tools/GenTables/src/gen_table_xor.c

   1 /* ----------------------------------------------------------------------------------------------- */
   2 /* MHash-384 - Generate tables utility program                                                     */
   3 /* Copyright(c) 2016-2017 LoRd_MuldeR <mulder2@gmx.de>                                             */
   4 /*                                                                                                 */
   5 /* Permission is hereby granted, free of charge, to any person obtaining a copy of this software   */
   6 /* and associated documentation files(the "Software"), to deal in the Software without             */
   7 /* restriction, including without limitation the rights to use, copy, modify, merge, publish,      */
   8 /* distribute, sublicense, and / or sell copies of the Software, and to permit persons to whom the */
   9 /* Software is furnished to do so, subject to the following conditions:                            */
  10 /*                                                                                                 */
  11 /* The above copyright notice and this permission notice shall be included in all copies or        */
  12 /* substantial portions of the Software.                                                           */
  13 /*                                                                                                 */
  14 /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING   */
  15 /* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND      */
  16 /* NONINFRINGEMENT.IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,     */
  17 /* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,  */
  18 /* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.         */
  19 /* ----------------------------------------------------------------------------------------------- */
  20
  21 #include "common.h"
  22 #include "thread_utils.h"
  23 #include "twister.h"
  24 #include "boxmuller.h"
  25
  26 #include <stdio.h>
  27 #include <stdint.h>
  28 #include <string.h>
  29 #include <time.h>
  30 #include <stdbool.h>
  31 #include <io.h>
  32 #include <float.h>
  33 #include <math.h>
  34
  35 //-----------------------------------------------------------------------------
  36 // Const
  37 //-----------------------------------------------------------------------------
  38
  39 #define HASH_LEN 384U
  40
  41 #define DISTANCE_MIN 182U
  42 #define DISTANCE_MAX DISTANCE_MIN + 16U
  43
  44 #define THREAD_COUNT 8U
  45 #undef ENABLE_STATS
  46
  47 #define ROW_NUM (UINT8_MAX+2)           /*total number of rows*/
  48 #define ROW_LEN (HASH_LEN / CHAR_BIT)   /*number of bits per row*/
  49
  50 #define __DISTANCE_STR(X) #X
  51 #define _DISTANCE_STR(X) __DISTANCE_STR(X)
  52 #define DISTANCE_STR _DISTANCE_STR(DISTANCE_MIN)
  53
  54 #define MAGIC_NUMBER 0x3C6058A7C1132CB2ui64
  55
  56 #ifdef ENABLE_STATS
  57 #include <intrin.h>
  58 #endif
  59
  60 //-----------------------------------------------------------------------------
  61 // Globals
  62 //-----------------------------------------------------------------------------
  63
  64 static uint8_t g_table[ROW_NUM][ROW_LEN];
  65 static uint8_t g_thread_buffer[THREAD_COUNT][ROW_LEN];
  66
  67 static size_t g_spinpos = 0;
  68 static char SPINNER[4] = { '/', '-', '\\', '|' };
  69
  70 #ifdef ENABLE_STATS
  71 static volatile long long g_stat_too_hi = 0i64;
  72 static volatile long long g_stat_too_lo = 0i64;
  73 #endif //ENABLE_STATS
  74
  75 //-----------------------------------------------------------------------------
  76 // Utility Functions
  77 //-----------------------------------------------------------------------------
  78
  79 static inline void print_row(uint8_t *const row_buffer)
  80 {
  81         for (size_t w = 0; w < ROW_LEN; ++w)
  82         {
  83                 printf("%02X", row_buffer[w]);
  84         }
  85         puts("");
  86 }
  87
  88 static inline void flip_bit_at(uint8_t *const row_buffer, const size_t pos)
  89 {
  90         row_buffer[(pos / CHAR_BIT)] ^= ((uint8_t)(1U << (pos % CHAR_BIT)));
  91 }
  92
  93 static inline void flip_all_bits(uint8_t *const row_buffer, const size_t *const pos_list, const size_t n)
  94 {
  95         for (size_t i = 0; i < n; ++i)
  96         {
  97                 flip_bit_at(row_buffer, pos_list[i]);
  98         }
  99 }
 100
 101 static inline void rand_indices_n(size_t *const indices_out, twister_t *const rand, const uint32_t n)
 102 {
 103         bool taken[HASH_LEN];
 104         memset(&taken, 0, sizeof(bool) * HASH_LEN);
 105         for (uint32_t i = 0; i < n; ++i)
 106         {
 107                 size_t next;
 108                 do
 109                 {
 110                         next = next_rand_range(rand, HASH_LEN);
 111                 }
 112                 while (taken[next]);
 113                 taken[indices_out[i] = next] = true;
 114         }
 115 }
