Handle transactions!
[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 void do_pre(struct tdb_context *tdb,
429                    char *filename[], struct op *op[],
430                    unsigned int file, int pre_fd, unsigned int i)
431 {
432         while (!list_empty(&op[file][i].pre)) {
433                 struct depend *dep;
434
435 #if DEBUG_DEPS
436                 printf("%s:%u:waiting for pre\n", filename[file], i+1);
437                 fflush(stdout);
438 #endif
439                 alarm(10);
440                 while (read(pre_fd, &dep, sizeof(dep)) != sizeof(dep)) {
441                         if (errno == EINTR) {
442                                 dump_pre(filename, op, file, i);
443                                 exit(1);
444                         } else
445                                 errx(1, "Reading from pipe");
446                 }
447                 alarm(0);
448
449 #if DEBUG_DEPS
450                 printf("%s:%u:got pre %u from %s:%u\n", filename[file], i+1,
451                        dep->needs_opnum+1, filename[dep->satisfies_file],
452                        dep->satisfies_opnum+1);
453                 fflush(stdout);
454 #endif
455                 /* This could be any op, not just this one. */
456                 talloc_free(dep);
457         }
458 }
459
460 static void do_post(char *filename[], struct op *op[],
461                     unsigned int file, unsigned int i)
462 {
463         struct depend *dep;
464
465         list_for_each(&op[file][i].post, dep, post_list) {
466 #if DEBUG_DEPS
467                 printf("%s:%u:sending to file %s:%u\n", filename[file], i+1,
468                        filename[dep->needs_file], dep->needs_opnum+1);
469 #endif
470                 if (write(pipes[dep->needs_file].fd[1], &dep, sizeof(dep))
471                     != sizeof(dep))
472                         err(1, "%s:%u failed to tell file %s",
473                             filename[file], i+1, filename[dep->needs_file]);
474         }
475 }
476
477 static int get_len(TDB_DATA key, TDB_DATA data, void *private_data)
478 {
479         return data.dsize;
480 }
481
482 static unsigned run_ops(struct tdb_context *tdb,
483                         int pre_fd,
484                         char *filename[],
485                         struct op *op[],
486                         unsigned int file,
487                         unsigned int start, unsigned int stop);
488
489 struct traverse_info {
490         struct op **op;
491         char **filename;
492         unsigned file;
493         int pre_fd;
494         unsigned int start;
495         unsigned int i;
496 };
497
498 /* More complex.  Just do whatever's they did at the n'th entry. */
499 static int nontrivial_traverse(struct tdb_context *tdb,
500                                TDB_DATA key, TDB_DATA data,
501                                void *_tinfo)
502 {
503         struct traverse_info *tinfo = _tinfo;
504         unsigned int trav_len = tinfo->op[tinfo->file][tinfo->start].group_len;
505
506         if (tinfo->i == tinfo->start + trav_len) {
507                 /* This can happen if traverse expects to be empty. */
508                 if (trav_len == 1)
509                         return 1;
510                 fail(tinfo->filename[tinfo->file], tinfo->start + 1,
511                      "traverse did not terminate");
512         }
513
514         if (tinfo->op[tinfo->file][tinfo->i].op != OP_TDB_TRAVERSE)
515                 fail(tinfo->filename[tinfo->file], tinfo->start + 1,
516                      "%s:%u:traverse terminated early");
517
518         /* Run any normal ops. */
519         tinfo->i = run_ops(tdb, tinfo->pre_fd, tinfo->filename, tinfo->op,
520                            tinfo->file, tinfo->i+1, tinfo->start + trav_len);
521
522         if (tinfo->i == tinfo->start + trav_len)
523                 return 1;
524
525         return 0;
526 }
527
528 static unsigned op_traverse(struct tdb_context *tdb,
529                             int pre_fd,
530                             char *filename[],
531                             unsigned int file,
532                             int (*traversefn)(struct tdb_context *,
533                                               tdb_traverse_func, void *),
534                             struct op *op[],
535                             unsigned int start)
536 {
537         struct traverse_info tinfo = { op, filename, file, pre_fd,
538                                        start, start+1 };
539
540         traversefn(tdb, nontrivial_traverse, &tinfo);
541
542         /* Traversing in wrong order can have strange effects: eg. if
543          * original traverse went A (delete A), B, we might do B
544          * (delete A).  So if we have ops left over, we do it now. */
545         while (tinfo.i != start + op[file][start].group_len) {
546                 if (op[file][tinfo.i].op == OP_TDB_TRAVERSE)
547                         tinfo.i++;
548                 else
549                         tinfo.i = run_ops(tdb, pre_fd, filename, op, file,
550                                           tinfo.i,
551                                           start + op[file][start].group_len);
552         }
553
554         return tinfo.i;
555 }
556
557 static void break_out(int sig)
558 {
559 }
560
561 static __attribute__((noinline))
562 unsigned run_ops(struct tdb_context *tdb,
563                  int pre_fd,
564                  char *filename[],
565                  struct op *op[],
566                  unsigned int file,
567                  unsigned int start, unsigned int stop)
568 {
569         unsigned int i;
570         struct sigaction sa;
571
572         sa.sa_handler = break_out;
573         sa.sa_flags = 0;
574
575         sigaction(SIGALRM, &sa, NULL);
576         for (i = start; i < stop; i++) {
577                 do_pre(tdb, filename, op, file, pre_fd, i);
578
579                 switch (op[file][i].op) {
580                 case OP_TDB_LOCKALL:
