加锁类

class Lock {
 public:
  Lock() : lock_() {}
  ~Lock() {}
  void Acquire() { lock_.Lock(); }
  void Release() { lock_.Unlock(); }

  // If the lock is not held, take it and return true. If the lock is already
  // held by another thread, immediately return false.
  bool Try() { return lock_.Try(); }

 

  // In debug builds this method checks that the lock has been acquired by the
  // calling thread.  If the lock has not been acquired, then the method
  // will DCHECK().  In non-debug builds, the LockImpl's implementation of
  // AssertAcquired() is an empty inline method.

  void AssertAcquired() const { return lock_.AssertAcquired(); }

  // Return the underlying lock implementation.
  // TODO(awalker): refactor lock and condition variables so that this is
  // unnecessary.

  LockImpl* lock_impl() { return &lock_; }

 private:
  LockImpl lock_;  // Platform specific underlying lock implementation.

  DISALLOW_COPY_AND_ASSIGN(Lock);
};

 

 

不明白这个类为什么要使用委托,其实使用继承也可以实现一样的效果,可以少写很多代码