fix(k1): stabilize live recovery and media admission

tests/test_plugin_runtime.py

@@ -37,6 +37,7 @@ from k1link.device_plugins.xgrids_k1.facade import (
     ACTION_PHYSICAL_COMMAND_RECONCILE,
     ACTION_PHYSICAL_COMMAND_REOPEN_RETIRED_RECONCILIATION,
     ACTION_PHYSICAL_COMMAND_RETIRE_UNAVAILABLE,
+    ACTION_STATE_READ,
     ACTION_STREAM_START_LIVE,
     ACTION_STREAM_START_REPLAY,
     ACTION_STREAM_STOP,
@@ -1285,6 +1286,57 @@ def test_sync_runtime_actions_run_outside_the_api_event_loop() -> None:
     assert service.thread_id != event_loop_thread
 
 
+def test_state_reads_are_single_flight_and_survive_one_cancelled_waiter() -> None:
+    class BlockingStateService(FakeXgridsService):
+        def __init__(self) -> None:
+            super().__init__()
+            self.state_calls = 0
+            self.started = threading.Event()
+            self.release = threading.Event()
+
+        def state(self) -> dict[str, Any]:
+            self.state_calls += 1
+            self.started.set()
+            if not self.release.wait(timeout=2):
+                raise AssertionError("state read was not released by the test")
+            return {"phase": "idle", "revision": self.state_calls}
+
+    service = BlockingStateService()
+    adapter = XgridsK1PluginFacade(service)
+
+    def invocation(invocation_id: str) -> RuntimeActionInvocation:
+        return RuntimeActionInvocation(
+            invocation_id=invocation_id,
+            plugin_id=adapter.plugin_id,
+            action_id=ACTION_STATE_READ,
+            requested_at=datetime.now(UTC),
+            parameters={},
+        )
+
+    async def exercise() -> None:
+        first = asyncio.create_task(adapter.invoke(invocation("state-read-first")))
+        while not service.started.is_set():
+            await asyncio.sleep(0)
+        second = asyncio.create_task(adapter.invoke(invocation("state-read-second")))
+        await asyncio.sleep(0.02)
+        assert service.state_calls == 1
+
+        first.cancel()
+        with pytest.raises(asyncio.CancelledError):
+            await first
+        assert service.state_calls == 1
+
+        service.release.set()
+        assert await second == {"phase": "idle", "revision": 1}
+        assert await adapter.invoke(invocation("state-read-fresh")) == {
+            "phase": "idle",
+            "revision": 2,
+        }
+
+    asyncio.run(exercise())
+    assert service.state_calls == 2
+
+
 def test_runtime_requires_successful_handshake_before_dispatch() -> None:
     adapter = XgridsK1PluginFacade(FakeXgridsService())
     runtime = _in_process_runtime(adapter, activate=False)