Improve updates handling (#4483)

client/src/telethon/_impl/client/client/auth.py

@@ -55,12 +55,16 @@ async def complete_login(client: Client, auth: abcs.auth.Authorization) -> User:
 
 
 async def handle_migrate(client: Client, dc_id: Optional[int]) -> None:
+    assert client._sender
     assert dc_id is not None
     sender, client._session.dcs = await connect_sender(
         client._config, client._session.dcs, DataCenter(id=dc_id)
     )
-    async with client._sender_lock:
+
+    async with client._sender.lock:
+        old_sender = client._sender
         client._sender = sender
+        await old_sender.disconnect()
 
 
 async def bot_sign_in(self: Client, token: str) -> User:

client/src/telethon/_impl/client/client/client.py

@@ -220,14 +220,15 @@ class Client:
         base_logger = logger or logging.getLogger(__package__[: __package__.index(".")])
 
         self._sender: Optional[Sender] = None
-        self._sender_lock = asyncio.Lock()
-        self._sender_lock_flag = False
+
         if isinstance(session, Storage):
-            self._storage = session
+            storage = session
         elif session is None:
-            self._storage = MemorySession()
+            storage = MemorySession()
         else:
-            self._storage = SqliteSession(session)
+            storage = SqliteSession(session)
+
+        self._storage = storage
 
         self._config = Config(
             api_id=api_id,
@@ -2074,10 +2075,7 @@ class Client:
         return await upload(self, fd, size, name)
 
     async def __call__(self, request: Request[Return]) -> Return:
-        if not self._sender:
-            raise ConnectionError("not connected")
-
-        return await invoke_request(self, self._sender, self._sender_lock, request)
+        return await invoke_request(self, request)
 
     async def __aenter__(self) -> Self:
         await connect(self)

client/src/telethon/_impl/client/client/net.py

@@ -238,15 +238,16 @@ async def disconnect(self: Client) -> None:
 
 async def invoke_request(
     client: Client,
-    sender: Sender,
-    lock: asyncio.Lock,
     request: Request[Return],
 ) -> Return:
+    if not client._sender:
+        raise ConnectionError("not connected")
+
     sleep_thresh = client._config.flood_sleep_threshold
-    rx = sender.enqueue(request)
+    rx = client._sender.enqueue(request)
     while True:
         while not rx.done():
-            await step_sender(client, sender, lock)
+            await step_sender(client)
         try:
             response = rx.result()
             break
@@ -254,30 +255,17 @@ async def invoke_request(
             if e.code == 420 and e.value is not None and e.value < sleep_thresh:
                 await asyncio.sleep(e.value)
                 sleep_thresh -= e.value
-                rx = sender.enqueue(request)
+                rx = client._sender.enqueue(request)
                 continue
             else:
                 raise adapt_rpc(e) from None
     return request.deserialize_response(response)
 
 
-async def step(client: Client) -> None:
-    if client._sender:
-        await step_sender(client, client._sender, client._sender_lock)
-
-
-async def step_sender(client: Client, sender: Sender, lock: asyncio.Lock) -> None:
-    flag = client._sender_lock_flag
-    async with lock:
-        if client._sender_lock_flag != flag:
-            # different task already received an item from the network
-            return
-        # current task is responsible for receiving
-        # toggle the flag so any other task that comes after does not run again
-        client._sender_lock_flag = not client._sender_lock_flag
-
+async def step_sender(client: Client) -> None:
     try:
-            updates = await sender.step()
+        assert client._sender
+        updates = await client._sender.step()
     except ConnectionError:
         if client.connected:
             raise
@@ -290,7 +278,8 @@ async def step_sender(client: Client, sender: Sender, lock: asyncio.Lock) -> Non
 
 async def run_until_disconnected(self: Client) -> None:
     while self.connected:
-        await step(self)
+        if self._sender:
+            await step_sender(self)
 
 
 def connected(client: Client) -> bool:

client/src/telethon/_impl/mtsender/sender.py

@@ -3,7 +3,7 @@ import logging
 import struct
 import time
 from abc import ABC
-from asyncio import FIRST_COMPLETED, Event, Future
+from asyncio import FIRST_COMPLETED, Event, Future, Lock
 from collections.abc import Iterator
 from dataclasses import dataclass
 from typing import Generic, Optional, Protocol, Type, TypeVar
@@ -162,6 +162,7 @@ class Request(Generic[Return]):
 class Sender:
     dc_id: int
     addr: str
+    lock: Lock
     _logger: logging.Logger
     _reader: AsyncReader
     _writer: AsyncWriter
@@ -191,6 +192,7 @@ class Sender:
         return cls(
             dc_id=dc_id,
             addr=addr,
+            lock=Lock(),
             _logger=base_logger.getChild("mtsender"),
             _reader=reader,
             _writer=writer,
@@ -233,6 +235,10 @@ class Sender:
                 return rx.result()
 
     async def step(self) -> list[Updates]:
+        async with self.lock:
+            return await self._step()
+
+    async def _step(self) -> list[Updates]:
         self._try_fill_write()
 
         recv_req = asyncio.create_task(self._request_event.wait())