 116
 117 static inline bool check_distance_rows(const size_t index_1, const size_t index_2)
 118 {
 119         const uint32_t dist = hamming_distance(&g_table[index_1][0], &g_table[index_2][0], ROW_LEN);
 120         return (dist <= DISTANCE_MAX) && (dist >= DISTANCE_MIN);
 121 }
 122
 123 static inline uint32_t check_distance_buff(const size_t index, const uint8_t *const row_buffer, const uint32_t limit)
 124 {
 125         uint32_t error = 0U;
 126 #ifdef ENABLE_STATS
 127         bool reason;
 128 #endif //ENABLE_STATS
 129         for (size_t k = 0; k < index; k++)
 130         {
 131
 132                 const uint32_t dist = hamming_distance(&g_table[k][0], row_buffer, ROW_LEN);
 133                 if (dist > DISTANCE_MAX)
 134                 {
 135                         const uint32_t current = dist - DISTANCE_MAX;
 136                         if (current > error)
 137                         {
 138 #ifdef ENABLE_STATS
 139                                 reason = false;
 140 #endif //ENABLE_STATS
 141                                 if ((error = current) >= limit)
 142                                 {
 143                                         break; /*early termination*/
 144                                 }
 145                         }
 146                 }
 147                 else if (dist < DISTANCE_MIN)
 148                 {
 149                         const uint32_t current = DISTANCE_MIN - dist;
 150                         if (current > error)
 151                         {
 152 #ifdef ENABLE_STATS
 153                                 reason = true;
 154 #endif //ENABLE_STATS
 155                                 if ((error = current) >= limit)
 156                                 {
 157                                         break; /*early termination*/
 158                                 }
 159                         }
 160                 }
 161         }
 162 #ifdef ENABLE_STATS
 163         _InterlockedIncrement64(reason ? &g_stat_too_lo : &g_stat_too_hi);
 164 #endif //ENABLE_STATS
 165         return error;
 166 }
 167
 168 static dump_table(FILE *out)
 169 {
 170         fputs("uint8_t MHASH_384_TABLE_XOR[UINT8_MAX+2][MHASH_384_LEN] =\n{\n", out);
 171         for (size_t i = 0; i < ROW_NUM; i++)
 172         {
 173                 fputs("\t{ ", out);
 174                 for (size_t j = 0; j < ROW_LEN; j++)
 175                 {
 176                         if (j > 0)
 177                         {
 178                                 fputc(',', out);
 179                         }
 180                         fprintf(out, "0x%02X", g_table[i][j]);
 181                 }
 182                 fprintf(out, " }%s /*%02X*/\n", (i != (ROW_NUM - 1)) ? "," : " ", (uint32_t)(i % 0x100));
 183         }
 184         fputs("};\n", out);
 185 }
 186
 187 //-----------------------------------------------------------------------------
 188 // Thread function
 189 //-----------------------------------------------------------------------------
 190
 191 typedef struct
 192 {
 193         size_t index;
 194         uint8_t *row_buffer;
 195         sem_t *stop;
 196         pthread_mutex_t *mutex;
 197         twister_t *rand;
 198 }
 199 thread_data_t;
 200
 201 static void* thread_main(void *const param)
 202 {
 203         const thread_data_t *const data = ((const thread_data_t*)param);
 204         bxmller_t bxmller;
 205         uint8_t temp[ROW_LEN];
 206         gaussian_noise_init(&bxmller);
 207         for(;;)
 208         {
 209                 rand_next_bytes(data->rand, data->row_buffer, ROW_LEN);
 210                 uint32_t error = check_distance_buff(data->index, data->row_buffer, HASH_LEN);
 211                 if(error > 0U)
 212                 {
 213                         for (size_t round = 0; round < 997; ++round)
 214                         {
 215                                 bool improved = false;
 216                                 if (SEM_TRYWAIT(data->stop))
 217                                 {
 218                                         return NULL;
 219                                 }
 220                                 for (size_t rand_loop = 0; rand_loop < 99991U; ++rand_loop)
 221                                 {
 222                                         rand_next_bytes(data->rand, temp, ROW_LEN);
 223                                         const uint32_t next_error = check_distance_buff(data->index, temp, error);
 224                                         if (next_error < error)
 225                                         {
 226                                                 improved = true;
 227                                                 memcpy(data->row_buffer, temp, sizeof(uint8_t) * ROW_LEN);
 228                                                 if (!((error = next_error) > 0U))
 229                                                 {
 230                                                         goto success;
