7dcecc476b76972110ddaed2cadf4fa9af41b7d0
[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 /* What's the data after this op?  pre if nothing changed. */
877 static const TDB_DATA *gives(const struct op *op, const TDB_DATA *pre)
878 {
879         /* Failed ops don't change state of db. */
880         if (op->ret < 0)
881                 return pre;
882
883         if (op->op == OP_TDB_DELETE || op->op == OP_TDB_WIPE_ALL)
884                 return &tdb_null;
885
886         if (op->op == OP_TDB_APPEND)
887                 return &op->append.post;
888
889         if (op->op == OP_TDB_STORE)
890                 return &op->data;
891
892         return pre;
893 }
894
895 static struct keyinfo *hash_ops(struct op *op[], unsigned int num_ops[],
896                                 unsigned int num)
897 {
898         unsigned int i, j, h;
899         struct keyinfo *hash;
900
901         hash = talloc_zero_array(op[0], struct keyinfo, total_keys*2);
902         for (i = 0; i < num; i++) {
903                 for (j = 1; j < num_ops[i]; j++) {
904                         /* We can't do this on allocation, due to realloc. */
905                         list_head_init(&op[i][j].post);
906                         list_head_init(&op[i][j].pre);
907
908                         if (!op[i][j].key.dptr)
909                                 continue;
910
911                         /* We don't wait for traverse keys */
912                         /* FIXME: We should, for trivial traversals. */
913                         if (op[i][j].op == OP_TDB_TRAVERSE)
914                                 continue;
915
916                         h = hash_key(&op[i][j].key) % (total_keys * 2);
917                         while (!key_eq(hash[h].key, op[i][j].key)) {
918                                 if (!hash[h].key.dptr) {
919                                         hash[h].key = op[i][j].key;
920                                         break;
921                                 }
922                                 h = (h + 1) % (total_keys * 2);
923                         }
924                         /* Might as well save some memory if we can. */
925                         if (op[i][j].key.dptr != hash[h].key.dptr) {
926                                 talloc_free(op[i][j].key.dptr);
927                                 op[i][j].key.dptr = hash[h].key.dptr;
928                         }
929                         hash[h].user = talloc_realloc(hash, hash[h].user,
930                                                      struct key_user,
931                                                      hash[h].num_users+1);
932                         hash[h].user[hash[h].num_users].op_num = j;
933                         hash[h].user[hash[h].num_users].file = i;
934                         hash[h].num_users++;
935                 }
936         }
937
938         return hash;
939 }
940
941 static bool satisfies(const TDB_DATA *data, const TDB_DATA *need)
942 {
943         /* Don't need anything?  Cool. */
944         if (!need)
945                 return true;
946
947         /* This should be tdb_null or a real value. */
948         assert(data != &must_exist);
949         assert(data != &must_not_exist);
950         assert(data != &not_exists_or_empty);
951
952         /* must_not_exist == must_not_exist, must_exist == must_exist, or
953            not_exists_or_empty == not_exists_or_empty. */
954         if (data->dsize == need->dsize && data->dptr == need->dptr)
955                 return true;
956
957         /* Must not exist?  data must not exist. */
958         if (need == &must_not_exist)
959                 return data->dptr == NULL;
960
961         /* Must exist? */
962         if (need == &must_exist)
963                 return data->dptr != NULL;
964
965         /* Either noexist or empty. */
966         if (need == &not_exists_or_empty)
967                 return data->dsize == 0;
968
969         /* Needs something specific. */
970         return key_eq(*data, *need);
971 }
972
973 static void move_to_front(struct key_user res[], unsigned int elem)
974 {
975         if (elem != 0) {
976                 struct key_user tmp = res[elem];
977                 memmove(res + 1, res, elem*sizeof(res[0]));
978                 res[0] = tmp;
979         }
980 }
981
982 static void restore_to_pos(struct key_user res[], unsigned int elem)
983 {
984         if (elem != 0) {
985                 struct key_user tmp = res[0];
986                 memmove(res, res + 1, elem*sizeof(res[0]));
987                 res[elem] = tmp;
988         }
989 }
990
991 static bool sort_deps(char *filename[], struct op *op[],
992                       struct key_user res[], unsigned num,
993                       const TDB_DATA *data, unsigned num_files)
994 {
995         unsigned int i, files_done;
996         struct op *this_op;
997         bool done[num_files];
998
999         /* Nothing left?  We're sorted. */
