Avoiding disaster and unbounded growth

Information gathering

Your project is dynamic:

  • Make it traceable

  • Constantly monitor


Backpressure is the process of "pushing back" on producers that are to fast.

This throttles the system, but allows it to not fail.

Bounded vs. unbounded growth

  • bounded channels are predictable

  • unbounded are more dynamic

  • bounded provide backpressure

  • unbounded are useful if you know they are never beyond a certain size

Holding state

  • Tasks can hold state

  • Otherwise, Mutexes and RWlocks allow sharing

Dropping futures

  • Dropping a futures means cancelling it

  • Be aware of what happens if it is cancelled

Shutting down

  • Make sure your signal handling is centralized

  • Every component should subscribe to a cancel notification

Implementing a custom Future: Pinning

  • Futures are not allowed to move in Memory

  • The type that describes that is called Pin

  • Pinning is hard, but there’s support libraries

The poll protocol

Futures are poll based - that means they get asked if they are complete.

  • This happens an infinite number of times, until they mark themselves complete

  • The process is optimised through the Waker type

  • Implementing poll yourself is rather easy