 231                                                 }
 232                                         }
 233                                 }
 234                                 if (!improved)
 235                                 {
 236                                         break; /*early termination*/
 237                                 }
 238                         }
 239                         for (size_t round = 0; round < 997U; ++round)
 240                         {
 241                                 bool improved = false;
 242                                 for (size_t flip_pos_x = 0U; flip_pos_x < HASH_LEN; ++flip_pos_x)
 243                                 {
 244                                         if (!(flip_pos_x % 31))
 245                                         {
 246                                                 if (SEM_TRYWAIT(data->stop))
 247                                                 {
 248                                                         return NULL;
 249                                                 }
 250                                         }
 251                                         flip_bit_at(data->row_buffer, flip_pos_x);
 252                                         bool revert_x = true;
 253                                         const uint32_t next_error = check_distance_buff(data->index, data->row_buffer, error);
 254                                         if (next_error < error)
 255                                         {
 256                                                 revert_x = false;
 257                                                 improved = true;
 258                                                 if (!((error = next_error) > 0U))
 259                                                 {
 260                                                         goto success;
 261                                                 }
 262                                         }
 263                                         for (size_t flip_pos_y = flip_pos_x + 1U; flip_pos_y < HASH_LEN; ++flip_pos_y)
 264                                         {
 265                                                 flip_bit_at(data->row_buffer, flip_pos_y);
 266                                                 bool revert_y = true;
 267                                                 const uint32_t next_error = check_distance_buff(data->index, data->row_buffer, error);
 268                                                 if (next_error < error)
 269                                                 {
 270                                                         revert_x = revert_y = false;
 271                                                         improved = true;
 272                                                         if (!((error = next_error) > 0U))
 273                                                         {
 274                                                                 goto success;
 275                                                         }
 276                                                 }
 277                                                 for (size_t flip_pos_z = flip_pos_y + 1U; flip_pos_z < HASH_LEN; ++flip_pos_z)
 278                                                 {
 279                                                         flip_bit_at(data->row_buffer, flip_pos_z);
 280                                                         const uint32_t next_error = check_distance_buff(data->index, data->row_buffer, error);
 281                                                         if (next_error < error)
 282                                                         {
 283                                                                 revert_x = revert_y = false;
 284                                                                 improved = true;
 285                                                                 if (!((error = next_error) > 0U))
 286                                                                 {
 287                                                                         goto success;
 288                                                                 }
 289                                                         }
 290                                                         else
 291                                                         {
 292                                                                 flip_bit_at(data->row_buffer, flip_pos_z);
 293                                                         }
 294                                                 }
 295                                                 if (revert_y)
 296                                                 {
 297                                                         flip_bit_at(data->row_buffer, flip_pos_y);
 298                                                 }
 299                                         }