1000         if (num == 0)
1001                 return true;
1002
1003         memset(done, 0, sizeof(done));
1004
1005         /* Since ops within a trace file are ordered, we just need to figure
1006          * out which file to try next.  Since we don't take into account
1007          * inter-key relationships (which exist by virtue of trace file order),
1008          * we minimize the chance of harm by trying to keep in serial order. */
1009         for (files_done = 0, i = 0; i < num && files_done < num_files; i++) {
1010                 if (done[res[i].file])
1011                         continue;
1012
1013                 this_op = &op[res[i].file][res[i].op_num];
1014                 /* Is what we have good enough for this op? */
1015                 if (satisfies(data, needs(this_op))) {
1016                         move_to_front(res, i);
1017                         if (sort_deps(filename, op, res+1, num-1,
1018                                       gives(this_op, data), num_files))
1019                                 return true;
1020                         restore_to_pos(res, i);
1021                 }
1022                 done[res[i].file] = true;
1023                 files_done++;
1024         }
1025
1026         /* No combination worked. */
1027         return false;
1028 }
1029
1030 static void check_dep_sorting(struct key_user user[], unsigned num_users,
1031                               unsigned num_files)
1032 {
1033 #if DEBUG_DEPS
1034         unsigned int i;
1035         unsigned minima[num_files];
1036
1037         memset(minima, 0, sizeof(minima));
1038         for (i = 0; i < num_users; i++) {
1039                 assert(minima[user[i].file] < user[i].op_num);
1040                 minima[user[i].file] = user[i].op_num;
1041         }
1042 #endif
1043 }
1044
1045 /* All these ops happen on the same key.  Which comes first?
1046  *
1047  * This can happen both because read ops or failed write ops don't
1048  * change serial number, and also due to race since we access the
1049  * number unlocked (the race can cause less detectable ordering problems,
1050  * in which case we'll deadlock and report: fix manually in that case).
1051  */
1052 static void figure_deps(char *filename[], struct op *op[],
1053                         struct key_user user[], unsigned num_users,
1054                         unsigned num_files)
1055 {
1056         /* We assume database starts empty. */
1057         const struct TDB_DATA *data = &tdb_null;
1058
1059         if (!sort_deps(filename, op, user, num_users, data, num_files))
1060                 fail(filename[user[0].file], user[0].op_num+1,
1061                      "Could not resolve inter-dependencies");
1062
1063         check_dep_sorting(user, num_users, num_files);
1064 }
1065
1066 static void sort_ops(struct keyinfo hash[], char *filename[], struct op *op[],
1067                      unsigned int num)
1068 {
1069         unsigned int h;
1070
1071         /* Gcc nexted function extension.  How cool is this? */
1072         int compare_serial(const void *_a, const void *_b)
1073         {
1074                 const struct key_user *a = _a, *b = _b;
1075
1076                 /* First, maintain order within any trace file. */
1077                 if (a->file == b->file)
1078                         return a->op_num - b->op_num;
1079
1080                 /* Otherwise, arrange by serial order. */
1081                 return op[a->file][a->op_num].serial
1082                         - op[b->file][b->op_num].serial;
1083         }
1084
1085         /* Now sort into serial order. */
1086         for (h = 0; h < total_keys * 2; h++) {
1087                 struct key_user *user = hash[h].user;
1088
1089                 qsort(user, hash[h].num_users, sizeof(user[0]), compare_serial);
1090                 figure_deps(filename, op, user, hash[h].num_users, num);
1091         }
1092 }
1093
1094 static int destroy_depend(struct depend *dep)
1095 {
1096         list_del(&dep->pre_list);
1097         list_del(&dep->post_list);
1098         return 0;
1099 }
1100
1101 static void add_dependency(void *ctx,
1102                            struct op *op[],
1103                            char *filename[],
1104                            unsigned int needs_file,
1105                            unsigned int needs_opnum,
1106                            unsigned int satisfies_file,
1107                            unsigned int satisfies_opnum)
1108 {
1109         struct depend *dep;
1110         unsigned int needs_start, sat_start;
1111
1112         /* We don't depend on ourselves. */
1113         if (needs_file == satisfies_file) {
1114                 assert(satisfies_opnum < needs_opnum);
1115                 return;
1116         }
1117
1118 #if DEBUG_DEPS
1119         printf("%s:%u: depends on %s:%u\n",
1120                filename[needs_file], needs_opnum+1,
1121                filename[satisfies_file], satisfies_opnum+1);
