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

Commit bd8a3539 authored by wilsonshih's avatar wilsonshih
Browse files

Implement a reference count for the REFERENCE_WRITE_TO_PARCEL flag. 

During the broadcast of a snapshot object to remote processes, a
writeToParcel operation is also performed. If this broadcast occurs
before the snapshot object is intended to be returned to a remote
process, the WRITE_TO_PARCEL reference flag becomes ambiguous.
To prevent the hardware buffer from being released too early, record
how many WRITE_TO_PARCEL operations are required for the snapshot
object. The flag is only removed when this count drops to zero.

Flag: EXEMPT bugfix
Bug: 412389050
Test: launch multiple apps and move they in the background. Repeatly
resume then close apps by swipe up gesture multiple times, verify the
broadcast occur after write_to_parcel(takeTaskSnapshot) flag removed.

Change-Id: I8a57993cb58d42350baf013443486a98c916f518
parent b3eb540d

core/java/android/window/TaskSnapshot.java

+9 −1
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ public class TaskSnapshot implements Parcelable { 
    // Must be one of the named color spaces, otherwise, always use SRGB color space.

    private final ColorSpace mColorSpace;

    private int mInternalReferences;

    private int mWriteToParcelCount;

    private Consumer<HardwareBuffer> mSafeSnapshotReleaser;



    /** Keep in cache, doesn't need reference. */
@@ -320,10 +321,13 @@ public class TaskSnapshot implements Parcelable { 
        dest.writeInt(mUiMode);

        synchronized (this) {

            if ((mInternalReferences & REFERENCE_WRITE_TO_PARCEL) != 0) {

                mWriteToParcelCount--;

                if (mWriteToParcelCount == 0) {

                    removeReference(REFERENCE_WRITE_TO_PARCEL);

                }

            }

        }

    }



    @Override

    public String toString() {
@@ -354,6 +358,7 @@ public class TaskSnapshot implements Parcelable { 
                + " mIsTranslucent=" + mIsTranslucent

                + " mHasImeSurface=" + mHasImeSurface

                + " mInternalReferences=" + mInternalReferences

                + " mWriteToParcelCount=" + mWriteToParcelCount

                + " mUiMode=" + Integer.toHexString(mUiMode);

    }
@@ -362,6 +367,9 @@ public class TaskSnapshot implements Parcelable { 
     * Only used in core.

     */

    public synchronized void addReference(@ReferenceFlags int usage) {

        if (usage == REFERENCE_WRITE_TO_PARCEL) {

            mWriteToParcelCount++;

        }

        mInternalReferences |= usage;

    }

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

+8 −2
Original line number Diff line number Diff line
@@ -64,7 +64,6 @@ class TaskChangeNotificationController { 
    private static final int NOTIFY_TASK_SNAPSHOT_INVALIDATED_LISTENERS_MSG = 29;

    private static final int NOTIFY_RECENT_TASK_REMOVED_FOR_ADD_TASK_LISTENERS_MSG = 30;





    // Delay in notifying task stack change listeners (in millis)

    private static final int NOTIFY_TASK_STACK_CHANGE_LISTENERS_DELAY = 100;
@@ -152,6 +151,13 @@ class TaskChangeNotificationController { 
    private final TaskStackConsumer mNotifyTaskSnapshotChanged = (l, m) -> {

        l.onTaskSnapshotChanged(m.arg1, (TaskSnapshot) m.obj);

    };



    private final TaskStackConsumer mNotifyTaskSnapshotChangedRemote = (l, m) -> {

        final TaskSnapshot taskSnapshot = (TaskSnapshot) m.obj;

        taskSnapshot.addReference(TaskSnapshot.REFERENCE_WRITE_TO_PARCEL);

        l.onTaskSnapshotChanged(m.arg1, taskSnapshot);

    };



    private final TaskStackConsumer mNotifyTaskSnapshotInvalidated = (l, m) -> {

        l.onTaskSnapshotInvalidated(m.arg1);

    };
@@ -251,7 +257,7 @@ class TaskChangeNotificationController { 
                    forAllRemoteListeners(mNotifyTaskProfileLocked, msg);

                    break;

                case NOTIFY_TASK_SNAPSHOT_CHANGED_LISTENERS_MSG:

                    forAllRemoteListeners(mNotifyTaskSnapshotChanged, msg);

                    forAllRemoteListeners(mNotifyTaskSnapshotChangedRemote, msg);

                    ((TaskSnapshot) msg.obj).removeReference(TaskSnapshot.REFERENCE_BROADCAST);

                    break;

                case NOTIFY_BACK_PRESSED_ON_TASK_ROOT: