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551ac1a3 | 1 | /* |
a60dadc5 MD |
2 | * mem.spin: Promela code to validate memory barriers with OOO memory |
3 | * and out-of-order instruction scheduling. | |
551ac1a3 MD |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
18 | * | |
19 | * Copyright (c) 2009 Mathieu Desnoyers | |
20 | */ | |
21 | ||
22 | /* Promela validation variables. */ | |
23 | ||
24 | /* specific defines "included" here */ | |
25 | /* DEFINES file "included" here */ | |
26 | ||
27 | #define NR_READERS 1 | |
28 | #define NR_WRITERS 1 | |
29 | ||
30 | #define NR_PROCS 2 | |
31 | ||
32 | #define get_pid() (_pid) | |
33 | ||
34 | #define get_readerid() (get_pid()) | |
35 | ||
36 | /* | |
37 | * Produced process control and data flow. Updated after each instruction to | |
38 | * show which variables are ready. Using one-hot bit encoding per variable to | |
39 | * save state space. Used as triggers to execute the instructions having those | |
40 | * variables as input. Leaving bits active to inhibit instruction execution. | |
41 | * Scheme used to make instruction disabling and automatic dependency fall-back | |
42 | * automatic. | |
43 | */ | |
44 | ||
45 | #define CONSUME_TOKENS(state, bits, notbits) \ | |
46 | ((!(state & (notbits))) && (state & (bits)) == (bits)) | |
47 | ||
48 | #define PRODUCE_TOKENS(state, bits) \ | |
49 | state = state | (bits); | |
50 | ||
51 | #define CLEAR_TOKENS(state, bits) \ | |
52 | state = state & ~(bits) | |
53 | ||
54 | /* | |
55 | * Types of dependency : | |
56 | * | |
57 | * Data dependency | |
58 | * | |
59 | * - True dependency, Read-after-Write (RAW) | |
60 | * | |
61 | * This type of dependency happens when a statement depends on the result of a | |
62 | * previous statement. This applies to any statement which needs to read a | |
63 | * variable written by a preceding statement. | |
64 | * | |
65 | * - False dependency, Write-after-Read (WAR) | |
66 | * | |
67 | * Typically, variable renaming can ensure that this dependency goes away. | |
68 | * However, if the statements must read and then write from/to the same variable | |
69 | * in the OOO memory model, renaming may be impossible, and therefore this | |
70 | * causes a WAR dependency. | |
71 | * | |
72 | * - Output dependency, Write-after-Write (WAW) | |
73 | * | |
74 | * Two writes to the same variable in subsequent statements. Variable renaming | |
75 | * can ensure this is not needed, but can be required when writing multiple | |
76 | * times to the same OOO mem model variable. | |
77 | * | |
78 | * Control dependency | |
79 | * | |
80 | * Execution of a given instruction depends on a previous instruction evaluating | |
81 | * in a way that allows its execution. E.g. : branches. | |
82 | * | |
83 | * Useful considerations for joining dependencies after branch | |
84 | * | |
85 | * - Pre-dominance | |
86 | * | |
87 | * "We say box i dominates box j if every path (leading from input to output | |
88 | * through the diagram) which passes through box j must also pass through box | |
89 | * i. Thus box i dominates box j if box j is subordinate to box i in the | |
90 | * program." | |
91 | * | |
92 | * http://www.hipersoft.rice.edu/grads/publications/dom14.pdf | |
93 | * Other classic algorithm to calculate dominance : Lengauer-Tarjan (in gcc) | |
94 | * | |
95 | * - Post-dominance | |
96 | * | |
97 | * Just as pre-dominance, but with arcs of the data flow inverted, and input vs | |
98 | * output exchanged. Therefore, i post-dominating j ensures that every path | |
99 | * passing by j will pass by i before reaching the output. | |
100 | * | |
101 | * Other considerations | |
102 | * | |
103 | * Note about "volatile" keyword dependency : The compiler will order volatile | |
104 | * accesses so they appear in the right order on a given CPU. They can be | |
105 | * reordered by the CPU instruction scheduling. This therefore cannot be | |
106 | * considered as a depencency. | |
107 | * | |
108 | * References : | |
109 | * | |
110 | * Cooper, Keith D.; & Torczon, Linda. (2005). Engineering a Compiler. Morgan | |
111 | * Kaufmann. ISBN 1-55860-698-X. | |
112 | * Kennedy, Ken; & Allen, Randy. (2001). Optimizing Compilers for Modern | |
113 | * Architectures: A Dependence-based Approach. Morgan Kaufmann. ISBN | |
114 | * 1-55860-286-0. | |
115 | * Muchnick, Steven S. (1997). Advanced Compiler Design and Implementation. | |
116 | * Morgan Kaufmann. ISBN 1-55860-320-4. | |
117 | */ | |
118 | ||
119 | /* | |
120 | * Note about loops and nested calls | |
121 | * | |
