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Revision 1.61 - (show annotations)
Tue Nov 18 15:15:18 2025 UTC (3 months, 4 weeks ago) by sysadm
Branch: MAIN
Changes since 1.60: +8 -22 lines
Content type: text/x-csrc
Skip remap shared memory in read only mode under Cygwin
shmat() again after shmdt() without SHM_REMAP would change the address

1 /* SPDX-License-Identifier: GPL-3.0-or-later */
2 /*
3 * section_list
4 * - data models and basic operations of section and article
5 *
6 * Copyright (C) 2004-2025 Leaflet <leaflet@leafok.com>
7 */
8
9 #ifdef HAVE_CONFIG_H
10 #include "config.h"
11 #endif
12
13 #include "log.h"
14 #include "section_list.h"
15 #include "trie_dict.h"
16 #include "user_list.h"
17 #include <errno.h>
18 #include <signal.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23 #include <sys/ipc.h>
24 #include <sys/param.h>
25 #include <sys/sem.h>
26 #include <sys/shm.h>
27
28 #if defined(_SEM_SEMUN_UNDEFINED) || defined(__CYGWIN__)
29 union semun
30 {
31 int val; /* Value for SETVAL */
32 struct semid_ds *buf; /* Buffer for IPC_STAT, IPC_SET */
33 unsigned short *array; /* Array for GETALL, SETALL */
34 struct seminfo *__buf; /* Buffer for IPC_INFO
35 (Linux-specific) */
36 };
37 #endif // #if defined(_SEM_SEMUN_UNDEFINED)
38
39 enum _section_list_constant_t
40 {
41 SECTION_TRY_LOCK_WAIT_TIME = 1, // second
42 SECTION_TRY_LOCK_TIMES = 10,
43
44 ARTICLE_BLOCK_PER_SHM = 1000, // sizeof(ARTICLE_BLOCK) * ARTICLE_BLOCK_PER_SHM is the size of each shm segment to allocate
45 ARTICLE_BLOCK_SHM_COUNT_LIMIT = 80, // limited by length (8-bit) of proj_id in ftok(path, proj_id)
46 ARTICLE_BLOCK_PER_POOL = (ARTICLE_BLOCK_PER_SHM * ARTICLE_BLOCK_SHM_COUNT_LIMIT),
47
48 CALCULATE_PAGE_THRESHOLD = 100, // Adjust to tune performance of moving topic between sections
49
50 SID_STR_LEN = 5, // 32-bit + NULL
51 };
52
53 struct article_block_t
54 {
55 ARTICLE articles[BBS_article_count_per_block];
56 int article_count;
57 struct article_block_t *p_next_block;
58 };
59 typedef struct article_block_t ARTICLE_BLOCK;
60
61 struct article_block_pool_t
62 {
63 int shmid;
64 struct
65 {
66 int shmid;
67 void *p_shm;
68 } shm_pool[ARTICLE_BLOCK_SHM_COUNT_LIMIT];
69 int shm_count;
70 ARTICLE_BLOCK *p_block_free_list;
71 ARTICLE_BLOCK *p_block[ARTICLE_BLOCK_PER_POOL];
72 int block_count;
73 };
74 typedef struct article_block_pool_t ARTICLE_BLOCK_POOL;
75
76 static ARTICLE_BLOCK_POOL *p_article_block_pool = NULL;
77
78 SECTION_LIST_POOL *p_section_list_pool = NULL;
79
80 int article_block_init(const char *filename, int block_count)
81 {
82 int shmid;
83 int proj_id;
84 key_t key;
85 size_t size;
86 void *p_shm;
87 int i;
88 int block_count_in_shm;
89 ARTICLE_BLOCK *p_block_in_shm;
90 ARTICLE_BLOCK **pp_block_next;
91
92 if (p_article_block_pool != NULL)
93 {
94 log_error("article_block_pool already initialized\n");
95 return -1;
96 }
97
98 if (block_count <= 0 || block_count > ARTICLE_BLOCK_PER_POOL)
99 {
100 log_error("article_block_count exceed limit %d\n", ARTICLE_BLOCK_PER_POOL);
101 return -2;
102 }
103
104 // Allocate shared memory
105 proj_id = ARTICLE_BLOCK_SHM_COUNT_LIMIT; // keep different from proj_id used to create block shm
106 key = ftok(filename, proj_id);
107 if (key == -1)
108 {
109 log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
110 return -3;
111 }
112
113 size = sizeof(ARTICLE_BLOCK_POOL);
114 shmid = shmget(key, size, IPC_CREAT | IPC_EXCL | 0600);
115 if (shmid == -1)
116 {
117 log_error("shmget(article_block_pool_shm, size = %d) error (%d)\n", size, errno);
118 return -3;
119 }
120 p_shm = shmat(shmid, NULL, 0);
121 if (p_shm == (void *)-1)
122 {
123 log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
124 return -3;
125 }
126
127 p_article_block_pool = p_shm;
128 p_article_block_pool->shmid = shmid;
129
130 p_article_block_pool->shm_count = 0;
131 pp_block_next = &(p_article_block_pool->p_block_free_list);
132
133 while (block_count > 0)
134 {
135 block_count_in_shm = MIN(block_count, ARTICLE_BLOCK_PER_SHM);
136 block_count -= block_count_in_shm;
137
138 proj_id = p_article_block_pool->shm_count;
139 key = ftok(filename, proj_id);
140 if (key == -1)
141 {
142 log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
143 article_block_cleanup();
144 return -3;
145 }
146
147 size = sizeof(ARTICLE_BLOCK) * (size_t)block_count_in_shm;
148 shmid = shmget(key, size, IPC_CREAT | IPC_EXCL | 0600);
149 if (shmid == -1)
150 {
151 log_error("shmget(shm_index = %d, size = %d) error (%d)\n", p_article_block_pool->shm_count, size, errno);
152 article_block_cleanup();
153 return -3;
154 }
155 p_shm = shmat(shmid, NULL, 0);
156 if (p_shm == (void *)-1)
157 {
158 log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
159 article_block_cleanup();
160 return -3;
161 }
162
163 (p_article_block_pool->shm_pool + p_article_block_pool->shm_count)->shmid = shmid;
164 (p_article_block_pool->shm_pool + p_article_block_pool->shm_count)->p_shm = p_shm;
165 p_article_block_pool->shm_count++;
166
167 p_block_in_shm = p_shm;
168 *pp_block_next = p_block_in_shm;
169
170 for (i = 0; i < block_count_in_shm; i++)
171 {
172 if (i < block_count_in_shm - 1)
173 {
174 (p_block_in_shm + i)->p_next_block = (p_block_in_shm + i + 1);
175 }
176 else
177 {
178 (p_block_in_shm + i)->p_next_block = NULL;
179 pp_block_next = &((p_block_in_shm + i)->p_next_block);
180 }
181 }
182 }
183
184 p_article_block_pool->block_count = 0;
185
186 return 0;
187 }
188
189 void article_block_cleanup(void)
190 {
191 int shmid;
192
193 if (p_article_block_pool == NULL)
194 {
195 return;
196 }
197
198 for (int i = 0; i < p_article_block_pool->shm_count; i++)
199 {
200 if (shmdt((p_article_block_pool->shm_pool + i)->p_shm) == -1)
201 {
202 log_error("shmdt(shmid = %d) error (%d)\n", (p_article_block_pool->shm_pool + i)->shmid, errno);
203 }
204
205 if (shmctl((p_article_block_pool->shm_pool + i)->shmid, IPC_RMID, NULL) == -1)
206 {
207 log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", (p_article_block_pool->shm_pool + i)->shmid, errno);
208 }
209 }
210
211 shmid = p_article_block_pool->shmid;
212
213 if (shmdt(p_article_block_pool) == -1)
214 {
215 log_error("shmdt(shmid = %d) error (%d)\n", shmid, errno);
216 }
217
218 if (shmid != 0 && shmctl(shmid, IPC_RMID, NULL) == -1)
219 {
220 log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", shmid, errno);
