Пример

Configuring abandon_on_cancel=False on anyio.to_thread.run_sync shields worker execution and blocks scope cancellation until the worker thread finishes, while abandon_on_cancel=True exits immediately but releases the CapacityLimiter slot before the background worker thread completes.

sha256:a14bcf1e15305a5701519193880ecabc0aab24fe04d053c597a482f66f869313

Кейс

Цель

Configuring abandon_on_cancel=False on anyio.to_thread.run_sync shields worker execution and blocks scope cancellation until the worker thread finishes, while abandon_on_cancel=True exits immediately but releases the CapacityLimiter slot before the background worker thread completes. HOW

Пакеты

anyio 4.13.0

Окружение

python

Создан

2026-08-17T11:44:01Z

Что обычно предполагают

Cancelling a task waiting on anyio.to_thread.run_sync cancels immediately without waiting for the synchronous thread, and setting abandon_on_cancel=True keeps worker thread concurrency strictly bounded by the CapacityLimiter.

Автор образца записал здесь то, чего ожидал бы разработчик или модель. Контракт ниже — это то, что действительно выполнялось.

Контракт

• With abandon_on_cancel=False, cancelling the calling scope blocks until the worker thread finishes running, whereas abandon_on_cancel=True exits the scope immediately while releasing the CapacityLimiter before the synchronous thread finishes.
• assert cancel_scope.cancel_called and sync_finished, 'With abandon_on_cancel=False, cancellation must be shielded until worker thread finishes'
• assert elapsed >= 0.18, 'Scope exit was blocked waiting for synchronous thread duration'
• assert elapsed < 0.15 and not sync_finished, 'With abandon_on_cancel=True, scope exits immediately while worker thread runs in background'
• assert limiter.available_tokens == 1 and limiter.borrowed_tokens == 0, 'CapacityLimiter token is immediately released upon cancellation despite worker thread running'
• assert acquired_concurrently, 'Second task acquires limiter token concurrently with abandoned background thread'
• assert collision_caught, 'Calling run_sync while holding default limiter raises RuntimeError'

Файлы

• NOTES.md
• csx.json
• requirements.txt
• test/contract.py

Скачать артефакт с исходным кодом (tar.gz)

Исходный сидер

csx-seed

Квитанции проверки

• python 3.12 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17 · ed25519:d91480838ac982c9