652af3a4fbf79e9195e0eba05f4bbdcd96002c8b
[ccan] / ccan / tdb / tools / replay_trace.c
1 #include <ccan/tdb/tdb.h>
2 #include <ccan/grab_file/grab_file.h>
3 #include <ccan/hash/hash.h>
4 #include <ccan/talloc/talloc.h>
5 #include <ccan/str_talloc/str_talloc.h>
6 #include <ccan/str/str.h>
7 #include <ccan/list/list.h>
8 #include <err.h>
9 #include <ctype.h>
10 #include <string.h>
11 #include <unistd.h>
12 #include <sys/types.h>
13 #include <sys/wait.h>
14 #include <sys/time.h>
15 #include <errno.h>
16 #include <signal.h>
17 #include <assert.h>
18
19 #define STRINGIFY2(x) #x
20 #define STRINGIFY(x) STRINGIFY2(x)
21
22 /* Avoid mod by zero */
23 static unsigned int total_keys = 1;
24
25 /* #define DEBUG_DEPS 1 */
26
27 /* Traversals block transactions in the current implementation. */
28 #define TRAVERSALS_TAKE_TRANSACTION_LOCK 1
29
30 struct pipe {
31         int fd[2];
32 };
33 static struct pipe *pipes;
34
35 static void __attribute__((noreturn)) fail(const char *filename,
36                                            unsigned int line,
37                                            const char *fmt, ...)
38 {
39         va_list ap;
40
41         va_start(ap, fmt);
42         fprintf(stderr, "%s:%u: FAIL: ", filename, line);
43         vfprintf(stderr, fmt, ap);
44         fprintf(stderr, "\n");
45         va_end(ap);
46         exit(1);
47 }
48         
49 /* Try or die. */
50 #define try(expr, expect)                                               \
51         do {                                                            \
52                 int ret = (expr);                                       \
53                 if (ret != (expect))                                    \
54                         fail(filename[file], i+1,                       \
55                              STRINGIFY(expr) "= %i", ret);              \
56         } while (0)
57
58 /* Try or imitate results. */
59 #define unreliable(expr, expect, force, undo)                           \
60         do {                                                            \
61                 int ret = expr;                                         \
62                 if (ret != expect) {                                    \
63                         fprintf(stderr, "%s:%u: %s gave %i not %i",     \
64                                 filename[file], i+1, STRINGIFY(expr),   \
65                                 ret, expect);                           \
66                         if (expect == 0)                                \
67                                 force;                                  \
68                         else                                            \
69                                 undo;                                   \
70                 }                                                       \
71         } while (0)
72
73 static bool key_eq(TDB_DATA a, TDB_DATA b)
74 {
75         if (a.dsize != b.dsize)
76                 return false;
77         return memcmp(a.dptr, b.dptr, a.dsize) == 0;
78 }
79
80 /* This is based on the hash algorithm from gdbm */
81 static unsigned int hash_key(TDB_DATA *key)
82 {
83         uint32_t value; /* Used to compute the hash value.  */
84         uint32_t   i;   /* Used to cycle through random values. */
85
86         /* Set the initial value from the key size. */
87         for (value = 0x238F13AF ^ key->dsize, i=0; i < key->dsize; i++)
88                 value = (value + (key->dptr[i] << (i*5 % 24)));
89
90         return (1103515243 * value + 12345);  
91 }
92
93 enum op_type {
94         OP_TDB_LOCKALL,
95         OP_TDB_LOCKALL_MARK,
96         OP_TDB_LOCKALL_UNMARK,
97         OP_TDB_LOCKALL_NONBLOCK,
98         OP_TDB_UNLOCKALL,
99         OP_TDB_LOCKALL_READ,
100         OP_TDB_LOCKALL_READ_NONBLOCK,
101         OP_TDB_UNLOCKALL_READ,
102         OP_TDB_CHAINLOCK,
103         OP_TDB_CHAINLOCK_NONBLOCK,
104         OP_TDB_CHAINLOCK_MARK,
105         OP_TDB_CHAINLOCK_UNMARK,
106         OP_TDB_CHAINUNLOCK,
107         OP_TDB_CHAINLOCK_READ,
108         OP_TDB_CHAINUNLOCK_READ,
109         OP_TDB_PARSE_RECORD,
110         OP_TDB_EXISTS,
111         OP_TDB_STORE,
112         OP_TDB_APPEND,
113         OP_TDB_GET_SEQNUM,
114         OP_TDB_WIPE_ALL,
115         OP_TDB_TRANSACTION_START,
116         OP_TDB_TRANSACTION_CANCEL,
117         OP_TDB_TRANSACTION_COMMIT,
118         OP_TDB_TRAVERSE_READ_START,
119         OP_TDB_TRAVERSE_START,
120         OP_TDB_TRAVERSE_END,
121         OP_TDB_TRAVERSE,
122         OP_TDB_FIRSTKEY,
123         OP_TDB_NEXTKEY,
124         OP_TDB_FETCH,
125         OP_TDB_DELETE,
126 };
127
128 struct op {
129         unsigned int serial;
130         enum op_type op;
131         TDB_DATA key;
132         TDB_DATA data;
133         int ret;
134
135         /* Who is waiting for us? */
136         struct list_head post;
137         /* What are we waiting for? */
138         struct list_head pre;
139
140         /* If I'm part of a group (traverse/transaction) where is
141          * start?  (Otherwise, 0) */
142         unsigned int group_start;
143
144         union {
145                 int flag; /* open and store */
146                 struct {  /* append */
147                         TDB_DATA pre;
148                         TDB_DATA post;
149                 } append;
150                 unsigned int group_len; /* transaction/traverse start */
151         };
152 };
153
154 static unsigned char hex_char(const char *filename, unsigned int line, char c)
155 {
156         c = toupper(c);
157         if (c >= 'A' && c <= 'F')
158                 return c - 'A' + 10;
159         if (c >= '0' && c <= '9')
160                 return c - '0';
161         fail(filename, line, "invalid hex character '%c'", c);
162 }
163
164 /* TDB data is <size>:<%02x>* */
165 static TDB_DATA make_tdb_data(const void *ctx,
166                               const char *filename, unsigned int line,
167                               const char *word)
168 {
169         TDB_DATA data;
170         unsigned int i;
171         const char *p;
172
173         if (streq(word, "NULL"))
174                 return tdb_null;
175
176         data.dsize = atoi(word);
177         data.dptr = talloc_array(ctx, unsigned char, data.dsize);
178         p = strchr(word, ':');
179         if (!p)
180                 fail(filename, line, "invalid tdb data '%s'", word);
181         p++;
182         for (i = 0; i < data.dsize; i++)
183                 data.dptr[i] = hex_char(filename, line, p[i*2])*16
184                         + hex_char(filename, line, p[i*2+1]);
185
186         return data;
187 }
188
189 static void add_op(const char *filename, struct op **op, unsigned int i,
190                    unsigned int serial, enum op_type type)
191 {
192         struct op *new;
193         *op = talloc_realloc(NULL, *op, struct op, i+1);
194         new = (*op) + i;
195         new->op = type;
196         new->serial = serial;
197         new->ret = 0;
198         new->group_start = 0;
199 }
200
201 static void op_add_nothing(const char *filename,
202                            struct op op[], unsigned int op_num, char *words[])
203 {
204         if (words[2])
205                 fail(filename, op_num+1, "Expected no arguments");
206         op[op_num].key = tdb_null;
207 }
208
209 static void op_add_key(const char *filename,
210                        struct op op[], unsigned int op_num, char *words[])
211 {
212         if (words[2] == NULL || words[3])
213                 fail(filename, op_num+1, "Expected just a key");
214
215         op[op_num].key = make_tdb_data(op, filename, op_num+1, words[2]);
216         if (op[op_num].op != OP_TDB_TRAVERSE)
217                 total_keys++;
218 }
219
