race on boost::shared_ptr copies

#include <iostream>
#include <boost/thread/mutex.hpp>
#include <boost/thread.hpp>

struct Consumer {
  void consume(const boost::shared_ptr<int> aBar)
  {
    const boost::unique_lock<boost::mutex> myLock(theMutex);
    thePtr = aBar;
  }

  void operator()() {
    while(1) {
      boost::shared_ptr<int> myLocal;
      {
        const boost::unique_lock<boost::mutex> myLock(theMutex);
        myLocal = thePtr;
      }
      myLocal.use_count();
    }
  }

  boost::shared_ptr<int> thePtr;
  boost::mutex           theMutex;
};

struct Producer {
  Producer(Consumer& aConsumer) : theConsumer(aConsumer) {}
  void operator()() {
    while(1) {
      boost::shared_ptr<int> myBar(new int(3));
      theConsumer.consume(myBar);
      myBar.use_count();
    }
  }

  Consumer& theConsumer;
};

int main() {
  Consumer myConsumer;
  Producer myProducer(myConsumer);

  boost::thread myConsumerThread(boost::ref(myConsumer));
  boost::thread myProducerThread(boost::ref(myProducer));

  myProducerThread.join();
  myConsumerThread.join();
}