高手请进，帮我看看这是什么意思？感谢非常

class MTDeque
{
protected :
const m_iMaxSize;
deque<char> m_Queue;
CRITICAL_SECTION m_Lock;

public:
MTdeque( int max_size ) : m_iMaxSize( max_size )
{
::InitializeCriticalSection( &m_Lock );
}
//
// The destructor for the m_Queue member will take care
// of properly cleaning up all of its data. We have to
// make sure we use the API call to properly free up
// the CRITICAL_SECTION object. And that's all!
//
~MTdeque()
{
::DeleteCriticalSection( &m_Lock );
}
}