Detect blocking calls in coroutines using BlockBuster

[cbornet]

What do these changes do?

This PR uses the blockbuster library to detect blocking calls made in the asyncio event loop during unit tests.
Avoiding blocking calls is hard as these can be deeply buried in the code or made in 3rd party libraries.
Blockbuster makes it easier to detect them by raising an exception when a call is made to a known blocking function (eg: time.sleep).

Are there changes in behavior for the user?

No

Is it a substantial burden for the maintainers to support this?

I think no. In 5 years, it's just a few lines to remove if you don't want to use it anymore.

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• If you provide code modification, please add yourself to CONTRIBUTORS.txt
  • The format is <Name> <Surname>.
  • Please keep alphabetical order, the file is sorted by names.
• Add a new news fragment into the CHANGES/ folder

[bdraco]

I think this is a very nice change. I'm going to run out of time to review it today.

I'd add excludes for the known issues and add inline comments that they blocking I/O so they can be fixed when someone h as time to work out each one.

[codspeed-hq]

CodSpeed Performance Report

Merging #10433 will improve performances by 11.57%

_{Comparing cbornet:blockbuster (70880b2) with master (ed84464)}

Summary

⚡ 1 improvements
✅ 47 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	test_one_hundred_get_requests_iter_chunks_on_512kib_chunked_payload[pyloop]	108.1 ms	96.9 ms	+11.57%

[cbornet]

I'd add excludes for the known issues and add inline comments that they blocking I/O so they can be fixed when someone h as time to work out each one.

done in 08e02f5

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.70%. Comparing base (ed84464) to head (70880b2).
Report is 3 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #10433   +/-   ##
=======================================
  Coverage   98.70%   98.70%           
=======================================
  Files         122      122           
  Lines       37191    37198    +7     
  Branches     2056     2060    +4     
=======================================
+ Hits        36709    36716    +7     
  Misses        335      335           
  Partials      147      147           

Flag	Coverage Δ
CI-GHA	98.59% <100.00%> (+<0.01%)	⬆️
OS-Linux	98.25% <100.00%> (+<0.01%)	⬆️
OS-Windows	96.18% <100.00%> (+<0.01%)	⬆️
OS-macOS	97.37% <100.00%> (+<0.01%)	⬆️
Py-3.10.11	97.28% <100.00%> (-0.01%)	⬇️
Py-3.10.16	97.82% <100.00%> (+<0.01%)	⬆️
Py-3.11.11	97.86% <100.00%> (-0.05%)	⬇️
Py-3.11.9	97.36% <100.00%> (+<0.01%)	⬆️
Py-3.12.8	97.15% <100.00%> (-0.01%)	⬇️
Py-3.12.9	98.34% <100.00%> (+<0.01%)	⬆️
Py-3.13.1	97.15% <100.00%> (-0.01%)	⬇️
Py-3.13.2	98.33% <100.00%> (+<0.01%)	⬆️
Py-3.9.13	97.15% <100.00%> (-0.02%)	⬇️
Py-3.9.21	97.69% <100.00%> (-0.01%)	⬇️
Py-pypy7.3.16	83.51% <83.87%> (-13.79%)	⬇️
VM-macos	97.37% <100.00%> (+<0.01%)	⬆️
VM-ubuntu	98.25% <100.00%> (+<0.01%)	⬆️
VM-windows	96.18% <100.00%> (+<0.01%)	⬆️

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[bdraco]

It looks like the checks are running in the benchmarks which is benchmarking the time for the checks. They should be excluded from the benchmark runs

[Dreamsorcerer]

Tests were working a few days ago, right? Maybe the version of blockbuster needs to be downgraded again?

[bdraco]

Thanks @cbornet

[patchback]

Backport to 3.12: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply 0c4b1c7 on top of patchback/backports/3.12/0c4b1c74cd7bffb544dacb4a4d8793f80fd4ad32/pr-10433

Backporting merged PR #10433 into master

1. Ensure you have a local repo clone of your fork. Unless you cloned it
   from the upstream, this would be your origin remote.
2. Make sure you have an upstream repo added as a remote too. In these
   instructions you'll refer to it by the name upstream. If you don't
   have it, here's how you can add it:

   $ git remote add upstream https://github.com/aio-libs/aiohttp.git

3. Ensure you have the latest copy of upstream and prepare a branch
   that will hold the backported code:

   $ git fetch upstream
   $ git checkout -b patchback/backports/3.12/0c4b1c74cd7bffb544dacb4a4d8793f80fd4ad32/pr-10433 upstream/3.12

4. Now, cherry-pick PR Detect blocking calls in coroutines using BlockBuster #10433 contents into that branch:

   $ git cherry-pick -x 0c4b1c74cd7bffb544dacb4a4d8793f80fd4ad32

   If it'll yell at you with something like fatal: Commit 0c4b1c74cd7bffb544dacb4a4d8793f80fd4ad32 is a merge but no -m option was given., add -m 1 as follows instead:

   $ git cherry-pick -m1 -x 0c4b1c74cd7bffb544dacb4a4d8793f80fd4ad32

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Detect blocking calls in coroutines using BlockBuster #10433 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.12/0c4b1c74cd7bffb544dacb4a4d8793f80fd4ad32/pr-10433

7. Create a PR, ensure that the CI is green. If it's not — update it so that
   the tests and any other checks pass. This is it!
   Now relax and wait for the maintainers to process your pull request
   when they have some cycles to do reviews. Don't worry — they'll tell you if
   any improvements are necessary when the time comes!

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[bdraco]

@cbornet Looks like this couldn't be backported automatically, can you take a look?