/*
 * Rick van der Zwet
 * 0433373
 * OS Assigment 3 - Part A
 * Licence: BSD
 * $Id: assignment4a.c 539 2008-04-01 20:23:55Z rick $
 */

#include <sysexits.h>
#include <stdlib.h>
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>

#define MAXCOUNTER 999999

struct thread_data {
    int *account1;
    int *account2;
    int threadid;
};

static int go_quit = 0;

void *balance(void *threadarg) {
    struct thread_data *my_data;
    my_data = (struct thread_data *) threadarg;

    int counter, temp1, temp2, amount;
    int *account1, *account2;
    account1 = my_data->account1;
    account2 = my_data->account2;

    counter = 0;
    do {
        temp1 = *account1;
        temp2 = *account2;
        amount = random() % 100;
//        printf("%i - %i: Temp1 %i, temp2 %i, amount %i\n", my_data->threadid,
//               counter, temp1, temp2, amount);
        *account1 = temp1 - amount;
        *account2 = temp2 + amount;
        counter++;
    } while (*account1+*account2 == 0  && counter < MAXCOUNTER && go_quit == 0);
    if (go_quit == 0) {
        printf("counter: %i\n", counter);
        go_quit = 1;
    }
    pthread_exit(NULL);
}



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

    pthread_t thread0, thread1;
    int account1, account2;
    struct thread_data thread0_data, thread1_data;
    thread0_data.account1 = &account1;
    thread0_data.account2 = &account2;
    thread0_data.threadid = 0;
    thread1_data.account1 = &account1;
    thread1_data.account2 = &account2;
    thread1_data.threadid = 1;

    account1 = 0;
    account2 = 0;
    pthread_create(&thread0, NULL, balance, (void *) &thread0_data);
    pthread_create(&thread1, NULL, balance, (void *) &thread1_data);

    pthread_exit(NULL);
    return(EX_OK);
}