581                         try(tdb_lockall(tdb), op[file][i].ret);
582                         break;
583                 case OP_TDB_LOCKALL_MARK:
584                         try(tdb_lockall_mark(tdb), op[file][i].ret);
585                         break;
586                 case OP_TDB_LOCKALL_UNMARK:
587                         try(tdb_lockall_unmark(tdb), op[file][i].ret);
588                         break;
589                 case OP_TDB_LOCKALL_NONBLOCK:
590                         unreliable(tdb_lockall_nonblock(tdb), op[file][i].ret,
591                                    tdb_lockall(tdb), tdb_unlockall(tdb));
592                         break;
593                 case OP_TDB_UNLOCKALL:
594                         try(tdb_unlockall(tdb), op[file][i].ret);
595                         break;
596                 case OP_TDB_LOCKALL_READ:
597                         try(tdb_lockall_read(tdb), op[file][i].ret);
598                         break;
599                 case OP_TDB_LOCKALL_READ_NONBLOCK:
600                         unreliable(tdb_lockall_read_nonblock(tdb),
601                                    op[file][i].ret,
602                                    tdb_lockall_read(tdb),
603                                    tdb_unlockall_read(tdb));
604                         break;
605                 case OP_TDB_UNLOCKALL_READ:
606                         try(tdb_unlockall_read(tdb), op[file][i].ret);
607                         break;
608                 case OP_TDB_CHAINLOCK:
609                         try(tdb_chainlock(tdb, op[file][i].key),
610                             op[file][i].ret);
611                         break;
612                 case OP_TDB_CHAINLOCK_NONBLOCK:
613                         unreliable(tdb_chainlock_nonblock(tdb, op[file][i].key),
614                                    op[file][i].ret,
615                                    tdb_chainlock(tdb, op[file][i].key),
616                                    tdb_chainunlock(tdb, op[file][i].key));
617                         break;
618                 case OP_TDB_CHAINLOCK_MARK:
619                         try(tdb_chainlock_mark(tdb, op[file][i].key),
620                             op[file][i].ret);
621                         break;
622                 case OP_TDB_CHAINLOCK_UNMARK:
623                         try(tdb_chainlock_unmark(tdb, op[file][i].key),
624                             op[file][i].ret);
625                         break;
626                 case OP_TDB_CHAINUNLOCK:
627                         try(tdb_chainunlock(tdb, op[file][i].key),
628                             op[file][i].ret);
629                         break;
630                 case OP_TDB_CHAINLOCK_READ:
631                         try(tdb_chainlock_read(tdb, op[file][i].key),
632                             op[file][i].ret);
633                         break;
634                 case OP_TDB_CHAINUNLOCK_READ:
635                         try(tdb_chainunlock_read(tdb, op[file][i].key),
636                             op[file][i].ret);
637                         break;
638                 case OP_TDB_PARSE_RECORD:
639                         try(tdb_parse_record(tdb, op[file][i].key, get_len,
640                                              NULL),
641                             op[file][i].ret);
642                         break;
643                 case OP_TDB_EXISTS:
644                         try(tdb_exists(tdb, op[file][i].key), op[file][i].ret);
645                         break;
646                 case OP_TDB_STORE:
647                         try(tdb_store(tdb, op[file][i].key, op[file][i].data,
648                                       op[file][i].flag),
649                             op[file][i].ret);
650                         break;
651                 case OP_TDB_APPEND:
652                         try(tdb_append(tdb, op[file][i].key, op[file][i].data),
653                             op[file][i].ret);
654                         break;
655                 case OP_TDB_GET_SEQNUM:
656                         try(tdb_get_seqnum(tdb), op[file][i].ret);
657                         break;
658                 case OP_TDB_WIPE_ALL:
659                         try(tdb_wipe_all(tdb), op[file][i].ret);
660                         break;
661                 case OP_TDB_TRANSACTION_START:
662                         try(tdb_transaction_start(tdb), op[file][i].ret);
663                         break;
664                 case OP_TDB_TRANSACTION_CANCEL:
665                         try(tdb_transaction_cancel(tdb), op[file][i].ret);
666                         break;
667                 case OP_TDB_TRANSACTION_COMMIT:
668                         try(tdb_transaction_commit(tdb), op[file][i].ret);
669                         break;
670                 case OP_TDB_TRAVERSE_READ_START:
671                         i = op_traverse(tdb, pre_fd, filename, file,
672                                         tdb_traverse_read, op, i);
673                         break;
674                 case OP_TDB_TRAVERSE_START:
675                         i = op_traverse(tdb, pre_fd, filename, file,
676                                         tdb_traverse, op, i);
677                         break;
678                 case OP_TDB_TRAVERSE:
679                         /* Terminate: we're in a traverse, and we've
680                          * done our ops. */
681                         return i;
682                 case OP_TDB_TRAVERSE_END:
683                         fail(filename[file], i+1, "unexpected end traverse");
684                 /* FIXME: These must be treated like traverse. */
685                 case OP_TDB_FIRSTKEY:
686                         if (!key_eq(tdb_firstkey(tdb), op[file][i].data))
687                                 fail(filename[file], i+1, "bad firstkey");
688                         break;
689                 case OP_TDB_NEXTKEY:
690                         if (!key_eq(tdb_nextkey(tdb, op[file][i].key),
691                                     op[file][i].data))
