[C++]C++11, mutex 샘플 정리

intro

• 이전엔 주로 아래와 같은식으로 사용했었는데, 역시나 C++11 편해졌네.

  class CCriticalSection
  {
  #if defined ( _WIN32 ) || defined ( _WIN64 )
  public:
    CCriticalSection(VOID)
    {
        InitializeCriticalSection(&mSync);
    }
    ~CCriticalSection(VOID)
    {
        DeleteCriticalSection(&mSync);
    }
    inline VOID Enter(VOID)
    {
        EnterCriticalSection(&mSync);
    }
    inline VOID Leave(VOID)
    {
        LeaveCriticalSection(&mSync);
    }
  private:
    CRITICAL_SECTION    mSync;
  #else
  public:
    CCriticalSection(void)
    {
        pthread_mutexattr_t     attr;
        if ( pthread_mutexattr_init( &attr ) != 0 )
        {
        }            
        if ( pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE ) != 0 )
        {
        }
        if ( pthread_mutex_init( &mSync, &attr ) != 0 )
        {
        }
        if ( pthread_mutexattr_destroy( &attr ) != 0 )
        {
        }
    }
    ~CCriticalSection(void)
    {
        pthread_mutex_destroy( &mSync );
    }
    inline void Enter(void)
    {
        pthread_mutex_lock( &mSync );
    }
    inline void Leave(void)
    {
        pthread_mutex_unlock( &mSync );
    }
  private:
    pthread_mutex_t mSync;
  #endif
  };
  

sample

• 아래는 자주 사용할만한 기능에 대한 샘플들

  #include <mutex>
  void test_mutex()
  {
    std::mutex mtx_lock;
    //case1
    {
        mtx_lock.lock();
        //do something
        mtx_lock.unlock();
    }
    //case2
    {
        //mutex 소유권을 획득하면 true를 리턴, 소유할수없으면 false를..
        bool ret = mtx_lock.try_lock();
        if (ret == true)
        {
            //....
            mtx_lock.unlock();
        }
        else
        {
            //....
        }
    }
    //case3, unique_lock 도 비슷
    {
        {
            //scoped lock
            std::lock_guard<std::mutex> guard(mtx_lock);
            //do something 
        }
    }
    //case4
    {
        //InitializeCriticalSectionAndSpinCount 랑 조금은 비슷한듯, 3초동안 lock시도 해보고 안되면 말기
        std::timed_mutex timed_mutex;
        bool ret = timed_mutex.try_lock_for(std::chrono::seconds(3));
        if (true == ret)
        {
            //do something
            timed_mutex.unlock();
        }
        else
        {
            //do something
        }
    }
  }