tests/test_urcu_wfs.c

   1 /*
   2  * test_urcu_wfs.c
   3  *
   4  * Userspace RCU library - example RCU-based lock-free stack
   5  *
   6  * Copyright February 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  * Copyright February 2010 - Paolo Bonzini <pbonzini@redhat.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  22  */
  23
  24 #define _GNU_SOURCE
  25 #include "../config.h"
  26 #include <stdio.h>
  27 #include <pthread.h>
  28 #include <stdlib.h>
  29 #include <stdint.h>
  30 #include <stdbool.h>
  31 #include <string.h>
  32 #include <sys/types.h>
  33 #include <sys/wait.h>
  34 #include <unistd.h>
  35 #include <stdio.h>
  36 #include <assert.h>
  37 #include <errno.h>
  38
  39 #include <urcu/arch.h>
  40 #include <urcu/tls-compat.h>
  41 #include <urcu/uatomic.h>
  42 #include "cpuset.h"
  43
  44 #ifdef __linux__
  45 #include <syscall.h>
  46 #endif
  47
  48 /* hardcoded number of CPUs */
  49 #define NR_CPUS 16384
  50
  51 #if defined(_syscall0)
  52 _syscall0(pid_t, gettid)
  53 #elif defined(__NR_gettid)
  54 static inline pid_t gettid(void)
  55 {
  56         return syscall(__NR_gettid);
  57 }
  58 #else
  59 #warning "use pid as tid"
  60 static inline pid_t gettid(void)
  61 {
  62         return getpid();
  63 }
  64 #endif
  65
  66 #ifndef DYNAMIC_LINK_TEST
  67 #define _LGPL_SOURCE
  68 #endif
  69 #include <urcu/wfstack.h>
  70
  71 /*
  72  * External synchronization used.
  73  */
  74 enum test_sync {
  75         TEST_SYNC_NONE = 0,
  76         TEST_SYNC_MUTEX,
  77 };
  78
  79 static enum test_sync test_sync;
  80
  81 static int test_force_sync;
  82
  83 static volatile int test_go, test_stop_enqueue, test_stop_dequeue;
  84
  85 static unsigned long rduration;
  86
  87 static unsigned long duration;
  88
  89 /* read-side C.S. duration, in loops */
  90 static unsigned long wdelay;
  91
  92 static inline void loop_sleep(unsigned long loops)
  93 {
  94         while (loops-- != 0)
  95                 caa_cpu_relax();
  96 }
  97
  98 static int verbose_mode;
  99
 100 static int test_pop, test_pop_all, test_wait_empty;
 101 static int test_enqueue_stopped;
 102
 103 #define printf_verbose(fmt, args...)            \
 104         do {                                    \
 105                 if (verbose_mode)               \
 106                         printf(fmt, ## args);   \
 107         } while (0)
 108
 109 static unsigned int cpu_affinities[NR_CPUS];
 110 static unsigned int next_aff = 0;
 111 static int use_affinity = 0;
 112
 113 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 114
 115 static void set_affinity(void)
 116 {
 117 #if HAVE_SCHED_SETAFFINITY
 118         cpu_set_t mask;
 119         int cpu, ret;
 120 #endif /* HAVE_SCHED_SETAFFINITY */
 121
 122         if (!use_affinity)
 123                 return;
 124
 125 #if HAVE_SCHED_SETAFFINITY
 126         ret = pthread_mutex_lock(&affinity_mutex);
 127         if (ret) {
 128                 perror("Error in pthread mutex lock");
 129                 exit(-1);
 130         }
 131         cpu = cpu_affinities[next_aff++];
 132         ret = pthread_mutex_unlock(&affinity_mutex);
 133         if (ret) {
 134                 perror("Error in pthread mutex unlock");
 135                 exit(-1);
 136         }
 137
 138         CPU_ZERO(&mask);
 139         CPU_SET(cpu, &mask);
 140 #if SCHED_SETAFFINITY_ARGS == 2
 141         sched_setaffinity(0, &mask);
 142 #else
 143         sched_setaffinity(0, sizeof(mask), &mask);
 144 #endif
 145 #endif /* HAVE_SCHED_SETAFFINITY */
 146 }
 147
 148 /*
 149  * returns 0 if test should end.
 150  */
 151 static int test_duration_dequeue(void)
 152 {
 153         return !test_stop_dequeue;
 154 }
 155
 156 static int test_duration_enqueue(void)
 157 {
 158         return !test_stop_enqueue;
 159 }
 160
 161 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues);
 162 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues);
 163
 164 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues);
 165 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues);
 166 static DEFINE_URCU_TLS(unsigned long long, nr_empty_dest_enqueues);
 167 static DEFINE_URCU_TLS(unsigned long long, nr_pop_all);
 168
 169 static unsigned int nr_enqueuers;
 170 static unsigned int nr_dequeuers;
 171
 172 static struct cds_wfs_stack s;
 173
 174 static void *thr_enqueuer(void *_count)
 175 {
 176         unsigned long long *count = _count;
 177         bool was_nonempty;
 178
 179         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 180                         "enqueuer", (unsigned long) pthread_self(),
 181                         (unsigned long) gettid());
 182
 183         set_affinity();
 184
 185         while (!test_go)
 186         {
 187         }
 188         cmm_smp_mb();
 189
 190         for (;;) {
 191                 struct cds_wfs_node *node = malloc(sizeof(*node));
 192                 if (!node)
 193                         goto fail;
 194                 cds_wfs_node_init(node);
 195                 was_nonempty = cds_wfs_push(&s, node);
 196                 URCU_TLS(nr_successful_enqueues)++;
 197                 if (!was_nonempty)
 198                         URCU_TLS(nr_empty_dest_enqueues)++;
 199
 200                 if (caa_unlikely(wdelay))
 201                         loop_sleep(wdelay);
 202 fail:
 203                 URCU_TLS(nr_enqueues)++;
 204                 if (caa_unlikely(!test_duration_enqueue()))
 205                         break;
 206         }
 207
 208         uatomic_inc(&test_enqueue_stopped);
 209         count[0] = URCU_TLS(nr_enqueues);
 210         count[1] = URCU_TLS(nr_successful_enqueues);
 211         count[2] = URCU_TLS(nr_empty_dest_enqueues);
 212         printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
 213                        "enqueues %llu successful_enqueues %llu, "
 214                        "empty_dest_enqueues %llu\n",
 215                        pthread_self(),
 216                         (unsigned long) gettid(),
 217                        URCU_TLS(nr_enqueues),
 218                        URCU_TLS(nr_successful_enqueues),
 219                        URCU_TLS(nr_empty_dest_enqueues));
 220         return ((void*)1);
 221
 222 }
 223
 224 static void do_test_pop(enum test_sync sync)
 225 {
 226         struct cds_wfs_node *node;
 227
 228         if (sync == TEST_SYNC_MUTEX)
 229                 cds_wfs_pop_lock(&s);
 230         node = __cds_wfs_pop_blocking(&s);
 231         if (sync == TEST_SYNC_MUTEX)
 232                 cds_wfs_pop_unlock(&s);
 233
 234         if (node) {
 235                 free(node);
 236                 URCU_TLS(nr_successful_dequeues)++;
 237         }
 238         URCU_TLS(nr_dequeues)++;
 239 }
 240
 241 static void do_test_pop_all(enum test_sync sync)
 242 {
 243         struct cds_wfs_head *head;
 244         struct cds_wfs_node *node, *n;
 245
 246         if (sync == TEST_SYNC_MUTEX)
 247                 cds_wfs_pop_lock(&s);
 248         head = __cds_wfs_pop_all(&s);
 249         if (sync == TEST_SYNC_MUTEX)
 250                 cds_wfs_pop_unlock(&s);
 251
 252         /* Check if empty */
 253         if (cds_wfs_first(head) == NULL)
 254                 return;
 255
 256         URCU_TLS(nr_pop_all)++;
 257
 258         cds_wfs_for_each_blocking_safe(head, node, n) {
 259                 free(node);
 260                 URCU_TLS(nr_successful_dequeues)++;
 261                 URCU_TLS(nr_dequeues)++;
 262         }
 263 }
 264
 265 static void *thr_dequeuer(void *_count)
 266 {
 267         unsigned long long *count = _count;
 268         unsigned int counter;
 269
 270         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 271                         "dequeuer", (unsigned long) pthread_self(),
 272                         (unsigned long) gettid());
 273
 274         set_affinity();
 275
 276         while (!test_go)
 277         {
 278         }
 279         cmm_smp_mb();
 280
 281         assert(test_pop || test_pop_all);
 282
 283         for (;;) {
 284                 if (test_pop && test_pop_all) {
 285                         if (counter & 1)
 286                                 do_test_pop(test_sync);
 287                         else
 288                                 do_test_pop_all(test_sync);
 289                         counter++;
 290                 } else {
 291                         if (test_pop)
 292                                 do_test_pop(test_sync);
 293                         else
 294                                 do_test_pop_all(test_sync);
 295                 }
 296
 297                 if (caa_unlikely(!test_duration_dequeue()))
 298                         break;
 299                 if (caa_unlikely(rduration))
 300                         loop_sleep(rduration);
 301         }
 302
 303         printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
 304                        "dequeues %llu, successful_dequeues %llu "
 305                        "pop_all %llu\n",
 306                        pthread_self(),
 307                         (unsigned long) gettid(),
 308                        URCU_TLS(nr_dequeues), URCU_TLS(nr_successful_dequeues),
 309                        URCU_TLS(nr_pop_all));
 310         count[0] = URCU_TLS(nr_dequeues);
 311         count[1] = URCU_TLS(nr_successful_dequeues);
 312         count[2] = URCU_TLS(nr_pop_all);
 313         return ((void*)2);
 314 }
 315
 316 static void test_end(struct cds_wfs_stack *s, unsigned long long *nr_dequeues)
 317 {
 318         struct cds_wfs_node *node;
 319
 320         do {
 321                 node = cds_wfs_pop_blocking(s);
 322                 if (node) {
 323                         free(node);
 324                         (*nr_dequeues)++;
 325                 }
 326         } while (node);
 327 }
 328
 329 static void show_usage(int argc, char **argv)
 330 {
 331         printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv[0]);
 332         printf(" [-d delay] (enqueuer period (in loops))");
 333         printf(" [-c duration] (dequeuer period (in loops))");
 334         printf(" [-v] (verbose output)");
 335         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 336         printf(" [-p] (test pop)");
 337         printf(" [-P] (test pop_all, enabled by default)");
 338         printf(" [-M] (use mutex external synchronization)");
 339         printf("      Note: default: no external synchronization used.");
 340         printf(" [-f] (force user-provided synchronization)");
 341         printf(" [-w] Wait for dequeuer to empty stack");
 342         printf("\n");
 343 }
 344
 345 int main(int argc, char **argv)
 346 {
 347         int err;
 348         pthread_t *tid_enqueuer, *tid_dequeuer;
 349         void *tret;
 350         unsigned long long *count_enqueuer, *count_dequeuer;
 351         unsigned long long tot_enqueues = 0, tot_dequeues = 0;
 352         unsigned long long tot_successful_enqueues = 0,
 353                            tot_successful_dequeues = 0,
 354                            tot_empty_dest_enqueues = 0,
 355                            tot_pop_all = 0;
 356         unsigned long long end_dequeues = 0;
 357         int i, a, retval = 0;
 358
 359         if (argc < 4) {
 360                 show_usage(argc, argv);
 361                 return -1;
 362         }
 363
 364         err = sscanf(argv[1], "%u", &nr_dequeuers);
 365         if (err != 1) {
 366                 show_usage(argc, argv);
 367                 return -1;
 368         }
 369
 370         err = sscanf(argv[2], "%u", &nr_enqueuers);
 371         if (err != 1) {
 372                 show_usage(argc, argv);
 373                 return -1;
 374         }
 375
 376         err = sscanf(argv[3], "%lu", &duration);
 377         if (err != 1) {
 378                 show_usage(argc, argv);
 379                 return -1;
 380         }
 381
 382         for (i = 4; i < argc; i++) {
 383                 if (argv[i][0] != '-')
 384                         continue;
 385                 switch (argv[i][1]) {
 386                 case 'a':