220 static void op_add_key_ret(const char *filename,
221                            struct op op[], unsigned int op_num, char *words[])
222 {
223         if (!words[2] || !words[3] || !words[4] || words[5]
224             || !streq(words[3], "="))
225                 fail(filename, op_num+1, "Expected <key> = <ret>");
226         op[op_num].ret = atoi(words[4]);
227         op[op_num].key = make_tdb_data(op, filename, op_num+1, words[2]);
228         /* May only be a unique key if it fails */
229         if (op[op_num].ret != 0)
230                 total_keys++;
231 }
232
233 static void op_add_key_data(const char *filename,
234                             struct op op[], unsigned int op_num, char *words[])
235 {
236         if (!words[2] || !words[3] || !words[4] || words[5]
237             || !streq(words[3], "="))
238                 fail(filename, op_num+1, "Expected <key> = <data>");
239         op[op_num].key = make_tdb_data(op, filename, op_num+1, words[2]);
240         op[op_num].data = make_tdb_data(op, filename, op_num+1, words[4]);
241         /* May only be a unique key if it fails */
242         if (!op[op_num].data.dptr)
243                 total_keys++;
244 }
245
246 /* <serial> tdb_store <rec> <rec> <flag> = <ret> */
247 static void op_add_store(const char *filename,
248                          struct op op[], unsigned int op_num, char *words[])
249 {
250         if (!words[2] || !words[3] || !words[4] || !words[5] || !words[6]
251             || words[7] || !streq(words[5], "="))
252                 fail(filename, op_num+1, "Expect <key> <data> <flag> = <ret>");
253
254         op[op_num].flag = strtoul(words[4], NULL, 0);
255         op[op_num].ret = atoi(words[6]);
256         op[op_num].key = make_tdb_data(op, filename, op_num+1, words[2]);
257         op[op_num].data = make_tdb_data(op, filename, op_num+1, words[3]);
258         total_keys++;
259 }
260
261 /* <serial> tdb_append <rec> <rec> = <rec> */
262 static void op_add_append(const char *filename,
263                           struct op op[], unsigned int op_num, char *words[])
264 {
265         if (!words[2] || !words[3] || !words[4] || !words[5] || words[6]
266             || !streq(words[4], "="))
267                 fail(filename, op_num+1, "Expect <key> <data> = <rec>");
268
269         op[op_num].key = make_tdb_data(op, filename, op_num+1, words[2]);
270         op[op_num].data = make_tdb_data(op, filename, op_num+1, words[3]);
271
272         op[op_num].append.post
273                 = make_tdb_data(op, filename, op_num+1, words[5]);
274
275         /* By subtraction, figure out what previous data was. */
276         op[op_num].append.pre.dptr = op[op_num].append.post.dptr;
277         op[op_num].append.pre.dsize
278                 = op[op_num].append.post.dsize - op[op_num].data.dsize;
279         total_keys++;
280 }
281
282 /* <serial> tdb_get_seqnum = <ret> */
283 static void op_add_seqnum(const char *filename,
284                           struct op op[], unsigned int op_num, char *words[])
285 {
286         if (!words[2] || !words[3] || words[4] || !streq(words[2], "="))
287                 fail(filename, op_num+1, "Expect = <ret>");
288
289         op[op_num].key = tdb_null;
290         op[op_num].ret = atoi(words[3]);
291 }
292
293 static void op_add_traverse(const char *filename,
294                             struct op op[], unsigned int op_num, char *words[])
295 {
296         if (words[2])
297                 fail(filename, op_num+1, "Expect no arguments");
298
299         op[op_num].key = tdb_null;
300         op[op_num].group_len = 0;
301 }
302
303 static void op_add_transaction(const char *filename, struct op op[],
304                                unsigned int op_num, char *words[])
305 {
306         if (words[2])
307                 fail(filename, op_num+1, "Expect no arguments");
308
309         op[op_num].key = tdb_null;
310         op[op_num].group_len = 0;
311 }
312
313 static int op_transaction_start(struct op op[], unsigned int op_num)
314 {
315         unsigned int i;
316
317         for (i = op_num-1; i > 0; i--) {
318                 if (op[i].op == OP_TDB_TRANSACTION_START && !op[i].group_len)
319                         return i;
320         }
321         return 0;
322 }
323
324 static void op_analyze_transaction(const char *filename,
325                                    struct op op[], unsigned int op_num,
326                                    char *words[])
327 {
328         unsigned int start, i;
329
330         op[op_num].key = tdb_null;
331
332         if (words[2])
333                 fail(filename, op_num+1, "Expect no arguments");
334
335         start = op_transaction_start(op, op_num);
336         if (!start)
337                 fail(filename, op_num+1, "no transaction start found");
338
339         op[start].group_len = op_num - start;
340
341         /* This rolls in nested transactions.  I think that's right. */
342         for (i = start; i <= op_num; i++)
343                 op[i].group_start = start;
344 }
345
346 struct traverse_hash {
347         TDB_DATA key;
348         unsigned int index;
349 };
350
351 static void op_analyze_traverse(const char *filename,
352                                 struct op op[], unsigned int op_num,
353                                 char *words[])
354 {
355         int i, start;
356
357         op[op_num].key = tdb_null;
358
359         /* = %u means traverse function terminated. */
360         if (words[2]) {
361                 if (!streq(words[2], "=") || !words[3] || words[4])
362                         fail(filename, op_num+1, "expect = <num>");
363                 op[op_num].ret = atoi(words[3]);
364         } else
365                 op[op_num].ret = 0;
366
367         for (i = op_num-1; i >= 0; i--) {
368                 if (op[i].op != OP_TDB_TRAVERSE_READ_START
369                     && op[i].op != OP_TDB_TRAVERSE_START)
370                         continue;
371                 if (op[i].group_len)
372                         continue;
373                 break;
374         }
375
376         if (i < 0)
377                 fail(filename, op_num+1, "no traversal start found");
378
379         start = i;
380         op[start].group_len = op_num - start;
381
382         for (i = start; i <= op_num; i++)
383                 op[i].group_start = start;
384 }
385
386 /* Keep -Wmissing-declarations happy: */
387 const struct op_table *
388 find_keyword (register const char *str, register unsigned int len);
389
390 #include "keywords.c"
391
392 struct depend {
393         /* We can have more than one */
394         struct list_node pre_list;
395         struct list_node post_list;
396         unsigned int needs_file;
397         unsigned int needs_opnum;
398         unsigned int satisfies_file;
399         unsigned int satisfies_opnum;
400 };
401
402 static void check_deps(const char *filename, struct op op[], unsigned int num)
403 {
404 #ifdef DEBUG_DEPS
405         unsigned int i;
406
407         for (i = 1; i < num; i++)
408                 if (!list_empty(&op[i].pre))
409                         fail(filename, i+1, "Still has dependencies");
410 #endif
411 }
412
413 static void dump_pre(char *filename[], struct op *op[],
414                      unsigned int file, unsigned int i)
415 {
416         struct depend *dep;
417
418         printf("%s:%u (%u) still waiting for:\n", filename[file], i+1,
419                 op[file][i].serial);
420         list_for_each(&op[file][i].pre, dep, pre_list)
421                 printf("    %s:%u (%u)\n",
422                        filename[dep->satisfies_file], dep->satisfies_opnum+1,
423                        op[dep->satisfies_file][dep->satisfies_opnum].serial);
424         check_deps(filename[file], op[file], i);
425 }
426
