samples/winrt/ImageManipulations/MediaExtensions/Common/CritSec.h

   1 #pragma once
   2
   3 //////////////////////////////////////////////////////////////////////////
   4 //  CritSec
   5 //  Description: Wraps a critical section.
   6 //////////////////////////////////////////////////////////////////////////
   7
   8 class CritSec
   9 {
  10 public:
  11     CRITICAL_SECTION m_criticalSection;
  12 public:
  13     CritSec()
  14     {
  15         InitializeCriticalSectionEx(&m_criticalSection, 100, 0);
  16     }
  17
  18     ~CritSec()
  19     {
  20         DeleteCriticalSection(&m_criticalSection);
  21     }
  22
  23         _Acquires_lock_(m_criticalSection)
  24     void Lock()
  25     {
  26         EnterCriticalSection(&m_criticalSection);
  27     }
  28
  29         _Releases_lock_(m_criticalSection)
  30     void Unlock()
  31     {
  32         LeaveCriticalSection(&m_criticalSection);
  33     }
  34 };
  35
  36
  37 //////////////////////////////////////////////////////////////////////////
  38 //  AutoLock
  39 //  Description: Provides automatic locking and unlocking of a
  40 //               of a critical section.
  41 //
  42 //  Note: The AutoLock object must go out of scope before the CritSec.
  43 //////////////////////////////////////////////////////////////////////////
  44
  45 class AutoLock
  46 {
  47 private:
  48     CritSec *m_pCriticalSection;
  49 public:
  50         _Acquires_lock_(m_pCriticalSection)
  51     AutoLock(CritSec& crit)
  52     {
  53         m_pCriticalSection = &crit;
  54         m_pCriticalSection->Lock();
  55     }
  56
  57         _Releases_lock_(m_pCriticalSection)
  58     ~AutoLock()
  59     {
  60             m_pCriticalSection->Unlock();
  61     }
  62 };