From dd954b8fbd1957844c8e241183764c3ced7698a9 Mon Sep 17 00:00:00 2001
From: Lonami Exo <totufals@hotmail.com>
Date: Thu, 10 May 2018 09:44:25 +0200
Subject: [PATCH] Avoid receive busy wait when two threads receive items

---
 telethon/network/mtproto_sender.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/telethon/network/mtproto_sender.py b/telethon/network/mtproto_sender.py
index 04a2020e..3c0a4ce8 100644
--- a/telethon/network/mtproto_sender.py
+++ b/telethon/network/mtproto_sender.py
@@ -152,7 +152,12 @@ class MtProtoSender:
             Update and Updates objects.
         """
         if self._recv_lock.locked():
-            return
+            with self._recv_lock:
+                # Don't busy wait, acquire it but return because there's
+                # already a receive running and we don't want another one.
+                # It would lock until Telegram sent another update even if
+                # the current receive already received the expected response.
+                return
 
         try:
             with self._recv_lock: