main.c

#include <stdio.h>
#include <assert.h>
#include <unistd.h>
#include "threadlib.h"

#define TESTING  /* once you understand the code undefine this (just comment)*/

#ifdef TESTING 
/* few threads to play around with*/

void thread1(void);
void thread2(void); 

void thread1(void) {
    printf("Thread 1\n");
    int i = 1;
    for(;i<100;) {
        printf("%s: count = %d\n",__func__,i++);
        //yield();
    }

    //delete_thread();
    //assert(0);
}

void thread2(void) {
    printf("Thread 2\n");
    int i = -100;
    for(;i<0;) {
        printf("%s: count = %d\n",__func__,i++);
        //yield();
    }

    //delete_thread();
    //assert(0);
}

int main(void) {
    printf("\n");
    printf("\nCreating thread 1\n");
    printf("%s : thread1 = %p\n", __func__, thread1);
    assert(!create_thread(thread1));

    printf("\nCreating thread 2\n");
    printf("%s : thread2 = %p\n", __func__, thread1);
    assert(!create_thread(thread2));

    //stop_main();        /* give up the CPU */
    //assert(0);          /* you should not come back */

    return  0;
}

#else                   /* real code this is what we'll test/mark */

int count = 1;
#define MAX 10          /* how may threads to create */
#define COUNT(x) x*100000

void simple_thread(void); /* want to create many instance of this */

void simple_thread(void) {
    int i, myID, sleep;

    myID = count;

    count ++; /* for the next thread 
    * It is shared, do I need to lock??? A lock is not necessary. Yielding is collaborative. So cant be pre-emptied at the middle */

    for(i = myID; i < MAX; i++) {
        /* print something, sleep for a while and yield */
        printf("I'm %s %d: Count=%d\n",__func__,myID,i);

        for(sleep = -COUNT(myID); sleep < COUNT(myID); sleep++);
        
        yield();
    }

    delete_thread();        /* die */
    assert(0);              /* I should not be running */
}

#define NO_THREADS 10       /* FixMe: this should work for any number of threads */

int main(void) { 
    int i; 
    for(i = 0; i < NO_THREADS; i++) {
        //assert(!create_thread(simple_thread));
    }

    stop_main();        /* give up the CPU */
    //assert(0);          /* you should not come back */

    return  0;
}

#endif