Although you shouldn't need to subclass
BTimedEventQueue,
there's no reason you can't do it.
The Be Book - System Overview - The Media Kit
The
BTimedEventQueue
class provides an easy way to queue a sequence of
events within your node. You can use it to queue up start, stop, and seek
requests, and to queue up incoming data buffers in preparation for
handling them. Each queue element is tagged with the time at which the
event should be processed, and functions are provided for locating the
next event that should be handled.
Although you shouldn't need to subclass
BTimedEventQueue,
there's no reason you can't do it.
Each event has a cleanup flag associated with it that indicates what sort
of special action needs to be performed when the event is removed from
the queue. If this value is B_NO_CLEANUP, nothing is done. If it's
B_RECYCLE, and the event is a
B_HANDLE_BUFFER event,
BTimedEventQueue
will automatically recycle the buffer associated with the event.
If the cleanup flag is B_DELETE or
is B_USER_CLEANUP or greater, the
cleanup hook function will be called. You can implement and establish a
cleanup hook function to handle deleting event data yourself. The hook
function is of type cleanup_hook:
typedef void (*cleanup_hook)(void *context, bigtime_ttime, int32what, void *pointer, uint32pointerCleanup, int64data);
You specify the cleanup hook function by calling
SetCleanupHook(),
like this:
SetCleanupHook(MyCleanupFunction,contextPtr);
The contextPtr is a pointer that your cleanup hook function uses, and can
contain whatever data you require.