427 /* We simply read/write pointers, since we all are children. */
428 static bool do_pre(struct tdb_context *tdb,
429                    char *filename[], struct op *op[],
430                    unsigned int file, int pre_fd, unsigned int i,
431                    bool backoff)
432 {
433         while (!list_empty(&op[file][i].pre)) {
434                 struct depend *dep;
435
436 #if DEBUG_DEPS
437                 printf("%s:%u:waiting for pre\n", filename[file], i+1);
438                 fflush(stdout);
439 #endif
440                 if (backoff)
441                         alarm(2);
442                 else
443                         alarm(10);
444                 while (read(pre_fd, &dep, sizeof(dep)) != sizeof(dep)) {
445                         if (errno == EINTR) {
446                                 if (backoff) {
447                                         warnx("%s:%u:avoiding deadlock",
448                                               filename[file], i+1);
449                                         return false;
450                                 }
451                                 dump_pre(filename, op, file, i);
452                                 exit(1);
453                         } else
454                                 errx(1, "Reading from pipe");
455                 }
456                 alarm(0);
457
458 #if DEBUG_DEPS
459                 printf("%s:%u:got pre %u from %s:%u\n", filename[file], i+1,
460                        dep->needs_opnum+1, filename[dep->satisfies_file],
461                        dep->satisfies_opnum+1);
462                 fflush(stdout);
463 #endif
464                 /* This could be any op, not just this one. */
465                 talloc_free(dep);
466         }
467         return true;
468 }
469
470 static void do_post(char *filename[], struct op *op[],
471                     unsigned int file, unsigned int i)
472 {
473         struct depend *dep;
474
475         list_for_each(&op[file][i].post, dep, post_list) {
476 #if DEBUG_DEPS
477                 printf("%s:%u:sending to file %s:%u\n", filename[file], i+1,
478                        filename[dep->needs_file], dep->needs_opnum+1);
479 #endif
480                 if (write(pipes[dep->needs_file].fd[1], &dep, sizeof(dep))
481                     != sizeof(dep))
482                         err(1, "%s:%u failed to tell file %s",
483                             filename[file], i+1, filename[dep->needs_file]);
484         }
485 }
486
487 static int get_len(TDB_DATA key, TDB_DATA data, void *private_data)
488 {
489         return data.dsize;
490 }
491
492 static unsigned run_ops(struct tdb_context *tdb,
493                         int pre_fd,
494                         char *filename[],
495                         struct op *op[],
496                         unsigned int file,
497                         unsigned int start, unsigned int stop,
498                         bool backoff);
499
500 struct traverse_info {
501         struct op **op;
502         char **filename;
503         unsigned file;
504         int pre_fd;
505         unsigned int start;
506         unsigned int i;
507 };
508
509 /* More complex.  Just do whatever's they did at the n'th entry. */
510 static int nontrivial_traverse(struct tdb_context *tdb,
511                                TDB_DATA key, TDB_DATA data,
512                                void *_tinfo)
513 {
514         struct traverse_info *tinfo = _tinfo;
515         unsigned int trav_len = tinfo->op[tinfo->file][tinfo->start].group_len;
516         bool avoid_deadlock = false;
517
518         if (tinfo->i == tinfo->start + trav_len) {
519                 /* This can happen if traverse expects to be empty. */
520                 if (trav_len == 1)
521                         return 1;
522                 fail(tinfo->filename[tinfo->file], tinfo->start + 1,
523                      "traverse did not terminate");
524         }
525
526         if (tinfo->op[tinfo->file][tinfo->i].op != OP_TDB_TRAVERSE)
527                 fail(tinfo->filename[tinfo->file], tinfo->start + 1,
528                      "%s:%u:traverse terminated early");
529
530 #if TRAVERSALS_TAKE_TRANSACTION_LOCK
531         avoid_deadlock = true;
532 #endif
533
534         /* Run any normal ops. */
535         tinfo->i = run_ops(tdb, tinfo->pre_fd, tinfo->filename, tinfo->op,
536                            tinfo->file, tinfo->i+1, tinfo->start + trav_len,
537                            avoid_deadlock);
538
539         /* We backed off, or we hit OP_TDB_TRAVERSE_END. */
540         if (tinfo->op[tinfo->file][tinfo->i].op != OP_TDB_TRAVERSE)
541                 return 1;
542
543         return 0;
544 }
545
546 static unsigned op_traverse(struct tdb_context *tdb,
547                             int pre_fd,
548                             char *filename[],
549                             unsigned int file,
550                             int (*traversefn)(struct tdb_context *,
551                                               tdb_traverse_func, void *),
552                             struct op *op[],
553                             unsigned int start)
554 {
555         struct traverse_info tinfo = { op, filename, file, pre_fd,
556                                        start, start+1 };
557
558         traversefn(tdb, nontrivial_traverse, &tinfo);
559
560         /* Traversing in wrong order can have strange effects: eg. if
561          * original traverse went A (delete A), B, we might do B
562          * (delete A).  So if we have ops left over, we do it now. */
563         while (tinfo.i != start + op[file][start].group_len) {
564                 if (op[file][tinfo.i].op == OP_TDB_TRAVERSE)
565                         tinfo.i++;
566                 else
567                         tinfo.i = run_ops(tdb, pre_fd, filename, op, file,
568                                           tinfo.i,
569                                           start + op[file][start].group_len,
570                                           false);
571         }
572
573         return tinfo.i;
574 }
575
576 static void break_out(int sig)
577 {
578 }
579
580 static __attribute__((noinline))
581 unsigned run_ops(struct tdb_context *tdb,
582                  int pre_fd,
583                  char *filename[],
584                  struct op *op[],
585                  unsigned int file,
586                  unsigned int start, unsigned int stop,
587                  bool backoff)
588 {
589         unsigned int i;
590         struct sigaction sa;
591
592         sa.sa_handler = break_out;
593         sa.sa_flags = 0;
594
595         sigaction(SIGALRM, &sa, NULL);
596         for (i = start; i < stop; i++) {
597                 if (!do_pre(tdb, filename, op, file, pre_fd, i, backoff))
598                         return i;
599
600                 switch (op[file][i].op) {
601                 case OP_TDB_LOCKALL:
602                         try(tdb_lockall(tdb), op[file][i].ret);
603                         break;
604                 case OP_TDB_LOCKALL_MARK:
605                         try(tdb_lockall_mark(tdb), op[file][i].ret);
606                         break;
607                 case OP_TDB_LOCKALL_UNMARK:
608                         try(tdb_lockall_unmark(tdb), op[file][i].ret);
609                         break;
610                 case OP_TDB_LOCKALL_NONBLOCK:
611                         unreliable(tdb_lockall_nonblock(tdb), op[file][i].ret,
612                                    tdb_lockall(tdb), tdb_unlockall(tdb));
613                         break;
614                 case OP_TDB_UNLOCKALL:
615                         try(tdb_unlockall(tdb), op[file][i].ret);
616                         break;
617                 case OP_TDB_LOCKALL_READ:
618                         try(tdb_lockall_read(tdb), op[file][i].ret);
619                         break;
620                 case OP_TDB_LOCKALL_READ_NONBLOCK:
621                         unreliable(tdb_lockall_read_nonblock(tdb),
622                                    op[file][i].ret,
623                                    tdb_lockall_read(tdb),
624                                    tdb_unlockall_read(tdb));
625                         break;
626                 case OP_TDB_UNLOCKALL_READ:
627                         try(tdb_unlockall_read(tdb), op[file][i].ret);
628                         break;
629                 case OP_TDB_CHAINLOCK:
630                         try(tdb_chainlock(tdb, op[file][i].key),
631                             op[file][i].ret);
632                         break;
633                 case OP_TDB_CHAINLOCK_NONBLOCK:
634                         unreliable(tdb_chainlock_nonblock(tdb, op[file][i].key),
635                                    op[file][i].ret,
636                                    tdb_chainlock(tdb, op[file][i].key),
637                                    tdb_chainunlock(tdb, op[file][i].key));
638                         break;
639                 case OP_TDB_CHAINLOCK_MARK:
640                         try(tdb_chainlock_mark(tdb, op[file][i].key),
641                             op[file][i].ret);
642                         break;
643                 case OP_TDB_CHAINLOCK_UNMARK:
644                         try(tdb_chainlock_unmark(tdb, op[file][i].key),
645                             op[file][i].ret);
646                         break;
647                 case OP_TDB_CHAINUNLOCK:
648                         try(tdb_chainunlock(tdb, op[file][i].key),
649                             op[file][i].ret);
650                         break;
651                 case OP_TDB_CHAINLOCK_READ:
652                         try(tdb_chainlock_read(tdb, op[file][i].key),
653                             op[file][i].ret);
654                         break;
655                 case OP_TDB_CHAINUNLOCK_READ:
656                         try(tdb_chainunlock_read(tdb, op[file][i].key),
657                             op[file][i].ret);
658                         break;
659                 case OP_TDB_PARSE_RECORD:
660                         try(tdb_parse_record(tdb, op[file][i].key, get_len,
661                                              NULL),
662                             op[file][i].ret);
663                         break;
664                 case OP_TDB_EXISTS:
665                         try(tdb_exists(tdb, op[file][i].key), op[file][i].ret);
666                         break;
667                 case OP_TDB_STORE:
668                         try(tdb_store(tdb, op[file][i].key, op[file][i].data,
669                                       op[file][i].flag),
670                             op[file][i].ret);
671                         break;
672                 case OP_TDB_APPEND:
673                         try(tdb_append(tdb, op[file][i].key, op[file][i].data),
674                             op[file][i].ret);
675                         break;
676                 case OP_TDB_GET_SEQNUM:
677                         try(tdb_get_seqnum(tdb), op[file][i].ret);
678                         break;
679                 case OP_TDB_WIPE_ALL:
680                         try(tdb_wipe_all(tdb), op[file][i].ret);
681                         break;
682                 case OP_TDB_TRANSACTION_START:
683                         try(tdb_transaction_start(tdb), op[file][i].ret);
684                         break;
685                 case OP_TDB_TRANSACTION_CANCEL:
686                         try(tdb_transaction_cancel(tdb), op[file][i].ret);
687                         break;
688                 case OP_TDB_TRANSACTION_COMMIT:
689                         try(tdb_transaction_commit(tdb), op[file][i].ret);
690                         break;
691                 case OP_TDB_TRAVERSE_READ_START:
692                         i = op_traverse(tdb, pre_fd, filename, file,
693                                         tdb_traverse_read, op, i);
694                         break;
695                 case OP_TDB_TRAVERSE_START:
696                         i = op_traverse(tdb, pre_fd, filename, file,
697                                         tdb_traverse, op, i);
698                         break;
699                 case OP_TDB_TRAVERSE:
700                         /* Terminate: we're in a traverse, and we've
701                          * done our ops. */
702                         return i;
703                 case OP_TDB_TRAVERSE_END:
704                         fail(filename[file], i+1, "unexpected end traverse");
705                 /* FIXME: These must be treated like traverse. */
706                 case OP_TDB_FIRSTKEY:
707                         if (!key_eq(tdb_firstkey(tdb), op[file][i].data))
708                                 fail(filename[file], i+1, "bad firstkey");
709                         break;
710                 case OP_TDB_NEXTKEY:
711                         if (!key_eq(tdb_nextkey(tdb, op[file][i].key),
712                                     op[file][i].data))
713                                 fail(filename[file], i+1, "bad nextkey");
714                         break;
715                 case OP_TDB_FETCH: {
716                         TDB_DATA f = tdb_fetch(tdb, op[file][i].key);
717                         if (!key_eq(f, op[file][i].data))
718                                 fail(filename[file], i+1, "bad fetch %u",
719                                      f.dsize);
720                         break;
721                 }
722                 case OP_TDB_DELETE:
723                         try(tdb_delete(tdb, op[file][i].key), op[file][i].ret);
724                         break;
725                 }
726                 do_post(filename, op, file, i);
727         }
728         return i;
729 }
730
731 /* tdbtorture, in particular, can do a tdb_close with a transaction in
732  * progress. */
733 static struct op *maybe_cancel_transaction(const char *filename,
734                                            struct op *op, unsigned int *num)
735 {
736         unsigned int start = op_transaction_start(op, *num);
737
738         if (start) {
739                 char *words[] = { "<unknown>", "tdb_close", NULL };
740                 add_op(filename, &op, *num, op[start].serial,
741                        OP_TDB_TRANSACTION_CANCEL);
742                 op_analyze_transaction(filename, op, *num, words);
743                 (*num)++;
744         }
745         return op;
746 }
747
748 static struct op *load_tracefile(const char *filename, unsigned int *num,
749                                  unsigned int *hashsize,
750                                  unsigned int *tdb_flags,
751                                  unsigned int *open_flags)
752 {
753         unsigned int i;
754         struct op *op = talloc_array(NULL, struct op, 1);
755         char **words;
756         char **lines;
757         char *file;
758
759         file = grab_file(NULL, filename, NULL);
760         if (!file)
761                 err(1, "Reading %s", filename);
762
763         lines = strsplit(file, file, "\n", NULL);
764         if (!lines[0])
765                 errx(1, "%s is empty", filename);
766
767         words = strsplit(lines, lines[0], " ", NULL);
768         if (!streq(words[1], "tdb_open"))
769                 fail(filename, 1, "does not start with tdb_open");
770
771         *hashsize = atoi(words[2]);
772         *tdb_flags = strtoul(words[3], NULL, 0);
773         *open_flags = strtoul(words[4], NULL, 0);
774
775         for (i = 1; lines[i]; i++) {
776                 const struct op_table *opt;
777