 300                                         if (revert_x)
 301                                         {
 302                                                 flip_bit_at(data->row_buffer, flip_pos_x);
 303                                         }
 304                                 }
 305                                 for (size_t refine_loop = 0; refine_loop < 9973U; ++refine_loop)
 306                                 {
 307                                         size_t flip_indices[HASH_LEN];
 308                                         if (!(refine_loop % 97))
 309                                         {
 310                                                 if (SEM_TRYWAIT(data->stop))
 311                                                 {
 312                                                         return NULL;
 313                                                 }
 314                                         }
 315                                         const uint32_t flip_count = gaussian_noise_next(data->rand, &bxmller, 11.0, 4U, HASH_LEN);
 316                                         for (size_t refine_step = 0; refine_step < 997U; ++refine_step)
 317                                         {
 318                                                 rand_indices_n(flip_indices, data->rand, flip_count);
 319                                                 flip_all_bits(data->row_buffer, flip_indices, flip_count);
 320                                                 const uint32_t next_error = check_distance_buff(data->index, data->row_buffer, error);
 321                                                 if (next_error >= error)
 322                                                 {
 323                                                         flip_all_bits(data->row_buffer, flip_indices, flip_count); /*revert*/
 324                                                         continue;
 325                                                 }
 326                                                 else
 327                                                 {
 328                                                         improved = true;
 329                                                         if (!((error = next_error) > 0U))
 330                                                         {
 331                                                                 goto success;
 332                                                         }
 333                                                 }
 334                                         }
 335                                 }
 336                                 if (!improved)
 337                                 {
 338                                         break; /*early termination*/
 339                                 }
 340                         }
 341                 }
 342                 else
 343                 {
 344                         break; /*success*/
 345                 }
 346         }
 347
 348 success:
 349         MUTEX_LOCK(data->mutex);
 350         if (SEM_TRYWAIT(data->stop))
 351         {
 352                 MUTEX_UNLOCK(data->mutex);
 353                 return NULL;
 354         }
 355
 356         SEM_POST(data->stop, THREAD_COUNT);
 357         MUTEX_UNLOCK(data->mutex);
 358         return data->row_buffer; /*success*/
 359 }
 360
 361 static void* thread_spin(void *const param)
 362 {
 363         unsigned long delay = 1U;
 364         sem_t *const stop = ((sem_t*)param);
 365         for (;;)
 366         {
 367                 if (SEM_TRYWAIT(stop))
 368                 {
 369                         printf("\b\b\b[!]");
 370                         return NULL;
 371                 }
 372                 _sleep(delay);
 373                 if (delay >= 500)
 374                 {
 375 #ifdef ENABLE_STATS
 376                         const long long s_too_lo = g_stat_too_lo, s_too_hi = g_stat_too_hi;
 377                         const long long s_too_ac = s_too_lo + s_too_hi;
 378                         printf("Too low: %lld (%.2f), too high: %lld (%.2f)\n", s_too_lo, s_too_lo / ((double)s_too_ac), s_too_hi, s_too_hi / ((double)s_too_ac));
 379 #endif //ENABLE_STATS
 380                         printf("\b\b\b[%c]", SPINNER[g_spinpos]);
 381                         g_spinpos = (g_spinpos + 1) % 4;
 382                 }
 383                 else
 384                 {
 385                         delay *= 2U;
 386                 }
 387         }
 388 }
 389
 390 //-----------------------------------------------------------------------------
 391 // Save / Load
 392 //-----------------------------------------------------------------------------
 393
 394 static bool save_table_data(const wchar_t *const filename, const size_t rows_completed_in)
 395 {
 396         FILE *const file = _wfopen(filename, L"wb");
 397         if (file)
 398         {
 399                 bool success = true;
 400                 const uint64_t magic_number = MAGIC_NUMBER;
