RtlBeginReadTickLock - NtDoc

#ifndef _NTRTL_H

FORCEINLINE
ULONGLONG
NTAPI
RtlBeginReadTickLock(
    _In_ PULONGLONG TimeUpdateLock // USER_SHARED_DATA->TimeUpdateLock
    )
{
    ULONGLONG result;

    for (result = *TimeUpdateLock; (*TimeUpdateLock & 1) != 0; result = *TimeUpdateLock)
    {
        YieldProcessor();
    }

    return result;
}

#endif
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