Restore buildLayer()'s old behavior; it's synchronous again

Bug #9193833

Change-Id: I4ee07e65c0a8967f0b55da030ecaad6dfc46136f

3 files changed, 128 insertions, 0 deletions

diff --git a/libs/hwui/Fence.h b/libs/hwui/Fence.h
new file mode 100644
index 0000000..f175e98
--- /dev/null
+++ b/libs/hwui/Fence.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HWUI_FENCE_H
+#define ANDROID_HWUI_FENCE_H
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+namespace android {
+namespace uirenderer {
+
+/**
+ * Creating a Fence instance inserts a new sync fence in the OpenGL
+ * commands stream. The caller can then wait for the fence to be signaled
+ * by calling the wait method.
+ */
+class Fence {
+public:
+    enum {
+        /**
+         * Default timeout in nano-seconds for wait()
+         */
+        kDefaultTimeout = 1000000000
+    };
+
+    /**
+     * Inserts a new sync fence in the OpenGL commands stream.
+     */
+    Fence() {
+        mDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+        if (mDisplay != EGL_NO_DISPLAY) {
+            mFence = eglCreateSyncKHR(mDisplay, EGL_SYNC_FENCE_KHR, NULL);
+        } else {
+            mFence = EGL_NO_SYNC_KHR;
+        }
+    }
+
+    /**
+     * Destroys the fence. Any caller waiting on the fence will be
+     * signaled immediately.
+     */
+    ~Fence() {
+        if (mFence != EGL_NO_SYNC_KHR) {
+            eglDestroySyncKHR(mDisplay, mFence);
+        }
+    }
+
+    /**
+     * Blocks the calling thread until this fence is signaled, or until
+     * <timeout> nanoseconds have passed.
+     *
+     * Returns true if waiting for the fence was successful, false if
+     * a timeout or an error occurred.
+     */
+    bool wait(EGLTimeKHR timeout = kDefaultTimeout) {
+        EGLint waitStatus = eglClientWaitSyncKHR(mDisplay, mFence,
+                EGL_SYNC_FLUSH_COMMANDS_BIT_KHR, timeout);
+        if (waitStatus == EGL_FALSE) {
+            ALOGW("Failed to wait for the fence %#x", eglGetError());
+        }
+        return waitStatus == EGL_CONDITION_SATISFIED_KHR;
+    }
+
+private:
+    EGLDisplay mDisplay;
+    EGLSyncKHR mFence;
+
+}; // class Fence
+
+/**
+ * An AutoFence creates a Fence instance and waits for the fence
+ * to be signaled when the AutoFence is destroyed. This is useful
+ * to automatically wait for a series of OpenGL commands to be
+ * executed. For example:
+ *
+ * void drawAndWait() {
+ *     glDrawElements();
+ *     AutoFence fence;
+ * }
+ */
+class AutoFence {
+public:
+    AutoFence(EGLTimeKHR timeout = Fence::kDefaultTimeout): mTimeout(timeout) {
+    }
+
+    ~AutoFence() {
+        mFence.wait(mTimeout);
+    }
+
+private:
+    EGLTimeKHR mTimeout;
+    Fence mFence;
+
+}; // class AutoFence
+
+}; // namespace uirenderer
+}; // namespace android
+
+#endif // ANDROID_HWUI_FENCE_H
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index d95a62c..fa1eb97 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -33,6 +33,7 @@
 #include "OpenGLRenderer.h"
 #include "DeferredDisplayList.h"
 #include "DisplayListRenderer.h"
+#include "Fence.h"
 #include "PathTessellator.h"
 #include "Properties.h"
 #include "Vector.h"
@@ -552,6 +553,8 @@ void OpenGLRenderer::countOverdraw() {
 bool OpenGLRenderer::updateLayer(Layer* layer, bool inFrame) {
     if (layer->deferredUpdateScheduled && layer->renderer &&
             layer->displayList && layer->displayList->isRenderable()) {
+        ATRACE_CALL();
+
         Rect& dirty = layer->dirtyRect;
 
         if (inFrame) {
@@ -619,8 +622,11 @@ void OpenGLRenderer::flushLayers() {
             sprintf(layerName, "Layer #%d", i);
             startMark(layerName);
 
+            ATRACE_BEGIN("flushLayer");
             Layer* layer = mLayerUpdates.itemAt(i);
             layer->flush();
+            ATRACE_END();
+
             mCaches.resourceCache.decrementRefcount(layer);
 
             endMark();
@@ -661,6 +667,14 @@ void OpenGLRenderer::clearLayerUpdates() {
     }
 }
 
+void OpenGLRenderer::flushLayerUpdates() {
+    syncState();
+    updateLayers();
+    flushLayers();
+    // Wait for all the layer updates to be executed
+    AutoFence fence;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // State management
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/libs/hwui/OpenGLRenderer.h b/libs/hwui/OpenGLRenderer.h
index ce4ce42..1ab493c 100644
--- a/libs/hwui/OpenGLRenderer.h
+++ b/libs/hwui/OpenGLRenderer.h
@@ -208,6 +208,7 @@ public:
 
     ANDROID_API void pushLayerUpdate(Layer* layer);
     ANDROID_API void clearLayerUpdates();
+    ANDROID_API void flushLayerUpdates();
 
     ANDROID_API int getSaveCount() const;
     virtual int save(int flags);