CS452 Thread Examples (.java, .c, .cpp)

happy-pthr.c

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

void* happy (void* arg) {
    int* N = (int *)arg;
    for (int k = 0; k < *N; k++)
        printf ("Happy %d\n", k);

    return (void *) 0xF00D;
}

int main () {
    pthread_t happy_id;
    pthread_attr_t happy_attr;

    pthread_attr_init (&happy_attr);
    int num;
    num = 6;
    pthread_create (&happy_id, &happy_attr, happy, &num);

    for (int k = 0; k < 20; k++)
        printf ("Before %d\n", k);

    int rc;
    pthread_join (happy_id, (void **) &rc);
    printf ("Thread status is %x\n", rc);

    printf ("End of program\n");

    return 0;
}

happy.cpp

// Must be compiled with -std=c++11 flag

#include <iostream>
#include <string>
#include <thread>
#include <future>

std::string happy(int N) {
    for (int k = 0; k < N; k++)
        std::cout << "HAPPY " << k << std::endl;
    return "Happyly ever after";
}

int main() {
    int val = 20;
    // Use std::async to create a thread
    // Use std::future to capture the thread return value
    std::future<std::string>  happy_end ( std::async(happy, val));

    for (int k = 0; k < 20; k++) {
        std::cout << "grumpy " << k << std::endl;
    }
    // wait for the "happy" thread to complete
    std::string out = happy_end.get();
    std::cout << "New value is " << val << std::endl;
    std::cout << "Happy value is " << out << std::endl;
    return 0;
}

Happy.java

public class Happy {
    private static class HappyThread extends Thread {

        private int limit;
        public HappyThread(int N) {
            this.limit = N;
        }

        public void run() {
            try {
                for (int k = 0; k < limit; k++) {
                    Thread.sleep (1000);
                    System.out.printf ("Happy %d\n", k);
                }
            } catch (InterruptedException e) {
            }
        }
    };

    public static void main (String[] args) {
        Thread t = new HappyThread(7);
        try {
            t.start();
            for (int k = 0; k < 15; k++) {
                for (int m = 0; m < 10000000; m++);
                System.out.printf ("Main %d\n", k);
            }
            System.out.println ("Waiting for HappyThread.....");
            t.join();
        }
        catch (InterruptedException ie) {
        }
        System.out.println ("End of program");
    }
}

pthr.c

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

void* happy (void* arg) {
    int* N = (int *)arg;
    for (int k = 0; k < *N; k++)
        printf ("Happy %d\n", k);

    return (void *) 0xF00D;
}

int main () {
    pthread_t happy_id;
    pthread_attr_t happy_attr;

    pthread_attr_init (&happy_attr);
    int num;
    num = 6;
    pthread_create (&happy_id, &happy_attr, happy, &num);

    for (int k = 0; k < 20; k++)
        printf ("Before %d\n", k);

    int rc;
    pthread_join (happy_id, (void **) &rc);
    printf ("Thread status is %x\n", rc);

    printf ("End of program\n");

    return 0;
}