test_urcu.c

   1 /*
   2  * test_urcu.c
   3  *
   4  * Userspace RCU library - test program
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   7  *
   8  * Distributed under GPLv2
   9  */
  10
  11 #include <stdio.h>
  12 #include <pthread.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <sys/types.h>
  16 #include <sys/wait.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <assert.h>
  20 #include <sys/syscall.h>
  21
  22 #if defined(_syscall0)
  23 _syscall0(pid_t, gettid)
  24 #elif defined(__NR_gettid)
  25 static inline pid_t gettid(void)
  26 {
  27         return syscall(__NR_gettid);
  28 }
  29 #else
  30 #warning "use pid as tid"
  31 static inline pid_t gettid(void)
  32 {
  33         return getpid();
  34 }
  35 #endif
  36
  37 #include "urcu.h"
  38
  39 struct test_array {
  40         int a;
  41 };
  42
  43 static struct test_array *test_rcu_pointer;
  44
  45 static unsigned long duration;
  46 static time_t start_time;
  47 static unsigned long __thread duration_interval;
  48 #define DURATION_TEST_DELAY 100
  49
  50 /*
  51  * returns 0 if test should end.
  52  */
  53 static int test_duration(void)
  54 {
  55         if (duration_interval++ >= DURATION_TEST_DELAY) {
  56                 duration_interval = 0;
  57                 if (time(NULL) - start_time >= duration)
  58                         return 0;
  59         }
  60         return 1;
  61 }
  62
  63 #define NR_READ 10
  64 #define NR_WRITE 9
  65
  66 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
  67
  68 void rcu_copy_mutex_lock(void)
  69 {
  70         int ret;
  71         ret = pthread_mutex_lock(&rcu_copy_mutex);
  72         if (ret) {
  73                 perror("Error in pthread mutex lock");
  74                 exit(-1);
  75         }
  76 }
  77
  78 void rcu_copy_mutex_unlock(void)
  79 {
  80         int ret;
  81
  82         ret = pthread_mutex_unlock(&rcu_copy_mutex);
  83         if (ret) {
  84                 perror("Error in pthread mutex unlock");
  85                 exit(-1);
  86         }
  87 }
  88
  89 void *thr_reader(void *arg)
  90 {
  91         struct test_array *local_ptr;
  92
  93         printf("thread_begin %s, thread id : %lx, tid %lu\n",
  94                         "reader", pthread_self(), (unsigned long)gettid());
  95
  96         urcu_register_thread();
  97
  98         for (;;) {
  99                 rcu_read_lock();
 100                 local_ptr = rcu_dereference(test_rcu_pointer);
 101                 if (local_ptr)
 102                         assert(local_ptr->a == 8);
 103                 rcu_read_unlock();
 104                 if (!test_duration())
 105                         break;
 106         }
 107
 108         urcu_unregister_thread();
 109
 110         printf("thread_end %s, thread id : %lx, tid %lu\n",
 111                         "reader", pthread_self(), (unsigned long)gettid());
 112         return ((void*)1);
 113
 114 }
 115
 116 void *thr_writer(void *arg)
 117 {
 118         struct test_array *new, *old;
 119
 120         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 121                         "writer", pthread_self(), (unsigned long)gettid());
 122
 123         for (;;) {
 124                 new = malloc(sizeof(struct test_array));
 125                 rcu_copy_mutex_lock();
 126                 old = test_rcu_pointer;
 127                 if (old)
 128                         assert(old->a == 8);
 129                 new->a = 8;
 130                 old = urcu_publish_content(&test_rcu_pointer, new);
 131                 rcu_copy_mutex_unlock();
 132                 /* can be done after unlock */
 133                 if (old)
 134                         old->a = 0;
 135                 free(old);
 136                 if (!test_duration())
 137                         break;
 138                 usleep(1);
 139         }
 140
 141         printf("thread_end %s, thread id : %lx, tid %lu\n",
 142                         "writer", pthread_self(), (unsigned long)gettid());
 143         return ((void*)2);
 144 }
 145
 146 void show_usage(int argc, char **argv)
 147 {
 148         printf("Usage : %s duration (s)", argv[0]);
 149 #ifdef DEBUG_YIELD
 150         printf(" [-r] [-w] (yield reader and/or writer)");
 151 #endif
 152         printf("\n");
 153 }
 154
 155 int main(int argc, char **argv)
 156 {
 157         int err;
 158         pthread_t tid_reader[NR_READ], tid_writer[NR_WRITE];
 159         void *tret;
 160         int i;
 161
 162         if (argc < 2) {
 163                 show_usage(argc, argv);
 164                 return -1;
 165         }
 166
 167         err = sscanf(argv[1], "%lu", &duration);
 168         if (err != 1) {
 169                 show_usage(argc, argv);
 170                 return -1;
 171         }
 172
 173 #ifdef DEBUG_YIELD
 174         for (i = 2; i < argc; i++) {
 175                 if (argv[i][0] != '-')
 176                         continue;
 177                 switch (argv[i][1]) {
 178                 case 'r':
 179                         yield_active |= YIELD_READ;
 180                         break;
 181                 case 'w':
 182                         yield_active |= YIELD_WRITE;
 183                         break;
 184                 }
 185         }
 186 #endif
 187
 188         printf("running test for %lu seconds.\n", duration);
 189         start_time = time(NULL);
 190         printf("thread %-6s, thread id : %lx, tid %lu\n",
 191                         "main", pthread_self(), (unsigned long)gettid());
 192
 193         for (i = 0; i < NR_READ; i++) {
 194                 err = pthread_create(&tid_reader[i], NULL, thr_reader, NULL);
 195                 if (err != 0)
 196                         exit(1);
 197         }
 198         for (i = 0; i < NR_WRITE; i++) {
 199                 err = pthread_create(&tid_writer[i], NULL, thr_writer, NULL);
 200                 if (err != 0)
 201                         exit(1);
 202         }
 203
 204         for (i = 0; i < NR_READ; i++) {
 205                 err = pthread_join(tid_reader[i], &tret);
 206                 if (err != 0)
 207                         exit(1);
 208         }
 209         for (i = 0; i < NR_WRITE; i++) {
 210                 err = pthread_join(tid_writer[i], &tret);
 211                 if (err != 0)
 212                         exit(1);
 213         }
 214         free(test_rcu_pointer);
 215
 216         return 0;
 217 }