692                                 fail(filename[file], i+1, "bad nextkey");
693                         break;
694                 case OP_TDB_FETCH: {
695                         TDB_DATA f = tdb_fetch(tdb, op[file][i].key);
696                         if (!key_eq(f, op[file][i].data))
697                                 fail(filename[file], i+1, "bad fetch %u",
698                                      f.dsize);
699                         break;
700                 }
701                 case OP_TDB_DELETE:
702                         try(tdb_delete(tdb, op[file][i].key), op[file][i].ret);
703                         break;
704                 }
705                 do_post(filename, op, file, i);
706         }
707         return i;
708 }
709
710 /* tdbtorture, in particular, can do a tdb_close with a transaction in
711  * progress. */
712 static struct op *maybe_cancel_transaction(const char *filename,
713                                            struct op *op, unsigned int *num)
714 {
715         unsigned int start = op_transaction_start(op, *num);
716
717         if (start) {
718                 char *words[] = { "<unknown>", "tdb_close", NULL };
719                 add_op(filename, &op, *num, op[start].serial,
720                        OP_TDB_TRANSACTION_CANCEL);
721                 op_analyze_transaction(filename, op, *num, words);
722                 (*num)++;
723         }
724         return op;
725 }
726
727 static struct op *load_tracefile(const char *filename, unsigned int *num,
728                                  unsigned int *hashsize,
729                                  unsigned int *tdb_flags,
730                                  unsigned int *open_flags)
731 {
732         unsigned int i;
733         struct op *op = talloc_array(NULL, struct op, 1);
734         char **words;
735         char **lines;
736         char *file;
737
738         file = grab_file(NULL, filename, NULL);
739         if (!file)
740                 err(1, "Reading %s", filename);
741
742         lines = strsplit(file, file, "\n", NULL);
743         if (!lines[0])
744                 errx(1, "%s is empty", filename);
745
746         words = strsplit(lines, lines[0], " ", NULL);
747         if (!streq(words[1], "tdb_open"))
748                 fail(filename, 1, "does not start with tdb_open");
749
750         *hashsize = atoi(words[2]);
751         *tdb_flags = strtoul(words[3], NULL, 0);
752         *open_flags = strtoul(words[4], NULL, 0);
753
754         for (i = 1; lines[i]; i++) {
755                 const struct op_table *opt;
756
757                 words = strsplit(lines, lines[i], " ", NULL);
758                 if (!words[0] || !words[1])
759                         fail(filename, i+1, "Expected serial number and op");
760                
761                 opt = find_keyword(words[1], strlen(words[1]));
762                 if (!opt) {
763                         if (streq(words[1], "tdb_close")) {
764                                 if (lines[i+1])
765                                         fail(filename, i+2,
766                                              "lines after tdb_close");
767                                 *num = i;
768                                 talloc_free(lines);
769                                 return maybe_cancel_transaction(filename,
770                                                                 op, num);
771                         }
772                         fail(filename, i+1, "Unknown operation '%s'", words[1]);
773                 }
774
775                 add_op(filename, &op, i, atoi(words[0]), opt->type);
776                 opt->enhance_op(filename, op, i, words);
777         }
778
779         fprintf(stderr, "%s:%u:last operation is not tdb_close: incomplete?",
780               filename, i);
781         talloc_free(lines);
782         *num = i - 1;
783         return maybe_cancel_transaction(filename, op, num);
784 }
785
786 /* We remember all the keys we've ever seen, and who has them. */
787 struct key_user {
788         unsigned int file;
789         unsigned int op_num;
790 };
791
792 struct keyinfo {
793         TDB_DATA key;
794         unsigned int num_users;
795         struct key_user *user;
796 };
797
798 static const TDB_DATA must_not_exist;
799 static const TDB_DATA must_exist;
800 static const TDB_DATA not_exists_or_empty;
801
802 /* NULL means doesn't care if it exists or not, &must_exist means
803  * it must exist but we don't care what, &must_not_exist means it must
804  * not exist, otherwise the data it needs. */
805 static const TDB_DATA *needs(const struct op *op)
806 {
807         switch (op->op) {
808         /* FIXME: Pull forward deps, since we can deadlock */
809         case OP_TDB_CHAINLOCK:
810         case OP_TDB_CHAINLOCK_NONBLOCK:
811         case OP_TDB_CHAINLOCK_MARK:
812         case OP_TDB_CHAINLOCK_UNMARK:
813         case OP_TDB_CHAINUNLOCK:
814         case OP_TDB_CHAINLOCK_READ:
815         case OP_TDB_CHAINUNLOCK_READ:
816                 return NULL;
817
818         case OP_TDB_APPEND:
819                 if (op->append.pre.dsize == 0)
820                         return &not_exists_or_empty;
821                 return &op->append.pre;
822
823         case OP_TDB_STORE:
824                 if (op->flag == TDB_INSERT) {
825                         if (op->ret < 0)
826                                 return &must_exist;
827                         else
828                                 return &must_not_exist;
829                 } else if (op->flag == TDB_MODIFY) {
830                         if (op->ret < 0)
831                                 return &must_not_exist;
832                         else
833                                 return &must_exist;
834                 }
835                 /* No flags?  Don't care */
836                 return NULL;
837
838         case OP_TDB_EXISTS:
839                 if (op->ret == 1)
840                         return &must_exist;
841                 else
