Merge "[sf] Release the currently presented buffer when setBuffer is called with null" into udc-dev

core/java/android/view/SurfaceControl.java

@@ -220,6 +220,7 @@ public final class SurfaceControl implements Parcelable {
             long newParentNativeObject);
     private static native void nativeSetBuffer(long transactionObj, long nativeObject,
             HardwareBuffer buffer, long fencePtr, Consumer<SyncFence> releaseCallback);
+    private static native void nativeUnsetBuffer(long transactionObj, long nativeObject);
     private static native void nativeSetBufferTransform(long transactionObj, long nativeObject,
             int transform);
     private static native void nativeSetDataSpace(long transactionObj, long nativeObject,
@@ -3663,6 +3664,22 @@ public final class SurfaceControl implements Parcelable {
             return setBuffer(sc, buffer, null);
         }
 
+        /**
+         * Unsets the buffer for the SurfaceControl in the current Transaction. This will not clear
+         * the buffer being rendered, but resets the buffer state in the Transaction only. The call
+         * will also invoke the release callback.
+         *
+         * Note, this call is different from passing a null buffer to
+         * {@link SurfaceControl.Transaction#setBuffer} which will release the last displayed
+         * buffer.
+         *
+         * @hide
+         */
+        public Transaction unsetBuffer(SurfaceControl sc) {
+            nativeUnsetBuffer(mNativeObject, sc.mNativeObject);
+            return this;
+        }
+
         /**
          * Updates the HardwareBuffer displayed for the SurfaceControl.
          *
@@ -3682,7 +3699,8 @@ public final class SurfaceControl implements Parcelable {
          * until all presentation fences have signaled, ensuring the transaction remains consistent.
          *
          * @param sc The SurfaceControl to update
-         * @param buffer The buffer to be displayed
+         * @param buffer The buffer to be displayed. Pass in a null buffer to release the last
+         * displayed buffer.
          * @param fence The presentation fence. If null or invalid, this is equivalent to
          *              {@link #setBuffer(SurfaceControl, HardwareBuffer)}
          * @return this

core/jni/android_view_SurfaceControl.cpp

@@ -616,6 +616,12 @@ static void nativeSetBuffer(JNIEnv* env, jclass clazz, jlong transactionObj, jlo
                            genReleaseCallback(env, releaseCallback));
 }
 
+static void nativeUnsetBuffer(JNIEnv* env, jclass clazz, jlong transactionObj, jlong nativeObject) {
+    auto transaction = reinterpret_cast<SurfaceComposerClient::Transaction*>(transactionObj);
+    SurfaceControl* const ctrl = reinterpret_cast<SurfaceControl*>(nativeObject);
+    transaction->unsetBuffer(ctrl);
+}
+
 static void nativeSetBufferTransform(JNIEnv* env, jclass clazz, jlong transactionObj,
                                      jlong nativeObject, jint transform) {
     auto transaction = reinterpret_cast<SurfaceComposerClient::Transaction*>(transactionObj);
@@ -2198,6 +2204,8 @@ static const JNINativeMethod sSurfaceControlMethods[] = {
             (void*)nativeSetGeometry },
     {"nativeSetBuffer", "(JJLandroid/hardware/HardwareBuffer;JLjava/util/function/Consumer;)V",
             (void*)nativeSetBuffer },
+    {"nativeUnsetBuffer", "(JJ)V", (void*)nativeUnsetBuffer },
+
     {"nativeSetBufferTransform", "(JJI)V", (void*) nativeSetBufferTransform},
     {"nativeSetDataSpace", "(JJI)V",
             (void*)nativeSetDataSpace },

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

@@ -5634,7 +5634,7 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
     private void dropBufferFrom(Transaction t) {
         SurfaceControl viewSurface = getClientViewRootSurface();
         if (viewSurface == null) return;
-        t.setBuffer(viewSurface, (android.hardware.HardwareBuffer) null);
+        t.unsetBuffer(viewSurface);
     }
 
     @Override