Inbound Outbound models in programming

Inbound/Outbound

1. Sync + blocking
   1. The thread is idle until it receives a response from the other application
2. Sync Non-blocking
   1. e.g. Use callbacks. The thread doesn’t have to wait. After the other application sends a response, the OS will notify the thread that initiated the request.
3. Async
   1. e.g. Use queues. The thread doesn’t have to wait.
4. Async + Non-blocking
   1. e.g. Similar to the callback scenario. The thread doesn’t have to wait. The difference is, after the other application sends a response, the OS will notify a different thread than the one that initiated the request.