1 /* A simple example with 4 threads */ 2 3 #include <pthread.h> 4 #include <unistd.h> 5 6 double a[1000]; 7 8 static void init() 9 { 10 int i; 11 for(i=0;i<1000;i++) a[i] = (double)i; 12 } 13 14 static void *th(void *v) 15 { 16 double sum = 0.0; 17 int i,j; 18 19 for(j=0;j<1000;j++) 20 for(i=0;i<1000;i++) 21 sum += a[i]; 22 23 *( (double*)v ) = sum; 24 25 /* make sure that no threads is so fast that it finishes 26 * before last thread is created, thus reusing the TID */ 27 sleep(1); 28 29 return 0; 30 } 31 32 int main() 33 { 34 pthread_t t[4]; 35 double sum[4]; 36 int i; 37 38 init(); 39 40 for(i=0;i<4;i++) 41 pthread_create(&t[i], NULL, th, &sum[i]); 42 43 for(i=0;i<4;i++) 44 pthread_join(t[i], NULL); 45 46 return 0; 47 } 48
