/*
Copyright 2006 Paul... don't copy this for your hw...
Author: Paul Picazo (http://pr.erau.edu/~picazdb3/)
Course: CS420 Operating Systems
Instructor : Matt Jaffe
Prime calculator code adapted from http://www.tekpool.com/
Compile with g++ instead of gcc, sqrt gives linker error in gcc
otherwise without the sqrt it should compile as c in gcc
Be sure to link the phthread (-lpthread option in g++) library.
Example:
g++ thread.cpp -lpthread -o thread
*/
#include <stdio.h>
#include <pthread.h>
#include <math.h>
#include <sys/select.h>

//largest number (+1) that will be checked to see if its a prime
#define MAXX 10000000

//thread description records
pthread_t display;
pthread_t calc;

//thread attribute records
pthread_attr_t display_attr;
pthread_attr_t calc_attr;

//current number to check if prime
int j;

//number of primes found
int count;

//Function adpated from http://www.tekpool.com/?p=18
void* calcPrimes(void* args)
{
  int i;
  j=3;
  count = 1;
  while(j < MAXX)
  {
    int check = (int)sqrt((double)(j));
    int fPrimeFound=1;
    for(i=2; i<=check; i++)
    {
      if(j%i==0)
      {
        fPrimeFound=0;
        break;
      }
    }
    if(fPrimeFound)
    {
      count++;
    }
    j++;
  }
}

void* displayInfo(void* args)
{
  int alive = 1;
  int percent = 0;
  timeval tv;
  tv.tv_sec = 0;
  tv.tv_usec = 0;
  while(alive)
  {
    percent = (int)((double)j / (double)MAXX * 100);   
    printf("\n%d%\tLast Number Checked:%d\tPrimes Found:%d",
      percent,j,count);
    if(percent == 100)
    { 
      printf("\n");
      alive = 0;
    }
    else
    {
      //wait for 10000 microseconds before looping again
      select(0, NULL, NULL, NULL, &tv);
      tv.tv_usec = 10000;
    }
  }
}

int main()
{
  //set the default thread attributes
  pthread_attr_init(&display_attr);
  pthread_attr_init(&calc_attr);
  
  //set the threads to kernel level
  pthread_attr_setscope(&display_attr, PTHREAD_SCOPE_SYSTEM);
  pthread_attr_setscope(&calc_attr, PTHREAD_SCOPE_SYSTEM);
  
  //create the threads
  pthread_create(&display, NULL, displayInfo, (void*)"hello");
  pthread_create(&calc, NULL, calcPrimes, (void*)"hi");

  //wait for threads to terminate
  pthread_join(display, NULL);
  pthread_join(calc, NULL);

  return 0;
}