842                         return &must_not_exist;
843
844         case OP_TDB_PARSE_RECORD:
845                 if (op->ret < 0)
846                         return &must_not_exist;
847                 return &must_exist;
848
849         /* FIXME: handle these. */
850         case OP_TDB_WIPE_ALL:
851         case OP_TDB_FIRSTKEY:
852         case OP_TDB_NEXTKEY:
853         case OP_TDB_GET_SEQNUM:
854         case OP_TDB_TRAVERSE:
855         case OP_TDB_TRANSACTION_COMMIT:
856         case OP_TDB_TRANSACTION_CANCEL:
857         case OP_TDB_TRANSACTION_START:
858                 return NULL;
859
860         case OP_TDB_FETCH:
861                 if (!op->data.dptr)
862                         return &must_not_exist;
863                 return &op->data;
864
865         case OP_TDB_DELETE:
866                 if (op->ret < 0)
867                         return &must_not_exist;
868                 return &must_exist;
869
870         default:
871                 errx(1, "Unexpected op %i", op->op);
872         }
873         
874 }
875
876 static bool is_transaction(const struct op *op)
877 {
878         return op->op == OP_TDB_TRANSACTION_START;
879 }
880
881 /* What's the data after this op?  pre if nothing changed. */
882 static const TDB_DATA *gives(const TDB_DATA *key, const TDB_DATA *pre,
883                              const struct op *op)
884 {
885         if (is_transaction(op)) {
886                 unsigned int i;
887
888                 /* Cancelled transactions don't change anything. */
889                 if (op[op->group_len].op == OP_TDB_TRANSACTION_CANCEL)
890                         return pre;
891                 assert(op[op->group_len].op == OP_TDB_TRANSACTION_COMMIT);
892
893                 for (i = 1; i < op->group_len; i++) {
894                         /* This skips nested transactions, too */
895                         if (op[i].op != OP_TDB_TRAVERSE
896                             && key_eq(op[i].key, *key))
897                                 pre = gives(key, pre, &op[i]);
898                 }
899                 return pre;
900         }
901
902         /* Failed ops don't change state of db. */
903         if (op->ret < 0)
904                 return pre;
905
906         if (op->op == OP_TDB_DELETE || op->op == OP_TDB_WIPE_ALL)
907                 return &tdb_null;
908
909         if (op->op == OP_TDB_APPEND)
910                 return &op->append.post;
911
912         if (op->op == OP_TDB_STORE)
913                 return &op->data;
914
915         return pre;
916 }
917
918 static bool in_transaction(const struct op op[], unsigned int i)
919 {
920         return op[i].group_start && is_transaction(&op[op[i].group_start]);
921 }
922
923 static bool in_traverse(const struct op op[], unsigned int i)
924 {
925         return op[i].group_start && !is_transaction(&op[op[i].group_start]);
926 }
927
928 static struct keyinfo *hash_ops(struct op *op[], unsigned int num_ops[],
929                                 unsigned int num)
930 {
931         unsigned int i, j, h;
932         struct keyinfo *hash;
933
934         hash = talloc_zero_array(op[0], struct keyinfo, total_keys*2);
935         for (i = 0; i < num; i++) {
936                 for (j = 1; j < num_ops[i]; j++) {
937                         /* We can't do this on allocation, due to realloc. */
938                         list_head_init(&op[i][j].post);
939                         list_head_init(&op[i][j].pre);
940
941                         if (!op[i][j].key.dptr)
942                                 continue;
943
944                         /* We don't wait for traverse keys */
945                         /* FIXME: We should, for trivial traversals. */
946                         if (op[i][j].op == OP_TDB_TRAVERSE)
947                                 continue;
948
949                         h = hash_key(&op[i][j].key) % (total_keys * 2);
950                         while (!key_eq(hash[h].key, op[i][j].key)) {
951                                 if (!hash[h].key.dptr) {
952                                         hash[h].key = op[i][j].key;
953                                         break;
954                                 }
955                                 h = (h + 1) % (total_keys * 2);
956                         }
957                         /* Might as well save some memory if we can. */
958                         if (op[i][j].key.dptr != hash[h].key.dptr) {
959                                 talloc_free(op[i][j].key.dptr);
960                                 op[i][j].key.dptr = hash[h].key.dptr;
961                         }
962                         hash[h].user = talloc_realloc(hash, hash[h].user,
963                                                      struct key_user,
964                                                      hash[h].num_users+1);
965
966                         /* If it's in a transaction, it's the transaction which
967                          * matters from an analysis POV. */
968                         if (in_transaction(op[i], j)) {
969                                 unsigned start = op[i][j].group_start;
970
971                                 /* Don't include twice. */
972                                 if (hash[h].num_users
973                                     && hash[h].user[hash[h].num_users-1].file
974                                         == i
975                                     && hash[h].user[hash[h].num_users-1].op_num
976                                         == start)
977                                         continue;
978
979                                 hash[h].user[hash[h].num_users].op_num = start;
980                         } else
981                                 hash[h].user[hash[h].num_users].op_num = j;
982                         hash[h].user[hash[h].num_users].file = i;
983                         hash[h].num_users++;
984                 }
985         }
986
987         return hash;
988 }
989
990 static bool satisfies(const TDB_DATA *key, const TDB_DATA *data,
