ASGI and Context Managers¶

Asyncz schedulers use reference counting for start() and shutdown(). That makes them safe to use from nested context managers, lifespan handlers, and wrapper middleware without double-starting or double-shutting down the same scheduler instance.

Wrapping an ASGI application¶

AsyncIOScheduler.asgi() can either wrap an application directly or return a decorator-style wrapper.

Direct wrapping¶

from asyncz.schedulers import AsyncIOScheduler

scheduler = AsyncIOScheduler()
application = scheduler.asgi(application)

Decorator-style wrapping¶

from asyncz.schedulers import AsyncIOScheduler

scheduler = AsyncIOScheduler()
application = scheduler.asgi()(application)

Parameters¶

• app: the ASGI application to wrap. When omitted, asgi() returns a wrapper function.
• handle_lifespan: intercept lifespan events instead of passing them through. This is useful when the wrapped application does not implement the ASGI lifespan protocol.
• wait: forwarded to shutdown(). Set it to False if you want running tasks to be cancelled during shutdown.

Manual startup and shutdown¶

Manual wiring is often the clearest option when your framework already has startup and shutdown hooks.

from asyncz.schedulers import AsyncIOScheduler

scheduler = AsyncIOScheduler()

app = Lilya(
    routes=[...],
    on_startup=[scheduler.start],
    on_shutdown=[scheduler.shutdown],
)

Starlette lifespan example¶

from asyncz.schedulers import AsyncIOScheduler

scheduler = AsyncIOScheduler()


async def lifespan(app):
    async with scheduler:
        yield


app = Starlette(lifespan=lifespan)

Sync and async context managers¶

Synchronous¶

from asyncz.schedulers import AsyncIOScheduler

with AsyncIOScheduler() as scheduler:
    ...

Asynchronous¶

from asyncz.schedulers import AsyncIOScheduler

async with AsyncIOScheduler() as scheduler:
    ...

Choosing between AsyncIOScheduler and NativeAsyncIOScheduler¶

• Use AsyncIOScheduler when Asyncz should manage or create the event loop integration for you.
• Use NativeAsyncIOScheduler when you are already inside a running event loop and want start() / shutdown() to be awaitable.