 401                 const uint32_t hash_len = HASH_LEN, distance_min = DISTANCE_MIN, distance_max = DISTANCE_MAX, rows_completed = (uint32_t)rows_completed_in;
 402                 fwrite(&magic_number, sizeof(uint64_t), 1, file);
 403                 fwrite(&hash_len, sizeof(uint32_t), 1, file);
 404                 fwrite(&distance_min, sizeof(uint32_t), 1, file);
 405                 fwrite(&distance_max, sizeof(uint32_t), 1, file);
 406                 fwrite(&rows_completed, sizeof(uint32_t), 1, file);
 407                 for (uint32_t i = 0; i < rows_completed; ++i)
 408                 {
 409                         const uint32_t checksum = adler32(&g_table[i][0], ROW_LEN);
 410                         fwrite(&checksum, sizeof(uint32_t), 1, file);
 411                         fwrite(&g_table[i][0], sizeof(uint8_t), ROW_LEN, file);
 412                 }
 413                 if (ferror(file))
 414                 {
 415                         printf("ERROR: Failed to write table data!\n");
 416                         success = false;
 417                 }
 418                 fclose(file);
 419                 return success;
 420         }
 421         else
 422         {
 423                 printf("ERROR: Failed to open table file for writing!\n");
 424                 return false;
 425         }
 426 }
 427
 428 static bool load_table_data(const wchar_t *const filename, size_t *const rows_completed_out)
 429 {
 430         FILE *const file = _wfopen(filename, L"rb");
 431         if (file)
 432         {
 433                 bool success = true;
 434                 uint64_t magic_number;
 435                 uint32_t hash_len, distance_min, distance_max, rows_completed;
 436                 fread(&magic_number, sizeof(uint64_t), 1, file);
 437                 fread(&hash_len, sizeof(uint32_t), 1, file);
 438                 fread(&distance_min, sizeof(uint32_t), 1, file);
 439                 fread(&distance_max, sizeof(uint32_t), 1, file);
 440                 fread(&rows_completed, sizeof(uint32_t), 1, file);
 441                 if (ferror(file) || feof(file))
 442                 {
 443                         printf("ERROR: Failed to read the table header!\n");
 444                         success = false;
 445                         goto failed;
 446                 }
 447                 if (magic_number != MAGIC_NUMBER)
 448                 {
 449                         printf("ERROR: Table file format could not be recognized!\n");
 450                         success = false;
 451                         goto failed;
 452                 }
 453                 if ((hash_len != HASH_LEN) || (distance_min != DISTANCE_MIN) || (distance_max != DISTANCE_MAX) || (rows_completed > ROW_NUM))
 454                 {
 455                         printf("ERROR: Table properties are incompatibe with this instance!\n");
 456                         success = false;
 457                         goto failed;
 458                 }
 459                 for (size_t i = 0; i < rows_completed; ++i)
 460                 {
 461                         uint32_t checksum_expected;
 462                         if ((fread(&checksum_expected, sizeof(uint32_t), 1, file) != 1) || (fread(&g_table[i][0], sizeof(uint8_t), ROW_LEN, file) != ROW_LEN))
 463                         {
 464                                 printf("ERROR: Failed to read table data from file!\n");
 465                                 success = false;
 466                                 goto failed;
 467                         }
 468                         if (adler32(&g_table[i][0], ROW_LEN) != checksum_expected)
 469                         {
 470                                 printf("ERROR: Table checksum does *not* match table contents!\n");
 471                                 success = false;
 472                                 goto failed;
 473                         }
 474                         for (size_t j = 0; j < i; j++)
 475                         {
 476                                 if (!check_distance_rows(i, j))
 477                                 {
 478                                         printf("ERROR: Table distance verification has failed!\n");
 479                                         success = false;
 480                                         goto failed;
 481                                 }
 482                         }
 483                 }
 484         failed:
 485                 fclose(file);
 486                 if (success && rows_completed_out)
 487                 {
 488                         *rows_completed_out = (size_t)rows_completed;
 489                 }
 490                 return success;
 491         }
 492         else
 493         {
 494                 printf("ERROR: Failed to open table file for reading!\n");
 495                 return false;
 496         }
 497 }
 498
 499 //-----------------------------------------------------------------------------
