initWithCapacity
Initializes an IODataQueue instance with the capacity specified in the size parameter.
Declaration
virtual Boolean initWithCapacity(
UInt32size);Parameters
- size:
The size of the data queue memory region.
Return Value
Returns true on success and false on failure.
Overview
The actual size of the entire data queue memory region (to be shared into a user process) is equal to the capacity plus the IODataQueueMemory overhead. This overhead value can be determined from the DATA_QUEUE_MEMORY_HEADER_SIZE macro in <IOKit/IODataQueueShared.h>. The size of the data queue memory region must include space for the overhead of each IODataQueueEntry. This entry overhead can be determined from the DATA_QUEUE_ENTRY_HEADER_SIZE macro in <IOKit/IODataQueueShared.h>.