122 | * To keep this model simple, loops expressed in the framework will behave as if | |
123 | * there was a core synchronizing instruction between loops. To see the effect | |
124 | * of loop unrolling, manually unrolling loops is required. Note that if loops | |
125 | * end or start with a core synchronizing instruction, the model is appropriate. | |
126 | * Nested calls are not supported. | |
127 | */ | |
128 | ||
129 | /* | |
130 | * Each process have its own data in cache. Caches are randomly updated. | |
131 | * smp_wmb and smp_rmb forces cache updates (write and read), smp_mb forces | |
132 | * both. | |
133 | */ | |
134 | ||
135 | typedef per_proc_byte { | |
136 | byte val[NR_PROCS]; | |
137 | }; | |
138 | ||
139 | /* Bitfield has a maximum of 8 procs */ | |
140 | typedef per_proc_bit { | |
141 | byte bitfield; | |
142 | }; | |
143 | ||
144 | #define DECLARE_CACHED_VAR(type, x) \ | |
145 | type mem_##x; \ | |
146 | per_proc_##type cached_##x; \ | |
147 | per_proc_bit cache_dirty_##x; | |
148 | ||
149 | #define INIT_CACHED_VAR(x, v, j) \ | |
150 | mem_##x = v; \ | |
151 | cache_dirty_##x.bitfield = 0; \ | |
152 | j = 0; \ | |
153 | do \ | |
154 | :: j < NR_PROCS -> \ | |
155 | cached_##x.val[j] = v; \ | |
156 | j++ \ | |
157 | :: j >= NR_PROCS -> break \ | |
158 | od; | |
159 | ||
160 | #define IS_CACHE_DIRTY(x, id) (cache_dirty_##x.bitfield & (1 << id)) | |
161 | ||
162 | #define READ_CACHED_VAR(x) (cached_##x.val[get_pid()]) | |
163 | ||
164 | #define WRITE_CACHED_VAR(x, v) \ | |
165 | atomic { \ | |
166 | cached_##x.val[get_pid()] = v; \ | |
167 | cache_dirty_##x.bitfield = \ | |
168 | cache_dirty_##x.bitfield | (1 << get_pid()); \ | |
169 | } | |
170 | ||
171 | #define CACHE_WRITE_TO_MEM(x, id) \ | |
172 | if \ | |
173 | :: IS_CACHE_DIRTY(x, id) -> \ | |
174 | mem_##x = cached_##x.val[id]; \ | |
175 | cache_dirty_##x.bitfield = \ | |
176 | cache_dirty_##x.bitfield & (~(1 << id)); \ | |
177 | :: else -> \ | |
178 | skip \ | |
179 | fi; | |
180 | ||
181 | #define CACHE_READ_FROM_MEM(x, id) \ | |
182 | if \ | |
183 | :: !IS_CACHE_DIRTY(x, id) -> \ | |
184 | cached_##x.val[id] = mem_##x;\ | |
185 | :: else -> \ | |
186 | skip \ | |
187 | fi; | |
188 | ||
189 | /* | |
190 | * May update other caches if cache is dirty, or not. | |
191 | */ | |
192 | #define RANDOM_CACHE_WRITE_TO_MEM(x, id)\ | |
193 | if \ | |
194 | :: 1 -> CACHE_WRITE_TO_MEM(x, id); \ | |
195 | :: 1 -> skip \ | |
196 | fi; | |
197 | ||
198 | #define RANDOM_CACHE_READ_FROM_MEM(x, id)\ | |
199 | if \ | |
200 | :: 1 -> CACHE_READ_FROM_MEM(x, id); \ | |
201 | :: 1 -> skip \ | |
202 | fi; | |
203 | ||
204 | /* Must consume all prior read tokens. All subsequent reads depend on it. */ | |
205 | inline smp_rmb(i, j) | |
206 | { | |
207 | atomic { | |
208 | CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); | |
209 | i = 0; | |
210 | do | |
211 | :: i < NR_READERS -> | |
212 | CACHE_READ_FROM_MEM(urcu_active_readers[i], get_pid()); | |
213 | i++ | |
214 | :: i >= NR_READERS -> break | |
215 | od; | |
216 | CACHE_READ_FROM_MEM(generation_ptr, get_pid()); | |
217 | } | |
218 | } | |
219 | ||
220 | /* Must consume all prior write tokens. All subsequent writes depend on it. */ | |
221 | inline smp_wmb(i, j) | |
222 | { | |
223 | atomic { | |
224 | CACHE_WRITE_TO_MEM(urcu_gp_ctr, get_pid()); | |
225 | i = 0; | |
226 | do | |
227 | :: i < NR_READERS -> | |
228 | CACHE_WRITE_TO_MEM(urcu_active_readers[i], get_pid()); | |
229 | i++ | |
230 | :: i >= NR_READERS -> break | |
231 | od; | |
232 | CACHE_WRITE_TO_MEM(generation_ptr, get_pid()); | |
233 | } | |
234 | } | |
235 | ||
236 | /* Synchronization point. Must consume all prior read and write tokens. All | |
237 | * subsequent reads and writes depend on it. */ | |
238 | inline smp_mb(i, j) | |
239 | { | |
240 | atomic { | |
241 | smp_wmb(i, j); | |
242 | smp_rmb(i, j); | |
243 | } | |
244 | } | |
245 | ||
246 | ||
247 | #ifdef REMOTE_BARRIERS | |
248 | ||
249 | bit reader_barrier[NR_READERS]; | |
250 | ||
251 | /* | |
252 | * We cannot leave the barriers dependencies in place in REMOTE_BARRIERS mode | |
253 | * because they would add unexisting core synchronization and would therefore | |
254 | * create an incomplete model. | |
255 | * Therefore, we model the read-side memory barriers by completely disabling the | |
256 | * memory barriers and their dependencies from the read-side. One at a time | |
257 | * (different verification runs), we make a different instruction listen for | |
258 | * signals. | |
259 | */ | |
260 | ||
261 | #define smp_mb_reader(i, j) | |
