src/main.py

@@ -586,7 +586,7 @@ async def sign_in(payload: DashboardSignIn, request: Request, response: Response
     )
     attempts = _login_attempt_store()
     try:
-        retry_after = attempts.retry_after(source)
+        retry_after = await asyncio.to_thread(attempts.retry_after, source)
     except LoginAttemptStoreError:
         return JSONResponse(
             {"detail": "Sign-in throttling is temporarily unavailable"},
@@ -607,7 +607,7 @@ async def sign_in(payload: DashboardSignIn, request: Request, response: Response
         payload.access_token, configured_token
     ):
         try:
-            attempts.record_failure(source)
+            await asyncio.to_thread(attempts.record_failure, source)
         except LoginAttemptStoreError:
             return JSONResponse(
                 {"detail": "Sign-in throttling is temporarily unavailable"},
@@ -616,7 +616,7 @@ async def sign_in(payload: DashboardSignIn, request: Request, response: Response
             )
         raise HTTPException(status_code=401, detail="Invalid access token")
     try:
-        attempts.clear(source)
+        await asyncio.to_thread(attempts.clear, source)
     except LoginAttemptStoreError:
         return JSONResponse(
             {"detail": "Sign-in throttling is temporarily unavailable"},
@@ -624,7 +624,7 @@ async def sign_in(payload: DashboardSignIn, request: Request, response: Response
             headers={"Cache-Control": "no-store"},
         )
     try:
-        signed, session = dashboard_auth.issue_session()
+        signed, session = await asyncio.to_thread(dashboard_auth.issue_session)
     except dashboard_auth.SessionStoreError:
         return JSONResponse(
             {"detail": "Session registry is temporarily unavailable"},
@@ -668,7 +668,7 @@ async def session_status(request: Request):
 async def sign_out(request: Request, response: Response):
     session = request.state.dashboard_session
     try:
-        dashboard_auth.revoke_session(session)
+        await asyncio.to_thread(dashboard_auth.revoke_session, session)
     except dashboard_auth.SessionStoreError:
         return JSONResponse(
             {"detail": "Session registry is temporarily unavailable"},

tests/test_dashboard_auth.py

@@ -430,6 +430,171 @@ async def test_session_registry_latency_does_not_block_the_event_loop(access_con
     assert heartbeat_elapsed < 0.08
 
