tests/test_urcu_wfcq.c

   1 /*
   2  * test_urcu_wfcq.c
   3  *
   4  * Userspace RCU library - example RCU-based lock-free concurrent queue
   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/wfcqueue.h>
  70
  71 enum test_sync {
  72         TEST_SYNC_NONE = 0,
  73         TEST_SYNC_MUTEX,
  74 };
  75
  76 static enum test_sync test_sync;
  77
  78 static int test_force_sync;
  79
  80 static volatile int test_go, test_stop_enqueue, test_stop_dequeue;
  81
  82 static unsigned long rduration;
  83
  84 static unsigned long duration;
  85
  86 /* read-side C.S. duration, in loops */
  87 static unsigned long wdelay;
  88
  89 static inline void loop_sleep(unsigned long loops)
  90 {
  91         while (loops-- != 0)
  92                 caa_cpu_relax();
  93 }
  94
  95 static int verbose_mode;
  96
  97 static int test_dequeue, test_splice, test_wait_empty;
  98 static int test_enqueue_stopped;
  99
 100 #define printf_verbose(fmt, args...)            \
 101         do {                                    \
 102                 if (verbose_mode)               \
 103                         printf(fmt, ## args);   \
 104         } while (0)
 105
 106 static unsigned int cpu_affinities[NR_CPUS];
 107 static unsigned int next_aff = 0;
 108 static int use_affinity = 0;
 109
 110 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 111
 112 static void set_affinity(void)
 113 {
 114 #if HAVE_SCHED_SETAFFINITY
 115         cpu_set_t mask;
 116         int cpu, ret;
 117 #endif /* HAVE_SCHED_SETAFFINITY */
 118
 119         if (!use_affinity)
 120                 return;
 121
 122 #if HAVE_SCHED_SETAFFINITY
 123         ret = pthread_mutex_lock(&affinity_mutex);
 124         if (ret) {
 125                 perror("Error in pthread mutex lock");
 126                 exit(-1);
 127         }
 128         cpu = cpu_affinities[next_aff++];
 129         ret = pthread_mutex_unlock(&affinity_mutex);
 130         if (ret) {
 131                 perror("Error in pthread mutex unlock");
 132                 exit(-1);
 133         }
 134
 135         CPU_ZERO(&mask);
 136         CPU_SET(cpu, &mask);
 137 #if SCHED_SETAFFINITY_ARGS == 2
 138         sched_setaffinity(0, &mask);
 139 #else
 140         sched_setaffinity(0, sizeof(mask), &mask);
 141 #endif
 142 #endif /* HAVE_SCHED_SETAFFINITY */
 143 }
 144
 145 /*
 146  * returns 0 if test should end.
 147  */
 148 static int test_duration_dequeue(void)
 149 {
 150         return !test_stop_dequeue;
 151 }
 152
 153 static int test_duration_enqueue(void)
 154 {
 155         return !test_stop_enqueue;
 156 }
 157
 158 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues);
 159 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues);
 160
 161 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues);
 162 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues);
 163 static DEFINE_URCU_TLS(unsigned long long, nr_empty_dest_enqueues);
 164 static DEFINE_URCU_TLS(unsigned long long, nr_splice);
 165 static DEFINE_URCU_TLS(unsigned long long, nr_dequeue_last);
 166
 167 static unsigned int nr_enqueuers;
 168 static unsigned int nr_dequeuers;
 169
 170 static struct cds_wfcq_head __attribute__((aligned(CAA_CACHE_LINE_SIZE))) head;
 171 static struct cds_wfcq_tail __attribute__((aligned(CAA_CACHE_LINE_SIZE))) tail;
 172
 173 static void *thr_enqueuer(void *_count)
 174 {
 175         unsigned long long *count = _count;
 176         bool was_nonempty;
 177
 178         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 179                         "enqueuer", (unsigned long) pthread_self(),
 180                         (unsigned long) gettid());
 181
 182         set_affinity();
 183
 184         while (!test_go)
 185         {
 186         }
 187         cmm_smp_mb();
 188
 189         for (;;) {
 190                 struct cds_wfcq_node *node = malloc(sizeof(*node));
 191                 if (!node)
 192                         goto fail;
 193                 cds_wfcq_node_init(node);
 194                 was_nonempty = cds_wfcq_enqueue(&head, &tail, node);
 195                 URCU_TLS(nr_successful_enqueues)++;
 196                 if (!was_nonempty)
 197                         URCU_TLS(nr_empty_dest_enqueues)++;
 198
