Creating Dynamic Threads in C

How do we create multiple thread during runtime in C programming language? If开发者_StackOverflow we need to create same amount of thread as specified by the user how do we do it?

On Linux use pthreads

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

void *print_message_function( void *ptr );

int main(int argc, char *argv[])
{
     pthread_t thread1, thread2;
     char *message1 = "Thread 1";
     char *message2 = "Thread 2";
     int  iret1, iret2;

    /* Create independent threads each of which will execute function */

     iret1 = pthread_create( &thread1, NULL, print_message_function, (void*) message1);
     iret2 = pthread_create( &thread2, NULL, print_message_function, (void*) message2);

     /* Wait till threads are complete before main continues. Unless we  */
     /* wait we run the risk of executing an exit which will terminate   */
     /* the process and all threads before the threads have completed.   */

     pthread_join( thread1, NULL);
     pthread_join( thread2, NULL); 

     printf("Thread 1 returns: %d\n",iret1);
     printf("Thread 2 returns: %d\n",iret2);
     exit(0);
}

void *print_message_function( void *ptr )
{
     char *message;
     message = (char *) ptr;
     printf("%s \n", message);
}

Check _beginthread for Windows and posix threads for linux

pthreads

#include<stdio.h>
#include<pthread.h>
#include<unistd.h>
#include<stdlib.h>
void *print()
{
   printf("\nThread Created");
}
int main()
{
    int ch,i;
    pthread_t *t;
    printf("Enter the number of threads you want to create : ");
    scanf("%d",&ch);
    t=(pthread_t *)malloc(ch * sizeof(pthread_t ));
    for(i=0;i<ch;i++)
    {
        pthread_create(&t[i],NULL,print,NULL); //Default Attributes
    }
    for(i=0;i<ch;i++)
    {
        pthread_join(t[i],NULL);
    }
}

This is the most basic code for creating threads during runtime in Linux OS using pthread library.