778                 words = strsplit(lines, lines[i], " ", NULL);
779                 if (!words[0] || !words[1])
780                         fail(filename, i+1, "Expected serial number and op");
781                
782                 opt = find_keyword(words[1], strlen(words[1]));
783                 if (!opt) {
784                         if (streq(words[1], "tdb_close")) {
785                                 if (lines[i+1])
786                                         fail(filename, i+2,
787                                              "lines after tdb_close");
788                                 *num = i;
789                                 talloc_free(lines);
790                                 return maybe_cancel_transaction(filename,
791                                                                 op, num);
792                         }
793                         fail(filename, i+1, "Unknown operation '%s'", words[1]);
794                 }
795
796                 add_op(filename, &op, i, atoi(words[0]), opt->type);
797                 opt->enhance_op(filename, op, i, words);
798         }
799
800         fprintf(stderr, "%s:%u:last operation is not tdb_close: incomplete?",
801               filename, i);
802         talloc_free(lines);
803         *num = i - 1;
804         return maybe_cancel_transaction(filename, op, num);
805 }
806
807 /* We remember all the keys we've ever seen, and who has them. */
808 struct key_user {
809         unsigned int file;
810         unsigned int op_num;
811 };
812
813 struct keyinfo {
814         TDB_DATA key;
815         unsigned int num_users;
816         struct key_user *user;
817 };
818
819 static const TDB_DATA must_not_exist;
820 static const TDB_DATA must_exist;
821 static const TDB_DATA not_exists_or_empty;
822
823 /* NULL means doesn't care if it exists or not, &must_exist means
824  * it must exist but we don't care what, &must_not_exist means it must
825  * not exist, otherwise the data it needs. */
826 static const TDB_DATA *needs(const struct op *op)
827 {
828         switch (op->op) {
829         /* FIXME: Pull forward deps, since we can deadlock */
830         case OP_TDB_CHAINLOCK:
831         case OP_TDB_CHAINLOCK_NONBLOCK:
832         case OP_TDB_CHAINLOCK_MARK:
833         case OP_TDB_CHAINLOCK_UNMARK:
834         case OP_TDB_CHAINUNLOCK:
835         case OP_TDB_CHAINLOCK_READ:
836         case OP_TDB_CHAINUNLOCK_READ:
837                 return NULL;
838
839         case OP_TDB_APPEND:
840                 if (op->append.pre.dsize == 0)
841                         return &not_exists_or_empty;
842                 return &op->append.pre;
843
844         case OP_TDB_STORE:
845                 if (op->flag == TDB_INSERT) {
846                         if (op->ret < 0)
847                                 return &must_exist;
848                         else
849                                 return &must_not_exist;
850                 } else if (op->flag == TDB_MODIFY) {
851                         if (op->ret < 0)
852                                 return &must_not_exist;
853                         else
854                                 return &must_exist;
855                 }
856                 /* No flags?  Don't care */
857                 return NULL;
858
859         case OP_TDB_EXISTS:
860                 if (op->ret == 1)
861                         return &must_exist;
862                 else
863                         return &must_not_exist;
864
865         case OP_TDB_PARSE_RECORD:
866                 if (op->ret < 0)
867                         return &must_not_exist;
868                 return &must_exist;
869
870         /* FIXME: handle these. */
871         case OP_TDB_WIPE_ALL:
872         case OP_TDB_FIRSTKEY:
873         case OP_TDB_NEXTKEY:
874         case OP_TDB_GET_SEQNUM:
875         case OP_TDB_TRAVERSE:
876         case OP_TDB_TRANSACTION_COMMIT:
877         case OP_TDB_TRANSACTION_CANCEL:
878         case OP_TDB_TRANSACTION_START:
879                 return NULL;
880
881         case OP_TDB_FETCH:
882                 if (!op->data.dptr)
883                         return &must_not_exist;
884                 return &op->data;
885
886         case OP_TDB_DELETE:
887                 if (op->ret < 0)
888                         return &must_not_exist;
889                 return &must_exist;
890
891         default:
892                 errx(1, "Unexpected op %i", op->op);
893         }
894         
895 }
896
897 static bool is_transaction(const struct op *op)
898 {
899         return op->op == OP_TDB_TRANSACTION_START;
900 }
901
902 /* What's the data after this op?  pre if nothing changed. */
903 static const TDB_DATA *gives(const TDB_DATA *key, const TDB_DATA *pre,
904                              const struct op *op)
905 {
906         if (is_transaction(op)) {
907                 unsigned int i;
908
909                 /* Cancelled transactions don't change anything. */
910                 if (op[op->group_len].op == OP_TDB_TRANSACTION_CANCEL)
911                         return pre;
912                 assert(op[op->group_len].op == OP_TDB_TRANSACTION_COMMIT);
913
914                 for (i = 1; i < op->group_len; i++) {
915                         /* This skips nested transactions, too */
916                         if (op[i].op != OP_TDB_TRAVERSE
917                             && key_eq(op[i].key, *key))
918                                 pre = gives(key, pre, &op[i]);
919                 }
920                 return pre;
921         }
922
923         /* Failed ops don't change state of db. */
924         if (op->ret < 0)
925                 return pre;
926
927         if (op->op == OP_TDB_DELETE || op->op == OP_TDB_WIPE_ALL)
928                 return &tdb_null;
929
930         if (op->op == OP_TDB_APPEND)
931                 return &op->append.post;
932
933         if (op->op == OP_TDB_STORE)
934                 return &op->data;
935
936         return pre;
937 }
938
939 static bool in_transaction(const struct op op[], unsigned int i)
940 {
941         return op[i].group_start && is_transaction(&op[op[i].group_start]);
942 }
943
944 static bool in_traverse(const struct op op[], unsigned int i)
945 {
946         return op[i].group_start && !is_transaction(&op[op[i].group_start]);
947 }
948
949 static struct keyinfo *hash_ops(struct op *op[], unsigned int num_ops[],
950                                 unsigned int num)
951 {
952         unsigned int i, j, h;
953         struct keyinfo *hash;
954
955         hash = talloc_zero_array(op[0], struct keyinfo, total_keys*2);
956         for (i = 0; i < num; i++) {
957                 for (j = 1; j < num_ops[i]; j++) {
958                         /* We can't do this on allocation, due to realloc. */
959                         list_head_init(&op[i][j].post);
960                         list_head_init(&op[i][j].pre);
961
962                         if (!op[i][j].key.dptr)
963                                 continue;
964
965                         /* We don't wait for traverse keys */
966                         /* FIXME: We should, for trivial traversals. */
967                         if (op[i][j].op == OP_TDB_TRAVERSE)
968                                 continue;
969
970                         h = hash_key(&op[i][j].key) % (total_keys * 2);
971                         while (!key_eq(hash[h].key, op[i][j].key)) {
972                                 if (!hash[h].key.dptr) {
973                                         hash[h].key = op[i][j].key;
974                                         break;
975                                 }
976                                 h = (h + 1) % (total_keys * 2);
977                         }
978                         /* Might as well save some memory if we can. */
