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Sets up a recurring advise with the reference clock.
HRESULT AdvisePeriodic( REFERENCE_TIME StartTime , REFERENCE_TIME PeriodTime , HSEMAPHORE hSemaphore , DWORD * pdwAdviseToken );
Parameters
Return Values
Returns one of the following HRESULTvalues:
E_OUTOFMEMORY | |
E_INVALIDARG | |
NOERROR | No error. |
Remarks
A semaphore is used, rather than an event, to ensure that multiple notifications can be seen by the user. Each time an amount of time specified in the PeriodTimeparameter elapses, the semaphore will be released.
When no further notifications are required, call CBaseReferenceClock::Unadviseand pass the pdwAdviseTokenvalue returned from this call.
For example, the following code extract sets up an advise link that fires its first advise five seconds from now and then signals every second until Unadviseis called. By using a semaphore with a count of 10, the clock is effectively able to cache 10 events.
HANDLE hSemaphore = CreateSemaphore(NULL, 0, 10, NULL); // Assume pRefClock is an IReferenceClock* variable. REFERENCE_TIME rtPeriodTime = 1000 * (UNITS / MILLISECONDS); // A one-second interval REFERENCE_TIME rtNow; DWORD dwAdviseToken; pRefClock->GetTime(&rtNow); pRefClock->AdvisePeriodic(rtNow+(5*rtPeriodTime), PeriodTime, hSemaphore, &dwAdviseToken);