#include <iostream>
#include <ctime>
using namespace std;

class Handler {
   int id;
   static int count;
public:
   Handler() {
      id = count++;
   }
   int handle() {
      if (rand() % 3 == 0) {
         cout << id << " handles" << endl;
         return true;
      } else {
         cout << "  " << id << " is busy" << endl;
         return false;
   }  }
};
int Handler::count = 1;

void main( void ) {
   srand( time(0) );

   Handler list[4];

   for (int i=0; i < 6; i++)
      for (int j=0; true ; j = (j + 1) % 4)
         if (list[j].handle())
            break;
}




#if 0

class Handler {
   int id;
   Handler* next;
   static int      count;
   static Handler* first;
   static Handler* previous;
public:
   Handler() {
      id = count++;
      if (first == 0) first = this;
      next = first;
      if (previous) previous->next = this;
      previous = this;
   }
   void handle() {
      if (rand() % 3 == 0)
         cout << id << " handles" << endl;
      else {
         cout << "  " << id << " is busy" << endl;
         next->handle();
   }  }
};
int Handler::count = 1;
Handler* Handler::first = 0;
Handler* Handler::previous = 0;

void main( void ) {
   srand( time(0) );

   Handler list[4];

   for (int i=0; i < 6; i++)
      list[0].handle();
}

#endif