 
+@pytest.mark.anyio
+async def test_sign_in_throttle_lookup_does_not_block_the_event_loop(
+    access_control, monkeypatch
+):
+    class SlowAttempts:
+        def retry_after(self, source):
+            time.sleep(0.15)
+            return 17
+
+    monkeypatch.setattr(main, "_login_attempt_store", lambda: SlowAttempts())
+    transport = httpx.ASGITransport(app=main.app, client=("203.0.113.10", 1234))
+    async with httpx.AsyncClient(transport=transport, base_url="https://test") as client:
+        sign_in = asyncio.create_task(
+            client.post("/api/v1/session", json={"access_token": "wrong"})
+        )
+        await asyncio.sleep(0)
+        started = time.perf_counter()
+        await asyncio.sleep(0.01)
+        heartbeat_elapsed = time.perf_counter() - started
+        response = await sign_in
+
+    assert response.status_code == 429
+    assert response.headers["retry-after"] == "17"
+    assert heartbeat_elapsed < 0.08
+
+
+@pytest.mark.anyio
+async def test_failed_sign_in_recording_does_not_block_the_event_loop(
+    access_control, monkeypatch
+):
+    class SlowAttempts:
+        def retry_after(self, source):
+            time.sleep(0.02)
+            return 0
+
+        def record_failure(self, source):
+            time.sleep(0.15)
+
+    monkeypatch.setattr(main, "_login_attempt_store", lambda: SlowAttempts())
+    transport = httpx.ASGITransport(app=main.app, client=("203.0.113.11", 1234))
+    async with httpx.AsyncClient(transport=transport, base_url="https://test") as client:
+        sign_in = asyncio.create_task(
+            client.post("/api/v1/session", json={"access_token": "wrong"})
+        )
+        await asyncio.sleep(0)
+        started = time.perf_counter()
+        await asyncio.sleep(0.04)
+        heartbeat_elapsed = time.perf_counter() - started
+        response = await sign_in
+
+    assert response.status_code == 401
+    assert heartbeat_elapsed < 0.08
+
+
+@pytest.mark.anyio
+async def test_successful_sign_in_throttle_clear_does_not_block_the_event_loop(
+    access_control, monkeypatch
+):
+    class SlowAttempts:
+        def retry_after(self, source):
+            time.sleep(0.02)
+            return 0
+
+        def clear(self, source):
+            time.sleep(0.15)
+
+    monkeypatch.setattr(main, "_login_attempt_store", lambda: SlowAttempts())
+    transport = httpx.ASGITransport(app=main.app, client=("203.0.113.12", 1234))
+    async with httpx.AsyncClient(transport=transport, base_url="https://test") as client:
+        sign_in = asyncio.create_task(
+            client.post(
+                "/api/v1/session",
+                json={"access_token": "correct horse battery staple"},
+            )
+        )
+        await asyncio.sleep(0)
+        started = time.perf_counter()
+        await asyncio.sleep(0.04)
+        heartbeat_elapsed = time.perf_counter() - started
+        response = await sign_in
+
+    assert response.status_code == 200
+    assert heartbeat_elapsed < 0.08
+
+
+@pytest.mark.anyio
+async def test_session_activation_does_not_block_the_event_loop(
+    access_control, monkeypatch
+):
+    class Attempts:
+        def retry_after(self, source):
+            time.sleep(0.02)
+            return 0
+
+        def clear(self, source):
+            return None
+
+    class SlowStore:
+        def activate(self, session_id, expires_at):
+            time.sleep(0.15)
+
+    monkeypatch.setattr(main, "_login_attempt_store", lambda: Attempts())
+    monkeypatch.setattr(main.dashboard_auth, "_session_store", lambda now=None: SlowStore())
+    transport = httpx.ASGITransport(app=main.app, client=("203.0.113.13", 1234))
+    async with httpx.AsyncClient(transport=transport, base_url="https://test") as client:
+        sign_in = asyncio.create_task(
+            client.post(
+                "/api/v1/session",
+                json={"access_token": "correct horse battery staple"},
+            )
+        )
+        await asyncio.sleep(0)
+        started = time.perf_counter()
+        await asyncio.sleep(0.04)
+        heartbeat_elapsed = time.perf_counter() - started
+        response = await sign_in
+
+    assert response.status_code == 200
+    assert any(
+        "stackchain_session=" in value
+        for value in response.headers.get_list("set-cookie")
+    )
+    assert heartbeat_elapsed < 0.08
+
+
+@pytest.mark.anyio
+async def test_single_session_revocation_does_not_block_the_event_loop(
+    access_control, monkeypatch
+):
+    transport = httpx.ASGITransport(app=main.app)
+    async with httpx.AsyncClient(transport=transport, base_url="https://test") as client:
+        await client.post(
+            "/api/v1/session",
+            json={"access_token": "correct horse battery staple"},
+        )
+        csrf = client.cookies["stackchain_csrf"]
+
+        class SlowStore:
+            def is_active(self, session_id, expires_at):
+                time.sleep(0.02)
+                return True
+
+            def revoke(self, session_id):
+                time.sleep(0.15)
+
+        monkeypatch.setattr(
+            main.dashboard_auth, "_session_store", lambda now=None: SlowStore()
+        )
+        sign_out = asyncio.create_task(
+            client.delete(
+                "/api/v1/session",
+                headers={"Origin": "https://test", "X-CSRF-Token": csrf},
+            )
+        )
+        await asyncio.sleep(0)
+        started = time.perf_counter()
+        await asyncio.sleep(0.04)
+        heartbeat_elapsed = time.perf_counter() - started
+        response = await sign_out
+
+    assert response.status_code == 200
+    assert response.json()["authenticated"] is False
+    assert heartbeat_elapsed < 0.08
+
+
 @pytest.mark.anyio
 async def test_session_registry_read_failure_fails_closed_before_gitea(
     access_control, monkeypatch