1122 #endif
1123
1124         needs_start = op[needs_file][needs_opnum].group_start;
1125         sat_start = op[satisfies_file][satisfies_opnum].group_start;
1126
1127         /* If needs is in a transaction, we need it before start. */
1128         if (needs_start) {
1129                 switch (op[needs_file][needs_start].op) {
1130                 case OP_TDB_TRANSACTION_START:
1131                         needs_opnum = needs_start;
1132 #ifdef DEBUG_DEPS
1133                         printf("  -> Back to %u\n", needs_start+1);
1134                         fflush(stdout);
1135 #endif
1136                         break;
1137                 default:
1138                         break;
1139                 }
1140         }
1141
1142         /* If satisfies is in a transaction, we wait until after commit. */
1143         /* FIXME: If transaction is cancelled, don't need dependency. */
1144         if (sat_start) {
1145                 if (op[satisfies_file][sat_start].op
1146                     == OP_TDB_TRANSACTION_START) {
1147                         satisfies_opnum = sat_start
1148                                 + op[satisfies_file][sat_start].group_len;
1149 #ifdef DEBUG_DEPS
1150                         printf("  -> Depends on %u\n", satisfies_opnum+1);
1151                         fflush(stdout);
1152 #endif
1153                 }
1154         }
1155
1156         assert(op[needs_file][needs_opnum].op != OP_TDB_TRAVERSE);
1157         assert(op[satisfies_file][satisfies_opnum].op != OP_TDB_TRAVERSE);
1158
1159         dep = talloc(ctx, struct depend);
1160         dep->needs_file = needs_file;
1161         dep->needs_opnum = needs_opnum;
1162         dep->satisfies_file = satisfies_file;
1163         dep->satisfies_opnum = satisfies_opnum;
1164         list_add(&op[satisfies_file][satisfies_opnum].post, &dep->post_list);
1165         list_add(&op[needs_file][needs_opnum].pre, &dep->pre_list);
1166         talloc_set_destructor(dep, destroy_depend);
1167 }
1168
1169 #if TRAVERSALS_TAKE_TRANSACTION_LOCK
1170 struct traverse_dep {
1171         unsigned int file;
1172         unsigned int op_num;
1173 };
1174
1175 /* Traversals can deadlock against each other, and transactions.  Force
1176  * order. */
1177 static void make_traverse_depends(char *filename[],
1178                                   struct op *op[], unsigned int num_ops[],
1179                                   unsigned int num)
1180 {
1181         unsigned int i, j, num_traversals = 0;
1182         struct traverse_dep *dep;
1183
1184         /* Sort by which one runs first. */
1185         int compare_traverse_dep(const void *_a, const void *_b)
1186         {
1187                 const struct traverse_dep *ta = _a, *tb = _b;
1188                 const struct op *a = &op[ta->file][ta->op_num],
1189                         *b = &op[tb->file][tb->op_num];
1190
1191                 if (a->serial != b->serial)
1192                         return a->serial - b->serial;
1193
1194                 /* If they have same serial, it means one didn't make any
1195                  * changes.  Thus sort by end in that case. */
1196                 return a[a->group_len].serial - b[b->group_len].serial;
1197         }
1198
1199         dep = talloc_array(NULL, struct traverse_dep, 1);
1200
1201         /* Count them. */
1202         for (i = 0; i < num; i++) {
1203                 for (j = 1; j < num_ops[i]; j++) {
1204                         /* Transaction or traverse start. */
1205                         if (op[i][j].group_start == j) {
1206                                 dep = talloc_realloc(NULL, dep,
1207                                                      struct traverse_dep,
1208                                                      num_traversals+1);
1209                                 dep[num_traversals].file = i;
1210                                 dep[num_traversals].op_num = j;
1211                                 num_traversals++;
1212                         }
1213                 }
1214         }
1215         qsort(dep, num_traversals, sizeof(dep[0]), compare_traverse_dep);
1216         for (i = 1; i < num_traversals; i++) {
1217                 /* i depends on end of traverse i-1. */
1218                 add_dependency(NULL, op, filename, dep[i].file, dep[i].op_num,
1219                                dep[i-1].file, dep[i-1].op_num
1220                                + op[dep[i-1].file][dep[i-1].op_num].group_len);
1221         }
1222         talloc_free(dep);
1223 }
1224 #endif /* TRAVERSALS_TAKE_TRANSACTION_LOCK */
1225
1226 static bool changes_db(const struct op *op)
1227 {
1228         return gives(op, NULL) != NULL;
1229 }
1230
1231 static void depend_on_previous(struct op *op[],
1232                                char *filename[],
1233                                unsigned int num,
1234                                struct key_user user[],
