实现boost::thread中RAII风格的共享锁

实现boost::thread中RAII风格的共享锁

实现代码：

    typedef enum { UNIQUE_LOCK, SHARED_LOCK } LockType;

template < LockType lt >
class  shared_lock;

template  <>
class  shared_lock < UNIQUE_LOCK > :  private  boost::noncopyable  {
public:
    shared_lock(boost::shared_mutex& sm): sm_(sm) { sm_.lock(); }
    ~shared_lock() { sm_.unlock(); }
private:
    boost::shared_mutex& sm_;
} ;

template  <>
class  shared_lock < SHARED_LOCK > :  private  boost::noncopyable  {
public:
    shared_lock(boost::shared_mutex& sm): sm_(sm) { sm_.lock_shared(); }
    ~shared_lock() { sm_.unlock_shared(); }
private:
    boost::shared_mutex& sm_;
} ;

调用方式：

    boost::shared_mutex session_mutex_;

// 独占锁定
shared_lock < UNIQUE_LOCK >   lock (session_mutex_);

// 共享锁定
shared_lock < SHARED_LOCK >   lock (session_mutex_);

http://www.cppblog.com/thisisbin/archive/2009/01/21/72417.html 一文 single-write/multi-read 就可以应用这种RAII风格的共享锁实