From 77f763258441fb9ce71db084703b64608559211d Mon Sep 17 00:00:00 2001
From: Mark Qvist <bc7291552be7a58f361522990465165c>
Date: Mon, 24 Aug 2026 20:52:23 +0200
Subject: [PATCH] Avoid extra epoll modifies when EPOLLOUT already set

---
 RNS/Interfaces/BackboneInterface.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/RNS/Interfaces/BackboneInterface.py b/RNS/Interfaces/BackboneInterface.py
index 27e22bb7..d503eea4 100644
--- a/RNS/Interfaces/BackboneInterface.py
+++ b/RNS/Interfaces/BackboneInterface.py
@@ -797,8 +797,9 @@ class BackboneClientInterface(Interface):
     def process_outgoing(self, data):
         if self.online and not self.detached:
             try:
+                buffer_was_empty = len(self.transmit_buffer) == 0
                 self.transmit_buffer += bytes([HDLC.FLAG])+HDLC.escape(data)+bytes([HDLC.FLAG])
-                BackboneInterface.tx_ready(self)
+                if buffer_was_empty: BackboneInterface.tx_ready(self)
 
             except Exception as e:
                 RNS.log("Exception occurred while transmitting via "+str(self)+", tearing down interface", RNS.LOG_ERROR)