CloseDevice

terminate access to the audio device

The CloseDevice routine notifies the audio device that it will no longer be used. It takes an I/O audio request block (IOAudio) and clears the device pointer (io_Device). If there are any channels allocated with the same allocation key (ioa_AllocKey), CloseDevice frees (ADCMD_FREE) them. CloseDevice decrements the open count, and if it falls to zero and an expunge (Expunge) is pending, the device is expunged.

iORequest

pointer to audio request block (struct IOAudio)

io_Device

pointer to device node, must be set by (or copied from I/O block set by) open (OpenDevice)

io_Unit

bit map of channels to free (ADCMD_FREE) (bits 0 thru 3 correspond to channels 0 thru 3)

ioa_AllocKey

allocation key, used to free channels

iORequest

Pointer to audio request block (struct IOAudio) io_Device - set to -1 io_Unit - set to zero