Canvas: trying to use a recycled bitmap android.graphics.Bitmap

Question

11-24 23:19:18.434: ERROR/AndroidRuntime(12660): Uncaught handler: thread main exiting due to uncaught exception
11-24 23:19:18.684: ERROR/AndroidRuntime(12660): java.lang.RuntimeException: Canvas: trying to use a recycled bitmap android.graphics.Bitmap@4384c218
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.graphics.Canvas.throwIfRecycled(Canvas.java:955)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.graphics.Canvas.drawBitmap(Canvas.java:1044)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.graphics.drawable.BitmapDrawable.draw(BitmapDrawable.java:291)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.widget.ImageView.onDraw(ImageView.java:908)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.View.draw(View.java:6283)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1581)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1579)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.View.draw(View.java:6286)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1581)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.widget.AbsListView.dispatchDraw(AbsListView.java:1323)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.widget.ListView.dispatchDraw(ListView.java:2933)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.View.draw(View.java:6389)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at         android.widget.AbsListView.draw(AbsListView.java:2142)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1581)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1579)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at     android.view.View.draw(View.java:6286)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1581)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.View.draw(View.java:6286)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.widget.FrameLayout.draw(FrameLayout.java:352)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewGroup.drawChild(ViewGroup.java:1581)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at     android.view.ViewGroup.dispatchDraw(ViewGroup.java:1311)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.View.draw(View.java:6286)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.widget.FrameLayout.draw(FrameLayout.java:352)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1928)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewRoot.draw(ViewRoot.java:1454)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewRoot.performTraversals(ViewRoot.java:1174)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1774)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.os.Looper.loop(Looper.java:123)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at android.app.ActivityThread.main(ActivityThread.java:4321)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at java.lang.reflect.Method.invokeNative(Native Method)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at java.lang.reflect.Method.invoke(Method.java:521)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
11-24 23:19:18.684: ERROR/AndroidRuntime(12660):     at dalvik.system.NativeStart.main(Native Method)

I implemented an image cache with SoftReference and set an ImageView with a Bitmap from the image cache.

I do not use Bitmap.recycle() and check the Bitmap.isRcycled() before setting the bitmap to an ImageView.

I can not figure out why the canvas is drawing with a recycled bitmap. It happens rarely but it does happened.

Any suggestion? Thanks!

Answer 1

If anyone ever gets here and is struggling to figure out which Bitmap is recycled (like I did), here's what I ended up doing to troubleshoot this:
1) I placed a global Thread.setDefaultUncaughtExceptionHandler which dumps the heap (I actually already had it in place to diagnose OOM errors). The code inside the handler is this:

File f = new File(Environment.getExternalStorageDirectory(),"oom-error.hprof");
String path = f.getAbsolutePath();
// force a few GC before dumping stuff
System.gc();
System.gc();    
Debug.dumpHprofData(path);

2) Using this great article, you can learn how to then load up and analyze the hprof dump file using MAT.

3) Inside the MAT, I first filtered classes by "Bitmap" regex, and then looked for the Bitmap reference id (in OP case: "4384c218"). This will give you a pretty good idea which view is holding this recycled bitmap and you can start thinking of the solution for it. (In my case, I was recycling images from a common cache, some of which were drawables that were also used in XML layouts and should have been "pinned" to the cache until OnDestroy).