fix(sync): 依赖超时后限制就绪检查工作量

server sync/tests/test_readiness.py

@@ -0,0 +1,56 @@
+"""Bounded worker use, request cancellation, cached failures and recovery."""
+import asyncio
+from threading import Event
+
+from sync_server.readiness import Readiness
+
+
+def test_timeout_and_cancel_never_spawn_overlapping_dependency_probes():
+    entered, release = Event(), Event()
+    calls = []
+
+    def slow():
+        calls.append(1)
+        entered.set()
+        if not release.wait(10):
+            raise TimeoutError("fixture was not released")
+        raise OSError("late dependency exception must be consumed")
+
+    async def run():
+        ready = Readiness(slow, timeout=.01, cache_seconds=0)
+        request = asyncio.create_task(ready.check())
+        try:
+            while not entered.is_set():
+                await asyncio.sleep(.001)
+            request.cancel()
+            await asyncio.gather(request, return_exceptions=True)
+            assert ready.running is not None and not ready.running.done()
+            assert await asyncio.gather(*(ready.check() for _ in range(20))) == [False] * 20
+            assert len(calls) == 1
+        finally:
+            release.set()
+            await asyncio.gather(ready.running, return_exceptions=True)
+        # A completed failed probe does not prevent a new healthy attempt.
+        ready.probe = lambda: None
+        assert await ready.check() is True
+    asyncio.run(run())
+
+
+def test_success_and_failure_cache_then_refresh():
+    calls = []
+
+    def probe():
+        calls.append(1)
+        if len(calls) == 1:
+            raise OSError("controlled dependency outage")
+
+    async def run():
+        ready = Readiness(probe, cache_seconds=.02)
+        assert await ready.check() is False
+        assert await asyncio.gather(*(ready.check() for _ in range(20))) == [False] * 20
+        assert len(calls) == 1
+        await asyncio.sleep(.03)
+        assert await ready.check() is True
+        assert await ready.check() is True
+        assert len(calls) == 2
+    asyncio.run(run())