Anonymous Listener of volley request causing memory leak

后端 未结 4 1881
别跟我提以往
别跟我提以往 2021-01-05 07:14

I am using volley library for making web-services call. I made a general class for making all web services call and making service call from there and made anonymous listene

4条回答
  •  青春惊慌失措
    2021-01-05 07:46

    I know I m a bit late to join the party, but few days back this problem did spoil my weekend. In order to figure out, I went on to research a bit which finally got the solution.

    The issue lies in the last request object getting leaked in Network Dispatcher & Cache Dispatcher.

    @Override
        public void run() {
            if (DEBUG) VolleyLog.v("start new dispatcher");
            Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
    
            // Make a blocking call to initialize the cache.
            mCache.initialize();
    
            Request request;
            while (true) {
                // release previous request object to avoid leaking request object when mQueue is drained.
                request = null;
                try {
                    // Take a request from the queue.
                    request = mCacheQueue.take();
                } catch (InterruptedException e) {
                    // We may have been interrupted because it was time to quit.
                    if (mQuit) {
                        return;
                    }
                    continue;
                }
                try {
                    request.addMarker("cache-queue-take");
    
                    // If the request has been canceled, don't bother dispatching it.
                    if (request.isCanceled()) {
                        request.finish("cache-discard-canceled");
                        continue;
                    }
    
                    // Attempt to retrieve this item from cache.
                    Cache.Entry entry = mCache.get(request.getCacheKey());
                    if (entry == null) {
                        request.addMarker("cache-miss");
                        // Cache miss; send off to the network dispatcher.
                        mNetworkQueue.put(request);
                        continue;
                    }
    
                    // If it is completely expired, just send it to the network.
                    if (entry.isExpired()) {
                        request.addMarker("cache-hit-expired");
                        request.setCacheEntry(entry);
                        mNetworkQueue.put(request);
                        continue;
                    }
    
                    // We have a cache hit; parse its data for delivery back to the request.
                    request.addMarker("cache-hit");
                    Response response = request.parseNetworkResponse(
                            new NetworkResponse(entry.data, entry.responseHeaders));
                    request.addMarker("cache-hit-parsed");
    
                    if (!entry.refreshNeeded()) {
                        // Completely unexpired cache hit. Just deliver the response.
                        mDelivery.postResponse(request, response);
                    } else {
                        // Soft-expired cache hit. We can deliver the cached response,
                        // but we need to also send the request to the network for
                        // refreshing.
                        request.addMarker("cache-hit-refresh-needed");
                        request.setCacheEntry(entry);
    
                        // Mark the response as intermediate.
                        response.intermediate = true;
    
                        // Post the intermediate response back to the user and have
                        // the delivery then forward the request along to the network.
                        final Request finalRequest = request;
                        mDelivery.postResponse(request, response, new Runnable() {
                            @Override
                            public void run() {
                                try {
                                    mNetworkQueue.put(finalRequest);
                                } catch (InterruptedException e) {
                                    // Not much we can do about this.
                                }
                            }
                        });
                    }
                } catch (Exception e) {
                    VolleyLog.e(e, "Unhandled exception %s", e.toString());
                }
            }
    

    As you can see a new request object is created before it takes from the queue. This overcomes the problem of memory leak.

    P.S: Don't use Volley from the Google repository as it is deprecated and has this bug since then. In order to use Volley, go for this :

    https://github.com/mcxiaoke/android-volley

    The above repository is free from any memory leaks whatsoever. Ciao.

提交回复
热议问题