fixes bumptech#738: Add optional threading lock for bitmap manipulati…

…on (affects only Moto X 2nd gen on api 22)

this addresses a threading bug on this specific device, the bug manifests itself by displaying
black images instead of resized images.

library/src/main/java/com/bumptech/glide/load/resource/bitmap/Downsampler.java

@@ -400,17 +400,19 @@ private static Bitmap decodeStream(InputStream is, BitmapFactory.Options options
     int sourceHeight = options.outHeight;
     String outMimeType = options.outMimeType;
     final Bitmap result;
+    TransformationUtils.getBitmapDrawableLock().lock();
     try {
       result = BitmapFactory.decodeStream(is, null, options);
     } catch (IllegalArgumentException e) {
       throw newIoExceptionForInBitmapAssertion(e, sourceWidth, sourceHeight, outMimeType, options);
+    } finally {
+      TransformationUtils.getBitmapDrawableLock().unlock();
     }
 
     if (options.inJustDecodeBounds) {
       is.reset();
 
     }
-
     return result;
   }
 

library/src/main/java/com/bumptech/glide/load/resource/bitmap/TransformationUtils.java

@@ -20,6 +20,11 @@
 import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
 import com.bumptech.glide.util.Preconditions;
 
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
 /**
  * A class with methods to efficiently resize Bitmaps.
  */
@@ -30,6 +35,11 @@ public final class TransformationUtils {
   private static final int CIRCLE_CROP_PAINT_FLAGS = PAINT_FLAGS | Paint.ANTI_ALIAS_FLAG;
   private static final Paint CIRCLE_CROP_SHAPE_PAINT = new Paint(CIRCLE_CROP_PAINT_FLAGS);
   private static final Paint CIRCLE_CROP_BITMAP_PAINT;
+  private static final Lock BITMAP_DRAWABLE_LOCK = "XT1097".equals(Build.MODEL)
+      && Build.VERSION.SDK_INT == Build.VERSION_CODES.LOLLIPOP_MR1
+      ? new ReentrantLock()
+      : new NoLock();
+
   static {
     CIRCLE_CROP_BITMAP_PAINT = new Paint(CIRCLE_CROP_PAINT_FLAGS);
     CIRCLE_CROP_BITMAP_PAINT.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
@@ -39,6 +49,11 @@ private TransformationUtils() {
     // Utility class.
   }
 
+
+  public static Lock getBitmapDrawableLock() {
+    return BITMAP_DRAWABLE_LOCK;
+  }
+
   /**
    * A potentially expensive operation to crop the given Bitmap so that it fills the given
    * dimensions. This operation is significantly less expensive in terms of memory if a mutable
@@ -74,9 +89,7 @@ public static Bitmap centerCrop(@NonNull BitmapPool pool, @NonNull Bitmap inBitm
     // We don't add or remove alpha, so keep the alpha setting of the Bitmap we were given.
     TransformationUtils.setAlpha(inBitmap, result);
 
-    Canvas canvas = new Canvas(result);
-    canvas.drawBitmap(inBitmap, m, DEFAULT_PAINT);
-    clear(canvas);
+    applyMatrix(inBitmap, result, m);
     return result;
   }
 
@@ -129,11 +142,9 @@ public static Bitmap fitCenter(@NonNull BitmapPool pool, @NonNull Bitmap inBitma
       Log.v(TAG, "minPct:   " + minPercentage);
     }
 
-    Canvas canvas = new Canvas(toReuse);
     Matrix matrix = new Matrix();
     matrix.setScale(minPercentage, minPercentage);
-    canvas.drawBitmap(inBitmap, matrix, DEFAULT_PAINT);
-    clear(canvas);
+    applyMatrix(inBitmap, toReuse, matrix);
 
     return toReuse;
   }
@@ -240,10 +251,7 @@ public static Bitmap rotateImageExif(@NonNull BitmapPool pool, @NonNull Bitmap i
 
     matrix.postTranslate(-newRect.left, -newRect.top);
 
-    final Canvas canvas = new Canvas(result);
-    canvas.drawBitmap(inBitmap, matrix, DEFAULT_PAINT);
-    clear(canvas);
-
+    applyMatrix(inBitmap, result, matrix);
     return result;
   }
 