991                       const struct op *op)
992 {
993         const TDB_DATA *need = NULL;
994
995         if (is_transaction(op)) {
996                 unsigned int i;
997
998                 /* Look through for an op in this transaction which
999                  * needs this key. */
1000                 for (i = 1; i < op->group_len; i++) {
1001                         if (op[i].op != OP_TDB_TRAVERSE
1002                             && key_eq(op[i].key, *key)) {
1003                                 need = needs(&op[i]);
1004                                 /* tdb_exists() is special: there might be
1005                                  * something in the transaction with more
1006                                  * specific requirements.  Other ops don't have
1007                                  * specific requirements (eg. store or delete),
1008                                  * but they change the value so we can't get
1009                                  * more information from future ops. */
1010                                 if (op[i].op != OP_TDB_EXISTS)
1011                                         break;
1012                         }
1013                 }
1014         } else
1015                 need = needs(op);
1016
1017         /* Don't need anything?  Cool. */
1018         if (!need)
1019                 return true;
1020
1021         /* This should be tdb_null or a real value. */
1022         assert(data != &must_exist);
1023         assert(data != &must_not_exist);
1024         assert(data != &not_exists_or_empty);
1025
1026         /* must_not_exist == must_not_exist, must_exist == must_exist, or
1027            not_exists_or_empty == not_exists_or_empty. */
1028         if (data->dsize == need->dsize && data->dptr == need->dptr)
1029                 return true;
1030
1031         /* Must not exist?  data must not exist. */
1032         if (need == &must_not_exist)
1033                 return data->dptr == NULL;
1034
1035         /* Must exist? */
1036         if (need == &must_exist)
1037                 return data->dptr != NULL;
1038
1039         /* Either noexist or empty. */
1040         if (need == &not_exists_or_empty)
1041                 return data->dsize == 0;
1042
1043         /* Needs something specific. */
1044         return key_eq(*data, *need);
1045 }
1046
1047 static void move_to_front(struct key_user res[], unsigned off, unsigned elem)
1048 {
1049         if (elem != off) {
1050                 struct key_user tmp = res[elem];
1051                 memmove(res + off + 1, res + off, (elem - off)*sizeof(res[0]));
1052                 res[off] = tmp;
1053         }
1054 }
1055
1056 static void restore_to_pos(struct key_user res[], unsigned off, unsigned elem)
1057 {
1058         if (elem != off) {
1059                 struct key_user tmp = res[off];
1060                 memmove(res + off, res + off + 1, (elem - off)*sizeof(res[0]));
1061                 res[elem] = tmp;
1062         }
1063 }
1064
1065 static bool sort_deps(char *filename[], struct op *op[],
1066                       struct key_user res[],
1067                       unsigned off, unsigned num,
1068                       const TDB_DATA *key, const TDB_DATA *data,
1069                       unsigned num_files, unsigned fuzz)
1070 {
1071         unsigned int i, files_done;
1072         struct op *this_op;
1073         bool done[num_files];
1074
1075         /* Does this make serial numbers go backwards?  Allow a little fuzz. */
1076         if (off > 0) {
1077                 int serial1 = op[res[off-1].file][res[off-1].op_num].serial;
1078                 int serial2 = op[res[off].file][res[off].op_num].serial;
1079
1080                 if (serial1 - serial2 > (int)fuzz) {
1081 #if DEBUG_DEPS
1082                         printf("Serial jump too far (%u -> %u)\n",
1083                                serial1, serial2);
1084 #endif
1085                         return false;
1086                 }
1087         }
1088
1089         /* One or none left?  We're sorted. */
1090         if (off + 1 >= num)
1091                 return true;
1092
1093         memset(done, 0, sizeof(done));
1094
1095         /* Since ops within a trace file are ordered, we just need to figure
1096          * out which file to try next.  Since we don't take into account
1097          * inter-key relationships (which exist by virtue of trace file order),
1098          * we minimize the chance of harm by trying to keep in serial order. */
1099         for (files_done = 0, i = off; i < num && files_done < num_files; i++) {
1100                 if (done[res[i].file])
1101                         continue;
1102
1103                 this_op = &op[res[i].file][res[i].op_num];
1104
1105                 /* Is what we have good enough for this op? */
1106                 if (satisfies(key, data, this_op)) {
1107                         move_to_front(res, off, i);
1108                         if (sort_deps(filename, op, res, off+1, num,
1109                                       key, gives(key, data, this_op),
1110                                       num_files, fuzz))
1111                                 return true;
1112                         restore_to_pos(res, off, i);
1113                 }
1114                 done[res[i].file] = true;
1115                 files_done++;
1116         }
1117
1118         /* No combination worked. */
1119         return false;
1120 }
1121
1122 static void check_dep_sorting(struct key_user user[], unsigned num_users,
1123                               unsigned num_files)
1124 {
1125 #if DEBUG_DEPS
1126         unsigned int i;
1127         unsigned minima[num_files];
1128
1129         memset(minima, 0, sizeof(minima));
1130         for (i = 0; i < num_users; i++) {
1131                 assert(minima[user[i].file] < user[i].op_num);
1132                 minima[user[i].file] = user[i].op_num;
1133         }
1134 #endif
1135 }
1136
1137 /* All these ops happen on the same key.  Which comes first?
