Question

i want to fix the solution and provide an explanation why the pthread_join is not working as intended?


#include <stdio.h>       /* standard I/O routines                 */
#include <pthread.h>     /* pthread functions and data structures */

void* PrintHello(void* data)
{
    pthread_t tid = (pthread_t)data;    /* data received by thread */

    pthread_join(tid, NULL);            /* wait for thread tid     */
    printf("Hello from new thread %u - got %u\n", pthread_self(), data);
    pthread_exit(NULL);                 /* terminate the thread    */
}

/* like any C program, program's execution begins in main */
int main(int argc, char* argv[])
{
    int        rc;                     /* return value                  */
    pthread_t  thread_id;              /* thread's ID (just an integer) */
    int        tid;

    tid = pthread_self();

    rc = pthread_create(&thread_id, NULL, PrintHello, (void*)tid);  
    if(rc)                             /* could not create thread */
    {
        printf("\n ERROR: return code from pthread_create is %d \n", rc);
        exit(1);
    }
    sleep(1);
    printf("\n Created new thread (%u) ... \n", thread_id);
    pthread_exit(NULL);         
}

Answer 1

$Solution: The code for thread based program is shown below: //Include libraries #include <stdio.h> #include <pthread.h> //Define method void* PrintHello (void* data) //Create thread pthread t tid - (pthread t) data; //Wait for thread pthread join (tid, NULL) //Display printf (Hello from new thread %u - got %u\n, pthread self (), data) //Exit thread exit (NULL) //Define mairn int main(int argc, char* argv[]) //Declare variable$

Code:

//Include libraries

#include <stdio.h>      

#include <pthread.h>    

//Define method

void* PrintHello(void* data)

{

    //Create thread

    pthread_t tid = (pthread_t)data;   

     //Wait for thread

    pthread_join(tid, NULL);          

    

     //Display

printf("Hello from new thread %u - got %u\n", pthread_self(), data);

    

     //Exit

    pthread_exit(NULL);                

}

//Define main

int main(int argc, char* argv[])

{

    //Declare variable

    int        rc;                    

    

     //Declare variable

    pthread_t thread_id;             

    

     //Declare variable

    int        tid;

     //Thread id

    tid = pthread_self();

     //Create

    rc = pthread_create(&thread_id, NULL, PrintHello, (void*)tid);

    

     //If condition satisfies

    if(rc)                           

    {

         //Display message

        printf("\n ERROR: return code from pthread_create is %d \n", rc);

      exit(1);

    }

    

    sleep(1);

    

     //Display

    printf("\n Created new thread (%u) ... \n", thread_id);

    

     //Exit

    pthread_exit(NULL);        

}