We were not handling the "sync next" fence properly as we sent the response
right after we got the request (instead of waiting for the next command).
This created a race where we could lose pixel format sync between the client
and the server.
git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4943 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/rfb/VNCSConnectionST.cxx b/common/rfb/VNCSConnectionST.cxx
index 1ecd78c..381ee21 100644
--- a/common/rfb/VNCSConnectionST.cxx
+++ b/common/rfb/VNCSConnectionST.cxx
@@ -66,7 +66,8 @@
VNCSConnectionST::VNCSConnectionST(VNCServerST* server_, network::Socket *s,
bool reverse)
: SConnection(reverse), sock(s), inProcessMessages(false),
- syncFence(false), fenceFlags(0), fenceDataLen(0), fenceData(NULL),
+ pendingSyncFence(false), syncFence(false), fenceFlags(0),
+ fenceDataLen(0), fenceData(NULL),
baseRTT(-1), minRTT(-1), seenCongestion(false), pingCounter(0),
ackedOffset(0), sentOffset(0), congWindow(0), congestionTimer(this),
server(server_),
@@ -156,7 +157,13 @@
network::TcpSocket::cork(sock->getFd(), true);
while (getInStream()->checkNoWait(1)) {
+ if (pendingSyncFence) {
+ syncFence = true;
+ pendingSyncFence = false;
+ }
+
processMsg();
+
if (syncFence) {
writer()->writeFence(fenceFlags, fenceDataLen, fenceData);
syncFence = false;
@@ -627,10 +634,7 @@
{
if (flags & fenceFlagRequest) {
if (flags & fenceFlagSyncNext) {
- if (syncFence)
- vlog.error("Fence trying to synchronise another fence");
-
- syncFence = true;
+ pendingSyncFence = true;
fenceFlags = flags & (fenceFlagBlockBefore | fenceFlagBlockAfter | fenceFlagSyncNext);
fenceDataLen = len;