Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0ba5c6dd authored by Fengjiang Li's avatar Fengjiang Li
Browse files

[Memory Leak] Avoid false-positive leak detection of TaskbarActivityContext... 

[Memory Leak] Avoid false-positive leak detection of TaskbarActivityContext via RotationButtonController's IRotationWatcher.Stub

Binder obj's lifecycle depends on remote process's GC and there is no
way for leak canary to coordinate with remote process's GC to watch
obj's lifecycle. Thus we explicitly clear the ref to host obj when
unregister IRotationWatcher.Stub.

In addition, user can rotate screen frequently and accumulate a few
IRotationWatcher.Stub and TaskbarActivityContext. These obj awaits
remote process's GC to be GCed from Launcher. This CL allows GC
these expensive objs earlier and should lower HWM memory usage.

Fix: 434032994
Flag: NONE - released code
Test: manual
Change-Id: Iadb6e0af4a63117294db5cb099ec06cfaab40761
parent 4b03c792

packages/SystemUI/shared/src/com/android/systemui/shared/rotation/RotationButtonController.java

+40 −5
Original line number Diff line number Diff line
@@ -27,8 +27,10 @@ import static com.android.systemui.shared.system.QuickStepContract.isGesturalMod 
import android.animation.Animator;

import android.animation.AnimatorListenerAdapter;

import android.animation.ObjectAnimator;

import android.annotation.AnyThread;

import android.annotation.ColorInt;

import android.annotation.DrawableRes;

import android.annotation.NonNull;

import android.annotation.SuppressLint;

import android.app.StatusBarManager;

import android.content.BroadcastReceiver;
@@ -150,18 +152,50 @@ public class RotationButtonController { 
        }

    };



    private final IRotationWatcher.Stub mRotationWatcher = new IRotationWatcher.Stub() {



    /**

     * {@link IRotationWatcher.Stub} that wraps {@link RotationButtonController} as host obj and

     * allow clearing it so that:

     * 1. Client process (like Launcher) doesn't accumulate expensive {@link #mContext} objects

     * (in a series of frequent screen rotations) which cannot be GCed until remote process runs GC

     * to clear the binder objects. This will reduce the high water mark memory usage for client

     * process.

     * 2. Leak canary in client process (like Launcher) doesn't raise false positive alarms.

     */

    private static class RotationWatcher extends IRotationWatcher.Stub {

        private @Nullable RotationButtonController mHost;



        private RotationWatcher(@NonNull RotationButtonController host) {

            mHost = host;

        }



        @WorkerThread

        @Override

        public void onRotationChanged(final int rotation) {

            @Nullable Boolean rotationLocked = RotationPolicyUtil.isRotationLocked(mContext);

            RotationButtonController host = mHost;

            if (host == null) {

                return;

            }

            Boolean rotationLocked = RotationPolicyUtil.isRotationLocked(host.mContext);

            // We need this to be scheduled as early as possible to beat the redrawing of

            // window in response to the orientation change.

            mMainThreadHandler.postAtFrontOfQueue(() -> {

                onRotationWatcherChanged(rotation, rotationLocked);

            host.mMainThreadHandler.postAtFrontOfQueue(() -> {

                host.onRotationWatcherChanged(rotation, rotationLocked);

            });

        }

    };



        /**

         * Since the lifecycle of this binder obj depends on remote process's GC, calling this

         * method will allow local process GC {@link mHost} earlier, and also avoid false positive

         * leak signal from leak canary.

         */

        @AnyThread

        private void clearHost() {

            mHost = null;

        }

    }



    private final RotationWatcher mRotationWatcher = new RotationWatcher(this);



    /**

     * Determines if rotation suggestions disabled2 flag exists in flag
@@ -292,6 +326,7 @@ public class RotationButtonController { 
                try {

                    WindowManagerGlobal.getWindowManagerService().removeRotationWatcher(

                            mRotationWatcher);

                    mRotationWatcher.clearHost();

                } catch (RemoteException e) {

                    Log.e(TAG, "UnregisterListeners caught a RemoteException", e);

                }