Consider a flow graph like: http://i.imgur.com/bNa6YuQ.png
Message source produces a short message. Period is quite long. Thus, There should be a long idle time.
I'd like to build a block 'pad idle'. The block pad a predefined sequence if the upstream block gives nothing.
By setting the number of required items to zero in forecast(), general_work() will be called even there is no items received. And general work() checks the ninput_items and if it is zero, generates some idle-padding samples/patterns. Otherwise, it just handles and passess a message/samples to downstream.
But it's just my thought. There may be a couple of considerations.
1. Is it allowed to forecast zero item? And does it behave as I expect?
2. If forecasting zero item is possible, willl general_work() be called extremely frequently so that other blocks are prevented from being called?