262 | ||
263 | /* | |
264 | * Service 0, 1 or many barrier requests. | |
265 | */ | |
266 | inline smp_mb_recv(i, j) | |
267 | { | |
268 | do | |
269 | :: (reader_barrier[get_readerid()] == 1) -> | |
270 | smp_mb(i, j); | |
271 | reader_barrier[get_readerid()] = 0; | |
272 | :: 1 -> skip; | |
273 | :: 1 -> break; | |
274 | od; | |
275 | } | |
276 | ||
277 | inline smp_mb_send(i, j) | |
278 | { | |
279 | smp_mb(i, j); | |
280 | i = 0; | |
281 | do | |
282 | :: i < NR_READERS -> | |
283 | reader_barrier[i] = 1; | |
284 | do | |
285 | :: (reader_barrier[i] == 1) -> skip; | |
286 | :: (reader_barrier[i] == 0) -> break; | |
287 | od; | |
288 | i++; | |
289 | :: i >= NR_READERS -> | |
290 | break | |
291 | od; | |
292 | smp_mb(i, j); | |
293 | } | |
294 | ||
295 | #else | |
296 | ||
297 | #define smp_mb_send smp_mb | |
298 | #define smp_mb_reader smp_mb | |
299 | #define smp_mb_recv(i, j) | |
300 | ||
301 | #endif | |
302 | ||
303 | /* Keep in sync manually with smp_rmb, wmp_wmb, ooo_mem and init() */ | |
304 | DECLARE_CACHED_VAR(byte, urcu_gp_ctr); | |
305 | /* Note ! currently only two readers */ | |
306 | DECLARE_CACHED_VAR(byte, urcu_active_readers[NR_READERS]); | |
307 | /* pointer generation */ | |
308 | DECLARE_CACHED_VAR(byte, generation_ptr); | |
309 | ||
310 | byte last_free_gen = 0; | |
311 | bit free_done = 0; | |
312 | byte read_generation[NR_READERS]; | |
313 | bit data_access[NR_READERS]; | |
314 | ||
315 | bit write_lock = 0; | |
316 | ||
317 | bit init_done = 0; | |
318 | ||
319 | bit sighand_exec = 0; | |
320 | ||
321 | inline wait_init_done() | |
322 | { | |
323 | do | |
324 | :: init_done == 0 -> skip; | |
325 | :: else -> break; | |
326 | od; | |
327 | } | |
328 | ||
329 | inline ooo_mem(i) | |
330 | { | |
331 | atomic { | |
332 | RANDOM_CACHE_WRITE_TO_MEM(urcu_gp_ctr, get_pid()); | |
333 | i = 0; | |
334 | do | |
335 | :: i < NR_READERS -> | |
336 | RANDOM_CACHE_WRITE_TO_MEM(urcu_active_readers[i], | |
337 | get_pid()); | |
338 | i++ | |
339 | :: i >= NR_READERS -> break | |
340 | od; | |
341 | RANDOM_CACHE_WRITE_TO_MEM(generation_ptr, get_pid()); | |
342 | RANDOM_CACHE_READ_FROM_MEM(urcu_gp_ctr, get_pid()); | |
343 | i = 0; | |
344 | do | |
345 | :: i < NR_READERS -> | |
346 | RANDOM_CACHE_READ_FROM_MEM(urcu_active_readers[i], | |
347 | get_pid()); | |
348 | i++ | |
349 | :: i >= NR_READERS -> break | |
350 | od; | |
351 | RANDOM_CACHE_READ_FROM_MEM(generation_ptr, get_pid()); | |
352 | } | |
353 | } | |
354 | ||
355 | /* | |
356 | * Bit encoding, urcu_reader : | |
357 | */ | |
358 | ||
359 | int _proc_urcu_reader; | |
360 | #define proc_urcu_reader _proc_urcu_reader | |
361 | ||
362 | /* Body of PROCEDURE_READ_LOCK */ | |
363 | #define READ_PROD_A_READ (1 << 0) | |
364 | #define READ_PROD_B_IF_TRUE (1 << 1) | |
365 | #define READ_PROD_B_IF_FALSE (1 << 2) | |
366 | #define READ_PROD_C_IF_TRUE_READ (1 << 3) | |
367 | ||
368 | #define PROCEDURE_READ_LOCK(base, consumetoken, producetoken) \ | |
369 | :: CONSUME_TOKENS(proc_urcu_reader, consumetoken, READ_PROD_A_READ << base) -> \ | |
370 | ooo_mem(i); \ | |
371 | tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); \ | |
372 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_A_READ << base); \ | |
373 | :: CONSUME_TOKENS(proc_urcu_reader, \ | |
374 | READ_PROD_A_READ << base, /* RAW, pre-dominant */ \ | |
375 | (READ_PROD_B_IF_TRUE | READ_PROD_B_IF_FALSE) << base) -> \ | |
376 | if \ | |
377 | :: (!(tmp & RCU_GP_CTR_NEST_MASK)) -> \ | |
378 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_B_IF_TRUE << base); \ | |
379 | :: else -> \ | |
380 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_B_IF_FALSE << base); \ | |
381 | fi; \ | |
382 | /* IF TRUE */ \ | |
383 | :: CONSUME_TOKENS(proc_urcu_reader, READ_PROD_B_IF_TRUE << base, \ | |
384 | READ_PROD_C_IF_TRUE_READ << base) -> \ | |
385 | ooo_mem(i); \ | |
386 | tmp2 = READ_CACHED_VAR(urcu_gp_ctr); \ | |
387 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_C_IF_TRUE_READ << base); \ | |
388 | :: CONSUME_TOKENS(proc_urcu_reader, \ | |
389 | (READ_PROD_C_IF_TRUE_READ /* pre-dominant */ \ | |
390 | | READ_PROD_A_READ) << base, /* WAR */ \ | |
391 | producetoken) -> \ | |
392 | ooo_mem(i); \ | |
393 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2); \ | |
394 | PRODUCE_TOKENS(proc_urcu_reader, producetoken); \ | |
395 | /* IF_MERGE implies \ | |
396 | * post-dominance */ \ | |
397 | /* ELSE */ \ | |
398 | :: CONSUME_TOKENS(proc_urcu_reader, \ | |
399 | (READ_PROD_B_IF_FALSE /* pre-dominant */ \ | |
400 | | READ_PROD_A_READ) << base, /* WAR */ \ | |
