Memory leak when using request.state

[galkahana]

Hi,
I noticed that setting properties on request.state results in memory leak.

Originally an issue I reported in fastapi, it seems that the following server definition will cause memory usage to grow on every request:

from starlette.applications import Starlette
from starlette.responses import JSONResponse
from starlette.routing import Route
from starlette.requests import Request


async def homepage(request: Request):
    request.state.test = [x for x in range(999999)]
    return JSONResponse({'hello': 'world'})


app = Starlette(routes=[
    Route('/', homepage),
])

The array set as the test property of request.state is never released. There's a workaround that I can use to resolve this by setting the the property to none at the end of the request - request.state.test = None.

I created a repo to demonstrate the issue here.

Figured i'll report, so at least if someones getting a memory leak, this can help in possibly finding the cause.

[jhominal]

Oh, it seems that #1749 has been opened for this.