 199                 if (caa_unlikely(wdelay))
 200                         loop_sleep(wdelay);
 201 fail:
 202                 URCU_TLS(nr_enqueues)++;
 203                 if (caa_unlikely(!test_duration_enqueue()))
 204                         break;
 205         }
 206
 207         uatomic_inc(&test_enqueue_stopped);
 208         count[0] = URCU_TLS(nr_enqueues);
 209         count[1] = URCU_TLS(nr_successful_enqueues);
 210         count[2] = URCU_TLS(nr_empty_dest_enqueues);
 211         printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
 212                        "enqueues %llu successful_enqueues %llu, "
 213                        "empty_dest_enqueues %llu\n",
 214                        pthread_self(),
 215                         (unsigned long) gettid(),
 216                        URCU_TLS(nr_enqueues),
 217                        URCU_TLS(nr_successful_enqueues),
 218                        URCU_TLS(nr_empty_dest_enqueues));
 219         return ((void*)1);
 220
 221 }
 222
 223 static void do_test_dequeue(enum test_sync sync)
 224 {
 225         struct cds_wfcq_node *node;
 226         int state;
 227
 228         if (sync == TEST_SYNC_MUTEX)
 229                 node = cds_wfcq_dequeue_with_state_blocking(&head, &tail,
 230                                 &state);
 231         else
 232                 node = __cds_wfcq_dequeue_with_state_blocking(&head, &tail,
 233                                 &state);
 234
 235         if (state & CDS_WFCQ_STATE_LAST)
 236                 URCU_TLS(nr_dequeue_last)++;
 237
 238         if (node) {
 239                 free(node);
 240                 URCU_TLS(nr_successful_dequeues)++;
 241         }
 242         URCU_TLS(nr_dequeues)++;
 243 }
 244
 245 static void do_test_splice(enum test_sync sync)
 246 {
 247         struct cds_wfcq_head tmp_head;
 248         struct cds_wfcq_tail tmp_tail;
 249         struct cds_wfcq_node *node, *n;
 250         enum cds_wfcq_ret ret;
 251
 252         cds_wfcq_init(&tmp_head, &tmp_tail);
 253
 254         if (sync == TEST_SYNC_MUTEX)
 255                 ret = cds_wfcq_splice_blocking(&tmp_head, &tmp_tail,
 256                         &head, &tail);
 257         else
 258                 ret = __cds_wfcq_splice_blocking(&tmp_head, &tmp_tail,
 259                         &head, &tail);
 260
 261         switch (ret) {
 262         case CDS_WFCQ_RET_WOULDBLOCK:
 263                 assert(0);      /* blocking call */
 264                 break;
 265         case CDS_WFCQ_RET_DEST_EMPTY:
 266                 URCU_TLS(nr_splice)++;
 267                 URCU_TLS(nr_dequeue_last)++;
 268                 /* ok */
 269                 break;
 270         case CDS_WFCQ_RET_DEST_NON_EMPTY:
 271                 assert(0);      /* entirely unexpected */
 272                 break;
 273         case CDS_WFCQ_RET_SRC_EMPTY:
 274                 /* ok, we could even skip iteration on dest if we wanted */
 275                 break;
 276         }
 277
 278         __cds_wfcq_for_each_blocking_safe(&tmp_head, &tmp_tail, node, n) {
 279                 free(node);
 280                 URCU_TLS(nr_successful_dequeues)++;
 281                 URCU_TLS(nr_dequeues)++;
 282         }
 283 }
 284
 285 static void *thr_dequeuer(void *_count)
 286 {
 287         unsigned long long *count = _count;
 288         unsigned int counter;
 289
 290         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 291                         "dequeuer", (unsigned long) pthread_self(),
 292                         (unsigned long) gettid());
 293
 294         set_affinity();
 295
 296         while (!test_go)
 297         {
 298         }
 299         cmm_smp_mb();
 300
 301         for (;;) {
 302                 if (test_dequeue && test_splice) {
 303                         if (counter & 1)
 304                                 do_test_dequeue(test_sync);
 305                         else
 306                                 do_test_splice(test_sync);
 307                         counter++;
 308                 } else {
 309                         if (test_dequeue)
 310                                 do_test_dequeue(test_sync);
 311                         else
 312                                 do_test_splice(test_sync);
