/[LeafOK_CVS]/lbbs/src/section_list.c
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Revision 1.40 - (show annotations)
Mon Oct 13 02:23:27 2025 UTC (5 months ago) by sysadm
Branch: MAIN
Changes since 1.39: +12 -2 lines
Content type: text/x-csrc
Support locate at specific article while listing section articles
Remember last located article of each section, before logout

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

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