ws.Client: module-level loop variable prevents multiple instances (multi-bot race condition)

[zj1123581321]

Problem

lark_oapi/ws/client.py uses a module-level loop variable (line 26-29):

try:
    loop = asyncio.get_event_loop()
except RuntimeError:
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)

All ws.Client instances share this single loop reference. When multiple Feishu bots are started in separate threads (a common pattern for multi-bot applications), they overwrite each other's loop, causing RuntimeError: This event loop is already running.

Race condition

1. Thread A: ws_mod.loop = loop_A
2. Thread B: ws_mod.loop = loop_B (overwrites A)
3. Thread A: cli.start() → reads ws_mod.loop → gets loop_B → loop_B.run_until_complete()
4. Thread B: cli.start() → reads ws_mod.loop → gets loop_B → ERROR: already running

Even after connecting, _receive_message_loop (line 171) uses loop.create_task() which may reference the wrong loop.

Current workaround

We replaced ws_mod.loop with a thread-local proxy:

class _ThreadLocalLoopProxy:
    def __getattr__(self, name):
        return getattr(asyncio.get_event_loop(), name)

ws_mod.loop = _ThreadLocalLoopProxy()

This works but is fragile against SDK changes.

Suggested fix

Make ws.Client instance-based, like the Node.js SDK (@larksuiteoapi/node-sdk) already does with WSClient:

class Client:
    def __init__(self, ...):
        self._loop = asyncio.new_event_loop()
        ...

    def start(self):
        self._loop.run_until_complete(self._connect())
        self._loop.create_task(self._ping_loop())
        self._loop.run_until_complete(_select())

Or provide an async start_async() method (as suggested in #96) so the client can integrate with existing event loops (e.g., uvicorn, FastAPI).

Related issues

• 建议添加 async的start方法里面的loop在异步的框架下会报错 #96 — loop conflicts with async frameworks
• 个人拙见:真有人在生产用这个库吗？感觉高并发下会崩 #109 — concerns about production readiness

Environment

• lark_oapi version: latest (PyPI)
• Python: 3.13
• Use case: multi-bot IM middleware (each bot = separate ws.Client instance in its own thread)