MAX_MIXER_NOTIFIES
dwIndex &= MAX_MIXER_NOTIFIES - 1;
(pClient->dwCount != MAX_MIXER_NOTIFIES))
pClient->dwHead = (pClient->dwHead + 1) & (MAX_MIXER_NOTIFIES - 1);
pClient->dwTail = (pClient->dwTail + 1) & (MAX_MIXER_NOTIFIES - 1);
MIXER_NOTIFY Notifies[MAX_MIXER_NOTIFIES];