 387                         if (argc < i + 2) {
 388                                 show_usage(argc, argv);
 389                                 return -1;
 390                         }
 391                         a = atoi(argv[++i]);
 392                         cpu_affinities[next_aff++] = a;
 393                         use_affinity = 1;
 394                         printf_verbose("Adding CPU %d affinity\n", a);
 395                         break;
 396                 case 'c':
 397                         if (argc < i + 2) {
 398                                 show_usage(argc, argv);
 399                                 return -1;
 400                         }
 401                         rduration = atol(argv[++i]);
 402                         break;
 403                 case 'd':
 404                         if (argc < i + 2) {
 405                                 show_usage(argc, argv);
 406                                 return -1;
 407                         }
 408                         wdelay = atol(argv[++i]);
 409                         break;
 410                 case 'v':
 411                         verbose_mode = 1;
 412                         break;
 413                 case 'p':
 414                         test_pop = 1;
 415                         break;
 416                 case 'P':
 417                         test_pop_all = 1;
 418                         break;
 419                 case 'M':
 420                         test_sync = TEST_SYNC_MUTEX;
 421                         break;
 422                 case 'w':
 423                         test_wait_empty = 1;
 424                         break;
 425                 case 'f':
 426                         test_force_sync = 1;
 427                         break;
 428                 }
 429         }
 430
 431         /* activate pop_all test by default */
 432         if (!test_pop && !test_pop_all)
 433                 test_pop_all = 1;
 434
 435         if (test_sync == TEST_SYNC_NONE && nr_dequeuers > 1 && test_pop) {
 436                 if (test_force_sync) {
 437                         fprintf(stderr, "[WARNING] Using pop concurrently "
 438                                 "with other pop or pop_all without external "
 439                                 "synchronization. Expect run-time failure.\n");
 440                 } else {
 441                         printf("Enforcing mutex synchronization\n");
 442                         test_sync = TEST_SYNC_MUTEX;
 443                 }
 444         }
 445
 446         printf_verbose("running test for %lu seconds, %u enqueuers, "
 447                        "%u dequeuers.\n",
 448                        duration, nr_enqueuers, nr_dequeuers);
 449         if (test_pop)
 450                 printf_verbose("pop test activated.\n");
 451         if (test_pop_all)
 452                 printf_verbose("pop_all test activated.\n");
 453         if (test_sync == TEST_SYNC_MUTEX)
 454                 printf_verbose("External sync: mutex.\n");
 455         else
 456                 printf_verbose("External sync: none.\n");
 457         if (test_wait_empty)
 458                 printf_verbose("Wait for dequeuers to empty stack.\n");
 459         printf_verbose("Writer delay : %lu loops.\n", rduration);
 460         printf_verbose("Reader duration : %lu loops.\n", wdelay);
 461         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 462                         "main", (unsigned long) pthread_self(),
 463                         (unsigned long) gettid());
 464
 465         tid_enqueuer = malloc(sizeof(*tid_enqueuer) * nr_enqueuers);
 466         tid_dequeuer = malloc(sizeof(*tid_dequeuer) * nr_dequeuers);
 467         count_enqueuer = malloc(3 * sizeof(*count_enqueuer) * nr_enqueuers);
 468         count_dequeuer = malloc(3 * sizeof(*count_dequeuer) * nr_dequeuers);
 469         cds_wfs_init(&s);
 470
 471         next_aff = 0;
 472
 473         for (i = 0; i < nr_enqueuers; i++) {
 474                 err = pthread_create(&tid_enqueuer[i], NULL, thr_enqueuer,
 475                                      &count_enqueuer[3 * i]);
 476                 if (err != 0)
 477                         exit(1);
 478         }
 479         for (i = 0; i < nr_dequeuers; i++) {