 313                 }
 314                 if (caa_unlikely(!test_duration_dequeue()))
 315                         break;
 316                 if (caa_unlikely(rduration))
 317                         loop_sleep(rduration);
 318         }
 319
 320         printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
 321                        "dequeues %llu, successful_dequeues %llu, "
 322                        "nr_splice %llu\n",
 323                        pthread_self(),
 324                         (unsigned long) gettid(),
 325                        URCU_TLS(nr_dequeues), URCU_TLS(nr_successful_dequeues),
 326                        URCU_TLS(nr_splice));
 327         count[0] = URCU_TLS(nr_dequeues);
 328         count[1] = URCU_TLS(nr_successful_dequeues);
 329         count[2] = URCU_TLS(nr_splice);
 330         count[3] = URCU_TLS(nr_dequeue_last);
 331         return ((void*)2);
 332 }
 333
 334 static void test_end(unsigned long long *nr_dequeues,
 335                 unsigned long long *nr_dequeue_last)
 336 {
 337         struct cds_wfcq_node *node;
 338         int state;
 339
 340         do {
 341                 node = cds_wfcq_dequeue_with_state_blocking(&head, &tail,
 342                                 &state);
 343                 if (node) {
 344                         if (state & CDS_WFCQ_STATE_LAST)
 345                                 (*nr_dequeue_last)++;
 346                         free(node);
 347                         (*nr_dequeues)++;
 348                 }
 349         } while (node);
 350 }
 351
 352 static void show_usage(int argc, char **argv)
 353 {
 354         printf("Usage : %s nr_dequeuers nr_enqueuers duration (s) <OPTIONS>\n",
 355                 argv[0]);
 356         printf("OPTIONS:\n");
 357         printf("        [-d delay] (enqueuer period (in loops))\n");
 358         printf("        [-c duration] (dequeuer period (in loops))\n");
 359         printf("        [-v] (verbose output)\n");
 360         printf("        [-a cpu#] [-a cpu#]... (affinity)\n");
 361         printf("        [-q] (test dequeue)\n");
 362         printf("        [-s] (test splice, enabled by default)\n");
 363         printf("        [-M] (use mutex external synchronization)\n");
 364         printf("                Note: default: no external synchronization used.\n");
 365         printf("        [-f] (force user-provided synchronization)\n");
 366         printf("        [-w] Wait for dequeuer to empty queue\n");
 367         printf("\n");
 368 }
 369
 370 int main(int argc, char **argv)
 371 {
 372         int err;
 373         pthread_t *tid_enqueuer, *tid_dequeuer;
 374         void *tret;
 375         unsigned long long *count_enqueuer, *count_dequeuer;
 376         unsigned long long tot_enqueues = 0, tot_dequeues = 0;
 377         unsigned long long tot_successful_enqueues = 0,
 378                            tot_successful_dequeues = 0,
 379                            tot_empty_dest_enqueues = 0,
 380                            tot_splice = 0, tot_dequeue_last = 0;
 381         unsigned long long end_dequeues = 0;
 382         int i, a, retval = 0;
 383
 384         if (argc < 4) {
 385                 show_usage(argc, argv);
 386                 return -1;
 387         }
 388
 389         err = sscanf(argv[1], "%u", &nr_dequeuers);
 390         if (err != 1) {
 391                 show_usage(argc, argv);
 392                 return -1;
 393         }
 394
 395         err = sscanf(argv[2], "%u", &nr_enqueuers);
 396         if (err != 1) {
 397                 show_usage(argc, argv);
 398                 return -1;
 399         }
 400
 401         err = sscanf(argv[3], "%lu", &duration);
 402         if (err != 1) {
 403                 show_usage(argc, argv);
 404                 return -1;
 405         }
 406
 407         for (i = 4; i < argc; i++) {
 408                 if (argv[i][0] != '-')
 409                         continue;
 410                 switch (argv[i][1]) {
 411                 case 'a':
 412                         if (argc < i + 2) {
 413                                 show_usage(argc, argv);
 414                                 return -1;
 415                         }
 416                         a = atoi(argv[++i]);
