRTY(x, id) -> \ | |
113 | cached_##x.val[id] = mem_##x;\ | |
114 | :: else -> \ | |
115 | skip \ | |
116 | fi; | |
117 | ||
118 | /* | |
119 | * May update other caches if cache is dirty, or not. | |
120 | */ | |
121 | #define RANDOM_CACHE_WRITE_TO_MEM(x, id)\ | |
122 | if \ | |
123 | :: 1 -> CACHE_WRITE_TO_MEM(x, id); \ | |
124 | :: 1 -> skip \ | |
125 | fi; | |
126 | ||
127 | #define RANDOM_CACHE_READ_FROM_MEM(x, id)\ | |
128 | if \ | |
129 | :: 1 -> CACHE_READ_FROM_MEM(x, id); \ | |
130 | :: 1 -> skip \ | |
131 | fi; | |
132 | ||
133 | /* | |
134 | * Remote barriers tests the scheme where a signal (or IPI) is sent to all | |
135 | * reader threads to promote their compiler barrier to a smp_mb(). | |
136 | */ | |
137 | #ifdef REMOTE_BARRIERS | |
138 | ||
139 | inline smp_rmb_pid(i, j) | |
140 | { | |
141 | atomic { | |
142 | CACHE_READ_FROM_MEM(urcu_gp_ctr, i); | |
143 | j = 0; | |
144 | do | |
145 | :: j < NR_READERS -> | |
146 | CACHE_READ_FROM_MEM(urcu_active_readers[j], i); | |
147 | j++ | |
148 | :: j >= NR_READERS -> break | |
149 | od; | |
150 | CACHE_READ_FROM_MEM(generation_ptr, i); | |
151 | } | |
152 | } | |
153 | ||
154 | inline smp_wmb_pid(i, j) | |
155 | { | |
156 | atomic { | |
157 | CACHE_WRITE_TO_MEM(urcu_gp_ctr, i); | |
158 | j = 0; | |
159 | do | |
160 | :: j < NR_READERS -> | |
161 | CACHE_WRITE_TO_MEM(urcu_active_readers[j], i); | |
162 | j++ | |
163 | :: j >= NR_READERS -> break | |
164 | od; | |
165 | CACHE_WRITE_TO_MEM(generation_ptr, i); | |
166 | } | |
167 | } | |
168 | ||
169 | inline smp_mb_pid(i, j) | |
170 | { | |
171 | atomic { | |
172 | #ifndef NO_WMB | |
173 | smp_wmb_pid(i, j); | |
174 | #endif | |
175 | #ifndef NO_RMB | |
176 | smp_rmb_pid(i, j); | |
177 | #endif | |
178 | #ifdef NO_WMB | |
179 | #ifdef NO_RMB | |
180 | ooo_mem(j); | |
181 | #endif | |
182 | #endif | |
183 | } | |
184 | } | |
185 | ||
186 | /* | |
187 | * Readers do a simple barrier(), writers are doing a smp_mb() _and_ sending a | |
188 | * signal or IPI to have all readers execute a smp_mb. | |
189 | * We are not modeling the whole rendez-vous between readers and writers here, | |
190 | * we just let the writer update each reader's caches remotely. | |
191 | */ | |
192 | inline smp_mb_writer(i, j) | |
193 | { | |
194 | smp_mb_pid(get_pid(), j); | |
195 | i = 0; | |
196 | do | |
197 | :: i < NR_READERS -> | |
198 | smp_mb_pid(i, j); | |
199 | i++; | |
200 | :: i >= NR_READERS -> break | |
201 | od; | |
202 | smp_mb_pid(get_pid(), j); | |
203 | } | |
204 | ||
205 | inline smp_mb_reader(i, j) | |
206 | { | |
207 | skip; | |
208 | } | |
209 | ||
210 | #else | |
211 | ||
212 | inline smp_rmb(i, j) | |
213 | { | |
214 | atomic { | |
215 | CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); | |
216 | i = 0; | |
217 | do | |
218 | :: i < NR_READERS -> | |
219 | CACHE_READ_FROM_MEM(urcu_active_readers[i], get_pid()); | |
220 | i++ | |
221 | :: i >= NR_READERS -> break | |
222 | od; | |
223 | CACHE_READ_FROM_MEM(generation_ptr, get_pid()); | |
224 | } | |
225 | } | |
226 | ||
227 | inline smp_wmb(i, j) | |
228 | { | |
229 | atomic { | |
230 | CACHE_WRITE_TO_MEM(urcu_gp_ctr, get_pid()); | |
231 | i = 0; | |
232 | do | |
233 | :: i < NR_READERS -> | |