@@ -275,15 +283,20 @@ public static Bitmap circleCrop(@NonNull BitmapPool pool, @NonNull Bitmap inBitm
 
     Bitmap result = pool.get(destWidth, destHeight, getSafeConfig(toTransform));
     setAlphaIfAvailable(result, true /*hasAlpha*/);
-    Canvas canvas = new Canvas(result);
 
-    // Draw a circle
-    canvas.drawCircle(destRect.left + radius, destRect.top + radius, radius,
-        CIRCLE_CROP_SHAPE_PAINT);
 
-    // Draw the bitmap in the circle
-    canvas.drawBitmap(toTransform, srcRect, destRect, CIRCLE_CROP_BITMAP_PAINT);
-    clear(canvas);
+    TransformationUtils.getBitmapDrawableLock().lock();
+    try {
+      Canvas canvas = new Canvas(result);
+      // Draw a circle
+      canvas.drawCircle(destRect.left + radius, destRect.top + radius, radius,
+          CIRCLE_CROP_SHAPE_PAINT);
+      // Draw the bitmap in the circle
+      canvas.drawBitmap(toTransform, srcRect, destRect, CIRCLE_CROP_BITMAP_PAINT);
+      clear(canvas);
+    } finally {
+      TransformationUtils.getBitmapDrawableLock().unlock();
+    }
 
     if (!toTransform.equals(inBitmap)) {
       pool.put(toTransform);
@@ -335,10 +348,15 @@ public static Bitmap roundedCorners(@NonNull BitmapPool pool, @NonNull Bitmap in
     paint.setAntiAlias(true);
     paint.setShader(shader);
     RectF rect = new RectF(0, 0, result.getWidth(), result.getHeight());
-    Canvas canvas = new Canvas(result);
-    canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
-    canvas.drawRoundRect(rect, roundingRadius, roundingRadius, paint);
-    clear(canvas);
+    TransformationUtils.getBitmapDrawableLock().lock();
+    try {
+      Canvas canvas = new Canvas(result);
+      canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
+      canvas.drawRoundRect(rect, roundingRadius, roundingRadius, paint);
+      clear(canvas);
+    } finally {
+      TransformationUtils.getBitmapDrawableLock().unlock();
+    }
 
     if (!toTransform.equals(inBitmap)) {
       pool.put(toTransform);
@@ -356,6 +374,18 @@ private static Bitmap.Config getSafeConfig(Bitmap bitmap) {
     return bitmap.getConfig() != null ? bitmap.getConfig() : Bitmap.Config.ARGB_8888;
   }
 
+  private static void applyMatrix(@NonNull Bitmap inBitmap, @NonNull Bitmap targetBitmap,
+      Matrix matrix) {
+    BITMAP_DRAWABLE_LOCK.lock();
+    try {
+      Canvas canvas = new Canvas(targetBitmap);
+      canvas.drawBitmap(inBitmap, matrix, DEFAULT_PAINT);
+      clear(canvas);
+    } finally {
+      BITMAP_DRAWABLE_LOCK.unlock();
+    }
+  }
+
   // Visible for testing.
   static void initializeMatrixForRotation(int exifOrientation, Matrix matrix) {
     switch (exifOrientation) {
@@ -387,4 +417,37 @@ static void initializeMatrixForRotation(int exifOrientation, Matrix matrix) {
         // Do nothing.
     }
   }
+
+  private static final class NoLock implements Lock {
+    @Override
+    public void lock() {
+      // do nothing
+    }
+
+    @Override
+    public void lockInterruptibly() throws InterruptedException {
+      // do nothing
+    }
+
+    @Override
+    public boolean tryLock() {
+      return true;
+    }
+
+    @Override
+    public boolean tryLock(long time, @NonNull TimeUnit unit) throws InterruptedException {
+      return true;
+    }
+
+    @Override
+    public void unlock() {
+      // do nothing
+    }
+
+    @NonNull
+    @Override
+    public Condition newCondition() {
+      throw new UnsupportedOperationException("Should not be called");
+    }
+  }
 }