pthread_ex

/* Includes */
#include <unistd.h>     /* Symbolic Constants */
#include <sys/types.h>  /* Primitive System Data Types */ 
#include <errno.h>      /* Errors */
#include <stdio.h>      /* Input/Output */
#include <stdlib.h>     /* General Utilities */
#include <pthread.h>    /* POSIX Threads */
#include <string.h>     /* String handling */

/* prototype for thread routine */
void print_message_function ( void *ptr );

/* struct to hold data to be passed to a thread
   this shows how multiple data items can be passed to a thread */
typedef struct str_thdata
{
    int thread_no;
    char message[100];
} thdata;

int global_val = 0;

int main()
{
    pthread_t thread1;  /* thread variables */
    thdata data1;         /* structs to be passed to threads */
    
    /* initialize data to pass to thread 1 */
    data1.thread_no = 1;
    strcpy(data1.message, "Hello!");

    pthread_create (&thread1, NULL, (void *) &print_message_function, (void *) &data1);

    while(global_val != 1)
    {
    } 
    printf("end\n");
    /* exit */  
    exit(0);
} /* main() */

/**
 * print_message_function is used as the start routine for the threads used
 * it accepts a void pointer 
**/
void print_message_function ( void *ptr )
{
    thdata *data;            
    data = (thdata *) ptr;  /* type cast to a pointer to thdata */
    
    /* do the work */
    printf("Thread %d says %s \n", data->thread_no, data->message);
    global_val = 1;
    while(1);   
} /* print_message_function ( void *ptr ) */