sdcc/support/regression/tcc/124_atomic_counter.c

   1 #include <stddef.h>
   2 #include <stdint.h>
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5 #include <pthread.h>
   6 #include <stdatomic.h>
   7
   8 #define NR_THREADS 16
   9 #define NR_STEPS   ((uint32_t)UINT16_MAX * 4)
  10
  11 #define BUG_ON(COND) \
  12     do { \
  13         if (!!(COND)) \
  14             abort(); \
  15     } while (0)
  16
  17 static
  18 void *adder_simple(void *arg)
  19 {
  20     size_t step;
  21     atomic_size_t *counter = arg;
  22
  23     for (step = 0; step < NR_STEPS; ++step)
  24         atomic_fetch_add_explicit(counter, 1, memory_order_relaxed);
  25
  26     return NULL;
  27 }
  28
  29 static
  30 void *adder_cmpxchg(void *arg)
  31 {
  32     size_t step;
  33     atomic_size_t *counter = arg;
  34
  35     for (step = 0; step < NR_STEPS; ++step) {
  36         size_t xchg;
  37         size_t cmp = atomic_load_explicit(counter, memory_order_relaxed);
  38
  39         do {
  40             xchg = (cmp + 1);
  41         } while (!atomic_compare_exchange_strong_explicit(counter,
  42             &cmp, xchg, memory_order_relaxed, memory_order_relaxed));
  43     }
  44
  45     return NULL;
  46 }
  47
  48 static
  49 void atomic_counter_test(void *(*adder)(void *arg))
  50 {
  51     size_t index;
  52     atomic_size_t counter;
  53     pthread_t thread[NR_THREADS];
  54
  55     atomic_init(&counter, 0);
  56
  57     for (index = 0; index < NR_THREADS; ++index)
  58         BUG_ON(pthread_create(&thread[index], NULL, adder, (void *)&counter));
  59
  60     for (index = 0; index < NR_THREADS; ++index)
  61         BUG_ON(pthread_join(thread[index], NULL));
  62
  63     if (atomic_load(&counter) == (NR_THREADS * NR_STEPS))
  64         printf("SUCCESS\n");
  65     else
  66         printf("FAILURE\n");
  67 }
  68
  69 int main(void)
  70 {
  71     atomic_counter_test(adder_simple);
  72     atomic_counter_test(adder_cmpxchg);
  73
  74     return 0;
  75 }