c++

// Filosofi.cpp : Defines the entry point for the console application.
//
// Date: 12.06.2013
// Time: 22:06
// Semaphores example program

#include "stdafx.h"
#include "windows.h"
#include "iostream"
#include "process.h"
#include "math.h"

using namespace std;

//global variables
//hMutex used for blocking threads
HANDLE hMutex;
//used to block entrance to access to check if mutex is blocked
int gCurrentAvailableSemaphores = 3;
//obvious
int gRequiredIterations=0;
//program output - factorial of iteration count value
long gOutput = 1;

//global enum used to set colors of text and backgroind in console using names of colors
enum ConsoleColor
{
    Black         = 0,
    Blue          = 1,
    Green         = 2,
    Cyan          = 3,
    Red           = 4,
    Magenta       = 5,
    Brown         = 6,
    LightGray     = 7,
    DarkGray      = 8,
    LightBlue     = 9,
    LightGreen    = 10,
    LightCyan     = 11,
    LightRed      = 12,
    LightMagenta  = 13,
    Yellow        = 14,
    White         = 15
};

//sets the console output text color to extText  and background to extBackground
void SetColor(ConsoleColor extText, ConsoleColor extBackground)
{
    HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
    SetConsoleTextAttribute(hStdOut, (WORD)((extBackground << 4) | extText));
}


class semaphore {
    bool state;
    public:
        //constructor
        semaphore() {
            state = true;
        }
        void setState(bool ex_state) {
            state = ex_state;
        }
        bool getState() const{
            return state;
        }
};

class philosophist {
    int forkA, forkB, number;
public:
    philosophist(int ex_number, int ex_forkAval, int ex_forkBval) {
        forkA = ex_forkAval;
        forkB = ex_forkBval;
        number = ex_number;
    }
    int getForkA () {return forkA;}
    int getForkB () {return forkB;}
    int getID() {return number;}
};

//all semaphores in one array
semaphore *gSems=new semaphore[5];

//static thread function __stdcall required for _beginthreadex
static unsigned __stdcall philosophistFunction(void *params)
{
    //getting id from thread params
    philosophist *ph = static_cast<philosophist*>(params);
    do {
        //if forks are available
        if (gSems[ph->getForkA()].getState() && gSems[ph->getForkB()].getState()) {
            //reducing available semaphores count
            gSems[ph->getForkA()].setState(false);
            gSems[ph->getForkB()].setState(false);
            Sleep(100);
            SetColor(Black,White);
            cout << "Philosophist #"<<ph->getID()<<" gets his spoons and started eating"<<endl;
            Sleep(1800);
            cout << "Philosophist #"<<ph->getID()<<" finished eating"<<endl;
            Sleep(100);
            gSems[ph->getForkA()].setState(true);
            gSems[ph->getForkB()].setState(true);
        }
        else {
            Sleep(250);
            cout << "Philosophist #"<<ph->getID()<<" is waiting for his spoons become available"<<endl;
            Sleep(250);
        }
    } while (true);
    return NULL;
}

int _tmain(int argc, _TCHAR* argv[])
{
    //creating threads
    philosophist *ph1 = new philosophist(1,0,1);
    _beginthreadex(NULL, 0, &philosophistFunction, &ph1, 0, 0);
    Sleep(50);
    philosophist *ph2 = new philosophist(2,1,2);
    _beginthreadex(NULL, 0, &philosophistFunction, &ph2, 0, 0);
    Sleep(50);
    philosophist *ph3 = new philosophist(3,2,3);
    _beginthreadex(NULL, 0, &philosophistFunction, &ph3, 0, 0);
    Sleep(50);
    philosophist *ph4 = new philosophist(4,3,4);
    _beginthreadex(NULL, 0, &philosophistFunction, &ph4, 0, 0);
    Sleep(50);
    philosophist *ph5 = new philosophist(5,4,5);
    _beginthreadex(NULL, 0, &philosophistFunction, &ph5, 0, 0);
    //loopin till the end
    cin;
    return 0;
}