221 }
222
223 p_article_block_pool = NULL;
224 }
225
226 int set_article_block_shm_readonly(void)
227 {
228 #ifndef __CYGWIN__
229 int shmid;
230 void *p_shm;
231 int i;
232
233 if (p_article_block_pool == NULL)
234 {
235 log_error("article_block_pool not initialized\n");
236 return -1;
237 }
238
239 for (i = 0; i < p_article_block_pool->shm_count; i++)
240 {
241 shmid = (p_article_block_pool->shm_pool + i)->shmid;
242
243 // Remap shared memory in read-only mode
244 p_shm = shmat(shmid, (p_article_block_pool->shm_pool + i)->p_shm, SHM_RDONLY | SHM_REMAP);
245 if (p_shm == (void *)-1)
246 {
247 log_error("shmat(article_block_pool shmid = %d) error (%d)\n", shmid, errno);
248 return -2;
249 }
250 }
251 #endif
252
253 return 0;
254 }
255
256 int detach_article_block_shm(void)
257 {
258 int shmid;
259
260 if (p_article_block_pool == NULL)
261 {
262 return -1;
263 }
264
265 for (int i = 0; i < p_article_block_pool->shm_count; i++)
266 {
267 if ((p_article_block_pool->shm_pool + i)->p_shm != NULL && shmdt((p_article_block_pool->shm_pool + i)->p_shm) == -1)
268 {
269 log_error("shmdt(shmid = %d) error (%d)\n", (p_article_block_pool->shm_pool + i)->shmid, errno);
270 return -2;
271 }
272 }
273
274 shmid = p_article_block_pool->shmid;
275
276 if (shmdt(p_article_block_pool) == -1)
277 {
278 log_error("shmdt(shmid = %d) error (%d)\n", shmid, errno);
279 return -3;
280 }
281
282 p_article_block_pool = NULL;
283
284 return 0;
285 }
286
287 inline static ARTICLE_BLOCK *pop_free_article_block(void)
288 {
289 ARTICLE_BLOCK *p_block = NULL;
290
291 if (p_article_block_pool->p_block_free_list != NULL)
292 {
293 p_block = p_article_block_pool->p_block_free_list;
294 p_article_block_pool->p_block_free_list = p_block->p_next_block;
295 p_block->p_next_block = NULL;
296 p_block->article_count = 0;
297 }
298
299 return p_block;
300 }
301
302 inline static void push_free_article_block(ARTICLE_BLOCK *p_block)
303 {
304 p_block->p_next_block = p_article_block_pool->p_block_free_list;
305 p_article_block_pool->p_block_free_list = p_block;
306 }
307
308 int article_block_reset(void)
309 {
310 ARTICLE_BLOCK *p_block;
311
312 if (p_article_block_pool == NULL)
313 {
314 log_error("article_block_pool not initialized\n");
315 return -1;
316 }
317
318 while (p_article_block_pool->block_count > 0)
319 {
320 p_article_block_pool->block_count--;
321 p_block = p_article_block_pool->p_block[p_article_block_pool->block_count];
322 push_free_article_block(p_block);
323 }
324
325 return 0;
326 }
327
328 ARTICLE *article_block_find_by_aid(int32_t aid)
329 {
330 ARTICLE_BLOCK *p_block;
331 int left;
332 int right;
333 int mid;
334
335 if (p_article_block_pool == NULL)
336 {
337 log_error("article_block_pool not initialized\n");
338 return NULL;
339 }
340
341 if (p_article_block_pool->block_count == 0) // empty
342 {
343 return NULL;
344 }
345
346 left = 0;
347 right = p_article_block_pool->block_count - 1;
348
349 // aid in the range [ head aid of blocks[left], tail aid of blocks[right] ]
350 while (left < right)
351 {
352 // get block offset no less than mid value of left and right block offsets
353 mid = (left + right) / 2 + (left + right) % 2;
354
355 if (aid < p_article_block_pool->p_block[mid]->articles[0].aid)
356 {
357 right = mid - 1;
358 }
359 else // if (aid >= p_article_block_pool->p_block[mid]->articles[0].aid)
360 {
361 left = mid;
362 }
363 }
364
365 p_block = p_article_block_pool->p_block[left];
366
367 left = 0;
368 right = p_block->article_count - 1;
369
370 // aid in the range [ aid of articles[left], aid of articles[right] ]
371 while (left < right)
372 {
373 mid = (left + right) / 2;
374
375 if (aid <= p_block->articles[mid].aid)
376 {
377 right = mid;
378 }
379 else
380 {
381 left = mid + 1;
382 }
383 }
384
385 if (aid != p_block->articles[left].aid) // not found
386 {
387 return NULL;
388 }
389
390 return (p_block->articles + left); // found
391 }
392
393 ARTICLE *article_block_find_by_index(int index)
394 {
395 ARTICLE_BLOCK *p_block;
396
397 if (p_article_block_pool == NULL)
398 {
399 log_error("article_block_pool not initialized\n");
400 return NULL;
401 }
402
403 if (index < 0 || index / BBS_article_count_per_block >= p_article_block_pool->block_count)
404 {
405 log_error("article_block_find_by_index(%d) is out of boundary of block [0, %d)\n", index, p_article_block_pool->block_count);
406 return NULL;
407 }
408
409 p_block = p_article_block_pool->p_block[index / BBS_article_count_per_block];
410
411 if (index % BBS_article_count_per_block >= p_block->article_count)
412 {
413 log_error("article_block_find_by_index(%d) is out of boundary of article [0, %d)\n", index, p_block->article_count);
414 return NULL;
415 }
416
417 return (p_block->articles + (index % BBS_article_count_per_block));
418 }
419
420 extern int section_list_init(const char *filename)
421 {
422 int semid;
423 int shmid;
424 int proj_id;
425 key_t key;
426 size_t size;
427 void *p_shm;
428 union semun arg;
429 int i;
430
431 if (p_section_list_pool != NULL)
432 {
433 section_list_cleanup();
434 }
435
436 proj_id = (int)(time(NULL) % getpid());
437 key = ftok(filename, proj_id);
438 if (key == -1)
439 {
440 log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
441 return -3;
442 }
443
444 // Allocate shared memory
445 size = sizeof(SECTION_LIST_POOL);
446 shmid = shmget(key, size, IPC_CREAT | IPC_EXCL | 0600);
447 if (shmid == -1)
448 {
449 log_error("shmget(section_list_pool_shm, size = %d) error (%d)\n", size, errno);
450 return -3;
451 }
452 p_shm = shmat(shmid, NULL, 0);
453 if (p_shm == (void *)-1)
454 {
455 log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
456 return -3;
457 }
458
459 p_section_list_pool = p_shm;
460 p_section_list_pool->shmid = shmid;
461 p_section_list_pool->section_count = 0;
462
463 // Allocate semaphore as section locks
464 size = 2 * (BBS_max_section + 1); // r_sem and w_sem per section, the last pair for all sections
465 semid = semget(key, (int)size, IPC_CREAT | IPC_EXCL | 0600);
466 if (semid == -1)
467 {
468 log_error("semget(section_list_pool_sem, size = %d) error (%d)\n", size, errno);
469 return -3;
470 }
471
472 // Initialize sem value to 0
473 arg.val = 0;
474 for (i = 0; i < size; i++)
475 {
476 if (semctl(semid, i, SETVAL, arg) == -1)
477 {
478 log_error("semctl(section_list_pool_sem, SETVAL) error (%d)\n", errno);