401 | producetoken) -> \ | |
402 | ooo_mem(i); \ | |
403 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], \ | |
404 | tmp + 1); \ | |
405 | PRODUCE_TOKENS(proc_urcu_reader, producetoken); \ | |
406 | /* IF_MERGE implies \ | |
407 | * post-dominance */ \ | |
408 | /* ENDIF */ \ | |
409 | skip | |
410 | ||
411 | /* Body of PROCEDURE_READ_LOCK */ | |
412 | #define READ_PROC_READ_UNLOCK (1 << 0) | |
413 | ||
414 | #define PROCEDURE_READ_UNLOCK(base, consumetoken, producetoken) \ | |
415 | :: CONSUME_TOKENS(proc_urcu_reader, \ | |
416 | consumetoken, \ | |
417 | READ_PROC_READ_UNLOCK << base) -> \ | |
418 | ooo_mem(i); \ | |
419 | tmp2 = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); \ | |
420 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_UNLOCK << base); \ | |
421 | :: CONSUME_TOKENS(proc_urcu_reader, \ | |
422 | consumetoken \ | |
423 | | (READ_PROC_READ_UNLOCK << base), /* WAR */ \ | |
424 | producetoken) -> \ | |
425 | ooo_mem(i); \ | |
426 | WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2 - 1); \ | |
427 | PRODUCE_TOKENS(proc_urcu_reader, producetoken); \ | |
428 | skip | |
429 | ||
430 | ||
431 | #define READ_PROD_NONE (1 << 0) | |
432 | ||
433 | /* PROCEDURE_READ_LOCK base = << 1 : 1 to 5 */ | |
434 | #define READ_LOCK_BASE 1 | |
435 | #define READ_LOCK_OUT (1 << 5) | |
436 | ||
437 | #define READ_PROC_FIRST_MB (1 << 6) | |
438 | ||
439 | /* PROCEDURE_READ_LOCK (NESTED) base : << 7 : 7 to 11 */ | |
440 | #define READ_LOCK_NESTED_BASE 7 | |
441 | #define READ_LOCK_NESTED_OUT (1 << 11) | |
442 | ||
443 | #define READ_PROC_READ_GEN (1 << 12) | |
444 | ||
445 | /* PROCEDURE_READ_UNLOCK (NESTED) base = << 13 : 13 to 14 */ | |
446 | #define READ_UNLOCK_NESTED_BASE 13 | |
447 | #define READ_UNLOCK_NESTED_OUT (1 << 14) | |
448 | ||
449 | #define READ_PROC_SECOND_MB (1 << 15) | |
450 | ||
451 | /* PROCEDURE_READ_UNLOCK base = << 16 : 16 to 17 */ | |
452 | #define READ_UNLOCK_BASE 16 | |
453 | #define READ_UNLOCK_OUT (1 << 17) | |
454 | ||
455 | /* PROCEDURE_READ_LOCK_UNROLL base = << 18 : 18 to 22 */ | |
456 | #define READ_LOCK_UNROLL_BASE 18 | |
457 | #define READ_LOCK_OUT_UNROLL (1 << 22) | |
458 | ||
459 | #define READ_PROC_THIRD_MB (1 << 23) | |
460 | ||
461 | #define READ_PROC_READ_GEN_UNROLL (1 << 24) | |
462 | ||
463 | #define READ_PROC_FOURTH_MB (1 << 25) | |
464 | ||
465 | /* PROCEDURE_READ_UNLOCK_UNROLL base = << 26 : 26 to 27 */ | |
466 | #define READ_UNLOCK_UNROLL_BASE 26 | |
467 | #define READ_UNLOCK_OUT_UNROLL (1 << 27) | |
468 | ||
469 | ||
470 | /* Should not include branches */ | |
471 | #define READ_PROC_ALL_TOKENS (READ_PROD_NONE \ | |
472 | | READ_LOCK_OUT \ | |
473 | | READ_PROC_FIRST_MB \ | |
474 | | READ_LOCK_NESTED_OUT \ | |
475 | | READ_PROC_READ_GEN \ | |
476 | | READ_UNLOCK_NESTED_OUT \ | |
477 | | READ_PROC_SECOND_MB \ | |
478 | | READ_UNLOCK_OUT \ | |
479 | | READ_LOCK_OUT_UNROLL \ | |
480 | | READ_PROC_THIRD_MB \ | |
481 | | READ_PROC_READ_GEN_UNROLL \ | |
482 | | READ_PROC_FOURTH_MB \ | |
483 | | READ_UNLOCK_OUT_UNROLL) | |
484 | ||
485 | /* Must clear all tokens, including branches */ | |
486 | #define READ_PROC_ALL_TOKENS_CLEAR ((1 << 28) - 1) | |
487 | ||
488 | inline urcu_one_read(i, j, nest_i, tmp, tmp2) | |
489 | { | |
490 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROD_NONE); | |
491 | ||
492 | #ifdef NO_MB | |
493 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB); | |
494 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_SECOND_MB); | |
495 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_THIRD_MB); | |
496 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FOURTH_MB); | |
497 | #endif | |
498 | ||
499 | #ifdef REMOTE_BARRIERS | |
500 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB); | |
501 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_SECOND_MB); | |
502 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_THIRD_MB); | |
503 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FOURTH_MB); | |
504 | #endif | |
505 | ||
506 | do | |
507 | :: 1 -> | |
508 | ||
509 | #ifdef REMOTE_BARRIERS | |
510 | /* | |
511 | * Signal-based memory barrier will only execute when the | |
512 | * execution order appears in program order. | |
513 | */ | |
514 | if | |
515 | :: 1 -> | |
516 | atomic { | |
517 | if | |
518 | :: CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE, | |
519 | READ_LOCK_OUT | READ_LOCK_NESTED_OUT | |
520 | | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
521 | | READ_UNLOCK_OUT | |
522 | | READ_LOCK_OUT_UNROLL | |
523 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
