Repository navigation

gh-74028: `concurrent.futures.Executor.map`: avoid reference cycles when an exception is raised - #131701

Merged

ambv merged 41 commits into

python:mainfrom

ebonnal:test/executor-map-ref-cycles

Oct 21, 2026

Merged

gh-74028: `concurrent.futures.Executor.map`: avoid reference cycles when an exception is raised#131701
ambv merged 41 commits into
python:mainfrom
ebonnal:test/executor-map-ref-cycles

Commits on Oct 20, 2026
- `test_concurrent_futures.test_map_exception`: assert no reference cycle from failed future captured in its exception’s traceback
  
  ebonnal
  authored and
  ambv
  committed
  3d481c8
- test there is no future in referrers
  
  ebonnal
  authored and
  ambv
  committed
  f6f08a6
- switch to assertTrue(all(...))
  
  ebonnal
  authored and
  ambv
  committed
  a7a595d
- add test msg
  
  ebonnal
  authored and
  ambv
  committed
  984d228
- format msgs
  
  ebonnal
  authored and
  ambv
  committed
  4cd4820
- switch to assert list empty for a better assertion error message
  
  ebonnal
  authored and
  ambv
  committed
  b7551c8
- edit comment
  
  ebonnal
  authored and
  ambv
  committed
  ec2b028
- assert there are no reference cycles at all
  
  graingert
  authored and
  ambv
  committed
  171e083
- test that traceback frames should not contain any variables referring to an Exception or a failed Future
  
  ebonnal
  authored and
  ambv
  committed
  9710843
- interpreter.WorkerContext.run: finally unassign exc_wrapper
  
  ebonnal
  authored and
  ambv
  committed
  00e7aee
- fix msg grammar
  
  ebonnal
  authored and
  ambv
  committed
  c62b24e
- fix access to exception
  
  ebonnal
  authored and
  ambv
  committed
  a3046c1
- narrow test: traceback frames should not contain any exception
  
  ebonnal
  authored and
  ambv
  committed
  7b1021a
- test_map_exception: only search for exception that captures itself in its own traceback
  
  ebonnal
  authored and
  ambv
  committed
  e617e82
- concurrent.futures.process: avoid ref cycle in _sendback_result
  
  ebonnal
  authored and
  ambv
  committed
  f2e4dbe
- concurrent.futures.process: avoid ref cycle in _process_worker
  
  ebonnal
  authored and
  ambv
  committed
  1245a9a
- format test msg
  
  ebonnal
  authored and
  ambv
  committed
  e984592
- refactor ZeroDivisionError assert
  
  ebonnal
  authored and
  ambv
  committed
  d3dee34
- Revert "concurrent.futures.process: avoid ref cycle in _process_worker"
  
  ebonnal
  authored and
  ambv
  committed
  fc2a351
- Revert "concurrent.futures.process: avoid ref cycle in _sendback_result"
  
  ebonnal
  authored and
  ambv
  committed
  2e29020
- skip referrers test for free-threading build on win/linux
  
  ebonnal
  authored and
  ambv
  committed
  51269d9
- call gc.collect for free-threading on linux/windows
  
  ebonnal
  authored and
  ambv
  committed
  ed0e87f
- Revert "call gc.collect for free-threading on linux/windows"
  
  ebonnal
  authored and
  ambv
  committed
  b3f3f4a
- Revert "skip referrers test for free-threading build on win/linux"
  
  ebonnal
  authored and
  ambv
  committed
  e3e75ce
- more gc referrers
  
  graingert
  authored and
  ambv
  committed
  70e22a1
- even more gc referrers
  
  graingert
  authored and
  ambv
  committed
  12abc0e
- delete a ref to work_item
  
  graingert
  authored and
  ambv
  committed
  cac4aac
- delete reference to result_item before joining process
  
  graingert
  authored and
  ambv
  committed
  66b98b4
- unpack ResultItem and WorkItem
  
  graingert
  authored and
  ambv
  committed
  68fcecb
- fix typo
  
  graingert
  authored and
  ambv
  committed
  0be8f49
- bit of a hack?
  
  graingert
  authored and
  ambv
  committed
  6c2406d
- Revert investigations
  
  ebonnal
  authored and
  ambv
  committed
  7037c4a
- pause before checking referrers
  
  ebonnal
  authored and
  ambv
  committed
  0568262
- add comment about the avoided ref cycle with exc_wrapper
  
  ebonnal
  authored and
  ambv
  committed
  cfeaa9b
- format test
  
  ebonnal
  authored and
  ambv
  committed
  346b4ea
- make the self-captured exceptions check not rely on var name
  
  ebonnal
  authored and
  ambv
  committed
  2a25b9a
- use traceback.walk_tb
  
  ebonnal
  authored and
  ambv
  committed
  fd9b9bb
- comment the skipping of the current frame
  
  ebonnal
  authored and
  ambv
  committed
  682a719
- test_map_exception: improve readability
  
  ebonnal
  authored and
  ambv
  committed
  fb0c522
Commits on Oct 21, 2026
- Fix CI: break exception ref cycle in _MapResultIterator.__next__ (gh-74028)
  ambv
  committed
  e0a031d
- test_map_exception: wait for transient referrers instead of sleep(1)
  ambv
  committed
  6c8f6d6

Commits

Commits on Oct 20, 2026

Commits on Oct 21, 2026