Question

Consider that there are 100 plus ways of interrupts occuring from various sensors. There are chances that all can occur at the same time too. How can the software be designed to handle it efficiently ?

Answer 1

It depends if you’re optimizing for latency or throughput.

Since you asked about efficiency, I’ll guess you’re looking at throughput. In that case, one tried-and-true pattern is to have the interrupt handlers read the sensors, queue a command and state, and return immediately.

You have a non-interrupt software thread pick the commands off the queue and announce events for handlers. This minimizes your task switch time. You can use domain specific logic to combine commands, throw out commands that are no longer relevant, etc.

This is essentially how windowing systems work. Each mouse click, mouse movement, keyboard press, etc. results in a command being queued. The windowing system picks the commands off and calls a corresponding handler. There’s extensive logic for throwing out commands that are not relevant by the time they are picked off the queue, for combining commands, and for expediting them.

Network stacks use the same model. Packets are queued by the network level, then a main loop picks them off and uses an inversion of control model to process each packet.