 417                         cpu_affinities[next_aff++] = a;
 418                         use_affinity = 1;
 419                         printf_verbose("Adding CPU %d affinity\n", a);
 420                         break;
 421                 case 'c':
 422                         if (argc < i + 2) {
 423                                 show_usage(argc, argv);
 424                                 return -1;
 425                         }
 426                         rduration = atol(argv[++i]);
 427                         break;
 428                 case 'd':
 429                         if (argc < i + 2) {
 430                                 show_usage(argc, argv);
 431                                 return -1;
 432                         }
 433                         wdelay = atol(argv[++i]);
 434                         break;
 435                 case 'v':
 436                         verbose_mode = 1;
 437                         break;
 438                 case 'q':
 439                         test_dequeue = 1;
 440                         break;
 441                 case 's':
 442                         test_splice = 1;
 443                         break;
 444                 case 'M':
 445                         test_sync = TEST_SYNC_MUTEX;
 446                         break;
 447                 case 'w':
 448                         test_wait_empty = 1;
 449                         break;
 450                 case 'f':
 451                         test_force_sync = 1;
 452                         break;
 453                 }
 454         }
 455
 456         /* activate splice test by default */
 457         if (!test_dequeue && !test_splice)
 458                 test_splice = 1;
 459
 460         if (test_sync == TEST_SYNC_NONE && nr_dequeuers > 1 && test_dequeue) {
 461                 if (test_force_sync) {
 462                         fprintf(stderr, "[WARNING] Using dequeue concurrently "
 463                                 "with other dequeue or splice without external "
 464                                 "synchronization. Expect run-time failure.\n");
 465                 } else {
 466                         printf("Enforcing mutex synchronization\n");
 467                         test_sync = TEST_SYNC_MUTEX;
 468                 }
 469         }
 470
 471         printf_verbose("running test for %lu seconds, %u enqueuers, "
 472                        "%u dequeuers.\n",
 473                        duration, nr_enqueuers, nr_dequeuers);
 474         if (test_dequeue)
 475                 printf_verbose("dequeue test activated.\n");
 476         else
 477                 printf_verbose("splice test activated.\n");
 478         if (test_sync == TEST_SYNC_MUTEX)
 479                 printf_verbose("External sync: mutex.\n");
 480         else
 481                 printf_verbose("External sync: none.\n");
 482         if (test_wait_empty)
 483                 printf_verbose("Wait for dequeuers to empty queue.\n");
 484         printf_verbose("Writer delay : %lu loops.\n", rduration);
 485         printf_verbose("Reader duration : %lu loops.\n", wdelay);
 486         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 487                         "main", (unsigned long) pthread_self(),
 488                         (unsigned long) gettid());
 489
 490         tid_enqueuer = malloc(sizeof(*tid_enqueuer) * nr_enqueuers);
 491         tid_dequeuer = malloc(sizeof(*tid_dequeuer) * nr_dequeuers);
 492         count_enqueuer = malloc(3 * sizeof(*count_enqueuer) * nr_enqueuers);
 493         count_dequeuer = malloc(4 * sizeof(*count_dequeuer) * nr_dequeuers);
 494         cds_wfcq_init(&head, &tail);
 495
 496         next_aff = 0;
 497
 498         for (i = 0; i < nr_enqueuers; i++) {
 499                 err = pthread_create(&tid_enqueuer[i], NULL, thr_enqueuer,
 500                                      &count_enqueuer[3 * i]);
 501                 if (err != 0)
 502                         exit(1);
 503         }
 504         for (i = 0; i < nr_dequeuers; i++) {
 505                 err = pthread_create(&tid_dequeuer[i], NULL, thr_dequeuer,
 506                                      &count_dequeuer[4 * i]);
 507                 if (err != 0)
 508                         exit(1);
 509         }
 510
 511         cmm_smp_mb();
 512
 513         test_go = 1;
 514
 515         for (i = 0; i < duration; i++) {
 516                 sleep(1);
 517                 if (verbose_mode)
 518                         write (1, ".", 1);
 519         }
 520
 521         test_stop_enqueue = 1;
 522
 523         if (test_wait_empty) {
 524                 while (nr_enqueuers != uatomic_read(&test_enqueue_stopped)) {
 525                         sleep(1);
 526                 }
 527                 while (!cds_wfcq_empty(&head, &tail)) {
 528                         sleep(1);
 529                 }
 530         }
 531
 532         test_stop_dequeue = 1;
 533
 534         for (i = 0; i < nr_enqueuers; i++) {
 535                 err = pthread_join(tid_enqueuer[i], &tret);
 536                 if (err != 0)
 537                         exit(1);
 538                 tot_enqueues += count_enqueuer[3 * i];
 539                 tot_successful_enqueues += count_enqueuer[3 * i + 1];
 540                 tot_empty_dest_enqueues += count_enqueuer[3 * i + 2];
 541         }
 542         for (i = 0; i < nr_dequeuers; i++) {
 543                 err = pthread_join(tid_dequeuer[i], &tret);
 544                 if (err != 0)
 545                         exit(1);
 546                 tot_dequeues += count_dequeuer[4 * i];
 547                 tot_successful_dequeues += count_dequeuer[4 * i + 1];
 548                 tot_splice += count_dequeuer[4 * i + 2];
 549                 tot_dequeue_last += count_dequeuer[4 * i + 3];
 550         }
 551
 552         test_end(&end_dequeues, &tot_dequeue_last);
 553
 554         printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
 555                        tot_enqueues, tot_dequeues);
 556         printf_verbose("total number of successful enqueues : %llu, "
 557                        "enqueues to empty dest : %llu, "
 558                        "successful dequeues %llu, "
 559                        "splice : %llu, dequeue_last : %llu\n",
 560                        tot_successful_enqueues,
 561                        tot_empty_dest_enqueues,
 562                        tot_successful_dequeues,
 563                        tot_splice, tot_dequeue_last);
 564         printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
 565                 "nr_dequeuers %3u "
 566                 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
 567                 "successful enqueues %12llu enqueues to empty dest %12llu "
 568                 "successful dequeues %12llu splice %12llu "
 569                 "dequeue_last %llu "
 570                 "end_dequeues %llu nr_ops %12llu\n",
 571                 argv[0], duration, nr_enqueuers, wdelay,
 572                 nr_dequeuers, rduration, tot_enqueues, tot_dequeues,
 573                 tot_successful_enqueues,
 574                 tot_empty_dest_enqueues,
 575                 tot_successful_dequeues, tot_splice, tot_dequeue_last,
 576                 end_dequeues,
 577                 tot_enqueues + tot_dequeues);
 578
 579         if (tot_successful_enqueues != tot_successful_dequeues + end_dequeues) {
 580                 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
 581                        "succ. dequeues + end dequeues %llu.\n",
 582                        tot_successful_enqueues,
 583                        tot_successful_dequeues + end_dequeues);
 584                 retval = 1;
 585         }
 586
 587         /*
 588          * If only using splice to dequeue, the enqueuer should see
 589          * exactly as many empty queues than the number of non-empty
 590          * src splice.
 591          */
 592         if (tot_empty_dest_enqueues != tot_dequeue_last) {
 593                 printf("WARNING! Discrepancy between empty enqueue (%llu) and "
 594                         "number of dequeue of last element (%llu)\n",
 595                         tot_empty_dest_enqueues,
 596                         tot_dequeue_last);
 597                 retval = 1;
 598         }
 599         free(count_enqueuer);
 600         free(count_dequeuer);
 601         free(tid_enqueuer);
 602         free(tid_dequeuer);
 603         return retval;
 604 }