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Commit f574b479 authored by Jesse Hall's avatar Jesse Hall Committed by The Android Automerger
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Fix ImageReader onImageAvailable synchronization 

This avoids a race where close() can return while there are still
onImageAvailable callbacks pending.

Bug: 10666923
Change-Id: Ic519b68f3132ceb7f95a9a42ebd1032c1638fbf5
parent a68bf416

media/java/android/media/ImageReader.java

+49 −19
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ import android.graphics.ImageFormat; 
import android.graphics.PixelFormat;

import android.os.Handler;

import android.os.Looper;

import android.os.Message;

import android.view.Surface;



import java.lang.ref.WeakReference;
@@ -378,16 +379,20 @@ public class ImageReader implements AutoCloseable { 
     *            If no handler specified and the calling thread has no looper.

     */

    public void setOnImageAvailableListener(OnImageAvailableListener listener, Handler handler) {

        mImageListener = listener;



        Looper looper;

        mHandler = handler;

        if (listener != null && mHandler == null) {

            if ((looper = Looper.myLooper()) != null) {

                mHandler = new Handler();

            } else {

        synchronized (mListenerLock) {

            if (listener != null) {

                Looper looper = handler != null ? handler.getLooper() : Looper.myLooper();

                if (looper == null) {

                    throw new IllegalArgumentException(

                        "Looper doesn't exist in the calling thread");

                            "handler is null but the current thread is not a looper");

                }

                if (mListenerHandler == null || mListenerHandler.getLooper() != looper) {

                    mListenerHandler = new ListenerHandler(looper);

                }

                mListener = listener;

            } else {

                mListener = null;

                mListenerHandler = null;

            }

        }

    }
@@ -426,6 +431,7 @@ public class ImageReader implements AutoCloseable { 
     */

    @Override

    public void close() {

        setOnImageAvailableListener(null, null);

        nativeClose();

    }
@@ -474,6 +480,9 @@ public class ImageReader implements AutoCloseable { 


    /**

     * Called from Native code when an Event happens.

     *

     * This may be called from an arbitrary Binder thread, so access to the ImageReader must be

     * synchronized appropriately.

     */

    private static void postEventFromNative(Object selfRef) {

        @SuppressWarnings("unchecked")
@@ -483,16 +492,16 @@ public class ImageReader implements AutoCloseable { 
            return;

        }



        if (ir.mHandler != null && ir.mImageListener != null) {

            ir.mHandler.post(new Runnable() {

                @Override

                public void run() {

                    ir.mImageListener.onImageAvailable(ir);

        final Handler handler;

        synchronized (ir.mListenerLock) {

            handler = ir.mListenerHandler;

        }

              });

        if (handler != null) {

            handler.sendEmptyMessage(0);

        }

    }





    private final int mWidth;

    private final int mHeight;

    private final int mFormat;
@@ -500,14 +509,35 @@ public class ImageReader implements AutoCloseable { 
    private final int mNumPlanes;

    private final Surface mSurface;



    private Handler mHandler;

    private OnImageAvailableListener mImageListener;

    private final Object mListenerLock = new Object();

    private OnImageAvailableListener mListener;

    private ListenerHandler mListenerHandler;



    /**

     * This field is used by native code, do not access or modify.

     */

    private long mNativeContext;



    /**

     * This custom handler runs asynchronously so callbacks don't get queued behind UI messages.

     */

    private final class ListenerHandler extends Handler {

        public ListenerHandler(Looper looper) {

            super(looper, null, true /*async*/);

        }



        @Override

        public void handleMessage(Message msg) {

            OnImageAvailableListener listener;

            synchronized (mListenerLock) {

                listener = mListener;

            }

            if (listener != null) {

                listener.onImageAvailable(ImageReader.this);

            }

        }

    }



    private class SurfaceImage extends android.media.Image {

        public SurfaceImage() {

            mIsImageValid = false;