randomness.c

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

#define THREADED 1
#define PRINT_IN_PIECES 0

#define N 4

typedef struct {
  int id;
  FILE *f;
} data_t;

void *go(void *_data) {
  data_t *data = _data;
  for (int i = 0; i < 100000; i++) {
    if (PRINT_IN_PIECES) {
      fprintf(data->f, "\"");
      fprintf(data->f, "Thread %d: %d\n", data->id, i);
      fprintf(data->f, "\"");
      fprintf(data->f, "\n");
    } else
      fprintf(data->f, "Thread %d: %d\n", data->id, i);
  }
  return NULL;
}

void *nothing(void *no_data) {
  return NULL;
}

int main() {
  FILE *f;
  pthread_t th[N];
  data_t data[N];

  f = fopen("/tmp/randomness.txt", "w");
  for (int i = 0; i < N; i++) {
    data[i].id = i;
    data[i].f = f;
    if (THREADED)
      pthread_create(&th[i], NULL, go, &data[i]);
    else {
      pthread_create(&th[i], NULL, nothing, NULL);
      go(&data[i]);
    }
  }

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

  return 0;
}