Question

1. Create a program that does the following, make sure you can complete this before moving to further questions, when compiling add the -Ipthread argument, if you are using gcc use the -pthread argument. Creates two threads, the first uses a function hello world() which prints hello world, the second uses a function goodbye() which prints goodbye. • Each function has a random sleep duration before printing the output - After running your program a few times you should notice that the order of hello world and goodbye being printed to the screen is not consistent, as each thread is executing independently. 2. Create a program the does the following. - Prompts the professor for five student's grades. Creates 5 threads, one for each student. Each thread uses a function called bellcurve(grade) which takes as an argument the grade and bellcurves it by multiplying the grade by 1.50 and then printing the bellcurved grade to the terminal. - The program must create the 5 threads and initialize them only after receiving all 5 grades.

C - language please

Answer 1

solution:

1)
#include <stdio.h>
#include <stdlib.h> // Header file for rand()
#include <unistd.h> //Header file for sleep()
#include <pthread.h> // header for pthread library

// A normal C function that is executed as a thread
// when its name is specified in pthread_create()
void *hello_world()
{
        sleep(rand()); // sleep for random amount of seconds
        printf("Hello world\n"); // print hello world
}

void *goodbye(){
        sleep(rand());   // sleep for random amount of seconds
        printf("Good bye \n"); // print goodbye
}

int main()
{
        pthread_t thread1, thread2; // create thread variable which stores thread id of the thread
        // create the thread passing addresss to thread id and second argument is to attributes of thread if
        // NULL default is used
        // third is the function to executed by thread
        // arguments to the function executed by thread

        pthread_create(&thread1, NULL, hello_world, NULL);
        pthread_create(&thread2, NULL, goodbye, NULL);

        // exit when threads are complete
        pthread_exit(NULL);

}

2)

#include <stdio.h>
#include <stdlib.h> // Header file for rand()
#include <unistd.h> //Header file for sleep()
#include <pthread.h> // header for pthread library

// A normal C function that is executed as a thread
// when its name is specified in pthread_create()
void *bellcurve_grad(void *argp){
        sleep(1); //sleep for 1 second
        float *grades = (float *)argp; // cast the argument to float because pthread sends all arguments to function as a void pointer
        float bellcurve = *grades * 1.5;
        printf("%f\n", bellcurve); // print the bellcurve
}

int main()
{
        // get grades of five students
        float grades[5];
        for(int i=0;i<5;i++){
                printf("Enter grade of student %d: ", i+1);
                scanf("%f", &grades[i]);
        }

        pthread_t thread1, thread2, thread3, thread4, thread5; // create thread variable which stores thread id of the thread
        // create the thread passing addresss to thread id and second argument is to attributes of thread if
        // NULL default is used
        // third is the function to executed by thread
        // arguments to the function executed by thread must be casted as void pointer
        //
        pthread_create(&thread1, NULL, bellcurve_grad, (void *)&grades[0]);
        pthread_create(&thread2, NULL, bellcurve_grad, (void *)&grades[1]);
        pthread_create(&thread3, NULL, bellcurve_grad, (void *)&grades[2]);
        pthread_create(&thread4, NULL, bellcurve_grad, (void *)&grades[3]);
        pthread_create(&thread5, NULL, bellcurve_grad, (void *)&grades[4]);

        // exit when threads are complete
        pthread_exit(NULL);

}

please give me thumb up