From 427df5f312bda5f8655e2a1124c16dbb0dcd01d9 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 14 Feb 2019 10:06:41 +0100
Subject: [PATCH] LibGUI: Yield (using select()) in
 GEventLoop::wait_for_specific_event().

This is factored a bit stupidly. It would be nicer to just have the
read() in drain_events_from_server() be blocking, but the fd is opened
with O_NONBLOCK right now.

This makes everything run real snappy once again. :^)
---
 LibGUI/GEventLoop.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/LibGUI/GEventLoop.cpp b/LibGUI/GEventLoop.cpp
index f2e279d1a75..f7dfe73555b 100644
--- a/LibGUI/GEventLoop.cpp
+++ b/LibGUI/GEventLoop.cpp
@@ -365,6 +365,12 @@ bool GEventLoop::post_message_to_server(const GUI_ClientMessage& message)
 bool GEventLoop::wait_for_specific_event(GUI_ServerMessage::Type type, GUI_ServerMessage& event)
 {
     for (;;) {
+        fd_set rfds;
+        FD_ZERO(&rfds);
+        FD_SET(m_event_fd, &rfds);
+        int rc = select(m_event_fd + 1, &rfds, nullptr, nullptr, nullptr);
+        ASSERT(rc > 0);
+        ASSERT(FD_ISSET(m_event_fd, &rfds));
         bool success = drain_messages_from_server();
         if (!success)
             return false;