DSSetChannel

Sets the status of a channel.

Synopsis

int32 DSSetChannel (Item msgItem, DSRequestMsgPtr reqMsg, DSStreamCBPtr streamCBPtr, DSDataType streamType, long channelNumber, long channelStatus)

Description

Sets the status of a channel. DSSetChannel() sets the status of the specified channel within the stream.

DSSetChannel() sets the members of the message data structure required to set the channel status. (The message is the DSRequestMsg identified by reqMsg.) DSSetChannel() will call either SendMsg() or WaitMsg() to send the message. to the DataStreamer: SendMsg() if reqMsg specifies a message; WaitMsg() if reqMsg is set to NULL.

Arguments

msgItem
Item of the message.
reqMsg
Pointer to the DSRequestMsg message that is formatted and sent to the DataStreamer. A value of NULL forces creation of an internal DSRequestMsg message and synchronous operation.
streamCBPtr
Pointer to the stream context block.
streamType
Type of stream to which the request applies.
channelNumber
Number of the channel whose status is being set.
channelStatus
New status of the channel.

Messages

The members of reqMsg are set to the following values:

whatToDo
kDSOpSetChannel
msg.setChannel.streamType
msg.setChannel.channelNumber
msg.setChannel.channelStatusPtr

Return Value

Value
Error Condition
0
None
These values are returned if the DataStreamer encounters an error while processing the message request:

kDSInvalidDSRequest
Invalid message (whatToDo set to invalid value)
kDSNoReplyPortErr
Could not locate item of the reply port
-1
Could not locate pointer to msgItem
(Portfolio error code)
SendMsg() or WaitPort() failed
The DataStreamer checks the validity of messages only if message checking is enabled when the DataStreamer is compiled (if the VALIDATE_REQUEST_CODE symbol is enabled).

See "Error Messages" in the 3DO Portfolio Reference Manual for a listing of error messages returned by SendMsg() and WaitPort().

Associated Files

DataStreamLib.h

See Also

DSGetChannel