emulator opengl: guest/host rendering syncronization.

Added a return value for rcFlushWindowColorBuffer and
rcUpdateColorBuffer in order to make those calls to block
with a round-trip to the host. This is to make sure that
the color buffer is up-to-date before the flinger use it
for rendering.
Also added a call to the native windows's lock function after
EGL is attached and bound to render on the window. This call
was missed before.

This syncronization can be optimized by removing the round-trip
and insert sync primitive to the stream at every draw command that
reads from a color buffer to make the sync happen on the host
before rendering the color buffer and remove the need for the
guest to wait for that update.

Change-Id: I1c2d8bc407b69663e992a68d5aa755f19bbe0ec3

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)

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;

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)