1235                                unsigned int i,
1236                                int prev)
1237 {
1238         bool deps[num];
1239         int j;
1240
1241         if (i == 0)
1242                 return;
1243
1244         if (prev == i - 1) {
1245                 /* Just depend on previous. */
1246                 add_dependency(NULL, op, filename,
1247                                user[i].file, user[i].op_num,
1248                                user[prev].file, user[prev].op_num);
1249                 return;
1250         }
1251
1252         /* We have to wait for the readers.  Find last one in *each* file. */
1253         memset(deps, 0, sizeof(deps));
1254         deps[user[i].file] = true;
1255         for (j = i - 1; j > prev; j--) {
1256                 if (!deps[user[j].file]) {
1257                         add_dependency(NULL, op, filename,
1258                                        user[i].file, user[i].op_num,
1259                                        user[j].file, user[j].op_num);
1260                         deps[user[j].file] = true;
1261                 }
1262         }
1263 }
1264
1265 /* This is simple, but not complete.  We don't take into account
1266  * indirect dependencies. */
1267 static void optimize_dependencies(struct op *op[], unsigned int num_ops[],
1268                                   unsigned int num)
1269 {
1270         unsigned int i, j;
1271
1272         /* There can only be one real dependency on each file */
1273         for (i = 0; i < num; i++) {
1274                 for (j = 1; j < num_ops[i]; j++) {
1275                         struct depend *dep, *next;
1276                         struct depend *prev[num];
1277
1278                         memset(prev, 0, sizeof(prev));
1279
1280                         list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
1281                                 if (!prev[dep->satisfies_file]) {
1282                                         prev[dep->satisfies_file] = dep;
1283                                         continue;
1284                                 }
1285                                 if (prev[dep->satisfies_file]->satisfies_opnum
1286                                     < dep->satisfies_opnum) {
1287                                         talloc_free(prev[dep->satisfies_file]);
1288                                         prev[dep->satisfies_file] = dep;
1289                                 } else
1290                                         talloc_free(dep);
1291                         }
1292                 }
1293         }
1294
1295         for (i = 0; i < num; i++) {
1296                 int deps[num];
1297
1298                 for (j = 0; j < num; j++)
1299                         deps[j] = -1;
1300
1301                 for (j = 1; j < num_ops[i]; j++) {
1302                         struct depend *dep, *next;
1303
1304                         list_for_each_safe(&op[i][j].pre, dep, next, pre_list) {
1305                                 if (deps[dep->satisfies_file]
1306                                     >= (int)dep->satisfies_opnum)
1307                                         talloc_free(dep);
1308                                 else
1309                                         deps[dep->satisfies_file]
1310                                                 = dep->satisfies_opnum;
1311                         }
1312                 }
1313         }
1314 }
1315
1316 static void derive_dependencies(char *filename[],
1317                                 struct op *op[], unsigned int num_ops[],
1318                                 unsigned int num)
1319 {
1320         struct keyinfo *hash;
1321         unsigned int h, i;
1322
1323         /* Create hash table for faster key lookup. */
1324         hash = hash_ops(op, num_ops, num);
1325
1326         /* Sort them by serial number. */
1327         sort_ops(hash, filename, op, num);
1328
1329         /* Create dependencies back to the last change, rather than
1330          * creating false dependencies by naively making each one
1331          * depend on the previous.  This has two purposes: it makes
1332          * later optimization simpler, and it also avoids deadlock with
1333          * same sequence number ops inside traversals (if one
1334          * traversal doesn't write anything, two ops can have the same
1335          * sequence number yet we can create a traversal dependency
1336          * the other way). */
1337         for (h = 0; h < total_keys * 2; h++) {
1338                 int prev = -1;
1339
1340                 if (hash[h].num_users < 2)
1341                         continue;
1342
1343                 for (i = 0; i < hash[h].num_users; i++) {
1344                         if (changes_db(&op[hash[h].user[i].file]
1345                                        [hash[h].user[i].op_num])) {
1346                                 depend_on_previous(op, filename, num,
1347                                                    hash[h].user, i, prev);
1348                                 prev = i;
1349                         } else if (prev >= 0)
1350                                 add_dependency(hash, op, filename,
1351                                                hash[h].user[i].file,
1352                                                hash[h].user[i].op_num,
1353                                                hash[h].user[prev].file,
1354                                                hash[h].user[prev].op_num);
1355                 }
1356         }
1357
1358 #if TRAVERSALS_TAKE_TRANSACTION_LOCK
1359         make_traverse_depends(filename, op, num_ops, num);
1360 #endif
1361
1362         optimize_dependencies(op, num_ops, num);
1363 }
1364
1365 int main(int argc, char *argv[])
1366 {
1367         struct timeval start, end;
1368         unsigned int i, num_ops[argc], hashsize[argc], tdb_flags[argc], open_flags[argc];
1369         struct op *op[argc];
1370         int fds[2];
1371         char c;
1372         bool ok = true;
1373
1374         if (argc < 3)
1375                 errx(1, "Usage: %s <tdbfile> <tracefile>...", argv[0]);
1376
1377         pipes = talloc_array(NULL, struct pipe, argc - 2);
1378         for (i = 0; i < argc - 2; i++) {
1379                 printf("Loading tracefile %s...", argv[2+i]);
1380                 fflush(stdout);
1381                 op[i] = load_tracefile(argv[2+i], &num_ops[i], &hashsize[i],
1382                                        &tdb_flags[i], &open_flags[i]);
1383                 if (pipe(pipes[i].fd) != 0)
1384                         err(1, "creating pipe");
1385                 printf("done\n");
1386         }
1387
1388         printf("Calculating inter-dependencies...");
1389         fflush(stdout);
1390         derive_dependencies(argv+2, op, num_ops, i);
1391         printf("done\n");
1392
1393         /* Don't fork for single arg case: simple debugging. */
1394         if (argc == 3) {
1395                 struct tdb_context *tdb;
1396                 tdb = tdb_open_ex(argv[1], hashsize[0], tdb_flags[0],
1397                                   open_flags[0], 0600,
1398                                   NULL, hash_key);
1399                 printf("Single threaded run...");
1400                 fflush(stdout);
1401
1402                 run_ops(tdb, pipes[0].fd[0], argv+2, op, 0, 1, num_ops[0]);
1403                 check_deps(argv[2], op[0], num_ops[0]);
1404
1405                 printf("done\n");
1406                 exit(0);
1407         }
1408
1409         if (pipe(fds) != 0)
1410                 err(1, "creating pipe");
1411
1412         for (i = 0; i < argc - 2; i++) {
1413                 struct tdb_context *tdb;
1414
1415                 switch (fork()) {
1416                 case -1:
1417                         err(1, "fork failed");
1418                 case 0:
1419                         close(fds[1]);
1420                         tdb = tdb_open_ex(argv[1], hashsize[i], tdb_flags[i],
1421                                           open_flags[i], 0600,
1422                                           NULL, hash_key);
1423                         if (!tdb)
1424                                 err(1, "Opening tdb %s", argv[1]);
1425
1426                         /* This catches parent exiting. */
1427                         if (read(fds[0], &c, 1) != 1)
1428                                 exit(1);
1429                         run_ops(tdb, pipes[i].fd[0], argv+2, op, i, 1,
1430                                 num_ops[i]);
1431                         check_deps(argv[2+i], op[i], num_ops[i]);
1432                         exit(0);
1433                 default:
1434                         break;
1435                 }
1436         }
1437
1438         /* Let everything settle. */
1439         sleep(1);
1440
1441         printf("Starting run...");
1442         fflush(stdout);
1443         gettimeofday(&start, NULL);
1444         /* Tell them all to go!  Any write of sufficient length will do. */
1445         if (write(fds[1], hashsize, i) != i)
1446                 err(1, "Writing to wakeup pipe");
1447
1448         for (i = 0; i < argc - 2; i++) {
1449                 int status;
1450                 wait(&status);
1451                 if (!WIFEXITED(status)) {
1452                         warnx("Child died with signal %i", WTERMSIG(status));
1453                         ok = false;
1454                 } else if (WEXITSTATUS(status) != 0)
1455                         /* Assume child spat out error. */
1456                         ok = false;
1457         }
1458         if (!ok)
1459                 exit(1);
1460
1461         gettimeofday(&end, NULL);
1462         printf("done\n");
1463
1464         end.tv_sec -= start.tv_sec;
1465         printf("Time replaying: %lu usec\n",
1466                end.tv_sec * 1000000UL + (end.tv_usec - start.tv_usec));
1467         
1468         exit(0);
1469 }