Merge "Force pending transactions to flush before screenshot." into nyc-dev

core/java/android/view/SurfaceControl.java

@@ -46,7 +46,7 @@ public class SurfaceControl {
             boolean allLayers, boolean useIdentityTransform);
 
     private static native void nativeOpenTransaction();
-    private static native void nativeCloseTransaction();
+    private static native void nativeCloseTransaction(boolean sync);
     private static native void nativeSetAnimationTransaction();
 
     private static native void nativeSetLayer(long nativeObject, int zorder);
@@ -372,7 +372,11 @@ public class SurfaceControl {
 
     /** end a transaction */
     public static void closeTransaction() {
-        nativeCloseTransaction();
+        nativeCloseTransaction(false);
+    }
+
+    public static void closeTransactionSync() {
+        nativeCloseTransaction(true);
     }
 
     public void deferTransactionUntil(IBinder handle, long frame) {

core/jni/android_view_SurfaceControl.cpp

@@ -223,8 +223,9 @@ static void nativeOpenTransaction(JNIEnv* env, jclass clazz) {
     SurfaceComposerClient::openGlobalTransaction();
 }
 
-static void nativeCloseTransaction(JNIEnv* env, jclass clazz) {
-    SurfaceComposerClient::closeGlobalTransaction();
+
+static void nativeCloseTransaction(JNIEnv* env, jclass clazz, jboolean sync) {
+    SurfaceComposerClient::closeGlobalTransaction(sync);
 }
 
 static void nativeSetAnimationTransaction(JNIEnv* env, jclass clazz) {
@@ -649,7 +650,7 @@ static const JNINativeMethod sSurfaceControlMethods[] = {
             (void*)nativeScreenshot },
     {"nativeOpenTransaction", "()V",
             (void*)nativeOpenTransaction },
-    {"nativeCloseTransaction", "()V",
+    {"nativeCloseTransaction", "(Z)V",
             (void*)nativeCloseTransaction },
     {"nativeSetAnimationTransaction", "()V",
             (void*)nativeSetAnimationTransaction },

services/core/java/com/android/server/wm/WindowManagerService.java

@@ -6386,6 +6386,11 @@ public class WindowManagerService extends IWindowManager.Stub
             if (DEBUG_SCREENSHOT && inRotation) Slog.v(TAG_WM,
                     "Taking screenshot while rotating");
 
+            // We force pending transactions to flush before taking
+            // the screenshot by pushing an empty synchronous transaction.
+            SurfaceControl.openTransaction();
+            SurfaceControl.closeTransactionSync();
+
             bm = SurfaceControl.screenshot(crop, width, height, minLayer, maxLayer,
                     inRotation, rot);
             if (bm == null) {