pthread example - basic 2

A simple pthread example which creates a thread with pthread_create() and

exits with pthread_exit() and pthread_join().

Code for the ptrehad example is listed below.

#include <stdio.h> 
#include <string.h> 
#include <pthread.h> 
 
pthread_t threads[5]; 
int done[5]; 
 
void *thread_main(void *); 
 
int main(void) 
{ 
    int i; 
    int rc; 
    int status; 
     
    printf("pid=%d\n", getpid()); 
     
    for (i = 0; i < 5; i++) 
    {     
        done[i] = 0; 
        pthread_create(&threads[i], NULL, &thread_main, (void *)i); 
        printf("%d, %d\n", i, threads[i]); 
    } 
 
    for (i = 4; i >= 0; i--) 
    { 
        done[i] = 1; 
             rc = pthread_join(threads[i], (void **)&status); 
        if (rc == 0) 
        { 
            printf("Completed join with thread %d status= %d\n",i, status); 
        } 
        else 
        { 
            printf("ERROR; return code from pthread_join() is %d, thread %d\n", rc, i); 
                          return -1; 
        } 
    } 
 
    return 0; 
} 
 
void *thread_main(void *arg) 
{ 
    int i; 
    double result=0.0; 
 
    printf("therad: %d, %d\n", (int)arg, getpid()); 
 
    while (!done[(int)arg]) 
    { 
       for (i=0; i < 1000000; i++) 
          { 
               result = result + (double)random(); 
          } 
          printf("thread: %d, result = %e\n", (int)arg, result); 
    } 
 
    pthread_exit((void *) 0); 
}