234 | CACHE_WRITE_TO_MEM(urcu_active_readers[i], get_pid()); | |
235 | i++ | |
236 | :: i >= NR_READERS -> break | |
237 | od; | |
238 | CACHE_WRITE_TO_MEM(generation_ptr, get_pid()); | |
239 | } | |
240 | } | |
241 | ||
242 | inline smp_mb(i, j) | |
243 | { | |
244 | atomic { | |
245 | #ifndef NO_WMB | |
246 | smp_wmb(i, j); | |
247 | #endif | |
248 | #ifndef NO_RMB | |
249 | smp_rmb(i, j); | |
250 | #endif | |
251 | #ifdef NO_WMB | |
252 | #ifdef NO_RMB | |
253 | ooo_mem(i); | |
254 | #endif | |
255 | #endif | |
256 | } | |
257 | } | |
258 | ||
259 | inline smp_mb_writer(i, j) | |
260 | { | |
261 | smp_mb(i, j); | |
262 | } | |
263 | ||
264 | inline smp_mb_reader(i, j) | |
265 | { | |
266 | smp_mb(i, j); | |
267 | } | |
268 | ||
269 | #endif | |
270 | ||
271 | /* Keep in sync manually with smp_rmb, wmp_wmb, ooo_mem and init() */ | |
272 | DECLARE_CACHED_VAR(byte, urcu_gp_ctr); | |
273 | /* Note ! currently only two readers */ | |
274 | DECLARE_CACHED_VAR(byte, urcu_active_readers[NR_READERS]); | |
275 | /* pointer generation */ | |
276 | DECLARE_CACHED_VAR(byte, generation_ptr); | |
277 | ||
278 | byte last_free_gen = 0; | |
279 | bit free_done = 0; | |
280 | byte read_generation[NR_READERS]; | |
281 | bit data_access[NR_READERS]; | |
282 | ||
283 | bit write_lock = 0; | |
284 | ||
285 | bit init_done = 0; | |
286 | ||
287 | bit sighand_exec = 0; | |
288 | ||
289 | inline wait_init_done() | |
290 | { | |
291 | do | |
292 | :: init_done == 0 -> skip; | |
293 | :: else -> break; | |
294 | od; | |
295 | } | |
296 | ||
297 | #ifdef TEST_SIGNAL | |
298 | ||
299 | inline wait_for_sighand_exec() | |
300 | { | |
301 | sighand_exec = 0; | |
302 | do | |
303 | :: sighand_exec == 0 -> skip; | |
304 | :: else -> break; | |
305 | od; | |
306 | } | |
307 | ||
308 | #ifdef TOO_BIG_STATE_SPACE | |
309 | inline wait_for_sighand_exec() | |
310 | { | |
311 | sighand_exec = 0; | |
312 | do | |
313 | :: sighand_exec == 0 -> skip; | |
314 | :: else -> | |
315 | if | |
316 | :: 1 -> break; | |
317 | :: 1 -> sighand_exec = 0; | |
318 | skip; | |
319 | fi; | |
320 | od; | |
321 | } | |
322 | #endif | |
323 | ||
324 | #else | |
325 | ||
326 | inline wait_for_sighand_exec() | |
327 | { | |
328 | skip; | |
329 | } | |
330 | ||
331 | #endif | |
332 | ||
333 | #ifdef TEST_SIGNAL_ON_WRITE | |
334 | /* Block on signal handler execution */ | |
335 | inline dispatch_sighand_write_exec() | |
336 | { | |
337 | sighand_exec = 1; | |
338 | do | |
339 | :: sighand_exec == 1 -> | |
340 | skip; | |
341 | :: else -> | |
342 | break; | |
343 | od; | |
344 | } | |
345 | ||
346 | #else | |
347 | ||
348 | inline dispatch_sighand_write_exec() | |
349 | { | |
350 | skip; | |
351 | } | |
352 | ||
353 | #endif | |
354 | ||
355 | #ifdef TEST_SIGNAL_ON_READ | |
356 | /* Block on signal handler execution */ | |
357 | inline dispatch_sighand_read_exec() | |
358 | { | |
359 | sighand_exec = 1; | |
360 | do | |
361 | :: sighand_exec == 1 -> | |
362 | skip; | |
363 | :: else -> | |
364 | break; | |
365 | od; | |
366 | } | |
367 | ||
368 | #else | |
369 | ||
370 | inline dispatch_sighand_read_exec() | |
371 | { | |
372 | skip; | |
373 | } | |
374 | ||
375 | #endif | |
376 | ||
377 | ||
378 | inline ooo_mem(i) | |
