gistfile1.c

#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/resource.h>
#define STACKSIZE (16 * 1024)
#define NUM_THREADS 100000
#define getlimit(x) getrlimit(RLIMIT_##x, &limit); printf("%s current: %lu, max: %lu\n", #x, limit.rlim_cur, limit.rlim_max);

void *do_nothing(void *args)
{
  pthread_mutex_t* mtx = (pthread_mutex_t*) args;
  pthread_mutex_lock(mtx);
  pthread_mutex_unlock(mtx);
  return NULL;

}

int main()
{
  
  struct rlimit limit;
  
  pthread_t threads[NUM_THREADS];
  pthread_attr_t attr;
  pthread_mutex_t mtx;
  int i = 0;
  int err;

  pthread_mutex_init(&mtx, NULL);
  pthread_attr_init(&attr);
  i = pthread_attr_setstacksize(&attr, STACKSIZE);
  if (i != 0) {
    fprintf(stderr, "Error setting stack size to %ul", STACKSIZE); 
    return 1;
  }
  pthread_mutex_lock(&mtx);
  for (; i < NUM_THREADS; ++i)
  {
    if((err = pthread_create(&threads[i], &attr, do_nothing, (void*) &mtx))) {
      fprintf(stderr, "Error creating thread: %d\n", err);
      getlimit(NPROC);
      getlimit(STACK);
      return 1;
    }
    fprintf(stdout, "%d \n", i);
  }

  sleep(5);
  pthread_mutex_unlock(&mtx);
  
  if(pthread_join(threads[1], NULL)) {
    fprintf(stderr, "Error joining thread\n");
    return 2;
  }

  printf("total threads: %d\n", i);

  return 0;
}