ASGI and Contextmanager¶

The scheduler uses refcounting for start and stop calls. Every start call increases the ref count, every shutdown reduces it. Only if the refcount is 0 the scheduler is started or the shutdown is executed. This way it is compatible to lifespan and nested contextmanager calls.

ASGI¶

The asgi call of a scheduler object supports following argument:

app: (Optionally) The ASGI application to wrap. If not specified, a decorator is returned

And following keyword arguments

handle_lifespan: (Default: False) Fixes the issue with lifespan and django. Django doesn't support the lifespan protocol and fails horrible. This argument fixes this by handling the lifespan protocol and don't passing it through to django.
wait: (Default: True) Set the wait argument of shutdown. If wait is False all tasks are cancelled on shutdown.

Wrapping an asgi applicationUsing with lilya

from asyncz.schedulers import AsyncIOScheduler
...

# handle_lifespan is optional, set to True if you don't want to pass it down because the underlying app doesn't support it
# this is true for django
application = AsyncIOScheduler().asgi(application, handle_lifespan=False)
# or more simple (please do not use both together)
application = AsyncIOScheduler().asgi()(application)

from asyncz.schedulers import AsyncIOScheduler

# Lilya middleware doesn't pass lifespan events

app = AsyncIOScheduler().asgi(Lilya(
    routes=[...],
))

Or manually:

from asyncz.schedulers import AsyncIOScheduler

scheduler = AsyncIOScheduler()

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

Contextmanager support¶

Use as sync contextmanagerUse as async contextmanager

from asyncz.schedulers import AsyncIOScheduler

with AsyncIOScheduler() as scheduler:
    # nesting is no problem
    with AsyncIOScheduler() as scheduler2:
        ...

from asyncz.schedulers import AsyncIOScheduler

async with AsyncIOScheduler() as scheduler:
    # nesting is no problem
    async with AsyncIOScheduler() as scheduler2:
        ...

For using with lifespan of starlette

Starlette

from asyncz.schedulers import AsyncIOScheduler

async lifespan(app):
    with AsyncIOScheduler() as scheduler:
        yield
        # or yield a state
app = Starlette(
    lifespan=lifespan,
)