3.10.0rc0

Bug fixes

• Adjusted FileResponse to check file existence and access when preparing the response -- by :user:steverep.

  The :py:class:~aiohttp.web.FileResponse class was modified to respond with
  403 Forbidden or 404 Not Found as appropriate. Previously, it would cause a
  server error if the path did not exist or could not be accessed. Checks for
  existence, non-regular files, and permissions were expected to be done in the
  route handler. For static routes, this now permits a compressed file to exist
  without its uncompressed variant and still be served. In addition, this
  changes the response status for files without read permission to 403, and for
  non-regular files from 404 to 403 for consistency.

  Related issues and pull requests on GitHub:
  #8182.

Removals and backward incompatible breaking changes

• The shutdown logic in 3.9 waited on all tasks, which caused issues with some libraries.
  In 3.10 we've changed this logic to only wait on request handlers. This means that it's
  important for developers to correctly handle the lifecycle of background tasks using a
  library such as aiojobs. If an application is using handler_cancellation=True then
  it is also a good idea to ensure that any :func:asyncio.shield calls are replaced with
  :func:aiojobs.aiohttp.shield.

  Please read the updated documentation on these points:
  https://docs.aiohttp.org/en/stable/web_advanced.html#graceful-shutdown
  https://docs.aiohttp.org/en/stable/web_advanced.html#web-handler-cancellation

  -- by :user:Dreamsorcerer

  Related issues and pull requests on GitHub:
  #8495.

Miscellaneous internal changes

• Improve performance of filtering cookies -- by :user:bdraco.

  This change is a followup to the improvements in #7583

  Related issues and pull requests on GitHub:
  #8535.

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