Add a workaround for simulate secondary display

To workaround a deadlock caused by bufferqueue locks
we force RenderThread over to use async mode which
we enable via eglSwapInterval(0)

Bug: 38372997
Test: steps in the bug
Change-Id: Ia305f73abbdd64ab0c25d1f7d32792cc6295a0ce

3 files changed, 10 insertions, 0 deletions

diff --git a/libs/hwui/renderthread/EglManager.cpp b/libs/hwui/renderthread/EglManager.cpp
index 44af5fd8d0dd..ed3070887b8b 100644
--- a/libs/hwui/renderthread/EglManager.cpp
+++ b/libs/hwui/renderthread/EglManager.cpp
@@ -279,6 +279,9 @@ bool EglManager::makeCurrent(EGLSurface surface, EGLint* errOut) {
         }
     }
     mCurrentSurface = surface;
+    if (Properties::disableVsync) {
+        eglSwapInterval(mEglDisplay, 0);
+    }
     return true;
 }
 
diff --git a/libs/hwui/renderthread/RenderProxy.cpp b/libs/hwui/renderthread/RenderProxy.cpp
index eed523810403..d842be9e7d6e 100644
--- a/libs/hwui/renderthread/RenderProxy.cpp
+++ b/libs/hwui/renderthread/RenderProxy.cpp
@@ -18,6 +18,7 @@
 
 #include "DeferredLayerUpdater.h"
 #include "DisplayList.h"
+#include "Properties.h"
 #include "Readback.h"
 #include "Rect.h"
 #include "renderthread/CanvasContext.h"
@@ -708,6 +709,10 @@ void RenderProxy::onBitmapDestroyed(uint32_t pixelRefId) {
     thread.queue(task);
 }
 
+void RenderProxy::disableVsync() {
+    Properties::disableVsync = true;
+}
+
 void RenderProxy::post(RenderTask* task) {
     mRenderThread.queue(task);
 }
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index b21772cd88de..6f4e8cef4502 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -137,6 +137,8 @@ public:
     static int copyGraphicBufferInto(GraphicBuffer* buffer, SkBitmap* bitmap);
 
     static void onBitmapDestroyed(uint32_t pixelRefId);
+
+    ANDROID_API static void disableVsync();
 private:
     RenderThread& mRenderThread;
     CanvasContext* mContext;