379 | { | |
380 | atomic { | |
381 | RANDOM_CACHE_WRITE_TO_MEM(urcu_gp_ctr, get_pid()); | |
382 | i = 0; | |
383 | do | |
384 | :: i < NR_READERS -> | |
385 | RANDOM_CACHE_WRITE_TO_MEM(urcu_active_readers[i], | |
386 | get_pid()); | |
387 | i++ | |
388 | :: i >= NR_READERS -> break | |
389 | od; | |
390 | RANDOM_CACHE_WRITE_TO_MEM(generation_ptr, get_pid()); | |
391 | RANDOM_CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); | |
392 | i = 0; | |
393 | do | |
394 | :: i < NR_READERS -> | |
395 | RANDOM_CACHE_READ_FROM_MEM(urcu_active_readers[i], | |
396 | get_pid()); | |
397 | i++ | |
398 | :: i >= NR_READERS -> break | |
399 | od; | |
400 | RANDOM_CACHE_READ_FROM_MEM(generation_ptr, get_pid()); | |
401 | } | |
402 | } | |
403 | ||
404 | inline wait_for_reader(tmp, tmp2, i, j) | |
405 | { | |
406 | do | |
407 | :: 1 -> | |
408 | tmp2 = READ_CACHED_VAR(urcu_active_readers[tmp]); | |
409 | ooo_mem(i); | |
410 | dispatch_sighand_write_exec(); | |
411 | if | |
412 | :: (tmp2 & RCU_GP_CTR_NEST_MASK) | |
413 | && ((tmp2 ^ READ_CACHED_VAR(urcu_gp_ctr)) | |
414 | & RCU_GP_CTR_BIT) -> | |
415 | #ifndef GEN_ERROR_WRITER_PROGRESS | |
416 | smp_mb_writer(i, j); | |
417 | #else | |
418 | ooo_mem(i); | |
419 | #endif | |
420 | dispatch_sighand_write_exec(); | |
421 | :: else -> | |
422 | break; | |
423 | fi; | |
424 | od; | |
425 | } | |
426 | ||
427 | inline wait_for_quiescent_state(tmp, tmp2, i, j) | |
428 | { | |
429 | tmp = 0; | |
430 | do | |
431 | :: tmp < NR_READERS -> | |
432 | wait_for_reader(tmp, tmp2, i, j); | |
433 | if | |
434 | :: (NR_READERS > 1) && (tmp < NR_READERS - 1) | |
435 | -> ooo_mem(i); | |
436 | dispatch_sighand_write_exec(); | |
437 | :: else | |
438 | -> skip; | |
439 | fi; | |
440 | tmp++ | |
441 | :: tmp >= NR_READERS -> break | |
442 | od; | |
443 | } | |
444 | ||
445 | /* Model the RCU read-side critical section. */ | |
446 | ||
447 | #ifndef TEST_SIGNAL_ON_WRITE | |
448 | ||
449 | inline urcu_one_read(i, j, nest_i, tmp, tmp2) | |
450 | { | |
451 | nest_i = 0; | |
452 | do | |
453 | :: nest_i < READER_NEST_LEVEL -> | |
454 | ooo_mem(i); | |
455 | dispatch_sighand_read_exec(); | |
456 | tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); | |
457 | ooo_mem(i); | |
458 | dispatch_sighand_read_exec(); | |
459 | if | |
460 | :: (!(tmp & RCU_GP_CTR_NEST_MASK)) | |
461 | -> | |
462 | tmp2 = READ_CACHED_VAR(urcu_gp_ctr); | |
463 | ooo_mem(i); | |
464 | dispatch_sighand_read_exec(); | |
465 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], | |
466 | tmp2); | |
467 | :: else -> | |
468 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], | |
469 | tmp + 1); | |
470 | fi; | |
471 | smp_mb_reader(i, j); | |
472 | dispatch_sighand_read_exec(); | |
473 | nest_i++; | |
474 | :: nest_i >= READER_NEST_LEVEL -> break; | |
475 | od; | |
476 | ||
477 | read_generation[get_readerid()] = READ_CACHED_VAR(generation_ptr); | |
478 | data_access[get_readerid()] = 1; | |
479 | data_access[get_readerid()] = 0; | |
480 | ||
481 | nest_i = 0; | |
482 | do | |
483 | :: nest_i < READER_NEST_LEVEL -> | |
484 | smp_mb_reader(i, j); | |
485 | dispatch_sighand_read_exec(); | |
486 | tmp2 = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); | |
