Implementation of Locks and Condition Variables(Example)

Example using locks and condition variables:
  

So in this code, like in the title said, we are showing how our locks and c. v. work. It's a basic consumer-producer program(with 2 consumers) where each consumer will "consume" 3 units if available, if not then he will go to sleep, until the producer finishes producing 'i' quantity units. The units are represented with a counter, and can be modified to try different results, in this examples, the consumer consumes 3, and the producer produces 4.

Code:

#include "example.h"
using namespace std;
Thread *t;
Lock *l;
Condition *c;
int avail = 0;
int p, i=0;

static void consumer(int n) {
  for(int j = 0; j< 3; j++){
    l->Acquire();
    if (avail == 0) {
      cout <<"Consumer "<< n << " Sleeping" << endl;
      c->Wait(l);
    }
    cout <<"Consumer "<< n << " Consuming something - Total :" << avail << endl;
    avail--;
    l->Release();
    i--;
  }
}

static void producer(int n) {
  while (i!=4) {
    l->Acquire();
    avail++;
    cout <<"Producer " << n << " Producing something - Total :" << avail << endl;
    c->Signal(l);
    l->Release();
    i++;
  }
}
Example::Example() {
  l = new Lock("l");
  c = new Condition("c",l);
  t = new Thread("consumer");
  t->Fork((VoidFunctionPtr)consumer, (void *)1);
  t = new Thread("consumer");
  t->Fork((VoidFunctionPtr)consumer, (void *)2);
  t = new Thread("producer");
  t->Fork((VoidFunctionPtr)producer, (void *)1);
}


 Screen Capture: