From: Pierre Ossman <ossman@cendio.se>
Date: Wed, 6 Apr 2022 13:45:36 +0000 (+0200)
Subject: Ignore socket whilst processing data
X-Git-Tag: v1.12.90~40
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=caa976c4e6e7737aba08e9daf878cd51d581f42c;p=tigervnc.git

Ignore socket whilst processing data

FLTK has a lot of synchronous stuff (like dialogs), which mean that the
main loop might be run recursively in some cases. If there is data
available on our socket then CConn::socketEvent() will be called
constantly in a busy loop.

Avoid this by removing socket notifications whilst we are processing
data.
---

diff --git a/vncviewer/CConn.cxx b/vncviewer/CConn.cxx
index b1f97b98..011dd971 100644
--- a/vncviewer/CConn.cxx
+++ b/vncviewer/CConn.cxx
@@ -238,10 +238,10 @@ void CConn::socketEvent(FL_SOCKET fd, void *data)
   cc = (CConn*)data;
 
   // I don't think processMsg() is recursion safe, so add this check
-  if (recursing)
-    return;
+  assert(!recursing);
 
   recursing = true;
+  Fl::remove_fd(fd);
 
   try {
     // We might have been called to flush unwritten socket data
@@ -287,6 +287,7 @@ void CConn::socketEvent(FL_SOCKET fd, void *data)
   Fl::add_fd(fd, when, socketEvent, data);
 
   recursing = false;
+  Fl::add_fd(fd, FL_READ | FL_EXCEPT, socketEvent, data);
 }
 
 ////////////////////// CConnection callback methods //////////////////////