487 | ooo_mem(i); | |
488 | dispatch_sighand_read_exec(); | |
489 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2 - 1); | |
490 | nest_i++; | |
491 | :: nest_i >= READER_NEST_LEVEL -> break; | |
492 | od; | |
493 | //ooo_mem(i); | |
494 | //dispatch_sighand_read_exec(); | |
495 | //smp_mc(i); /* added */ | |
496 | } | |
497 | ||
498 | active proctype urcu_reader() | |
499 | { | |
500 | byte i, j, nest_i; | |
501 | byte tmp, tmp2; | |
502 | ||
503 | wait_init_done(); | |
504 | ||
505 | assert(get_pid() < NR_PROCS); | |
506 | ||
507 | end_reader: | |
508 | do | |
509 | :: 1 -> | |
510 | /* | |
511 | * We do not test reader's progress here, because we are mainly | |
512 | * interested in writer's progress. The reader never blocks | |
513 | * anyway. We have to test for reader/writer's progress | |
514 | * separately, otherwise we could think the writer is doing | |
515 | * progress when it's blocked by an always progressing reader. | |
516 | */ | |
517 | #ifdef READER_PROGRESS | |
518 | progress_reader: | |
519 | #endif | |
520 | urcu_one_read(i, j, nest_i, tmp, tmp2); | |
521 | od; | |
522 | } | |
523 | ||
524 | #endif //!TEST_SIGNAL_ON_WRITE | |
525 | ||
526 | #ifdef TEST_SIGNAL | |
527 | /* signal handler reader */ | |
528 | ||
529 | inline urcu_one_read_sig(i, j, nest_i, tmp, tmp2) | |
530 | { | |
531 | nest_i = 0; | |
532 | do | |
533 | :: nest_i < READER_NEST_LEVEL -> | |
534 | ooo_mem(i); | |
535 | tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); | |
536 | ooo_mem(i); | |
537 | if | |
538 | :: (!(tmp & RCU_GP_CTR_NEST_MASK)) | |
539 | -> | |
540 | tmp2 = READ_CACHED_VAR(urcu_gp_ctr); | |
541 | ooo_mem(i); | |
542 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], | |
543 | tmp2); | |
544 | :: else -> | |
545 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], | |
546 | tmp + 1); | |
547 | fi; | |
548 | smp_mb_reader(i, j); | |
549 | nest_i++; | |
550 | :: nest_i >= READER_NEST_LEVEL -> break; | |
551 | od; | |
552 | ||
553 | read_generation[get_readerid()] = READ_CACHED_VAR(generation_ptr); | |
554 | data_access[get_readerid()] = 1; | |
555 | data_access[get_readerid()] = 0; | |
556 | ||
557 | nest_i = 0; | |
558 | do | |
559 | :: nest_i < READER_NEST_LEVEL -> | |
560 | smp_mb_reader(i, j); | |
561 | tmp2 = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); | |
562 | ooo_mem(i); | |
563 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2 - 1); | |
564 | nest_i++; | |
565 | :: nest_i >= READER_NEST_LEVEL -> break; | |
566 | od; | |
567 | //ooo_mem(i); | |
568 | //smp_mc(i); /* added */ | |
569 | } | |
570 | ||
571 | active proctype urcu_reader_sig() | |
572 | { | |
573 | byte i, j, nest_i; | |
574 | byte tmp, tmp2; | |
575 | ||
576 | wait_init_done(); | |
577 | ||
578 | assert(get_pid() < NR_PROCS); | |
579 | ||
580 | end_reader: | |
581 | do | |
582 | :: 1 -> | |
583 | wait_for_sighand_exec(); | |
584 | /* | |
585 | * We do not test reader's progress here, because we are mainly | |
586 | * interested in writer's progress. The reader never blocks | |
587 | * anyway. We have to test for reader/writer's progress | |
588 | * separately, otherwise we could think the writer is doing | |
