问如何操作这个接口？

EN

class Lock
{
public:
   Lock();
   ~Lock();

    // Acquire the lock.
   void
   acquire()
   { this->lock_->acquire(); }

    // Release the lock.
   void
   release()
   { this->lock_->release(); }

   private:
   // This class can not be copied.
   Lock(const Lock&);
   Lock& operator=(const Lock&);

   friend class Condvar;
   Lock_impl*
   get_impl() const
   { return this->lock_; }

   Lock_impl* lock_;
};

class Condvar
{
 public:
  Condvar(Lock& lock);
  ~Condvar();
  // Wait for the condition variable to be signalled.  This should
  // only be called when the lock is held.
  void
  wait()
  { this->condvar_->wait(this->lock_.get_impl()); }

  // Signal the condition variable--wake up at least one thread
  // waiting on the condition variable.  This should only be called
  // when the lock is held.
  void
  signal()
  { this->condvar_->signal(); }

  // Broadcast the condition variable--wake up all threads waiting on
  // the condition variable.  This should only be called when the lock
  // is held.
  void
  broadcast()
  { this->condvar_->broadcast(); }

  private:
  // This class can not be copied.
  Condvar(const Condvar&);
  Condvar& operator=(const Condvar&);

  Lock& lock_;
  Condvar_impl* condvar_;
};