C Thread Example

This is a simple C Thread example. Don't forget, to compile use:

      gcc -lpthread filename.c -o exename

This THREAD EXAMPLE in C is reads arg[1] as an integer (n) and starts n threads which print 100 numbers each. More specific if n is 5 then 5 threads will start and thread 1 will print from 0 - 99. thread 2 from 100 - 199.... thread i will print from i*100 - (i+1)*100.
As you see code is very simple. If you want to start threads in JAVA then read JAVA Thread example post.

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <pthread.h>

#define MAX_THREAD 100

typedef struct {
 int start,end;
} param;

void *count(void *arg) {
 int i =0;
 param *p=(param *)arg;
 for(i =p->start ; i< p->end ; i++){
  printf(" i = %d",i);
 }
 return (void*)(1);
}

int main(int argc, char* argv[]) {
 int n,i;
 pthread_t *threads;
 param *p;

 if (argc != 2) {
  printf ("Usage: %s n\n",argv[0]);
                printf ("\twhere n is no. of threads\n");
  exit(1);
 }

 n=atoi(argv[1]);

 if ((n < 1) || (n > MAX_THREAD)) {
  printf ("arg[1] should be 1 - %d.\n",MAX_THREAD);
  exit(1);
 }

 threads=(pthread_t *)malloc(n*sizeof(*threads));

 p=(param *)malloc(sizeof(param)*n);
 /* Assign args to a struct and start thread */
 for (i=0; i<n; i++) {
  p[i].start=i*100;
  p[i].end=(i+1)*100;
  pthread_create(&threads[i],NULL,count,(void *)(p+i));
 }
 printf("\nWait threads\n");
 sleep(1);
 /* Wait for all threads. */
 int *x = malloc(sizeof(int));
 for (i=0; i<n; i++) {
  pthread_join(threads[i],(void*)x);
 }
 free(p);
 exit(0);
}