479 return -3;
480 }
481 }
482
483 p_section_list_pool->semid = semid;
484
485 p_section_list_pool->p_trie_dict_section_by_name = trie_dict_create();
486 if (p_section_list_pool->p_trie_dict_section_by_name == NULL)
487 {
488 log_error("trie_dict_create() OOM\n", BBS_max_section);
489 return -2;
490 }
491
492 p_section_list_pool->p_trie_dict_section_by_sid = trie_dict_create();
493 if (p_section_list_pool->p_trie_dict_section_by_sid == NULL)
494 {
495 log_error("trie_dict_create() OOM\n", BBS_max_section);
496 return -2;
497 }
498
499 return 0;
500 }
501
502 void section_list_cleanup(void)
503 {
504 int shmid;
505
506 if (p_section_list_pool == NULL)
507 {
508 return;
509 }
510
511 if (p_section_list_pool->p_trie_dict_section_by_name != NULL)
512 {
513 trie_dict_destroy(p_section_list_pool->p_trie_dict_section_by_name);
514 p_section_list_pool->p_trie_dict_section_by_name = NULL;
515 }
516
517 if (p_section_list_pool->p_trie_dict_section_by_sid != NULL)
518 {
519 trie_dict_destroy(p_section_list_pool->p_trie_dict_section_by_sid);
520 p_section_list_pool->p_trie_dict_section_by_sid = NULL;
521 }
522
523 shmid = p_section_list_pool->shmid;
524
525 if (semctl(p_section_list_pool->semid, 0, IPC_RMID) == -1)
526 {
527 log_error("semctl(semid = %d, IPC_RMID) error (%d)\n", p_section_list_pool->semid, errno);
528 }
529
530 if (shmdt(p_section_list_pool) == -1)
531 {
532 log_error("shmdt(shmid = %d) error (%d)\n", shmid, errno);
533 }
534
535 if (shmid != 0 && shmctl(shmid, IPC_RMID, NULL) == -1)
536 {
537 log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", shmid, errno);
538 }
539
540 p_section_list_pool = NULL;
541 }
542
543 int set_section_list_shm_readonly(void)
544 {
545 #ifndef __CYGWIN__
546 int shmid;
547 void *p_shm;
548
549 if (p_section_list_pool == NULL)
550 {
551 log_error("p_section_list_pool not initialized\n");
552 return -1;
553 }
554
555 shmid = p_section_list_pool->shmid;
556
557 // Remap shared memory in read-only mode
558 p_shm = shmat(shmid, p_section_list_pool, SHM_RDONLY | SHM_REMAP);
559 if (p_shm == (void *)-1)
560 {
561 log_error("shmat(section_list_pool shmid = %d) error (%d)\n", shmid, errno);
562 return -3;
563 }
564
565 p_section_list_pool = p_shm;
566 #endif
567
568 return 0;
569 }
570
571 int detach_section_list_shm(void)
572 {
573 if (p_section_list_pool != NULL && shmdt(p_section_list_pool) == -1)
574 {
575 log_error("shmdt(section_list_pool) error (%d)\n", errno);
576 return -1;
577 }
578
579 p_section_list_pool = NULL;
580
581 return 0;
582 }
583
584 inline static void sid_to_str(int32_t sid, char *p_sid_str)
585 {
586 uint32_t u_sid;
587 int i;
588
589 u_sid = (uint32_t)sid;
590 for (i = 0; i < SID_STR_LEN - 1; i++)
591 {
592 p_sid_str[i] = (char)(u_sid % 255 + 1);
593 u_sid /= 255;
594 }
595 p_sid_str[i] = '\0';
596 }
597
598 SECTION_LIST *section_list_create(int32_t sid, const char *sname, const char *stitle, const char *master_list)
599 {
600 SECTION_LIST *p_section;
601 char sid_str[SID_STR_LEN];
602
603 if (p_section_list_pool == NULL)
604 {
605 log_error("session_list_pool not initialized\n");
606 return NULL;
607 }
608
609 if (p_section_list_pool->section_count >= BBS_max_section)
610 {
611 log_error("section_count reach limit %d >= %d\n", p_section_list_pool->section_count, BBS_max_section);
612 return NULL;
613 }
614
615 sid_to_str(sid, sid_str);
616
617 p_section = p_section_list_pool->sections + p_section_list_pool->section_count;
618
619 p_section->sid = sid;
620 p_section->ex_menu_tm = 0;
621
622 strncpy(p_section->sname, sname, sizeof(p_section->sname) - 1);
623 p_section->sname[sizeof(p_section->sname) - 1] = '\0';
624
625 strncpy(p_section->stitle, stitle, sizeof(p_section->stitle) - 1);
626 p_section->stitle[sizeof(p_section->stitle) - 1] = '\0';
627
628 strncpy(p_section->master_list, master_list, sizeof(p_section->master_list) - 1);
629 p_section->master_list[sizeof(p_section->master_list) - 1] = '\0';
630
631 if (trie_dict_set(p_section_list_pool->p_trie_dict_section_by_name, sname, p_section_list_pool->section_count) != 1)
632 {
633 log_error("trie_dict_set(section, %s, %d) error\n", sname, p_section_list_pool->section_count);
634 return NULL;
635 }
636
637 if (trie_dict_set(p_section_list_pool->p_trie_dict_section_by_sid, sid_str, p_section_list_pool->section_count) != 1)
638 {
639 log_error("trie_dict_set(section, %d, %d) error\n", sid, p_section_list_pool->section_count);
640 return NULL;
641 }
642
643 section_list_reset_articles(p_section);
644
645 p_section_list_pool->section_count++;
646
647 return p_section;
648 }
649
650 int section_list_update(SECTION_LIST *p_section, const char *sname, const char *stitle, const char *master_list)
651 {
652 int64_t index;
653
654 if (p_section == NULL || sname == NULL || stitle == NULL || master_list == NULL)
655 {
656 log_error("NULL pointer error\n");
657 return -1;
658 }
659
660 index = get_section_index(p_section);
661
662 strncpy(p_section->sname, sname, sizeof(p_section->sname) - 1);
663 p_section->sname[sizeof(p_section->sname) - 1] = '\0';
664
665 strncpy(p_section->stitle, stitle, sizeof(p_section->stitle) - 1);
666 p_section->stitle[sizeof(p_section->stitle) - 1] = '\0';
667
668 strncpy(p_section->master_list, master_list, sizeof(p_section->master_list) - 1);
669 p_section->master_list[sizeof(p_section->master_list) - 1] = '\0';
670
671 if (trie_dict_set(p_section_list_pool->p_trie_dict_section_by_name, sname, index) < 0)
672 {
673 log_error("trie_dict_set(section, %s, %d) error\n", sname, index);
674 return -2;
675 }
676
677 return 0;
678 }
679
680 void section_list_reset_articles(SECTION_LIST *p_section)
681 {
682 p_section->article_count = 0;
683 p_section->topic_count = 0;
684 p_section->visible_article_count = 0;
685 p_section->visible_topic_count = 0;
686 p_section->p_article_head = NULL;
687 p_section->p_article_tail = NULL;
688
689 p_section->page_count = 0;
690 p_section->last_page_visible_article_count = 0;
691
692 p_section->ontop_article_count = 0;
693 }
694
695 SECTION_LIST *section_list_find_by_name(const char *sname)
696 {
697 int64_t index;
698 int ret;
699
700 if (p_section_list_pool == NULL)
701 {
702 log_error("section_list not initialized\n");
703 return NULL;
704 }
705
706 ret = trie_dict_get(p_section_list_pool->p_trie_dict_section_by_name, sname, &index);
707 if (ret < 0)
