refactor: enforce background task ownership

tests/test_task_registry.py

@@ -1,6 +1,7 @@
 """进程内后台任务登记与关停语义测试。"""
 
 import asyncio
+import threading
 
 import pytest
 
@@ -84,3 +85,97 @@ def test_task_registry_runs_sync_function_and_tracks_until_completion() -> None:
         release.set()
 
     asyncio.run(scenario())
+
+
+def test_task_registry_keeps_timed_out_sync_owner_until_real_completion() -> None:
+    """同步线程超过关停预算后仍应保留 owner，不能把包装任务取消成伪完成。"""
+
+    async def scenario() -> None:
+        registry = TaskRegistry()
+        started = threading.Event()
+        release = threading.Event()
+        reports: list[dict[str, object]] = []
+        loop = asyncio.get_running_loop()
+        previous_handler = loop.get_exception_handler()
+        loop.set_exception_handler(lambda _, context: reports.append(context))
+
+        def worker() -> None:
+            """模拟无法由 asyncio 取消、需要外部资源自行结束的同步工作。"""
+            started.set()
+            release.wait()
+
+        try:
+            task = registry.create_sync(worker, owner="test.sync-timeout")
+            assert await asyncio.to_thread(started.wait, 1.0)
+
+            await registry.shutdown(timeout_seconds=0.001)
+
+            assert not task.done()
+            assert [record.owner for record in registry.records] == [
+                "test.sync-timeout"
+            ]
+            assert reports[-1]["owners"] == ("test.sync-timeout",)
+
+            release.set()
+            await task
+            await asyncio.sleep(0)
+            assert registry.records == ()
+        finally:
+            release.set()
+            loop.set_exception_handler(previous_handler)
+
+    asyncio.run(scenario())
+
+
+def test_task_registry_keeps_stubborn_cancelled_task_visible() -> None:
+    """协程清理超过预算时只收一次取消，并在最终退出后自动清理。"""
+
+    async def scenario() -> None:
+        registry = TaskRegistry()
+        started = asyncio.Event()
+        cleanup_started = asyncio.Event()
+        release = asyncio.Event()
+        cancellation_count = 0
+        reports: list[dict[str, object]] = []
+        loop = asyncio.get_running_loop()
+        previous_handler = loop.get_exception_handler()
+        loop.set_exception_handler(lambda _, context: reports.append(context))
+
+        async def worker() -> None:
+            """模拟收到取消后仍必须完成的异步清理。"""
+            nonlocal cancellation_count
+            started.set()
+            try:
+                await asyncio.Event().wait()
+            except asyncio.CancelledError:
+                cancellation_count += 1
+                cleanup_started.set()
+                await release.wait()
+
+        task = registry.create(worker(), owner="test.stubborn")
+        await started.wait()
+        try:
+            await registry.shutdown(timeout_seconds=0.001)
+
+            assert cleanup_started.is_set()
+            assert not task.done()
+            assert cancellation_count == 1
+            assert [record.owner for record in registry.records] == [
+                "test.stubborn"
+            ]
+            assert reports[-1]["owners"] == ("test.stubborn",)
+
+            await registry.shutdown(timeout_seconds=0.001)
+            assert not task.done()
+            assert cancellation_count == 1
+            assert len(reports) == 1
+
+            release.set()
+            await task
+            await asyncio.sleep(0)
+            assert registry.records == ()
+        finally:
+            release.set()
+            loop.set_exception_handler(previous_handler)
+
+    asyncio.run(scenario())