1 files changed, 26 insertions, 4 deletions
diff --git a/services/surfaceflinger/MessageQueue.cpp b/services/surfaceflinger/MessageQueue.cpp
index 290fff4..3f77f74 100644
--- a/services/surfaceflinger/MessageQueue.cpp
+++ b/services/surfaceflinger/MessageQueue.cpp
@@ -49,13 +49,13 @@ void MessageBase::handleMessage(const Message&) {
 
 // ---------------------------------------------------------------------------
 
-void MessageQueue::Handler::signalRefresh() {
+void MessageQueue::Handler::dispatchRefresh() {
     if ((android_atomic_or(eventMaskRefresh, &mEventMask) & eventMaskRefresh) == 0) {
         mQueue.mLooper->sendMessage(this, Message(MessageQueue::REFRESH));
     }
 }
 
-void MessageQueue::Handler::signalInvalidate() {
+void MessageQueue::Handler::dispatchInvalidate() {
     if ((android_atomic_or(eventMaskInvalidate, &mEventMask) & eventMaskInvalidate) == 0) {
         mQueue.mLooper->sendMessage(this, Message(MessageQueue::INVALIDATE));
     }
@@ -132,13 +132,31 @@ status_t MessageQueue::postMessage(
     return NO_ERROR;
 }
 
+/* when INVALIDATE_ON_VSYNC is set SF only processes
+ * buffer updates on VSYNC and performs a refresh immediately
+ * after.
+ *
+ * when INVALIDATE_ON_VSYNC is set to false, SF will instead
+ * perform the buffer updates immediately, but the refresh only
+ * at the next VSYNC.
+ * THIS MODE IS BUGGY ON GALAXY NEXUS AND WILL CAUSE HANGS
+ */
+#define INVALIDATE_ON_VSYNC 1
+
 void MessageQueue::invalidate() {
-//    mHandler->signalInvalidate();
+#if INVALIDATE_ON_VSYNC
     mEvents->requestNextVsync();
+#else
+    mHandler->dispatchInvalidate();
+#endif
 }
 
 void MessageQueue::refresh() {
+#if INVALIDATE_ON_VSYNC
+    mHandler->dispatchRefresh();
+#else
     mEvents->requestNextVsync();
+#endif
 }
 
 int MessageQueue::cb_eventReceiver(int fd, int events, void* data) {
@@ -152,7 +170,11 @@ int MessageQueue::eventReceiver(int fd, int events) {
     while ((n = DisplayEventReceiver::getEvents(mEventTube, buffer, 8)) > 0) {
         for (int i=0 ; i<n ; i++) {
             if (buffer[i].header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) {
-                mHandler->signalRefresh();
+#if INVALIDATE_ON_VSYNC
+                mHandler->dispatchInvalidate();
+#else
+                mHandler->dispatchRefresh();
+#endif
                 break;
             }
         }