708 {
709 log_error("trie_dict_get(section, %s) error\n", sname);
710 return NULL;
711 }
712 else if (ret == 0)
713 {
714 return NULL;
715 }
716
717 return (p_section_list_pool->sections + index);
718 }
719
720 SECTION_LIST *section_list_find_by_sid(int32_t sid)
721 {
722 int64_t index;
723 int ret;
724 char sid_str[SID_STR_LEN];
725
726 if (p_section_list_pool == NULL)
727 {
728 log_error("section_list not initialized\n");
729 return NULL;
730 }
731
732 sid_to_str(sid, sid_str);
733
734 ret = trie_dict_get(p_section_list_pool->p_trie_dict_section_by_sid, sid_str, &index);
735 if (ret < 0)
736 {
737 log_error("trie_dict_get(section, %d) error\n", sid);
738 return NULL;
739 }
740 else if (ret == 0)
741 {
742 return NULL;
743 }
744
745 return (p_section_list_pool->sections + index);
746 }
747
748 int section_list_append_article(SECTION_LIST *p_section, const ARTICLE *p_article_src)
749 {
750 ARTICLE_BLOCK *p_block;
751 int32_t last_aid = 0;
752 ARTICLE *p_article;
753 ARTICLE *p_topic_head;
754 ARTICLE *p_topic_tail;
755
756 if (p_section == NULL || p_article_src == NULL)
757 {
758 log_error("NULL pointer error\n");
759 return -1;
760 }
761
762 if (p_article_block_pool == NULL)
763 {
764 log_error("article_block_pool not initialized\n");
765 return -1;
766 }
767
768 if (p_section->sid != p_article_src->sid)
769 {
770 log_error("section_list_append_article() error: section sid %d != article sid %d\n", p_section->sid, p_article_src->sid);
771 return -2;
772 }
773
774 if (p_section->article_count >= BBS_article_limit_per_section)
775 {
776 log_error("section_list_append_article() error: article_count reach limit in section %d\n", p_section->sid);
777 return -2;
778 }
779
780 if (p_article_block_pool->block_count == 0 ||
781 p_article_block_pool->p_block[p_article_block_pool->block_count - 1]->article_count >= BBS_article_count_per_block)
782 {
783 if ((p_block = pop_free_article_block()) == NULL)
784 {
785 log_error("pop_free_article_block() error\n");
786 return -2;
787 }
788
789 if (p_article_block_pool->block_count > 0)
790 {
791 last_aid = p_article_block_pool->p_block[p_article_block_pool->block_count - 1]->articles[BBS_article_count_per_block - 1].aid;
792 }
793
794 p_article_block_pool->p_block[p_article_block_pool->block_count] = p_block;
795 p_article_block_pool->block_count++;
796 }
797 else
798 {
799 p_block = p_article_block_pool->p_block[p_article_block_pool->block_count - 1];
800 last_aid = p_block->articles[p_block->article_count - 1].aid;
801 }
802
803 // AID of articles should be strictly ascending
804 if (p_article_src->aid <= last_aid)
805 {
806 log_error("section_list_append_article(aid=%d) error: last_aid=%d\n", p_article_src->aid, last_aid);
807 return -3;
808 }
809
810 p_article = (p_block->articles + p_block->article_count);
811 p_block->article_count++;
812 p_section->article_count++;
813
814 // Copy article data
815 *p_article = *p_article_src;
816
817 if (p_article->visible)
818 {
819 p_section->visible_article_count++;
820 }
821
822 // Link appended article as tail node of topic bi-directional list
823 if (p_article->tid != 0)
824 {
825 p_topic_head = article_block_find_by_aid(p_article->tid);
826 if (p_topic_head == NULL)
827 {
828 log_error("search head of topic (aid=%d) error\n", p_article->tid);
829 return -4;
830 }
831
832 p_topic_tail = p_topic_head->p_topic_prior;
833 if (p_topic_tail == NULL)
834 {
835 log_error("tail of topic (aid=%d) is NULL\n", p_article->tid);
836 return -4;
837 }
838 }
839 else
840 {
841 p_section->topic_count++;
842
843 if (p_article->visible)
844 {
845 p_section->visible_topic_count++;
846 }
847
848 p_topic_head = p_article;
849 p_topic_tail = p_article;
850 }
851
852 p_article->p_topic_prior = p_topic_tail;
853 p_article->p_topic_next = p_topic_head;
854 p_topic_head->p_topic_prior = p_article;
855 p_topic_tail->p_topic_next = p_article;
856
857 // Link appended article as tail node of article bi-directional list
858 if (p_section->p_article_head == NULL)
859 {
860 p_section->p_article_head = p_article;
861 p_section->p_article_tail = p_article;
862 }
863 p_article->p_prior = p_section->p_article_tail;
864 p_article->p_next = p_section->p_article_head;
865 p_section->p_article_head->p_prior = p_article;
866 p_section->p_article_tail->p_next = p_article;
867 p_section->p_article_tail = p_article;
868
869 // Update page
870 if ((p_article->visible && p_section->last_page_visible_article_count == BBS_article_limit_per_page) ||
871 p_section->page_count == 0)
872 {
873 p_section->p_page_first_article[p_section->page_count] = p_article;
874 p_section->page_count++;
875 p_section->last_page_visible_article_count = 0;
876 }
877
878 if (p_article->visible)
879 {
880 p_section->last_page_visible_article_count++;
881 }
882
883 if (p_article->ontop && section_list_update_article_ontop(p_section, p_article) < 0)
884 {
885 log_error("section_list_update_article_ontop(sid=%d, aid=%d) error\n",
886 p_section->sid, p_article->aid);
887 return -5;
888 }
889
890 return 0;
891 }
892
893 int section_list_set_article_visible(SECTION_LIST *p_section, int32_t aid, int8_t visible)
894 {
895 ARTICLE *p_article;
896 ARTICLE *p_reply;
897 int affected_count = 0;
898
899 if (p_section == NULL)
900 {
901 log_error("NULL pointer error\n");
902 return -1;
903 }
904
905 p_article = article_block_find_by_aid(aid);
906 if (p_article == NULL)
907 {
908 return -1; // Not found
909 }
910
911 if (p_section->sid != p_article->sid)
912 {
913 log_error("Inconsistent section sid %d != article sid %d\n", p_section->sid, p_article->sid);
914 return -2;
915 }
916
917 if (p_article->visible == visible)
918 {
919 return 0; // Already set
920 }
921
922 if (visible == 0) // 1 -> 0
923 {
924 p_section->visible_article_count--;
925
926 if (user_article_cnt_inc(p_article->uid, -1) < 0)
927 {
928 log_error("user_article_cnt_inc(uid=%d, -1) error\n", p_article->uid);
929 }
930
931 if (p_article->tid == 0)
932 {
933 p_section->visible_topic_count--;
934
935 // Set related visible replies to invisible
936 for (p_reply = p_article->p_topic_next; p_reply->tid != 0; p_reply = p_reply->p_topic_next)
937 {
938 if (p_reply->tid != aid)
939 {
940 log_error("Inconsistent tid = %d found in reply %d of topic %d\n", p_reply->tid, p_reply->aid, aid);
941 continue;
942 }
943
944 if (p_reply->visible == 1)
945 {
946 p_reply->visible = 0;
947 p_section->visible_article_count--;
948 affected_count++;
949
950 if (user_article_cnt_inc(p_reply->uid, -1) < 0)
951 {
952 log_error("user_article_cnt_inc(uid=%d, -1) error\n", p_reply->uid);
953 }
954 }
955 }
956 }
957 }
958 else // 0 -> 1
959 {
960 p_section->visible_article_count++;
961
962 if (p_article->tid == 0)
963 {
964 p_section->visible_topic_count++;
965 }
966
967 if (user_article_cnt_inc(p_article->uid, 1) < 0)
968 {
969 log_error("user_article_cnt_inc(uid=%d, 1) error\n", p_article->uid);
970 }
971 }
972
973 p_article->visible = visible;
974 affected_count++;
975
976 return affected_count;
977 }
978
979 int section_list_update_article_ontop(SECTION_LIST *p_section, ARTICLE *p_article)
980 {
981 int i;
982
983 if (p_section == NULL || p_article == NULL)
984 {
985 log_error("NULL pointer error\n");
986 return -1;
987 }
988
989 if (p_section->sid != p_article->sid)
990 {
991 log_error("Inconsistent section sid %d != article sid %d\n", p_section->sid, p_article->sid);
992 return -2;
993 }
994
995 if (p_article->ontop)
996 {
997 for (i = 0; i < p_section->ontop_article_count; i++)
998 {
999 if (p_section->p_ontop_articles[i]->aid == p_article->aid)
1000 {
1001 log_error("Inconsistent state found: article %d already ontop in section %d\n", p_article->aid, p_section->sid);
1002 return 0;
1003 }
1004 else if (p_section->p_ontop_articles[i]->aid > p_article->aid)
1005 {
1006 break;
1007 }
1008 }
1009
1010 // Remove the oldest one if the array of ontop articles is full
1011 if (p_section->ontop_article_count >= BBS_ontop_article_limit_per_section)
1012 {
1013 if (i == 0) // p_article is the oldest one
1014 {
1015 return 0;
1016 }
1017 memmove((void *)(p_section->p_ontop_articles),
1018 (void *)(p_section->p_ontop_articles + 1),
1019 sizeof(ARTICLE *) * (size_t)(i - 1));
1020 p_section->ontop_article_count--;
1021 i--;
1022 }
1023 else
1024 {
1025 memmove((void *)(p_section->p_ontop_articles + i + 1),
1026 (void *)(p_section->p_ontop_articles + i),
1027 sizeof(ARTICLE *) * (size_t)(p_section->ontop_article_count - i));
1028 }
1029
1030 p_section->p_ontop_articles[i] = p_article;
1031 p_section->ontop_article_count++;
1032
1033 // TODO: debug
1034 }
1035 else // ontop == 0
1036 {
1037 for (i = 0; i < p_section->ontop_article_count; i++)
1038 {
1039 if (p_section->p_ontop_articles[i]->aid == p_article->aid)
1040 {
1041 break;
1042 }
1043 }
1044 if (i == p_section->ontop_article_count) // not found
1045 {
1046 log_error("Inconsistent state found: article %d not ontop in section %d\n", p_article->aid, p_section->sid);
1047 return 0;
1048 }
1049
1050 memmove((void *)(p_section->p_ontop_articles + i),
1051 (void *)(p_section->p_ontop_articles + i + 1),
1052 sizeof(ARTICLE *) * (size_t)(p_section->ontop_article_count - i - 1));
1053 p_section->ontop_article_count--;
1054 }
1055
1056 return 0;
1057 }
1058
1059 int section_list_page_count_with_ontop(SECTION_LIST *p_section)
1060 {
1061 int page_count;
1062
1063 if (p_section == NULL)
1064 {
1065 log_error("NULL pointer error\n");
1066 return -1;
1067 }
1068
1069 page_count = p_section->page_count - 1 +
1070 (p_section->last_page_visible_article_count + p_section->ontop_article_count + BBS_article_limit_per_page - 1) /
1071 BBS_article_limit_per_page;
1072
1073 if (page_count < 0)
1074 {
1075 page_count = 0;
1076 }
1077
1078 return page_count;
1079 }
1080
1081 int section_list_page_article_count_with_ontop(SECTION_LIST *p_section, int32_t page_id)
1082 {
1083 if (p_section == NULL)
1084 {
1085 log_error("NULL pointer error\n");
1086 return -1;
1087 }
1088
1089 if (page_id < p_section->page_count - 1)
1090 {
1091 return BBS_article_limit_per_page;
1092 }
1093 else // if (page_id >= p_section->page_count - 1)
1094 {
1095 return MIN(MAX(0,
1096 (p_section->last_page_visible_article_count + p_section->ontop_article_count -
1097 BBS_article_limit_per_page * (page_id - p_section->page_count + 1))),
1098 BBS_article_limit_per_page);
1099 }
1100 }
1101
1102 ARTICLE *section_list_find_article_with_offset(SECTION_LIST *p_section, int32_t aid, int32_t *p_page, int32_t *p_offset, ARTICLE **pp_next)
1103 {
1104 ARTICLE *p_article;
1105 int left;
1106 int right;
1107 int mid;
1108
1109 *p_page = -1;
1110 *p_offset = -1;
1111 *pp_next = NULL;
1112
1113 if (p_section == NULL)
1114 {
1115 log_error("NULL pointer error\n");
1116 return NULL;
1117 }
1118
1119 if (p_section->article_count == 0) // empty
1120 {
1121 *p_page = 0;
1122 *p_offset = 0;
1123 return NULL;
1124 }
1125
1126 left = 0;
1127 right = p_section->page_count - 1;
1128
1129 // aid in the range [ head aid of pages[left], tail aid of pages[right] ]
1130 while (left < right)
1131 {
1132 // get page id no less than mid value of left page id and right page id
1133 mid = (left + right) / 2 + (left + right) % 2;
1134
1135 if (aid < p_section->p_page_first_article[mid]->aid)
1136 {
1137 right = mid - 1;
1138 }
1139 else // if (aid < p_section->p_page_first_article[mid]->aid)
1140 {
1141 left = mid;
1142 }
1143 }
1144
1145 *p_page = left;
1146
1147 p_article = p_section->p_page_first_article[*p_page];
1148
1149 // p_section->p_page_first_article[*p_page]->aid <= aid < p_section->p_page_first_article[*p_page + 1]->aid
1150 right = (*p_page == MAX(0, p_section->page_count - 1) ? INT32_MAX : p_section->p_page_first_article[*p_page + 1]->aid);
1151
1152 // left will be the offset of article found or offset to insert
1153 left = 0;
1154
1155 while (aid > p_article->aid)
1156 {
1157 p_article = p_article->p_next;
1158 left++;
1159
1160 if (aid == p_article->aid)
1161 {
1162 *pp_next = p_article->p_next;
1163 break;
1164 }
1165
1166 // over last article in the page
1167 if (p_article == p_section->p_article_head || p_article->aid >= right)
1168 {
1169 *pp_next = (p_article == p_section->p_article_head ? p_section->p_article_head : p_section->p_page_first_article[*p_page + 1]);
1170 *p_offset = left;
1171 return NULL; // not found
1172 }
1173 }
1174
1175 if (aid < p_article->aid)
1176 {
1177 *pp_next = p_article;
1178 p_article = NULL; // not found
1179 }
1180 else // aid == p_article->aid
1181 {
1182 *pp_next = p_article->p_next;
1183 }
1184
1185 *p_offset = left;
1186
1187 return p_article;
1188 }
1189
1190 int section_list_calculate_page(SECTION_LIST *p_section, int32_t start_aid)
1191 {
1192 ARTICLE *p_article;
