Theme status monitor. How do I debug this? What causes this?

I am developing Android, and I can’t understand why some of my threads enter the status of “monitor”. I read that this may be due to a "synchronized" problem, but I'm not sure how the object will not release their lock.

Can someone help with how to debug this or do you see something that I am doing wrong? Is there a problem with synchronized objects that are not released, or is my download not syncing correctly and blocking all threads?

This is how I use synchronized.

private Bitmap getFromSyncCache(String url) {
    if (syncCache == null) return null;
    synchronized (syncCache) {
        if (syncCache.hasObject(url)) {
            return syncCache.get(url);
        } else {
            return null;
        }
    }
}

and here:

bitmapLoader.setOnCompleteListener(new BitmapLoader.OnCompleteListener() {
            @Override
            public void onComplete(Bitmap bitmap) {
                if (syncCache != null) {
                    synchronized (syncCache) {
                        syncCache.put(bitmapLoader.getLoadUrl(), bitmap);
                    }
                }
                if (asyncCache != null) addToAsyncCache(bitmapLoader.getLoadUrl(), bitmap);
                if (onCompleteListener != null) onCompleteListener.onComplete(bitmap);
            }
        });

and here is my cache

public class MemoryCache<T> implements Cache<T>{

private HashMap<String, SoftReference<T>> cache;

public MemoryCache() {
    cache = new HashMap<String, SoftReference<T>>();
}

@Override
public T get(String id) {
    if(!cache.containsKey(id)) return null;
    SoftReference<T> ref = cache.get(id);
    return ref.get();
}

@Override
public void put(String id, T object) {
    cache.put(id, new SoftReference<T>(object));
}

@Override
public void clearCache() {
    cache.clear();
}

@Override
public boolean hasObject(String id) {
    return cache.containsKey(id);
}

and here is how I download an image from the Internet:

private void threadedLoad(String url) {
    cancel();
    bytesLoaded = 0;
    bytesTotal = 0;
    try {
        state = State.DOWNLOADING;
        conn = (HttpURLConnection) new URL(url).openConnection();
        bytesTotal = conn.getContentLength();

        // if we don't have a total can't track the progress
        if (bytesTotal > 0 && onProgressListener != null) {
            // unused               
        } else {
            conn.connect();
            inStream = conn.getInputStream();
            Bitmap bitmap = BitmapFactory.decodeStream(inStream);
            state = State.COMPLETE;
            if (state != State.CANCELED) {
                if (bitmap != null) {
                    msgSendComplete(bitmap);
                } else {
                    handleIOException(new IOException("Skia could not decode the bitmap and returned null. Url: " + loadUrl));
                }
            }
            try {
                inStream.close();
            } catch(Exception e) {

            }
        }
    } catch (IOException e) {
        handleIOException(e);
    }
}