979                         if (op[i][j].key.dptr != hash[h].key.dptr) {
980                                 talloc_free(op[i][j].key.dptr);
981                                 op[i][j].key.dptr = hash[h].key.dptr;
982                         }
983                         hash[h].user = talloc_realloc(hash, hash[h].user,
984                                                      struct key_user,
985                                                      hash[h].num_users+1);
986
987                         /* If it's in a transaction, it's the transaction which
988                          * matters from an analysis POV. */
989                         if (in_transaction(op[i], j)) {
990                                 unsigned start = op[i][j].group_start;
991
992                                 /* Don't include twice. */
993                                 if (hash[h].num_users
994                                     && hash[h].user[hash[h].num_users-1].file
995                                         == i
996                                     && hash[h].user[hash[h].num_users-1].op_num
997                                         == start)
998                                         continue;
999
1000                                 hash[h].user[hash[h].num_users].op_num = start;
1001                         } else
1002                                 hash[h].user[hash[h].num_users].op_num = j;
1003                         hash[h].user[hash[h].num_users].file = i;
1004                         hash[h].num_users++;
1005                 }
1006         }
1007
1008         return hash;
1009 }
1010
1011 static bool satisfies(const TDB_DATA *key, const TDB_DATA *data,
1012                       const struct op *op)
1013 {
1014         const TDB_DATA *need = NULL;
1015
1016         if (is_transaction(op)) {
1017                 unsigned int i;
1018
1019                 /* Look through for an op in this transaction which
1020                  * needs this key. */
1021                 for (i = 1; i < op->group_len; i++) {
1022                         if (op[i].op != OP_TDB_TRAVERSE
1023                             && key_eq(op[i].key, *key)) {
1024                                 need = needs(&op[i]);
1025                                 /* tdb_exists() is special: there might be
1026                                  * something in the transaction with more
1027                                  * specific requirements.  Other ops don't have
1028                                  * specific requirements (eg. store or delete),
1029                                  * but they change the value so we can't get
1030                                  * more information from future ops. */
1031                                 if (op[i].op != OP_TDB_EXISTS)
1032                                         break;
1033                         }
1034                 }
1035         } else
1036                 need = needs(op);
1037
1038         /* Don't need anything?  Cool. */
1039         if (!need)
1040                 return true;
1041
1042         /* This should be tdb_null or a real value. */
1043         assert(data != &must_exist);
1044         assert(data != &must_not_exist);
1045         assert(data != &not_exists_or_empty);
1046
1047         /* Must not exist?  data must not exist. */
1048         if (need == &must_not_exist)
1049                 return data == &tdb_null;
1050
1051         /* Must exist? */
1052         if (need == &must_exist)
1053                 return data != &tdb_null;
1054
1055         /* Either noexist or empty. */
1056         if (need == &not_exists_or_empty)
1057                 return data->dsize == 0;
1058
1059         /* Needs something specific. */
1060         return key_eq(*data, *need);
1061 }
1062
1063 static void move_to_front(struct key_user res[], unsigned off, unsigned elem)
1064 {
1065         if (elem != off) {
1066                 struct key_user tmp = res[elem];
1067                 memmove(res + off + 1, res + off, (elem - off)*sizeof(res[0]));
1068                 res[off] = tmp;
1069         }
1070 }
1071
1072 static void restore_to_pos(struct key_user res[], unsigned off, unsigned elem)
1073 {
1074         if (elem != off) {
1075                 struct key_user tmp = res[off];
1076                 memmove(res + off, res + off + 1, (elem - off)*sizeof(res[0]));
1077                 res[elem] = tmp;
1078         }
1079 }
1080
1081 static bool sort_deps(char *filename[], struct op *op[],
1082                       struct key_user res[],
1083                       unsigned off, unsigned num,
1084                       const TDB_DATA *key, const TDB_DATA *data,
1085                       unsigned num_files, unsigned fuzz)
1086 {
1087         unsigned int i, files_done;
1088         struct op *this_op;
1089         bool done[num_files];
1090
1091         /* None left?  We're sorted. */
1092         if (off == num)
1093                 return true;
1094
1095         /* Does this make serial numbers go backwards?  Allow a little fuzz. */
1096         if (off > 0) {
1097                 int serial1 = op[res[off-1].file][res[off-1].op_num].serial;
1098                 int serial2 = op[res[off].file][res[off].op_num].serial;
1099
1100                 if (serial1 - serial2 > (int)fuzz) {
1101 #if DEBUG_DEPS
1102                         printf("Serial jump too far (%u -> %u)\n",
1103                                serial1, serial2);
1104 #endif
1105                         return false;
1106                 }
1107         }
1108
1109         memset(done, 0, sizeof(done));
1110
1111         /* Since ops within a trace file are ordered, we just need to figure
1112          * out which file to try next.  Since we don't take into account
1113          * inter-key relationships (which exist by virtue of trace file order),
1114          * we minimize the chance of harm by trying to keep in serial order. */
1115         for (files_done = 0, i = off; i < num && files_done < num_files; i++) {
1116                 if (done[res[i].file])
1117                         continue;
1118
1119                 this_op = &op[res[i].file][res[i].op_num];
1120
1121                 /* Is what we have good enough for this op? */
1122                 if (satisfies(key, data, this_op)) {
1123                         move_to_front(res, off, i);
1124                         if (sort_deps(filename, op, res, off+1, num,
1125                                       key, gives(key, data, this_op),
1126                                       num_files, fuzz))
1127                                 return true;
1128                         restore_to_pos(res, off, i);
1129                 }
1130                 done[res[i].file] = true;
1131                 files_done++;
1132         }
1133
1134         /* No combination worked. */
1135         return false;
1136 }
1137
1138 static void check_dep_sorting(struct key_user user[], unsigned num_users,
1139                               unsigned num_files)
1140 {
1141 #if DEBUG_DEPS
1142         unsigned int i;
1143         unsigned minima[num_files];
1144
1145         memset(minima, 0, sizeof(minima));
1146         for (i = 0; i < num_users; i++) {
1147                 assert(minima[user[i].file] < user[i].op_num);
1148                 minima[user[i].file] = user[i].op_num;
1149         }
1150 #endif
1151 }
1152
1153 /* All these ops happen on the same key.  Which comes first?
1154  *
1155  * This can happen both because read ops or failed write ops don't
1156  * change serial number, and also due to race since we access the
1157  * number unlocked (the race can cause less detectable ordering problems,
1158  * in which case we'll deadlock and report: fix manually in that case).