1193 ARTICLE *p_next;
1194 int32_t page;
1195 int32_t offset;
1196 int visible_article_count;
1197 int page_head_set;
1198
1199 if (p_section == NULL)
1200 {
1201 log_error("NULL pointer error\n");
1202 return -1;
1203 }
1204
1205 if (p_section->article_count == 0) // empty
1206 {
1207 p_section->page_count = 0;
1208 p_section->last_page_visible_article_count = 0;
1209
1210 return 0;
1211 }
1212
1213 if (start_aid > 0)
1214 {
1215 p_article = article_block_find_by_aid(start_aid);
1216 if (p_article == NULL)
1217 {
1218 return -1; // Not found
1219 }
1220
1221 if (p_section->sid != p_article->sid)
1222 {
1223 log_error("section_list_calculate_page() error: section sid %d != start article sid %d\n", p_section->sid, p_article->sid);
1224 return -2;
1225 }
1226
1227 p_article = section_list_find_article_with_offset(p_section, start_aid, &page, &offset, &p_next);
1228 if (p_article == NULL)
1229 {
1230 if (page < 0)
1231 {
1232 return -1;
1233 }
1234 log_error("section_list_calculate_page() aid = %d not found in section sid = %d\n",
1235 start_aid, p_section->sid);
1236 return -2;
1237 }
1238
1239 if (offset > 0)
1240 {
1241 p_article = p_section->p_page_first_article[page];
1242 }
1243 }
1244 else
1245 {
1246 p_article = p_section->p_article_head;
1247 page = 0;
1248 offset = 0;
1249 }
1250
1251 visible_article_count = 0;
1252 page_head_set = 0;
1253
1254 do
1255 {
1256 if (!page_head_set && visible_article_count == 0)
1257 {
1258 p_section->p_page_first_article[page] = p_article;
1259 page_head_set = 1;
1260 }
1261
1262 if (p_article->visible)
1263 {
1264 visible_article_count++;
1265 }
1266
1267 p_article = p_article->p_next;
1268
1269 // skip remaining invisible articles
1270 while (p_article->visible == 0 && p_article != p_section->p_article_head)
1271 {
1272 p_article = p_article->p_next;
1273 }
1274
1275 if (visible_article_count >= BBS_article_limit_per_page && p_article != p_section->p_article_head)
1276 {
1277 page++;
1278 visible_article_count = 0;
1279 page_head_set = 0;
1280
1281 if (page >= BBS_article_limit_per_section / BBS_article_limit_per_page && p_article != p_section->p_article_head)
1282 {
1283 log_error("Count of page exceed limit in section %d\n", p_section->sid);
1284 break;
1285 }
1286 }
1287 } while (p_article != p_section->p_article_head);
1288
1289 p_section->page_count = page + (visible_article_count > 0 ? 1 : 0);
1290 p_section->last_page_visible_article_count = (visible_article_count > 0
1291 ? visible_article_count
1292 : (page > 0 ? BBS_article_limit_per_page : 0));
1293
1294 return 0;
1295 }
1296
1297 int32_t article_block_last_aid(void)
1298 {
1299 ARTICLE_BLOCK *p_block = p_article_block_pool->p_block[p_article_block_pool->block_count - 1];
1300 int32_t last_aid = p_block->articles[p_block->article_count - 1].aid;
1301
1302 return last_aid;
1303 }
1304
1305 int article_block_article_count(void)
1306 {
1307 int ret;
1308
1309 if (p_article_block_pool == NULL || p_article_block_pool->block_count <= 0)
1310 {
1311 return -1;
1312 }
1313
1314 ret = (p_article_block_pool->block_count - 1) * BBS_article_count_per_block +
1315 p_article_block_pool->p_block[p_article_block_pool->block_count - 1]->article_count;
1316
1317 return ret;
1318 }
1319
1320 int article_count_of_topic(int32_t aid)
1321 {
1322 ARTICLE *p_article;
1323 int article_count;
1324
1325 p_article = article_block_find_by_aid(aid);
1326 if (p_article == NULL)
1327 {
1328 return 0; // Not found
1329 }
1330
1331 article_count = 0;
1332
1333 do
1334 {
1335 if (p_article->tid != 0 && p_article->tid != aid)
1336 {
1337 log_error("article_count_of_topic(%d) error: article %d not linked to the topic\n", aid, p_article->aid);
1338 break;
1339 }
1340
1341 article_count++;
1342 p_article = p_article->p_topic_next;
1343 } while (p_article->aid != aid);
1344
1345 return article_count;
1346 }
1347
1348 int section_list_move_topic(SECTION_LIST *p_section_src, SECTION_LIST *p_section_dest, int32_t aid)
1349 {
1350 ARTICLE *p_article;
1351 ARTICLE *p_next;
1352 int32_t page;
1353 int32_t offset;
1354 int32_t move_article_count;
1355 int32_t dest_article_count_old;
1356 int32_t last_unaffected_aid_src;
1357 int32_t first_inserted_aid_dest;
1358 int move_counter;
1359
1360 if (p_section_src == NULL || p_section_dest == NULL)
1361 {
1362 log_error("NULL pointer error\n");
1363 return -1;
1364 }
1365
1366 if (p_section_src->sid == p_section_dest->sid)
1367 {
1368 log_error("section_list_move_topic() src and dest section are the same\n");
1369 return -1;
1370 }
1371
1372 if ((p_article = article_block_find_by_aid(aid)) == NULL)
1373 {
1374 log_error("article_block_find_by_aid(aid = %d) error: article not found\n", aid);
1375 return -2;
1376 }
1377
1378 if (p_section_src->sid != p_article->sid)
1379 {
1380 log_error("section_list_move_topic() error: src section sid %d != article %d sid %d\n",
1381 p_section_src->sid, p_article->aid, p_article->sid);
1382 return -2;
1383 }
1384
1385 if (p_article->tid != 0)
1386 {
1387 log_error("section_list_move_topic(aid = %d) error: article is not head of topic, tid = %d\n", aid, p_article->tid);
1388 return -2;
1389 }
1390
1391 last_unaffected_aid_src = (p_article == p_section_src->p_article_head ? 0 : p_article->p_prior->aid);
1392
1393 move_article_count = article_count_of_topic(aid);
1394 if (move_article_count <= 0)
1395 {
1396 log_error("article_count_of_topic(aid = %d) <= 0\n", aid);
1397 return -2;
1398 }
1399
1400 if (p_section_dest->article_count + move_article_count > BBS_article_limit_per_section)
1401 {
1402 log_error("section_list_move_topic() error: article_count %d reach limit in section %d\n",
1403 p_section_dest->article_count + move_article_count, p_section_dest->sid);
1404 return -3;
1405 }
1406
1407 dest_article_count_old = p_section_dest->article_count;
1408 move_counter = 0;
1409 first_inserted_aid_dest = p_article->aid;
1410
1411 do
1412 {
1413 if (p_section_src->sid != p_article->sid)
1414 {
1415 log_error("section_list_move_topic() warning: src section sid %d != article %d sid %d\n",
1416 p_section_src->sid, p_article->aid, p_article->sid);
1417 p_article = p_article->p_topic_next;
1418 continue;
1419 }
1420
1421 // Remove from bi-directional article list of src section
1422 if (p_section_src->p_article_head == p_article)
1423 {
1424 p_section_src->p_article_head = p_article->p_next;