1138  *
1139  * This can happen both because read ops or failed write ops don't
1140  * change serial number, and also due to race since we access the
1141  * number unlocked (the race can cause less detectable ordering problems,
1142  * in which case we'll deadlock and report: fix manually in that case).
1143  */
1144 static void figure_deps(char *filename[], struct op *op[],
1145                         const TDB_DATA *key, struct key_user user[],
1146                         unsigned num_users, unsigned num_files)
1147 {
1148         /* We assume database starts empty. */
1149         const struct TDB_DATA *data = &tdb_null;
1150         unsigned int fuzz;
1151
1152         /* We prefer to keep strict serial order if possible: it's the
1153          * most likely.  We get more lax if that fails. */
1154         for (fuzz = 0; fuzz < 100; fuzz = (fuzz + 1)*2) {
1155                 if (sort_deps(filename, op, user, 0, num_users, key, data,
1156                               num_files, fuzz))
1157                         break;
1158         }
1159
1160         if (fuzz >= 100)
1161                 fail(filename[user[0].file], user[0].op_num+1,
1162                      "Could not resolve inter-dependencies");
1163
1164         check_dep_sorting(user, num_users, num_files);
1165 }
1166
1167 static void sort_ops(struct keyinfo hash[], char *filename[], struct op *op[],
1168                      unsigned int num)
1169 {
1170         unsigned int h;
1171
1172         /* Gcc nexted function extension.  How cool is this? */
1173         int compare_serial(const void *_a, const void *_b)
1174         {
1175                 const struct key_user *a = _a, *b = _b;
1176
1177                 /* First, maintain order within any trace file. */
1178                 if (a->file == b->file)
1179                         return a->op_num - b->op_num;
1180
1181                 /* Otherwise, arrange by serial order. */
1182                 return op[a->file][a->op_num].serial
1183                         - op[b->file][b->op_num].serial;
1184         }
1185
1186         /* Now sort into serial order. */
1187         for (h = 0; h < total_keys * 2; h++) {
1188                 struct key_user *user = hash[h].user;
1189
1190                 qsort(user, hash[h].num_users, sizeof(user[0]), compare_serial);
1191                 figure_deps(filename, op, &hash[h].key, user, hash[h].num_users,
1192                             num);
1193         }
1194 }
1195
1196 static int destroy_depend(struct depend *dep)
1197 {
1198         list_del(&dep->pre_list);
1199         list_del(&dep->post_list);
1200         return 0;
1201 }
1202
1203 static void add_dependency(void *ctx,
1204                            struct op *op[],
1205                            char *filename[],
1206                            unsigned int needs_file,
1207                            unsigned int needs_opnum,
1208                            unsigned int satisfies_file,
1209                            unsigned int satisfies_opnum)
1210 {
1211         struct depend *dep;
1212
1213         /* We don't depend on ourselves. */
1214         if (needs_file == satisfies_file) {
1215                 assert(satisfies_opnum < needs_opnum);
1216                 return;
1217         }
1218
1219 #if DEBUG_DEPS
1220         printf("%s:%u: depends on %s:%u\n",
1221                filename[needs_file], needs_opnum+1,
1222                filename[satisfies_file], satisfies_opnum+1);
1223 #endif
1224
1225 #if TRAVERSALS_TAKE_TRANSACTION_LOCK
1226         /* If something in a traverse depends on something in another
1227          * traverse/transaction, it creates a dependency between the
1228          * two groups. */
1229         if ((in_traverse(op[satisfies_file], satisfies_opnum)
1230              && op[needs_file][needs_opnum].group_start)
1231             || (in_traverse(op[needs_file], needs_opnum)
1232                 && op[satisfies_file][satisfies_opnum].group_start)) {
1233                 unsigned int sat;
1234
1235                 /* We are satisfied by end of group. */
1236                 sat = op[satisfies_file][satisfies_opnum].group_start;
1237                 satisfies_opnum = sat + op[satisfies_file][sat].group_len;
1238                 /* And we need that done by start of our group. */
1239                 needs_opnum = op[needs_file][needs_opnum].group_start;
1240         }
1241
1242         /* There is also this case:
1243          *  <traverse> <read foo> ...
1244          *  <transaction> ... </transaction> <create foo>
1245          * Where if we start the traverse then wait, we could block
1246          * the transaction and deadlock.
1247          *
1248          * We try to address this by ensuring that where seqnum indicates it's
1249          * possible, we wait for <create foo> before *starting* traverse.