1159  */
1160 static void figure_deps(char *filename[], struct op *op[],
1161                         const TDB_DATA *key, struct key_user user[],
1162                         unsigned num_users, unsigned num_files)
1163 {
1164         /* We assume database starts empty. */
1165         const struct TDB_DATA *data = &tdb_null;
1166         unsigned int fuzz;
1167
1168         /* We prefer to keep strict serial order if possible: it's the
1169          * most likely.  We get more lax if that fails. */
1170         for (fuzz = 0; fuzz < 100; fuzz = (fuzz + 1)*2) {
1171                 if (sort_deps(filename, op, user, 0, num_users, key, data,
1172                               num_files, fuzz))
1173                         break;
1174         }
1175
1176         if (fuzz >= 100)
1177                 fail(filename[user[0].file], user[0].op_num+1,
1178                      "Could not resolve inter-dependencies");
1179
1180         check_dep_sorting(user, num_users, num_files);
1181 }
1182
1183 static void sort_ops(struct keyinfo hash[], char *filename[], struct op *op[],
1184                      unsigned int num)
1185 {
1186         unsigned int h;
1187
1188         /* Gcc nexted function extension.  How cool is this? */
1189         int compare_serial(const void *_a, const void *_b)
1190         {
1191                 const struct key_user *a = _a, *b = _b;
1192
1193                 /* First, maintain order within any trace file. */
1194                 if (a->file == b->file)
1195                         return a->op_num - b->op_num;
1196
1197                 /* Otherwise, arrange by serial order. */
1198                 return op[a->file][a->op_num].serial
1199                         - op[b->file][b->op_num].serial;
1200         }
1201
1202         /* Now sort into serial order. */
1203         for (h = 0; h < total_keys * 2; h++) {
1204                 struct key_user *user = hash[h].user;
1205
1206                 qsort(user, hash[h].num_users, sizeof(user[0]), compare_serial);
1207                 figure_deps(filename, op, &hash[h].key, user, hash[h].num_users,
1208                             num);
1209         }
1210 }
1211
1212 static int destroy_depend(struct depend *dep)
1213 {
1214         list_del(&dep->pre_list);
1215         list_del(&dep->post_list);
1216         return 0;
1217 }
1218
1219 static void add_dependency(void *ctx,
1220                            struct op *op[],
1221                            char *filename[],
1222                            unsigned int needs_file,
1223                            unsigned int needs_opnum,
1224                            unsigned int satisfies_file,
1225                            unsigned int satisfies_opnum)
1226 {
1227         struct depend *dep;
1228
1229         /* We don't depend on ourselves. */
1230         if (needs_file == satisfies_file) {
1231                 assert(satisfies_opnum < needs_opnum);
1232                 return;
1233         }
1234
1235 #if DEBUG_DEPS
1236         printf("%s:%u: depends on %s:%u\n",
1237                filename[needs_file], needs_opnum+1,
1238                filename[satisfies_file], satisfies_opnum+1);
1239 #endif
1240
1241 #if TRAVERSALS_TAKE_TRANSACTION_LOCK
1242         /* If something in a traverse depends on something in another
1243          * traverse/transaction, it creates a dependency between the
1244          * two groups. */
1245         if ((in_traverse(op[satisfies_file], satisfies_opnum)
1246              && op[needs_file][needs_opnum].group_start)
1247             || (in_traverse(op[needs_file], needs_opnum)
1248                 && op[satisfies_file][satisfies_opnum].group_start)) {
1249                 unsigned int sat;
1250
1251                 /* We are satisfied by end of group. */
1252                 sat = op[satisfies_file][satisfies_opnum].group_start;
1253                 satisfies_opnum = sat + op[satisfies_file][sat].group_len;
1254                 /* And we need that done by start of our group. */
1255                 needs_opnum = op[needs_file][needs_opnum].group_start;
1256         }
1257
1258         /* There is also this case:
1259          *  <traverse> <read foo> ...
1260          *  <transaction> ... </transaction> <create foo>
1261          * Where if we start the traverse then wait, we could block
1262          * the transaction and deadlock.
1263          *
1264          * We try to address this by ensuring that where seqnum indicates it's
1265          * possible, we wait for <create foo> before *starting* traverse.
1266          */
1267         else if (in_traverse(op[needs_file], needs_opnum)) {
1268                 struct op *need = &op[needs_file][needs_opnum];
1269                 if (op[needs_file][need->group_start].serial >
1270                     op[satisfies_file][satisfies_opnum].serial) {
1271                         needs_opnum = need->group_start;
1272                 }
1273         }
1274 #endif
1275
1276         /* If you depend on a transaction, you actually depend on it ending. */
1277         if (is_transaction(&op[satisfies_file][satisfies_opnum])) {
1278                 satisfies_opnum
1279                         += op[satisfies_file][satisfies_opnum].group_len;
1280 #if DEBUG_DEPS
1281                 printf("-> Actually end of transaction %s:%u\n",
1282                        filename[satisfies_file], satisfies_opnum+1);
1283 #endif
1284         } else
1285                 /* We should never create a dependency from middle of
1286                  * a transaction. */
1287                 assert(!in_transaction(op[satisfies_file], satisfies_opnum)
1288                        || op[satisfies_file][satisfies_opnum].op
1289                        == OP_TDB_TRANSACTION_COMMIT
1290                        || op[satisfies_file][satisfies_opnum].op
1291                        == OP_TDB_TRANSACTION_CANCEL);
1292
1293         assert(op[needs_file][needs_opnum].op != OP_TDB_TRAVERSE);
1294         assert(op[satisfies_file][satisfies_opnum].op != OP_TDB_TRAVERSE);
1295
1296         dep = talloc(ctx, struct depend);
1297         dep->needs_file = needs_file;
1298         dep->needs_opnum = needs_opnum;
1299         dep->satisfies_file = satisfies_file;
1300         dep->satisfies_opnum = satisfies_opnum;
1301         list_add(&op[satisfies_file][satisfies_opnum].post, &dep->post_list);
1302         list_add(&op[needs_file][needs_opnum].pre, &dep->pre_list);
1303         talloc_set_destructor(dep, destroy_depend);
1304 }
1305
1306 static bool changes_db(const TDB_DATA *key, const struct op *op)
1307 {
1308         return gives(key, NULL, op) != NULL;
1309 }
1310
1311 static void depend_on_previous(struct op *op[],
1312                                char *filename[],
1313                                unsigned int num,
1314                                struct key_user user[],
1315                                unsigned int i,
1316                                int prev)
1317 {
1318         bool deps[num];
1319         int j;
1320
1321         if (i == 0)
1322                 return;
1323
1324         if (prev == i - 1) {
1325                 /* Just depend on previous. */
1326                 add_dependency(NULL, op, filename,
1327                                user[i].file, user[i].op_num,
1328                                user[prev].file, user[prev].op_num);
1329                 return;
1330         }
1331
1332         /* We have to wait for the readers.  Find last one in *each* file. */
1333         memset(deps, 0, sizeof(deps));
1334         deps[user[i].file] = true;
1335         for (j = i - 1; j > prev; j--) {
1336                 if (!deps[user[j].file]) {
1337                         add_dependency(NULL, op, filename,
1338                                        user[i].file, user[i].op_num,
1339                                        user[j].file, user[j].op_num);
1340                         deps[user[j].file] = true;
1341                 }
1342         }
1343 }
1344
1345 /* This is simple, but not complete.  We don't take into account
1346  * indirect dependencies. */
1347 static void optimize_dependencies(struct op *op[], unsigned int num_ops[],
1348                                   unsigned int num)
1349 {
1350         unsigned int i, j;
1351
1352         /* There can only be one real dependency on each file */