1425 }
1426 if (p_section_src->p_article_tail == p_article)
1427 {
1428 p_section_src->p_article_tail = p_article->p_prior;
1429 }
1430 if (p_section_src->p_article_head == p_article) // || p_section_src->p_article_tail == p_article
1431 {
1432 p_section_src->p_article_head = NULL;
1433 p_section_src->p_article_tail = NULL;
1434 }
1435
1436 p_article->p_prior->p_next = p_article->p_next;
1437 p_article->p_next->p_prior = p_article->p_prior;
1438
1439 // Update sid of article
1440 p_article->sid = p_section_dest->sid;
1441
1442 if (section_list_find_article_with_offset(p_section_dest, p_article->aid, &page, &offset, &p_next) != NULL)
1443 {
1444 log_error("section_list_move_topic() warning: article %d already in section %d\n", p_article->aid, p_section_dest->sid);
1445 p_article = p_article->p_topic_next;
1446 continue;
1447 }
1448
1449 // Insert into bi-directional article list of dest section
1450 if (p_next == NULL) // empty section
1451 {
1452 p_section_dest->p_article_head = p_article;
1453 p_section_dest->p_article_tail = p_article;
1454 p_article->p_prior = p_article;
1455 p_article->p_next = p_article;
1456 }
1457 else
1458 {
1459 if (p_section_dest->p_article_head == p_next)
1460 {
1461 if (p_article->aid < p_next->aid)
1462 {
1463 p_section_dest->p_article_head = p_article;
1464 }
1465 else // p_article->aid > p_next->aid
1466 {
1467 p_section_dest->p_article_tail = p_article;
1468 }
1469 }
1470
1471 p_article->p_prior = p_next->p_prior;
1472 p_article->p_next = p_next;
1473 p_next->p_prior->p_next = p_article;
1474 p_next->p_prior = p_article;
1475 }
1476
1477 // Update article / topic counter of src / desc section
1478 p_section_src->article_count--;
1479 p_section_dest->article_count++;
1480 if (p_article->tid == 0)
1481 {
1482 p_section_src->topic_count--;
1483 p_section_dest->topic_count++;
1484 }
1485
1486 // Update visible article / topic counter of src / desc section
1487 if (p_article->visible)
1488 {
1489 p_section_src->visible_article_count--;
1490 p_section_dest->visible_article_count++;
1491 if (p_article->tid == 0)
1492 {
1493 p_section_src->visible_topic_count--;
1494 p_section_dest->visible_topic_count++;
1495 }
1496 }
1497
1498 // Update page for empty dest section
1499 if (p_section_dest->article_count == 1)
1500 {
1501 p_section_dest->p_page_first_article[0] = p_article;
1502 p_section_dest->page_count = 1;
1503 p_section_dest->last_page_visible_article_count = (p_article->visible ? 1 : 0);
1504 }
1505
1506 p_article = p_article->p_topic_next;
1507
1508 move_counter++;
1509 if (move_counter % CALCULATE_PAGE_THRESHOLD == 0)
1510 {
1511 // Re-calculate pages of desc section
1512 if (section_list_calculate_page(p_section_dest, first_inserted_aid_dest) < 0)
1513 {
1514 log_error("section_list_calculate_page(dest section = %d, aid = %d) error\n",
1515 p_section_dest->sid, first_inserted_aid_dest);
1516 }
1517
1518 first_inserted_aid_dest = p_article->aid;
1519 }
1520 } while (p_article->aid != aid);
1521
1522 if (p_section_dest->article_count - dest_article_count_old != move_article_count)
1523 {
1524 log_error("section_list_move_topic() warning: count of moved articles %d != %d\n",
1525 p_section_dest->article_count - dest_article_count_old, move_article_count);
1526 }
1527
1528 // Re-calculate pages of src section
1529 if (section_list_calculate_page(p_section_src, last_unaffected_aid_src) < 0)
1530 {
1531 log_error("section_list_calculate_page(src section = %d, aid = %d) error at aid = %d\n",
1532 p_section_src->sid, last_unaffected_aid_src, aid);
1533 }
1534
1535 if (move_counter % CALCULATE_PAGE_THRESHOLD != 0)
1536 {
1537 // Re-calculate pages of desc section
1538 if (section_list_calculate_page(p_section_dest, first_inserted_aid_dest) < 0)
1539 {
1540 log_error("section_list_calculate_page(dest section = %d, aid = %d) error\n",
1541 p_section_dest->sid, first_inserted_aid_dest);
1542 }
1543 }
1544
1545 return move_article_count;
1546 }
1547
1548 int get_section_index(SECTION_LIST *p_section)
1549 {
1550 int index;
1551
1552 if (p_section_list_pool == NULL)
1553 {
1554 log_error("get_section_index() error: uninitialized\n");
1555 return -1;
1556 }
1557
1558 if (p_section == NULL)
1559 {
1560 index = BBS_max_section;
1561 }
1562 else
1563 {
1564 index = (int)(p_section - p_section_list_pool->sections);
1565 if (index < 0 || index >= BBS_max_section)
1566 {
1567 log_error("get_section_index(%d) error: index out of range\n", index);
1568 return -2;
1569 }
1570 }
1571
1572 return index;
1573 }
1574
1575 int get_section_info(SECTION_LIST *p_section, char *sname, char *stitle, char *master_list)
1576 {
1577 if (p_section == NULL)
1578 {
1579 log_error("NULL pointer error\n");
1580 return -1;
1581 }
1582
1583 if (section_list_rd_lock(p_section) < 0)
1584 {
1585 log_error("section_list_rd_lock(sid=%d) error\n", p_section->sid);
1586 return -2;
1587 }
1588
1589 if (sname != NULL)
1590 {
1591 memcpy(sname, p_section->sname, sizeof(p_section->sname));
1592 }
1593 if (stitle != NULL)
1594 {
1595 memcpy(stitle, p_section->stitle, sizeof(p_section->stitle));
1596 }
1597 if (master_list != NULL)
1598 {
1599 memcpy(master_list, p_section->master_list, sizeof(p_section->master_list));
1600 }
1601
1602 // release lock of section
1603 if (section_list_rd_unlock(p_section) < 0)
1604 {
1605 log_error("section_list_rd_unlock(sid=%d) error\n", p_section->sid);
1606 return -2;
1607 }
1608
1609 return 0;
1610 }
1611
1612 int section_list_try_rd_lock(SECTION_LIST *p_section, int wait_sec)
1613 {
1614 int index;
1615 struct sembuf sops[4];
1616 #ifndef __CYGWIN__
1617 struct timespec timeout;
1618 #endif
1619 int ret;
1620
1621 index = get_section_index(p_section);
1622 if (index < 0)
1623 {
1624 return -2;
1625 }
1626
1627 sops[0].sem_num = (unsigned short)(index * 2 + 1); // w_sem of section index
1628 sops[0].sem_op = 0; // wait until unlocked
1629 sops[0].sem_flg = 0;
1630
1631 sops[1].sem_num = (unsigned short)(index * 2); // r_sem of section index
1632 sops[1].sem_op = 1; // lock
1633 sops[1].sem_flg = SEM_UNDO; // undo on terminate
1634
1635 // Read lock on any specific section will also acquire single read lock on "all section"
1636 // so that write lock on all section only need to acquire single write on on "all section"
1637 // rather than to acquire multiple write locks on all the available sections.
