diff --git a/tools/emulator/opengl/host/libs/libOpenglRender/RenderControl.cpp b/tools/emulator/opengl/host/libs/libOpenglRender/RenderControl.cpp
index 9c973e9f6..c5097a4ab 100644
--- a/tools/emulator/opengl/host/libs/libOpenglRender/RenderControl.cpp
+++ b/tools/emulator/opengl/host/libs/libOpenglRender/RenderControl.cpp
@@ -224,13 +224,14 @@ static void rcDestroyColorBuffer(uint32_t colorbuffer)
     fb->DestroyColorBuffer( colorbuffer );
 }
 
-static void rcFlushWindowColorBuffer(uint32_t windowSurface)
+static int rcFlushWindowColorBuffer(uint32_t windowSurface)
 {
     FrameBuffer *fb = FrameBuffer::getFB();
     if (!fb) {
-        return;
+        return -1;
     }
     fb->flushWindowSurfaceColorBuffer(windowSurface);
+    return 0;
 }
 
 static void rcSetWindowColorBuffer(uint32_t windowSurface,
@@ -296,17 +297,18 @@ static void rcReadColorBuffer(uint32_t colorBuffer,
    // XXX: TBD - should be implemented
 }
 
-static void rcUpdateColorBuffer(uint32_t colorBuffer,
+static int rcUpdateColorBuffer(uint32_t colorBuffer,
                                 GLint x, GLint y,
                                 GLint width, GLint height,
                                 GLenum format, GLenum type, void* pixels)
 {
     FrameBuffer *fb = FrameBuffer::getFB();
     if (!fb) {
-        return;
+        return -1;
     }
 
     fb->updateColorBuffer(colorBuffer, x, y, width, height, format, type, pixels);
+    return 0;
 }
 
 void initRenderControlContext(renderControl_decoder_context_t *dec)
diff --git a/tools/emulator/opengl/system/egl/egl.cpp b/tools/emulator/opengl/system/egl/egl.cpp
index 698aa842c..50fb2c56b 100644
--- a/tools/emulator/opengl/system/egl/egl.cpp
+++ b/tools/emulator/opengl/system/egl/egl.cpp
@@ -325,8 +325,12 @@ EGLBoolean egl_window_surface_t::connect()
     if (nativeWindow->dequeueBuffer(nativeWindow, &buffer) != NO_ERROR) {
         setErrorReturn(EGL_BAD_ALLOC, EGL_FALSE);
     }
+
     buffer->common.incRef(&buffer->common);
 
+    // lock the buffer
+    nativeWindow->lockBuffer(nativeWindow, buffer);
+
     DEFINE_AND_VALIDATE_HOST_CONNECTION(EGL_FALSE);
     rcEnc->rcSetWindowColorBuffer(rcEnc, rcSurface, ((cb_handle_t *)(buffer->handle))->hostHandle);
 
@@ -360,6 +364,9 @@ EGLBoolean egl_window_surface_t::swapBuffers()
         setErrorReturn(EGL_BAD_ALLOC, EGL_FALSE);
     }
 
+    // lock the buffer
+    nativeWindow->lockBuffer(nativeWindow, buffer);
+
     rcEnc->rcSetWindowColorBuffer(rcEnc, rcSurface, ((cb_handle_t *)(buffer->handle))->hostHandle);
 
     return EGL_TRUE;
diff --git a/tools/emulator/opengl/system/renderControl_enc/renderControl.in b/tools/emulator/opengl/system/renderControl_enc/renderControl.in
index 37a8e9013..9ee3d3f1e 100644
--- a/tools/emulator/opengl/system/renderControl_enc/renderControl.in
+++ b/tools/emulator/opengl/system/renderControl_enc/renderControl.in
@@ -13,11 +13,11 @@ GL_ENTRY(void, rcDestroyWindowSurface, uint32_t windowSurface)
 GL_ENTRY(uint32_t, rcCreateColorBuffer, uint32_t width, uint32_t height, GLenum internalFormat)
 GL_ENTRY(void, rcDestroyColorBuffer, uint32_t colorbuffer)
 GL_ENTRY(void, rcSetWindowColorBuffer, uint32_t windowSurface, uint32_t colorBuffer)
-GL_ENTRY(void, rcFlushWindowColorBuffer, uint32_t windowSurface)
+GL_ENTRY(int, rcFlushWindowColorBuffer, uint32_t windowSurface)
 GL_ENTRY(EGLint, rcMakeCurrent, uint32_t context, uint32_t drawSurf, uint32_t readSurf)
 GL_ENTRY(void, rcFBPost, uint32_t colorBuffer)
 GL_ENTRY(void, rcFBSetSwapInterval, EGLint interval)
 GL_ENTRY(void, rcBindTexture, uint32_t colorBuffer)
 GL_ENTRY(EGLint, rcColorBufferCacheFlush, uint32_t colorbuffer, EGLint postCount,int forRead)
 GL_ENTRY(void, rcReadColorBuffer, uint32_t colorbuffer, GLint x, GLint y, GLint width, GLint height, GLenum format, GLenum type, void *pixels)
-GL_ENTRY(void, rcUpdateColorBuffer, uint32_t colorbuffer, GLint x, GLint y, GLint width, GLint height, GLenum format, GLenum type, void *pixels)
+GL_ENTRY(int, rcUpdateColorBuffer, uint32_t colorbuffer, GLint x, GLint y, GLint width, GLint height, GLenum format, GLenum type, void *pixels)