524 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT, | |
525 | READ_LOCK_NESTED_OUT | |
526 | | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
527 | | READ_UNLOCK_OUT | |
528 | | READ_LOCK_OUT_UNROLL | |
529 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
530 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | READ_LOCK_NESTED_OUT, | |
531 | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
532 | | READ_UNLOCK_OUT | |
533 | | READ_LOCK_OUT_UNROLL | |
534 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
535 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | |
536 | | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN, | |
537 | READ_UNLOCK_NESTED_OUT | |
538 | | READ_UNLOCK_OUT | |
539 | | READ_LOCK_OUT_UNROLL | |
540 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
541 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | |
542 | | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT, | |
543 | READ_UNLOCK_OUT | |
544 | | READ_LOCK_OUT_UNROLL | |
545 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
546 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | |
547 | | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
548 | | READ_UNLOCK_OUT, | |
549 | READ_LOCK_OUT_UNROLL | |
550 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
551 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | |
552 | | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
553 | | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL, | |
554 | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL) | |
555 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | |
556 | | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
557 | | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | |
558 | | READ_PROC_READ_GEN_UNROLL, | |
559 | READ_UNLOCK_OUT_UNROLL) | |
560 | || CONSUME_TOKENS(proc_urcu_reader, READ_PROD_NONE | READ_LOCK_OUT | |
561 | | READ_LOCK_NESTED_OUT | READ_PROC_READ_GEN | READ_UNLOCK_NESTED_OUT | |
562 | | READ_UNLOCK_OUT | READ_LOCK_OUT_UNROLL | |
563 | | READ_PROC_READ_GEN_UNROLL | READ_UNLOCK_OUT_UNROLL, | |
564 | 0) -> | |
565 | goto non_atomic3; | |
566 | non_atomic3_end: | |
567 | skip; | |
568 | fi; | |
569 | } | |
570 | :: 1 -> skip; | |
571 | fi; | |
572 | ||
573 | goto non_atomic3_skip; | |
574 | non_atomic3: | |
575 | smp_mb_recv(i, j); | |
576 | goto non_atomic3_end; | |
577 | non_atomic3_skip: | |
578 | ||
579 | #endif /* REMOTE_BARRIERS */ | |
580 | ||
581 | atomic { | |
582 | if | |
583 | PROCEDURE_READ_LOCK(READ_LOCK_BASE, READ_PROD_NONE, READ_LOCK_OUT); | |
584 | ||
585 | :: CONSUME_TOKENS(proc_urcu_reader, | |
586 | READ_LOCK_OUT, /* post-dominant */ | |
587 | READ_PROC_FIRST_MB) -> | |
588 | smp_mb_reader(i, j); | |
589 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FIRST_MB); | |
590 | ||
591 | PROCEDURE_READ_LOCK(READ_LOCK_NESTED_BASE, READ_PROC_FIRST_MB | READ_LOCK_OUT, | |
592 | READ_LOCK_NESTED_OUT); | |
593 | ||
594 | :: CONSUME_TOKENS(proc_urcu_reader, | |
595 | READ_PROC_FIRST_MB, /* mb() orders reads */ | |
596 | READ_PROC_READ_GEN) -> | |
597 | ooo_mem(i); | |
598 | read_generation[get_readerid()] = | |
599 | READ_CACHED_VAR(generation_ptr); | |
600 | goto non_atomic; | |
601 | non_atomic_end: | |
602 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN); | |
603 | ||
604 | /* Note : we remove the nested memory barrier from the read unlock | |
605 | * model, given it is not usually needed. The implementation has the barrier | |
606 | * because the performance impact added by a branch in the common case does not | |
607 | * justify it. | |
608 | */ | |
609 | ||
610 | PROCEDURE_READ_UNLOCK(READ_UNLOCK_NESTED_BASE, | |
611 | READ_PROC_FIRST_MB | |
612 | | READ_LOCK_OUT | |
613 | | READ_LOCK_NESTED_OUT, | |
614 | READ_UNLOCK_NESTED_OUT); | |
615 | ||
616 | ||
617 | :: CONSUME_TOKENS(proc_urcu_reader, | |
618 | READ_PROC_READ_GEN /* mb() orders reads */ | |
619 | | READ_PROC_FIRST_MB /* mb() ordered */ | |
620 | | READ_LOCK_OUT /* post-dominant */ | |
621 | | READ_LOCK_NESTED_OUT /* post-dominant */ | |
622 | | READ_UNLOCK_NESTED_OUT, | |
623 | READ_PROC_SECOND_MB) -> | |
624 | smp_mb_reader(i, j); | |
625 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_SECOND_MB); | |
626 | ||
627 | PROCEDURE_READ_UNLOCK(READ_UNLOCK_BASE, | |
628 | READ_PROC_SECOND_MB /* mb() orders reads */ | |
629 | | READ_PROC_FIRST_MB /* mb() orders reads */ | |
630 | | READ_LOCK_NESTED_OUT /* RAW */ | |
631 | | READ_LOCK_OUT /* RAW */ | |
632 | | READ_UNLOCK_NESTED_OUT, /* RAW */ | |
633 | READ_UNLOCK_OUT); | |
634 | ||
635 | /* Unrolling loop : second consecutive lock */ | |
636 | /* reading urcu_active_readers, which have been written by | |
637 | * READ_UNLOCK_OUT : RAW */ | |
638 | PROCEDURE_READ_LOCK(READ_LOCK_UNROLL_BASE, | |
639 | READ_UNLOCK_OUT /* RAW */ | |
640 | | READ_PROC_SECOND_MB /* mb() orders reads */ | |
641 | | READ_PROC_FIRST_MB /* mb() orders reads */ | |
642 | | READ_LOCK_NESTED_OUT /* RAW */ | |
643 | | READ_LOCK_OUT /* RAW */ | |
644 | | READ_UNLOCK_NESTED_OUT, /* RAW */ | |
645 | READ_LOCK_OUT_UNROLL); | |
646 | ||
647 | ||
648 | :: CONSUME_TOKENS(proc_urcu_reader, | |
649 | READ_PROC_FIRST_MB /* mb() ordered */ | |
650 | | READ_PROC_SECOND_MB /* mb() ordered */ | |
651 | | READ_LOCK_OUT_UNROLL /* post-dominant */ | |
652 | | READ_LOCK_NESTED_OUT | |
653 | | READ_LOCK_OUT | |
654 | | READ_UNLOCK_NESTED_OUT | |
655 | | READ_UNLOCK_OUT, | |
656 | READ_PROC_THIRD_MB) -> | |
657 | smp_mb_reader(i, j); | |
658 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_THIRD_MB); | |
659 | ||
660 | :: CONSUME_TOKENS(proc_urcu_reader, | |
661 | READ_PROC_FIRST_MB /* mb() orders reads */ | |
662 | | READ_PROC_SECOND_MB /* mb() orders reads */ | |
663 | | READ_PROC_THIRD_MB, /* mb() orders reads */ | |
664 | READ_PROC_READ_GEN_UNROLL) -> | |
665 | ooo_mem(i); | |
666 | read_generation[get_readerid()] = | |
667 | READ_CACHED_VAR(generation_ptr); | |
668 | goto non_atomic2; | |
669 | non_atomic2_end: | |
670 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_READ_GEN_UNROLL); | |
671 | ||
672 | :: CONSUME_TOKENS(proc_urcu_reader, | |
673 | READ_PROC_READ_GEN_UNROLL /* mb() orders reads */ | |
674 | | READ_PROC_FIRST_MB /* mb() ordered */ | |
675 | | READ_PROC_SECOND_MB /* mb() ordered */ | |
676 | | READ_PROC_THIRD_MB /* mb() ordered */ | |
677 | | READ_LOCK_OUT_UNROLL /* post-dominant */ | |
678 | | READ_LOCK_NESTED_OUT | |
679 | | READ_LOCK_OUT | |
680 | | READ_UNLOCK_NESTED_OUT | |
681 | | READ_UNLOCK_OUT, | |
682 | READ_PROC_FOURTH_MB) -> | |
683 | smp_mb_reader(i, j); | |
684 | PRODUCE_TOKENS(proc_urcu_reader, READ_PROC_FOURTH_MB); | |
685 | ||
686 | PROCEDURE_READ_UNLOCK(READ_UNLOCK_UNROLL_BASE, | |
687 | READ_PROC_FOURTH_MB /* mb() orders reads */ | |
688 | | READ_PROC_THIRD_MB /* mb() orders reads */ | |
689 | | READ_LOCK_OUT_UNROLL /* RAW */ | |
690 | | READ_PROC_SECOND_MB /* mb() orders reads */ | |
691 | | READ_PROC_FIRST_MB /* mb() orders reads */ | |
692 | | READ_LOCK_NESTED_OUT /* RAW */ | |
693 | | READ_LOCK_OUT /* RAW */ | |
694 | | READ_UNLOCK_NESTED_OUT, /* RAW */ | |
695 | READ_UNLOCK_OUT_UNROLL); | |
696 | :: CONSUME_TOKENS(proc_urcu_reader, READ_PROC_ALL_TOKENS, 0) -> | |
697 | CLEAR_TOKENS(proc_urcu_reader, READ_PROC_ALL_TOKENS_CLEAR); | |
698 | break; | |
699 | fi; | |
700 | } | |
701 | od; | |
702 | /* | |
703 | * Dependency between consecutive loops : | |
704 | * RAW dependency on | |
705 | * WRITE_CACHED_VAR(urcu_active_readers[get_readerid()], tmp2 - 1) | |
706 | * tmp = READ_CACHED_VAR(urcu_active_readers[get_readerid()]); | |
707 | * between loops. | |
708 | * _WHEN THE MB()s are in place_, they add full ordering of the | |
709 | * generation pointer read wrt active reader count read, which ensures | |
710 | * execution will not spill across loop execution. | |
711 | * However, in the event mb()s are removed (execution using signal | |
712 | * handler to promote barrier()() -> smp_mb()), nothing prevents one loop | |
713 | * to spill its execution on other loop's execution. | |
714 | */ | |
715 | goto end; | |
716 | non_atomic: | |
717 | data_access[get_readerid()] = 1; | |
718 | data_access[get_readerid()] = 0; | |
719 | goto non_atomic_end; | |
720 | non_atomic2: | |
721 | data_access[get_readerid()] = 1; | |
722 | data_access[get_readerid()] = 0; | |
723 | goto non_atomic2_end; | |
724 | end: | |
725 | skip; | |
726 | } | |
727 | ||
728 | ||
729 | ||
730 | active proctype urcu_reader() | |
731 | { | |
732 | byte i, j, nest_i; | |
733 | byte tmp, tmp2; | |
734 | ||
735 | wait_init_done(); | |
736 | ||
737 | assert(get_pid() < NR_PROCS); | |
738 | ||
739 | end_reader: | |
740 | do | |
741 | :: 1 -> | |
742 | /* | |
743 | * We do not test reader's progress here, because we are mainly | |
744 | * interested in writer's progress. The reader never blocks | |
745 | * anyway. We have to test for reader/writer's progress | |
746 | * separately, otherwise we could think the writer is doing | |
747 | * progress when it's blocked by an always progressing reader. | |
748 | */ | |
749 | #ifdef READER_PROGRESS | |
750 | progress_reader: | |