1250          */
1251         else if (in_traverse(op[needs_file], needs_opnum)) {
1252                 struct op *need = &op[needs_file][needs_opnum];
1253                 if (op[needs_file][need->group_start].serial <
1254                     op[satisfies_file][satisfies_opnum].serial) {
1255                         needs_opnum = need->group_start;
1256                 }
1257         }
1258 #endif
1259
1260         /* If you depend on a transaction, you actually depend on it ending. */
1261         if (is_transaction(&op[satisfies_file][satisfies_opnum])) {
1262                 satisfies_opnum
1263                         += op[satisfies_file][satisfies_opnum].group_len;
1264 #if DEBUG_DEPS
1265                 printf("-> Actually end of transaction %s:%u\n",
1266                        filename[satisfies_file], satisfies_opnum+1);
1267 #endif
1268         } else
1269                 /* We should never create a dependency from middle of
1270                  * a transaction. */
1271                 assert(!in_transaction(op[satisfies_file], satisfies_opnum)
1272                        || op[satisfies_file][satisfies_opnum].op
1273                        == OP_TDB_TRANSACTION_COMMIT
1274                        || op[satisfies_file][satisfies_opnum].op
1275                        == OP_TDB_TRANSACTION_CANCEL);
1276
1277         assert(op[needs_file][needs_opnum].op != OP_TDB_TRAVERSE);
1278         assert(op[satisfies_file][satisfies_opnum].op != OP_TDB_TRAVERSE);
1279
1280         dep = talloc(ctx, struct depend);
1281         dep->needs_file = needs_file;
1282         dep->needs_opnum = needs_opnum;
1283         dep->satisfies_file = satisfies_file;
1284         dep->satisfies_opnum = satisfies_opnum;
1285         list_add(&op[satisfies_file][satisfies_opnum].post, &dep->post_list);
1286         list_add(&op[needs_file][needs_opnum].pre, &dep->pre_list);
1287         talloc_set_destructor(dep, destroy_depend);
1288 }
1289
1290 static bool changes_db(const TDB_DATA *key, const struct op *op)
1291 {
1292         return gives(key, NULL, op) != NULL;
1293 }
1294
1295 static void depend_on_previous(struct op *op[],
1296                                char *filename[],
1297                                unsigned int num,
1298                                struct key_user user[],
1299                                unsigned int i,
1300                                int prev)
1301 {
1302         bool deps[num];
1303         int j;
1304
1305         if (i == 0)
1306                 return;
1307
1308         if (prev == i - 1) {
1309                 /* Just depend on previous. */
1310                 add_dependency(NULL, op, filename,
1311                                user[i].file, user[i].op_num,
1312                                user[prev].file, user[prev].op_num);
1313                 return;
1314         }
1315
1316         /* We have to wait for the readers.  Find last one in *each* file. */
1317         memset(deps, 0, sizeof(deps));
1318         deps[user[i].file] = true;
1319         for (j = i - 1; j > prev; j--) {
1320                 if (!deps[user[j].file]) {
1321                         add_dependency(NULL, op, filename,
1322                                        user[i].file, user[i].op_num,
1323                                        user[j].file, user[j].op_num);
1324                         deps[user[j].file] = true;
1325                 }
1326         }
1327 }
1328
1329 /* This is simple, but not complete.  We don't take into account
1330  * indirect dependencies. */
1331 static void optimize_dependencies(struct op *op[], unsigned int num_ops[],
1332                                   unsigned int num)
1333 {
1334         unsigned int i, j;
1335
1336         /* There can only be one real dependency on each file */
1337         for (i = 0; i < num; i++) {
1338                 for (j = 1; j < num_ops[i]; j++) {
1339                         struct depend *dep, *next;
1340                         struct depend *prev[num];
1341
1342                         memset(prev, 0, sizeof(prev));
1343
1344                         list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
1345                                 if (!prev[dep->satisfies_file]) {
1346                                         prev[dep->satisfies_file] = dep;
1347                                         continue;
1348                                 }
1349                                 if (prev[dep->satisfies_file]->satisfies_opnum
1350                                     < dep->satisfies_opnum) {
1351                                         talloc_free(prev[dep->satisfies_file]);
1352                                         prev[dep->satisfies_file] = dep;
1353                                 } else
1354                                         talloc_free(dep);
1355                         }
1356                 }
1357         }
1358
1359         for (i = 0; i < num; i++) {
1360                 int deps[num];
1361
1362                 for (j = 0; j < num; j++)
1363                         deps[j] = -1;
1364
1365                 for (j = 1; j < num_ops[i]; j++) {
1366                         struct depend *dep, *next;
1367
1368                         list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
1369                                 if (deps[dep->satisfies_file]
1370                                     >= (int)dep->satisfies_opnum)
1371                                         talloc_free(dep);
1372                                 else
1373                                         deps[dep->satisfies_file]
1374                                                 = dep->satisfies_opnum;
1375                         }
1376                 }
1377         }
1378 }
1379
1380 static void derive_dependencies(char *filename[],
1381                                 struct op *op[], unsigned int num_ops[],
1382                                 unsigned int num)
1383 {
1384         struct keyinfo *hash;
1385         unsigned int h, i;
1386
1387         /* Create hash table for faster key lookup. */
