Task scheduler is a topic for Operation System about how to implement multiple tasks execution.
PSoC1 is 8-bit single chip MCU based. Its resource is hard to run a full-featured OS. So AN2046 gives a method about how to implement multiple tasks execution.
For PSoC4, RTOS can be ran on it. So users don't need to pay much more attention onto task scheduler code.
As mentioned in the AN:
Full-featured commercial RTOS for other PSoC families are available; visit the third-party websites listed below for more details
Another helpful link is FYI,