751 | #endif | |
752 | urcu_one_read(i, j, nest_i, tmp, tmp2); | |
753 | od; | |
754 | } | |
755 | ||
756 | /* no name clash please */ | |
757 | #undef proc_urcu_reader | |
758 | ||
759 | ||
760 | /* Model the RCU update process. */ | |
761 | ||
762 | /* | |
763 | * Bit encoding, urcu_writer : | |
764 | * Currently only supports one reader. | |
765 | */ | |
766 | ||
767 | int _proc_urcu_writer; | |
768 | #define proc_urcu_writer _proc_urcu_writer | |
769 | ||
770 | #define WRITE_PROD_NONE (1 << 0) | |
771 | ||
772 | #define WRITE_PROC_FIRST_MB (1 << 1) | |
773 | ||
774 | /* first flip */ | |
775 | #define WRITE_PROC_FIRST_READ_GP (1 << 2) | |
776 | #define WRITE_PROC_FIRST_WRITE_GP (1 << 3) | |
777 | #define WRITE_PROC_FIRST_WAIT (1 << 4) | |
778 | #define WRITE_PROC_FIRST_WAIT_LOOP (1 << 5) | |
779 | ||
780 | /* second flip */ | |
781 | #define WRITE_PROC_SECOND_READ_GP (1 << 6) | |
782 | #define WRITE_PROC_SECOND_WRITE_GP (1 << 7) | |
783 | #define WRITE_PROC_SECOND_WAIT (1 << 8) | |
784 | #define WRITE_PROC_SECOND_WAIT_LOOP (1 << 9) | |
785 | ||
786 | #define WRITE_PROC_SECOND_MB (1 << 10) | |
787 | ||
788 | #define WRITE_PROC_ALL_TOKENS (WRITE_PROD_NONE \ | |
789 | | WRITE_PROC_FIRST_MB \ | |
790 | | WRITE_PROC_FIRST_READ_GP \ | |
791 | | WRITE_PROC_FIRST_WRITE_GP \ | |
792 | | WRITE_PROC_FIRST_WAIT \ | |
793 | | WRITE_PROC_SECOND_READ_GP \ | |
794 | | WRITE_PROC_SECOND_WRITE_GP \ | |
795 | | WRITE_PROC_SECOND_WAIT \ | |
796 | | WRITE_PROC_SECOND_MB) | |
797 | ||
798 | #define WRITE_PROC_ALL_TOKENS_CLEAR ((1 << 11) - 1) | |
799 | ||
800 | active proctype urcu_writer() | |
801 | { | |
802 | byte i, j; | |
803 | byte tmp, tmp2, tmpa; | |
804 | byte old_gen; | |
805 | ||
806 | wait_init_done(); | |
807 | ||
808 | assert(get_pid() < NR_PROCS); | |
809 | ||
810 | do | |
811 | :: (READ_CACHED_VAR(generation_ptr) < 5) -> | |
812 | #ifdef WRITER_PROGRESS | |
813 | progress_writer1: | |
814 | #endif | |
815 | ooo_mem(i); | |
816 | atomic { | |
817 | old_gen = READ_CACHED_VAR(generation_ptr); | |
818 | WRITE_CACHED_VAR(generation_ptr, old_gen + 1); | |
819 | } | |
820 | ooo_mem(i); | |
821 | ||
822 | do | |
823 | :: 1 -> | |
824 | atomic { | |
825 | if | |
826 | :: write_lock == 0 -> | |
827 | write_lock = 1; | |
828 | break; | |
829 | :: else -> | |
830 | skip; | |
831 | fi; | |
832 | } | |
833 | od; | |
834 | ||
835 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROD_NONE); | |
836 | ||
837 | #ifdef NO_MB | |
838 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB); | |
839 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_MB); | |
840 | #endif | |
841 | ||
842 | #ifdef SINGLE_FLIP | |
843 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP); | |
844 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WRITE_GP); | |
845 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT); | |
846 | #endif | |
847 | ||
848 | do | |
849 | :: CONSUME_TOKENS(proc_urcu_writer, | |
850 | WRITE_PROD_NONE, | |
851 | WRITE_PROC_FIRST_MB) -> | |
852 | smp_mb_send(i, j); | |
853 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_MB); | |
854 | ||
855 | /* first flip */ | |
856 | :: CONSUME_TOKENS(proc_urcu_writer, | |
857 | WRITE_PROC_FIRST_MB, | |
858 | WRITE_PROC_FIRST_READ_GP) -> | |
859 | tmpa = READ_CACHED_VAR(urcu_gp_ctr); | |
860 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_READ_GP); | |
861 | :: CONSUME_TOKENS(proc_urcu_writer, | |
862 | WRITE_PROC_FIRST_MB | WRITE_PROC_FIRST_READ_GP, | |
863 | WRITE_PROC_FIRST_WRITE_GP) -> | |
864 | ooo_mem(i); | |
865 | WRITE_CACHED_VAR(urcu_gp_ctr, tmpa ^ RCU_GP_CTR_BIT); | |
866 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WRITE_GP); | |
867 | ||
868 | :: CONSUME_TOKENS(proc_urcu_writer, | |
869 | //WRITE_PROC_FIRST_WRITE_GP /* TEST ADDING SYNC CORE */ | |
870 | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ | |
871 | WRITE_PROC_FIRST_WAIT | WRITE_PROC_FIRST_WAIT_LOOP) -> | |
872 | ooo_mem(i); | |
873 | /* ONLY WAITING FOR READER 0 */ | |
874 | tmp2 = READ_CACHED_VAR(urcu_active_readers[0]); | |
875 | if | |
876 | :: (tmp2 & RCU_GP_CTR_NEST_MASK) | |
877 | && ((tmp2 ^ RCU_GP_CTR_BIT) & RCU_GP_CTR_BIT) -> | |
878 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT_LOOP); | |
879 | :: else -> | |
880 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT); | |
881 | fi; | |
882 | ||
883 | :: CONSUME_TOKENS(proc_urcu_writer, | |
884 | //WRITE_PROC_FIRST_WRITE_GP /* TEST ADDING SYNC CORE */ | |
885 | WRITE_PROC_FIRST_WRITE_GP | |
886 | | WRITE_PROC_FIRST_READ_GP | |
887 | | WRITE_PROC_FIRST_WAIT_LOOP | |