 500 // MAIN
 501 //-----------------------------------------------------------------------------
 502
 503 int wmain(int argc, wchar_t *argv[])
 504 {
 505         pthread_t thread_id[THREAD_COUNT + 1];
 506         thread_data_t thread_data[THREAD_COUNT];
 507         twister_t thread_rand[THREAD_COUNT];
 508         sem_t stop_flag;
 509         pthread_mutex_t stop_mutex;
 510         FILE *file_out = NULL;
 511         size_t initial_row_index = 0;
 512
 513         printf("MHash GenTableXOR [%s]\n\n", __DATE__);
 514         printf("HashLen: %d, Distance Min/Max: %d/%d, Threads: %d\n\n", HASH_LEN, DISTANCE_MIN, DISTANCE_MAX, THREAD_COUNT);
 515
 516         if ((HASH_LEN % (8 * sizeof(uint32_t))) != 0)
 517         {
 518                 crit_exit("FATAL: Hash length must be a multiple of 32 bits!");
 519         }
 520
 521         if (argc < 2)
 522         {
 523                 printf("Table file not specified!\n\n");
 524                 printf("Usage:\n");
 525                 printf("   GenTables_XOR.exe <table_file>\n\n");
 526                 return 1;
 527         }
 528
 529         for (size_t i = 0; i < ROW_NUM; i++)
 530         {
 531                 memset(&g_table[i][0], 0, sizeof(uint8_t) * ROW_LEN);
 532         }
 533
 534         memset(&thread_id, 0, sizeof(pthread_t) * (THREAD_COUNT + 1));
 535         memset(&thread_data, 0, sizeof(thread_data_t) * THREAD_COUNT);
 536         for (size_t t = 0; t < THREAD_COUNT; t++)
 537         {
 538                 memset(&g_thread_buffer[t][0], 0, sizeof(uint8_t) * ROW_LEN);
 539                 rand_init(&thread_rand[t], make_seed());
 540         }
 541
 542         SEM_INIT(&stop_flag);
 543         MUTEX_INIT(&stop_mutex);
 544
 545         if (_waccess(argv[1], 4) == 0)
 546         {
 547                 printf("Loading existing table data and proceeding...\n");
 548                 if (!load_table_data(argv[1], &initial_row_index))
 549                 {
 550                         return 1;
 551                 }
 552         }
 553
 554         for (size_t i = initial_row_index; i < ROW_NUM; i++)
 555         {
 556                 char time_string[64];
 557                 printf("Row %03u of %03u [%c]", (uint32_t)(i+1U), ROW_NUM, SPINNER[g_spinpos]);
 558                 g_spinpos = (g_spinpos + 1) % 4;
 559 #ifdef ENABLE_STATS
 560                 g_stat_too_hi = g_stat_too_lo = 0i64;
 561 #endif //INCREMENT_STAT
 562                 PTHREAD_CREATE(&thread_id[THREAD_COUNT], NULL, thread_spin, &stop_flag);
 563                 for (size_t t = 0; t < THREAD_COUNT; t++)
 564                 {
 565                         thread_data[t].index = i;
 566                         thread_data[t].row_buffer = &g_thread_buffer[t][0];
 567                         thread_data[t].stop = &stop_flag;
 568                         thread_data[t].mutex = &stop_mutex;
 569                         thread_data[t].rand = &thread_rand[t];
 570                         PTHREAD_CREATE(&thread_id[t], NULL, thread_main, &thread_data[t]);
 571                 }
 572
 573                 for (size_t t = 0; t < THREAD_COUNT; t++)
 574                 {
 575                         void *return_value = NULL;
 576                         PTHREAD_JOIN(thread_id[t], &return_value);
 577                         if (return_value)
 578                         {
 579                                 memcpy(&g_table[i][0], return_value, sizeof(uint8_t) * ROW_LEN);
 580                         }
 581                 }
 582
 583                 PTHREAD_JOIN(thread_id[THREAD_COUNT], NULL);
 584                 get_time_str(time_string, 64);
 585                 printf("\b\b\b[#] - %s\n", time_string);
 586
 587                 if (!save_table_data(argv[1], i + 1U))
 588                 {
 589                         return 1; /*failed to save current table data*/
 590                 }
 591         }
 592
 593         printf("\n-----\n\n");
 594
 595         dump_table(stdout);
 596         if (fopen_s(&file_out, "table_XOR." DISTANCE_STR ".txt", "w") == 0)
 597         {
 598                 dump_table(file_out);
 599                 fclose(file_out);
 600         }
 601
 602         printf("\n-----\n\n");
 603
 604         for (size_t i = 0; i < ROW_NUM; i++)
 605         {
 606                 for (size_t j = 0; j < ROW_NUM; j++)
 607                 {
 608                         if (i == j)
 609                         {
 610                                 continue;
 611                         }
 612                         if (!check_distance_rows(i, j))
 613                         {
 614                                 crit_exit("FATAL: Table verification has failed!");
 615                         }
 616                 }
 617         }
 618
 619         SEM_DESTROY(&stop_flag);
 620         MUTEX_DESTROY(&stop_mutex);
 621
 622         printf("COMPLETED.\n\n");
 623         system("shutdown /s /t 180");
 624         return getchar();
 625 }