 480                 err = pthread_create(&tid_dequeuer[i], NULL, thr_dequeuer,
 481                                      &count_dequeuer[3 * i]);
 482                 if (err != 0)
 483                         exit(1);
 484         }
 485
 486         cmm_smp_mb();
 487
 488         test_go = 1;
 489
 490         for (i = 0; i < duration; i++) {
 491                 sleep(1);
 492                 if (verbose_mode)
 493                         write (1, ".", 1);
 494         }
 495
 496         test_stop_enqueue = 1;
 497
 498         if (test_wait_empty) {
 499                 while (nr_enqueuers != uatomic_read(&test_enqueue_stopped)) {
 500                         sleep(1);
 501                 }
 502                 while (!cds_wfs_empty(&s)) {
 503                         sleep(1);
 504                 }
 505         }
 506
 507         test_stop_dequeue = 1;
 508
 509         for (i = 0; i < nr_enqueuers; i++) {
 510                 err = pthread_join(tid_enqueuer[i], &tret);
 511                 if (err != 0)
 512                         exit(1);
 513                 tot_enqueues += count_enqueuer[3 * i];
 514                 tot_successful_enqueues += count_enqueuer[3 * i + 1];
 515                 tot_empty_dest_enqueues += count_enqueuer[3 * i + 2];
 516         }
 517         for (i = 0; i < nr_dequeuers; i++) {
 518                 err = pthread_join(tid_dequeuer[i], &tret);
 519                 if (err != 0)
 520                         exit(1);
 521                 tot_dequeues += count_dequeuer[3 * i];
 522                 tot_successful_dequeues += count_dequeuer[3 * i + 1];
 523                 tot_pop_all += count_dequeuer[3 * i + 2];
 524         }
 525
 526         test_end(&s, &end_dequeues);
 527
 528         printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
 529                        tot_enqueues, tot_dequeues);
 530         printf_verbose("total number of successful enqueues : %llu, "
 531                        "enqueues to empty dest : %llu, "
 532                        "successful dequeues %llu, "
 533                        "pop_all : %llu\n",
 534                        tot_successful_enqueues,
 535                        tot_empty_dest_enqueues,
 536                        tot_successful_dequeues,
 537                        tot_pop_all);
 538         printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
 539                 "nr_dequeuers %3u "
 540                 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
 541                 "successful enqueues %12llu enqueues to empty dest %12llu "
 542                 "successful dequeues %12llu pop_all %12llu "
 543                 "end_dequeues %llu nr_ops %12llu\n",
 544                 argv[0], duration, nr_enqueuers, wdelay,
 545                 nr_dequeuers, rduration, tot_enqueues, tot_dequeues,
 546                 tot_successful_enqueues,
 547                 tot_empty_dest_enqueues,
 548                 tot_successful_dequeues, tot_pop_all, end_dequeues,
 549                 tot_enqueues + tot_dequeues);
 550         if (tot_successful_enqueues != tot_successful_dequeues + end_dequeues) {
 551                 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
 552                        "succ. dequeues + end dequeues %llu.\n",
 553                        tot_successful_enqueues,
 554                        tot_successful_dequeues + end_dequeues);
 555                 retval = 1;
 556         }
 557         /*
 558          * If only using pop_all to dequeue, the enqueuer should see
 559          * exactly as many empty queues than the number of non-empty
 560          * stacks dequeued.
 561          */
 562         if (test_wait_empty && test_pop_all && !test_pop
 563                         && tot_empty_dest_enqueues != tot_pop_all) {
 564                 printf("WARNING! Discrepancy between empty enqueue (%llu) and "
 565                         "number of non-empty pop_all (%llu)\n",
 566                         tot_empty_dest_enqueues,
 567                         tot_pop_all);
 568                 retval = 1;
 569         }
 570         free(count_enqueuer);
 571         free(count_dequeuer);
 572         free(tid_enqueuer);
 573         free(tid_dequeuer);
 574         return retval;
 575 }