888 | | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ | |
889 | 0) -> | |
890 | #ifndef GEN_ERROR_WRITER_PROGRESS | |
891 | smp_mb_send(i, j); | |
892 | #else | |
893 | ooo_mem(i); | |
894 | #endif | |
895 | /* This instruction loops to WRITE_PROC_FIRST_WAIT */ | |
896 | CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_FIRST_WAIT_LOOP | WRITE_PROC_FIRST_WAIT); | |
897 | ||
898 | /* second flip */ | |
899 | :: CONSUME_TOKENS(proc_urcu_writer, | |
900 | WRITE_PROC_FIRST_WAIT /* Control dependency : need to branch out of | |
901 | * the loop to execute the next flip (CHECK) */ | |
902 | | WRITE_PROC_FIRST_WRITE_GP | |
903 | | WRITE_PROC_FIRST_READ_GP | |
904 | | WRITE_PROC_FIRST_MB, | |
905 | WRITE_PROC_SECOND_READ_GP) -> | |
906 | //smp_mb_send(i, j); //TEST | |
907 | ooo_mem(i); | |
908 | tmpa = READ_CACHED_VAR(urcu_gp_ctr); | |
909 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_READ_GP); | |
910 | :: CONSUME_TOKENS(proc_urcu_writer, | |
911 | WRITE_PROC_FIRST_MB | |
912 | | WRITE_PROC_FIRST_READ_GP | |
913 | | WRITE_PROC_FIRST_WRITE_GP | |
914 | | WRITE_PROC_SECOND_READ_GP, | |
915 | WRITE_PROC_SECOND_WRITE_GP) -> | |
916 | ooo_mem(i); | |
917 | WRITE_CACHED_VAR(urcu_gp_ctr, tmpa ^ RCU_GP_CTR_BIT); | |
918 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WRITE_GP); | |
919 | ||
920 | :: CONSUME_TOKENS(proc_urcu_writer, | |
921 | //WRITE_PROC_FIRST_WRITE_GP /* TEST ADDING SYNC CORE */ | |
922 | WRITE_PROC_FIRST_WAIT | |
923 | | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ | |
924 | WRITE_PROC_SECOND_WAIT | WRITE_PROC_SECOND_WAIT_LOOP) -> | |
925 | ooo_mem(i); | |
926 | /* ONLY WAITING FOR READER 0 */ | |
927 | tmp2 = READ_CACHED_VAR(urcu_active_readers[0]); | |
928 | if | |
929 | :: (tmp2 & RCU_GP_CTR_NEST_MASK) | |
930 | && ((tmp2 ^ 0) & RCU_GP_CTR_BIT) -> | |
931 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT_LOOP); | |
932 | :: else -> | |
933 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT); | |
934 | fi; | |
935 | ||
936 | :: CONSUME_TOKENS(proc_urcu_writer, | |
937 | //WRITE_PROC_FIRST_WRITE_GP /* TEST ADDING SYNC CORE */ | |
938 | WRITE_PROC_SECOND_WRITE_GP | |
939 | | WRITE_PROC_FIRST_WRITE_GP | |
940 | | WRITE_PROC_SECOND_READ_GP | |
941 | | WRITE_PROC_FIRST_READ_GP | |
942 | | WRITE_PROC_SECOND_WAIT_LOOP | |
943 | | WRITE_PROC_FIRST_MB, /* can be reordered before/after flips */ | |
944 | 0) -> | |
945 | #ifndef GEN_ERROR_WRITER_PROGRESS | |
946 | smp_mb_send(i, j); | |
947 | #else | |
948 | ooo_mem(i); | |
949 | #endif | |
950 | /* This instruction loops to WRITE_PROC_SECOND_WAIT */ | |
951 | CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_WAIT_LOOP | WRITE_PROC_SECOND_WAIT); | |
952 | ||
953 | ||
954 | :: CONSUME_TOKENS(proc_urcu_writer, | |
955 | WRITE_PROC_FIRST_WAIT | |
956 | | WRITE_PROC_SECOND_WAIT | |
957 | | WRITE_PROC_FIRST_READ_GP | |
958 | | WRITE_PROC_SECOND_READ_GP | |
959 | | WRITE_PROC_FIRST_WRITE_GP | |
960 | | WRITE_PROC_SECOND_WRITE_GP | |
961 | | WRITE_PROC_FIRST_MB, | |
962 | WRITE_PROC_SECOND_MB) -> | |
963 | smp_mb_send(i, j); | |
964 | PRODUCE_TOKENS(proc_urcu_writer, WRITE_PROC_SECOND_MB); | |
965 | ||
966 | :: CONSUME_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS, 0) -> | |
967 | CLEAR_TOKENS(proc_urcu_writer, WRITE_PROC_ALL_TOKENS_CLEAR); | |
968 | break; | |
969 | od; | |
970 | ||
971 | write_lock = 0; | |
972 | /* free-up step, e.g., kfree(). */ | |
973 | atomic { | |
974 | last_free_gen = old_gen; | |
975 | free_done = 1; | |
976 | } | |
977 | :: else -> break; | |
978 | od; | |
979 | /* | |
980 | * Given the reader loops infinitely, let the writer also busy-loop | |
981 | * with progress here so, with weak fairness, we can test the | |
982 | * writer's progress. | |
983 | */ | |
984 | end_writer: | |
985 | do | |
986 | :: 1 -> | |
987 | #ifdef WRITER_PROGRESS | |
988 | progress_writer2: | |
989 | #endif | |
990 | skip; | |
991 | od; | |
992 | } | |
993 | ||
994 | /* no name clash please */ | |
995 | #undef proc_urcu_writer | |
996 | ||
997 | ||
998 | /* Leave after the readers and writers so the pid count is ok. */ | |
999 | init { | |
1000 | byte i, j; | |
1001 | ||
1002 | atomic { | |
1003 | INIT_CACHED_VAR(urcu_gp_ctr, 1, j); | |
1004 | INIT_CACHED_VAR(generation_ptr, 0, j); | |
1005 | ||
1006 | i = 0; | |
1007 | do | |
1008 | :: i < NR_READERS -> | |
1009 | INIT_CACHED_VAR(urcu_active_readers[i], 0, j); | |
1010 | read_generation[i] = 1; | |
1011 | data_access[i] = 0; | |
1012 | i++; | |
1013 | :: i >= NR_READERS -> break | |
1014 | od; | |
1015 | init_done = 1; | |
1016 | } | |
1017 | } |