From cea8db7eaa35657fe594377ff30ae1e028329b2d Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Fri, 4 Dec 2020 09:55:01 +0100
Subject: [PATCH] event/SocketEvent: add comment

---
 src/event/SocketEvent.cxx | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/event/SocketEvent.cxx b/src/event/SocketEvent.cxx
index ad2aa576a..23ab50f2a 100644
--- a/src/event/SocketEvent.cxx
+++ b/src/event/SocketEvent.cxx
@@ -44,6 +44,9 @@ SocketEvent::Close() noexcept
 	if (!fd.IsDefined())
 		return;
 
+	/* closing the socket automatically unregisters it from epoll,
+	   so we can omit the epoll_ctl(EPOLL_CTL_DEL) call and save
+	   one system call */
 	if (std::exchange(scheduled_flags, 0) != 0)
 		loop.AbandonFD(*this);
 	fd.Close();