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