cas.cpp

#include <pthread.h>
#include <stdio.h>
#include <time.h>

void *func(void *param_p)
{
   int *p = (int *)param_p;
   printf("## start: %u\n", (unsigned int)pthread_self());

   for(int i = 0; i < 100000; i++) {
      while(!__sync_bool_compare_and_swap(p, *p, *p + 1));
      printf("%u\n", *p);
   }
   pthread_exit(NULL);
}

int main()
{
   int *p = new int;
   pthread_t *tid = new pthread_t[300];

   *p = 0;
   for(int i = 0; i < 300; i++) {
      if(pthread_create(tid + i, NULL, func, (void *)p) != 0) {
         perror("pthread_create(3)");
      }
   }

   for(int i = 0; i < 300; i++) {
      pthread_join(tid[i], NULL);
   }

   printf("*p=%u\n", *p);
   return 0;
}