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The CAutoLockclass holds a critical section for the scope of a block or function. The constructor locks the critical section and the destructor unlocks it. The object passed to the CAutoLockconstructor must be derived from the CCritSecclass. Thus, by declaring a CAutoLockobject as a local variable in a function, a critical section can be locked without the danger of forgetting to unlock it in some of the code paths: the destructor ensures that upon exit from the function (or the scope of the declaration), the critical section will be unlocked. Member functions in this class are not designed for overriding.
/* Typical usage ensuring object is always
unlocked correctly */ HRESULT MyFunc(IMediaSample *pSample) {
CAutoLock cObjectLock(m_pMyLock); /* Ignore samples passed when
inactive */ if (!m_bActive) { return NOERROR; } /* Add the sample
to the pending queue */ HRESULT hr =
m_PendingList.AddTail(pSample); if (FAILED(hr)) {
pSample->Release(); return hr; } return NOERROR; }
Protected Data Members
| M_pLock | Critical section for this lock. |
Member Functions
| CAutoLock | Takes a pointer to a critical section object and locks it. |