fork download 
  1. #include <stdio.h>
  2. #include <pthread.h>
  3. #include <time.h>
  4.  
  5. #define NUM_THREADS 4
  6. #define ITERATIONS 1000000
  7.  
  8. long counters[NUM_THREADS];
  9.  
  10. void* increment(void* arg) {
  11.     int id = *(int*)arg;
  12.     for (int i = 0; i < ITERATIONS; i++) {
  13.         counters[id]++;
  14.     }
  15.     return NULL;
  16. }
  17.  
  18. int main() {
  19.     pthread_t threads[NUM_THREADS];
  20.     int ids[NUM_THREADS];
  21.  
  22.     clock_t start = clock();
  23.  
  24.     for (int i = 0; i < NUM_THREADS; i++) {
  25.         ids[i] = i;
  26.         pthread_create(&threads[i], NULL, increment, &ids[i]);
  27.     }
  28.  
  29.     for (int i = 0; i < NUM_THREADS; i++) {
  30.         pthread_join(threads[i], NULL);
  31.     }
  32.  
  33.     clock_t end = clock();
  34.  
  35.     printf("Time (normal): %f seconds\n",
  36.            (double)(end - start) / CLOCKS_PER_SEC);
  37.  
  38.     return 0;
  39. }
Success #stdin #stdout 0s 5320KB
comments (?)
stdin 
Standard input is empty
stdout 
Time (normal): 0.000654 seconds
https://ideone.com/yGE2cw
language:
C (gcc 8.3)
created:
3 hours ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!