1388         hash = hash_ops(op, num_ops, num);
1389
1390         /* Sort them by serial number. */
1391         sort_ops(hash, filename, op, num);
1392
1393         /* Create dependencies back to the last change, rather than
1394          * creating false dependencies by naively making each one
1395          * depend on the previous.  This has two purposes: it makes
1396          * later optimization simpler, and it also avoids deadlock with
1397          * same sequence number ops inside traversals (if one
1398          * traversal doesn't write anything, two ops can have the same
1399          * sequence number yet we can create a traversal dependency
1400          * the other way). */
1401         for (h = 0; h < total_keys * 2; h++) {
1402                 int prev = -1;
1403
1404                 if (hash[h].num_users < 2)
1405                         continue;
1406
1407                 for (i = 0; i < hash[h].num_users; i++) {
1408                         if (changes_db(&hash[h].key, &op[hash[h].user[i].file]
1409                                        [hash[h].user[i].op_num])) {
1410                                 depend_on_previous(op, filename, num,
1411                                                    hash[h].user, i, prev);
1412                                 prev = i;
1413                         } else if (prev >= 0)
1414                                 add_dependency(hash, op, filename,
1415                                                hash[h].user[i].file,
1416                                                hash[h].user[i].op_num,
1417                                                hash[h].user[prev].file,
1418                                                hash[h].user[prev].op_num);
1419                 }
1420         }
1421
1422         optimize_dependencies(op, num_ops, num);
1423 }
1424
1425 int main(int argc, char *argv[])
1426 {
1427         struct timeval start, end;
1428         unsigned int i, num_ops[argc], hashsize[argc], tdb_flags[argc], open_flags[argc];
1429         struct op *op[argc];
1430         int fds[2];
1431         char c;
1432         bool ok = true;
1433
1434         if (argc < 3)
1435                 errx(1, "Usage: %s <tdbfile> <tracefile>...", argv[0]);
1436
1437         pipes = talloc_array(NULL, struct pipe, argc - 2);
1438         for (i = 0; i < argc - 2; i++) {
1439                 printf("Loading tracefile %s...", argv[2+i]);
1440                 fflush(stdout);
1441                 op[i] = load_tracefile(argv[2+i], &num_ops[i], &hashsize[i],
1442                                        &tdb_flags[i], &open_flags[i]);
1443                 if (pipe(pipes[i].fd) != 0)
1444                         err(1, "creating pipe");
1445                 printf("done\n");
1446         }
1447
1448         printf("Calculating inter-dependencies...");
1449         fflush(stdout);
1450         derive_dependencies(argv+2, op, num_ops, i);
1451         printf("done\n");
1452
1453         /* Don't fork for single arg case: simple debugging. */
1454         if (argc == 3) {
1455                 struct tdb_context *tdb;
1456                 tdb = tdb_open_ex(argv[1], hashsize[0], tdb_flags[0],
1457                                   open_flags[0], 0600,
1458                                   NULL, hash_key);
1459                 printf("Single threaded run...");
1460                 fflush(stdout);
1461
1462                 run_ops(tdb, pipes[0].fd[0], argv+2, op, 0, 1, num_ops[0]);
1463                 check_deps(argv[2], op[0], num_ops[0]);
1464
1465                 printf("done\n");
1466                 exit(0);
1467         }
1468
1469         if (pipe(fds) != 0)
1470                 err(1, "creating pipe");
1471
1472         for (i = 0; i < argc - 2; i++) {
1473                 struct tdb_context *tdb;
1474
1475                 switch (fork()) {
1476                 case -1:
1477                         err(1, "fork failed");
1478                 case 0:
1479                         close(fds[1]);
1480                         tdb = tdb_open_ex(argv[1], hashsize[i], tdb_flags[i],
1481                                           open_flags[i], 0600,
1482                                           NULL, hash_key);
1483                         if (!tdb)
1484                                 err(1, "Opening tdb %s", argv[1]);
1485
1486                         /* This catches parent exiting. */
1487                         if (read(fds[0], &c, 1) != 1)
1488                                 exit(1);
1489                         run_ops(tdb, pipes[i].fd[0], argv+2, op, i, 1,
1490                                 num_ops[i]);
1491                         check_deps(argv[2+i], op[i], num_ops[i]);
1492                         exit(0);
1493                 default:
1494                         break;
1495                 }
1496         }
1497
1498         /* Let everything settle. */
1499         sleep(1);
1500
1501         printf("Starting run...");
1502         fflush(stdout);
1503         gettimeofday(&start, NULL);
1504         /* Tell them all to go!  Any write of sufficient length will do. */
1505         if (write(fds[1], hashsize, i) != i)
1506                 err(1, "Writing to wakeup pipe");
1507
1508         for (i = 0; i < argc - 2; i++) {
1509                 int status;
1510                 wait(&status);
1511                 if (!WIFEXITED(status)) {
1512                         warnx("Child died with signal %i", WTERMSIG(status));
1513                         ok = false;
1514                 } else if (WEXITSTATUS(status) != 0)
1515                         /* Assume child spat out error. */
1516                         ok = false;
1517         }
1518         if (!ok)
1519                 exit(1);
1520
1521         gettimeofday(&end, NULL);
1522         printf("done\n");
1523
1524         end.tv_sec -= start.tv_sec;
1525         printf("Time replaying: %lu usec\n",
1526                end.tv_sec * 1000000UL + (end.tv_usec - start.tv_usec));
1527         
1528         exit(0);
1529 }