SurfaceTexture: fix a couple tests

This change fixes some robustness issues with the
EglDestroySurfaceUnrefsBuffers and
EglDestroySurfaceAfterAbandonUnrefsBuffers tests.  The tests previously
depended upon GL implementation details that should not have been relied
upon.

Change-Id: I37fd43b56568efe1dbe69d85e892be8a1cf44d20

Author: Jamie Gennis

libs/gui/tests/SurfaceTexture_test.cpp

@@ -1176,6 +1176,13 @@ TEST_F(SurfaceTextureGLToGLTest, TexturingFromGLFilledRGBABufferPow2) {
 TEST_F(SurfaceTextureGLToGLTest, EglDestroySurfaceUnrefsBuffers) {
     sp<GraphicBuffer> buffers[3];
 
+    // This test requires async mode to run on a single thread.
+    EXPECT_TRUE(eglMakeCurrent(mEglDisplay, mProducerEglSurface,
+            mProducerEglSurface, mProducerEglContext));
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+    EXPECT_TRUE(eglSwapInterval(mEglDisplay, 0));
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+
     for (int i = 0; i < 3; i++) {
         // Produce a frame
         EXPECT_TRUE(eglMakeCurrent(mEglDisplay, mProducerEglSurface,
@@ -1205,12 +1212,25 @@ TEST_F(SurfaceTextureGLToGLTest, EglDestroySurfaceUnrefsBuffers) {
 
     EXPECT_EQ(1, buffers[0]->getStrongCount());
     EXPECT_EQ(1, buffers[1]->getStrongCount());
-    EXPECT_EQ(1, buffers[2]->getStrongCount());
+
+    // Depending on how lazily the GL driver dequeues buffers, we may end up
+    // with either two or three total buffers.  If there are three, make sure
+    // the last one was properly down-ref'd.
+    if (buffers[2] != buffers[0]) {
+        EXPECT_EQ(1, buffers[2]->getStrongCount());
+    }
 }
 
 TEST_F(SurfaceTextureGLToGLTest, EglDestroySurfaceAfterAbandonUnrefsBuffers) {
     sp<GraphicBuffer> buffers[3];
 
+    // This test requires async mode to run on a single thread.
+    EXPECT_TRUE(eglMakeCurrent(mEglDisplay, mProducerEglSurface,
+            mProducerEglSurface, mProducerEglContext));
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+    EXPECT_TRUE(eglSwapInterval(mEglDisplay, 0));
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+
     for (int i = 0; i < 3; i++) {
         // Produce a frame
         EXPECT_TRUE(eglMakeCurrent(mEglDisplay, mProducerEglSurface,
@@ -1242,7 +1262,13 @@ TEST_F(SurfaceTextureGLToGLTest, EglDestroySurfaceAfterAbandonUnrefsBuffers) {
 
     EXPECT_EQ(1, buffers[0]->getStrongCount());
     EXPECT_EQ(1, buffers[1]->getStrongCount());
-    EXPECT_EQ(1, buffers[2]->getStrongCount());
+
+    // Depending on how lazily the GL driver dequeues buffers, we may end up
+    // with either two or three total buffers.  If there are three, make sure
+    // the last one was properly down-ref'd.
+    if (buffers[2] != buffers[0]) {
+        EXPECT_EQ(1, buffers[2]->getStrongCount());
+    }
 }
 
 TEST_F(SurfaceTextureGLToGLTest, EglSurfaceDefaultsToSynchronousMode) {