From 9707f4df640c3369f873a934bb05ffa5a68a5640 Mon Sep 17 00:00:00 2001
From: Riley Andrews <riandrews@google.com>
Date: Thu, 23 Oct 2014 16:17:04 -0700
Subject: [PATCH] Add glFlush in surfaceflinger screenshot code.

After creating a syncKHR object with type EGL_SYNC_NATIVE_FENCE_ANDROID,
glFlush must be called before the EGL_SYNC_NATIVE_FENCE_FD_ANDROID attribute
is populated with a sync fd. We currently call eglDupNativeFenceFDANDROID
before issuing the flush.

Bug 18052459
Taken verbatim from matthew.k.gumbel@intel.com.

Change-Id: I3781d14f92862076e2bca7d27341a6dc6e7e3775
---
 services/surfaceflinger/RenderEngine/RenderEngine.cpp | 4 ++++
 services/surfaceflinger/RenderEngine/RenderEngine.h   | 1 +
 services/surfaceflinger/SurfaceFlinger.cpp            | 2 ++
 3 files changed, 7 insertions(+)

diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.cpp b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
index d5d5da8fc..a77e0e9d2 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
@@ -219,6 +219,10 @@ void RenderEngine::fillRegionWithColor(const Region& region, uint32_t height,
     drawMesh(mesh);
 }
 
+void RenderEngine::flush() {
+    glFlush();
+}
+
 void RenderEngine::clearWithColor(float red, float green, float blue, float alpha) {
     glClearColor(red, green, blue, alpha);
     glClear(GL_COLOR_BUFFER_BIT);
diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.h b/services/surfaceflinger/RenderEngine/RenderEngine.h
index acbff9b5a..8d7529cb3 100644
--- a/services/surfaceflinger/RenderEngine/RenderEngine.h
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.h
@@ -67,6 +67,7 @@ public:
     virtual void dump(String8& result);
 
     // helpers
+    void flush();
     void clearWithColor(float red, float green, float blue, float alpha);
     void fillRegionWithColor(const Region& region, uint32_t height,
             float red, float green, float blue, float alpha);
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 96a8adbaf..50968e793 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3201,6 +3201,8 @@ status_t SurfaceFlinger::captureScreenImplLocked(
                         EGLSyncKHR sync;
                         if (!DEBUG_SCREENSHOTS) {
                            sync = eglCreateSyncKHR(mEGLDisplay, EGL_SYNC_NATIVE_FENCE_ANDROID, NULL);
+                           // native fence fd will not be populated until flush() is done.
+                           getRenderEngine().flush();
                         } else {
                             sync = EGL_NO_SYNC_KHR;
                         }