Async¶

Demonstrates running an OPC UA server cooperatively on an asyncio event loop — no background threads needed.

opc.tcp://localhost:4840

Multitasking¶

This server runs on a single asyncio event loop instead of a background thread. Because everything is cooperative, the server can only switch to another task — handling a client request, for instance — at an await point.

The async with statement manages the server lifecycle, ensuring clean startup and shutdown without blocking the main event loop.

async with server:

The await asyncio.sleep(1) is non-blocking. Unlike time.sleep(1), it hands control back to the event loop, letting the server process client requests while waiting.

await asyncio.sleep(1)

asyncio.run is the entry point that kicks off the event loop and manages the lifecycle of the main task.

asyncio.run(main())

Source Code¶

Download S08_asynchronous.py to run it locally.