Improve eglSwapBuffers error handling.

We now distinguish EGL_CONTEXT_LOST errors from
other kinds of errors. We return "true" if
the swap completes successfully, "false" if
the swap fails due to EGL_CONTEXT_LOST, and
throw a RuntimeException if the swap fails due
to any other cause.

If eglSwapBuffers succeeds, we now avoid calling
eglGetError at all, which means we avoid clearing
any EGL errors that might already have been
pending before eglSwapBuffers is called.

1 files changed, 20 insertions, 9 deletions

diff --git a/opengl/java/android/opengl/GLSurfaceView.java b/opengl/java/android/opengl/GLSurfaceView.java
index 882cbc5..3f029a6 100644
--- a/opengl/java/android/opengl/GLSurfaceView.java
+++ b/opengl/java/android/opengl/GLSurfaceView.java
@@ -977,15 +977,22 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
          * @return false if the context has been lost.
          */
         public boolean swap() {
-            mEgl.eglSwapBuffers(mEglDisplay, mEglSurface);
+            if (! mEgl.eglSwapBuffers(mEglDisplay, mEglSurface)) {
 
-            /*
-             * Always check for EGL_CONTEXT_LOST, which means the context
-             * and all associated data were lost (For instance because
-             * the device went to sleep). We need to sleep until we
-             * get a new surface.
-             */
-            return mEgl.eglGetError() != EGL11.EGL_CONTEXT_LOST;
+                /*
+                 * Check for EGL_CONTEXT_LOST, which means the context
+                 * and all associated data were lost (For instance because
+                 * the device went to sleep). We need to sleep until we
+                 * get a new surface.
+                 */
+                int error = mEgl.eglGetError();
+                if (error == EGL11.EGL_CONTEXT_LOST) {
+                    return false;
+                } else {
+                    throwEglException("eglSwapBuffers", error);
+                }
+            }
+            return true;
         }
 
         public void destroySurface() {
@@ -1010,7 +1017,11 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
         }
 
         private void throwEglException(String function) {
-            throw new RuntimeException(function + " failed: " + mEgl.eglGetError());
+            throwEglException(function, mEgl.eglGetError());
+        }
+
+        private void throwEglException(String function, int error) {
+            throw new RuntimeException(function + " failed: " + error);
         }
 
         EGL10 mEgl;