PollForMsg

Retrieves a message.

Synopsis

Boolean PollForMsg (Item msgPortItem, Item* msgItemPtr, Message** 
pMsgPtr, void** pMsgDataPtr, int32 *status)

Description

Retrieves a message from the specified port. PollForMsg() is used by the DataStreamer kernel thread and acquisition threads to poll for messages sent to them.

PollForMsg() calls GetMsg() to retrieve the message and then LookupItem() to find the pointer to the message. PollForMsg() returns immediately whether or not a is message waiting at the specified message port.

Arguments

msgPortItem: Item of the message port from which the message is retrieved.

msgItemPtr: Pointer assigned to the item of the retrieved message. If NULL, no pointer is assigned.

pMsgPtr: Pointer assigned to the retrieved message. If NULL, no pointer is assigned.

pMsgDataPtr: Pointer assigned to data buffer of the retrieved message. If NULL, no pointer is assigned.

status: Variable to which the Portfolio error code is assigned. PollForMsg() assigns status a value of zero if there were no errors.

Return Value

Value: Error Condition

TRUE: None

FALSE: GetMsg() or LookupItem() failed

See "Error Messages" in the 3DO Portfolio Reference Manual for a listing of error messages returned by GetMsg() or LookupItem().

Associated Files