1638 if (index != BBS_max_section)
1639 {
1640 sops[2].sem_num = BBS_max_section * 2 + 1; // w_sem of all section
1641 sops[2].sem_op = 0; // wait until unlocked
1642 sops[2].sem_flg = 0;
1643
1644 sops[3].sem_num = BBS_max_section * 2; // r_sem of all section
1645 sops[3].sem_op = 1; // lock
1646 sops[3].sem_flg = SEM_UNDO; // undo on terminate
1647 }
1648
1649 #ifdef __CYGWIN__
1650 ret = semop(p_section_list_pool->semid, sops, (index == BBS_max_section ? 2 : 4));
1651 #else
1652 timeout.tv_sec = wait_sec;
1653 timeout.tv_nsec = 0;
1654
1655 ret = semtimedop(p_section_list_pool->semid, sops, (index == BBS_max_section ? 2 : 4), &timeout);
1656 #endif
1657 if (ret == -1 && errno != EAGAIN && errno != EINTR)
1658 {
1659 log_error("semop(index = %d, lock read) error %d\n", index, errno);
1660 }
1661
1662 return ret;
1663 }
1664
1665 int section_list_try_rw_lock(SECTION_LIST *p_section, int wait_sec)
1666 {
1667 int index;
1668 struct sembuf sops[3];
1669 #ifndef __CYGWIN__
1670 struct timespec timeout;
1671 #endif
1672 int ret;
1673
1674 index = get_section_index(p_section);
1675 if (index < 0)
1676 {
1677 return -2;
1678 }
1679
1680 sops[0].sem_num = (unsigned short)(index * 2 + 1); // w_sem of section index
1681 sops[0].sem_op = 0; // wait until unlocked
1682 sops[0].sem_flg = 0;
1683
1684 sops[1].sem_num = (unsigned short)(index * 2 + 1); // w_sem of section index
1685 sops[1].sem_op = 1; // lock
1686 sops[1].sem_flg = SEM_UNDO; // undo on terminate
1687
1688 sops[2].sem_num = (unsigned short)(index * 2); // r_sem of section index
1689 sops[2].sem_op = 0; // wait until unlocked
1690 sops[2].sem_flg = 0;
1691
1692 #ifdef __CYGWIN__
1693 ret = semop(p_section_list_pool->semid, sops, 3);
1694 #else
1695 timeout.tv_sec = wait_sec;
1696 timeout.tv_nsec = 0;
1697
1698 ret = semtimedop(p_section_list_pool->semid, sops, 3, &timeout);
1699 #endif
1700 if (ret == -1 && errno != EAGAIN && errno != EINTR)
1701 {
1702 log_error("semop(index = %d, lock write) error %d\n", index, errno);
1703 }
1704
1705 return ret;
1706 }
1707
1708 int section_list_rd_unlock(SECTION_LIST *p_section)
1709 {
1710 int index;
1711 struct sembuf sops[2];
1712 int ret;
1713
1714 index = get_section_index(p_section);
1715 if (index < 0)
1716 {
1717 return -2;
1718 }
1719
1720 sops[0].sem_num = (unsigned short)(index * 2); // r_sem of section index
1721 sops[0].sem_op = -1; // unlock
1722 sops[0].sem_flg = IPC_NOWAIT | SEM_UNDO; // no wait
1723
1724 if (index != BBS_max_section)
1725 {
1726 sops[1].sem_num = BBS_max_section * 2; // r_sem of all section
1727 sops[1].sem_op = -1; // unlock
1728 sops[1].sem_flg = IPC_NOWAIT | SEM_UNDO; // no wait
1729 }
1730
1731 ret = semop(p_section_list_pool->semid, sops, (index == BBS_max_section ? 1 : 2));
1732 if (ret == -1 && errno != EAGAIN && errno != EINTR)
1733 {
1734 log_error("semop(index = %d, unlock read) error %d\n", index, errno);
1735 }
1736
1737 return ret;
1738 }
1739
1740 int section_list_rw_unlock(SECTION_LIST *p_section)
1741 {
1742 int index;
1743 struct sembuf sops[1];
1744 int ret;
1745
1746 index = get_section_index(p_section);
1747 if (index < 0)
1748 {
1749 return -2;
1750 }
1751
1752 sops[0].sem_num = (unsigned short)(index * 2 + 1); // w_sem of section index
1753 sops[0].sem_op = -1; // unlock
1754 sops[0].sem_flg = IPC_NOWAIT | SEM_UNDO; // no wait
1755
1756 ret = semop(p_section_list_pool->semid, sops, 1);
1757 if (ret == -1 && errno != EAGAIN && errno != EINTR)
1758 {
1759 log_error("semop(index = %d, unlock write) error %d\n", index, errno);
1760 }
1761
1762 return ret;
1763 }
1764
1765 int section_list_rd_lock(SECTION_LIST *p_section)
1766 {
1767 int timer = 0;
1768 int sid = (p_section == NULL ? 0 : p_section->sid);
1769 int ret = -1;
1770
1771 while (!SYS_server_exit)
1772 {
1773 ret = section_list_try_rd_lock(p_section, SECTION_TRY_LOCK_WAIT_TIME);
1774 if (ret == 0) // success
1775 {
1776 break;
1777 }
1778 else if (errno == EAGAIN || errno == EINTR) // retry
1779 {
1780 timer++;
1781 if (timer % SECTION_TRY_LOCK_TIMES == 0)
1782 {
1783 log_error("section_list_try_rd_lock() tried %d times on section %d\n", timer, sid);
1784 }
1785 }
1786 else // failed
1787 {
1788 log_error("section_list_try_rd_lock() failed on section %d\n", sid);
1789 break;
1790 }
1791 }
1792
1793 return ret;
1794 }
1795
1796 int section_list_rw_lock(SECTION_LIST *p_section)
1797 {
1798 int timer = 0;
1799 int sid = (p_section == NULL ? 0 : p_section->sid);
1800 int ret = -1;
1801
1802 while (!SYS_server_exit)
1803 {
1804 ret = section_list_try_rw_lock(p_section, SECTION_TRY_LOCK_WAIT_TIME);
1805 if (ret == 0) // success
1806 {
1807 break;
1808 }
1809 else if (errno == EAGAIN || errno == EINTR) // retry
1810 {
1811 timer++;
1812 if (timer % SECTION_TRY_LOCK_TIMES == 0)
1813 {
1814 log_error("section_list_try_rw_lock() tried %d times on section %d\n", timer, sid);
1815 }
1816 }
1817 else // failed
1818 {
1819 log_error("section_list_try_rw_lock() failed on section %d\n", sid);
1820 break;
1821 }
1822 }
1823
1824 return ret;
1825 }

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