1353         for (i = 0; i < num; i++) {
1354                 for (j = 1; j < num_ops[i]; j++) {
1355                         struct depend *dep, *next;
1356                         struct depend *prev[num];
1357
1358                         memset(prev, 0, sizeof(prev));
1359
1360                         list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
1361                                 if (!prev[dep->satisfies_file]) {
1362                                         prev[dep->satisfies_file] = dep;
1363                                         continue;
1364                                 }
1365                                 if (prev[dep->satisfies_file]->satisfies_opnum
1366                                     < dep->satisfies_opnum) {
1367                                         talloc_free(prev[dep->satisfies_file]);
1368                                         prev[dep->satisfies_file] = dep;
1369                                 } else
1370                                         talloc_free(dep);
1371                         }
1372                 }
1373         }
1374
1375         for (i = 0; i < num; i++) {
1376                 int deps[num];
1377
1378                 for (j = 0; j < num; j++)
1379                         deps[j] = -1;
1380
1381                 for (j = 1; j < num_ops[i]; j++) {
1382                         struct depend *dep, *next;
1383
1384                         list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
1385                                 if (deps[dep->satisfies_file]
1386                                     >= (int)dep->satisfies_opnum)
1387                                         talloc_free(dep);
1388                                 else
1389                                         deps[dep->satisfies_file]
1390                                                 = dep->satisfies_opnum;
1391                         }
1392                 }
1393         }
1394 }
1395
1396 static void derive_dependencies(char *filename[],
1397                                 struct op *op[], unsigned int num_ops[],
1398                                 unsigned int num)
1399 {
1400         struct keyinfo *hash;
1401         unsigned int h, i;
1402
1403         /* Create hash table for faster key lookup. */
1404         hash = hash_ops(op, num_ops, num);
1405
1406         /* Sort them by serial number. */
1407         sort_ops(hash, filename, op, num);
1408
1409         /* Create dependencies back to the last change, rather than
1410          * creating false dependencies by naively making each one
1411          * depend on the previous.  This has two purposes: it makes
1412          * later optimization simpler, and it also avoids deadlock with
1413          * same sequence number ops inside traversals (if one
1414          * traversal doesn't write anything, two ops can have the same
1415          * sequence number yet we can create a traversal dependency
1416          * the other way). */
1417         for (h = 0; h < total_keys * 2; h++) {
1418                 int prev = -1;
1419
1420                 if (hash[h].num_users < 2)
1421                         continue;
1422
1423                 for (i = 0; i < hash[h].num_users; i++) {
1424                         if (changes_db(&hash[h].key, &op[hash[h].user[i].file]
1425                                        [hash[h].user[i].op_num])) {
1426                                 depend_on_previous(op, filename, num,
1427                                                    hash[h].user, i, prev);
1428                                 prev = i;
1429                         } else if (prev >= 0)
1430                                 add_dependency(hash, op, filename,
1431                                                hash[h].user[i].file,
1432                                                hash[h].user[i].op_num,
1433                                                hash[h].user[prev].file,
1434                                                hash[h].user[prev].op_num);
1435                 }
1436         }
1437
1438         optimize_dependencies(op, num_ops, num);
1439 }
1440
1441 int main(int argc, char *argv[])
1442 {
1443         struct timeval start, end;
1444         unsigned int i, num_ops[argc], hashsize[argc], tdb_flags[argc], open_flags[argc];
1445         struct op *op[argc];
1446         int fds[2];
1447         char c;
1448         bool ok = true;
1449
1450         if (argc < 3)
1451                 errx(1, "Usage: %s <tdbfile> <tracefile>...", argv[0]);
1452
1453         pipes = talloc_array(NULL, struct pipe, argc - 2);
1454         for (i = 0; i < argc - 2; i++) {
1455                 printf("Loading tracefile %s...", argv[2+i]);
1456                 fflush(stdout);
1457                 op[i] = load_tracefile(argv[2+i], &num_ops[i], &hashsize[i],
1458                                        &tdb_flags[i], &open_flags[i]);
1459                 if (pipe(pipes[i].fd) != 0)
1460                         err(1, "creating pipe");
1461                 printf("done\n");
1462         }
1463
1464         printf("Calculating inter-dependencies...");
1465         fflush(stdout);
1466         derive_dependencies(argv+2, op, num_ops, i);
1467         printf("done\n");
1468
1469         /* Don't fork for single arg case: simple debugging. */
1470         if (argc == 3) {
1471                 struct tdb_context *tdb;
1472                 tdb = tdb_open_ex(argv[1], hashsize[0], tdb_flags[0]|TDB_NOSYNC,
1473                                   open_flags[0], 0600, NULL, hash_key);
1474                 printf("Single threaded run...");
1475                 fflush(stdout);
1476
1477                 run_ops(tdb, pipes[0].fd[0], argv+2, op, 0, 1, num_ops[0],
1478                         false);
1479                 check_deps(argv[2], op[0], num_ops[0]);
1480
1481                 printf("done\n");
1482                 exit(0);
1483         }
1484
1485         if (pipe(fds) != 0)
1486                 err(1, "creating pipe");
1487
1488         for (i = 0; i < argc - 2; i++) {
1489                 struct tdb_context *tdb;
1490
1491                 switch (fork()) {
1492                 case -1:
1493                         err(1, "fork failed");
1494                 case 0:
1495                         close(fds[1]);
1496                         tdb = tdb_open_ex(argv[1], hashsize[i],
1497                                           tdb_flags[i]|TDB_NOSYNC,
1498                                           open_flags[i], 0600, NULL, hash_key);
1499                         if (!tdb)
1500                                 err(1, "Opening tdb %s", argv[1]);
1501
1502                         /* This catches parent exiting. */
1503                         if (read(fds[0], &c, 1) != 1)
1504                                 exit(1);
1505                         run_ops(tdb, pipes[i].fd[0], argv+2, op, i, 1,
1506                                 num_ops[i], false);
1507                         check_deps(argv[2+i], op[i], num_ops[i]);
1508                         exit(0);
1509                 default:
1510                         break;
1511                 }
1512         }
1513
1514         /* Let everything settle. */
1515         sleep(1);
1516
1517         printf("Starting run...");
1518         fflush(stdout);
1519         gettimeofday(&start, NULL);
1520         /* Tell them all to go!  Any write of sufficient length will do. */
1521         if (write(fds[1], hashsize, i) != i)
1522                 err(1, "Writing to wakeup pipe");
1523
1524         for (i = 0; i < argc - 2; i++) {
1525                 int status;
1526                 wait(&status);
1527                 if (!WIFEXITED(status)) {
1528                         warnx("Child died with signal %i", WTERMSIG(status));
1529                         ok = false;
1530                 } else if (WEXITSTATUS(status) != 0)
1531                         /* Assume child spat out error. */
1532                         ok = false;
1533         }
1534         if (!ok)
1535                 exit(1);
1536
1537         gettimeofday(&end, NULL);
1538         printf("done\n");
1539
1540         end.tv_sec -= start.tv_sec;
1541         printf("Time replaying: %lu usec\n",
1542                end.tv_sec * 1000000UL + (end.tv_usec - start.tv_usec));
1543         
1544         exit(0);
1545 }