589 | * progress when it's blocked by an always progressing reader. | |
590 | */ | |
591 | #ifdef READER_PROGRESS | |
592 | progress_reader: | |
593 | #endif | |
594 | urcu_one_read_sig(i, j, nest_i, tmp, tmp2); | |
595 | od; | |
596 | } | |
597 | ||
598 | #endif | |
599 | ||
600 | /* Model the RCU update process. */ | |
601 | ||
602 | active proctype urcu_writer() | |
603 | { | |
604 | byte i, j; | |
605 | byte tmp, tmp2; | |
606 | byte old_gen; | |
607 | ||
608 | wait_init_done(); | |
609 | ||
610 | assert(get_pid() < NR_PROCS); | |
611 | ||
612 | do | |
613 | :: (READ_CACHED_VAR(generation_ptr) < 5) -> | |
614 | #ifdef WRITER_PROGRESS | |
615 | progress_writer1: | |
616 | #endif | |
617 | ooo_mem(i); | |
618 | dispatch_sighand_write_exec(); | |
619 | atomic { | |
620 | old_gen = READ_CACHED_VAR(generation_ptr); | |
621 | WRITE_CACHED_VAR(generation_ptr, old_gen + 1); | |
622 | } | |
623 | ooo_mem(i); | |
624 | dispatch_sighand_write_exec(); | |
625 | ||
626 | do | |
627 | :: 1 -> | |
628 | atomic { | |
629 | if | |
630 | :: write_lock == 0 -> | |
631 | write_lock = 1; | |
632 | break; | |
633 | :: else -> | |
634 | skip; | |
635 | fi; | |
636 | } | |
637 | od; | |
638 | smp_mb_writer(i, j); | |
639 | dispatch_sighand_write_exec(); | |
640 | tmp = READ_CACHED_VAR(urcu_gp_ctr); | |
641 | ooo_mem(i); | |
642 | dispatch_sighand_write_exec(); | |
643 | WRITE_CACHED_VAR(urcu_gp_ctr, tmp ^ RCU_GP_CTR_BIT); | |
644 | ooo_mem(i); | |
645 | dispatch_sighand_write_exec(); | |
646 | //smp_mc(i); | |
647 | wait_for_quiescent_state(tmp, tmp2, i, j); | |
648 | //smp_mc(i); | |
649 | #ifndef SINGLE_FLIP | |
650 | ooo_mem(i); | |
651 | dispatch_sighand_write_exec(); | |
652 | tmp = READ_CACHED_VAR(urcu_gp_ctr); | |
653 | ooo_mem(i); | |
654 | dispatch_sighand_write_exec(); | |
655 | WRITE_CACHED_VAR(urcu_gp_ctr, tmp ^ RCU_GP_CTR_BIT); | |
656 | //smp_mc(i); | |
657 | ooo_mem(i); | |
658 | dispatch_sighand_write_exec(); | |
659 | wait_for_quiescent_state(tmp, tmp2, i, j); | |
660 | #endif | |
661 | smp_mb_writer(i, j); | |
662 | dispatch_sighand_write_exec(); | |
663 | write_lock = 0; | |
664 | /* free-up step, e.g., kfree(). */ | |
665 | atomic { | |
666 | last_free_gen = old_gen; | |
667 | free_done = 1; | |
668 | } | |
669 | :: else -> break; | |
670 | od; | |
671 | /* | |
672 | * Given the reader loops infinitely, let the writer also busy-loop | |
673 | * with progress here so, with weak fairness, we can test the | |
674 | * writer's progress. | |
675 | */ | |
676 | end_writer: | |
677 | do | |
678 | :: 1 -> | |
679 | #ifdef WRITER_PROGRESS | |
680 | progress_writer2: | |
681 | #endif | |
682 | dispatch_sighand_write_exec(); | |
683 | od; | |
684 | } | |
685 | ||
686 | /* Leave after the readers and writers so the pid count is ok. */ | |
687 | init { | |
688 | byte i, j; | |
689 | ||
690 | atomic { | |
691 | INIT_CACHED_VAR(urcu_gp_ctr, 1, j); | |
692 | INIT_CACHED_VAR(generation_ptr, 0, j); | |
693 | ||
694 | i = 0; | |
695 | do | |
696 | :: i < NR_READERS -> | |
697 | INIT_CACHED_VAR(urcu_active_readers[i], 0, j); | |
698 | read_generation[i] = 1; | |
699 | data_access[i] = 0; | |
700 | i++; | |
701 | :: i >= NR_READERS -> break | |
702 | od; | |
703 | init_done = 1; | |
704 | } | |
705 | } |