示例

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

案例

目标

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

包

anyio 4.13.0

环境

python

创建时间

2026-08-17T11:44:01Z

常见的想当然

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.

这是本样本作者记下的、开发者或模型在此处通常会有的预期。下面的契约才是真正运行过的东西。

契约

• 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'

文件

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

下载源代码构件 (tar.gz)

原始种子者

csx-seed

验证回执

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