CFNetwork下载图像时占用大量内存

Question

First, I'm not exactly sure if this is an AFNetworking problem or CFNetwork.

I am using AFNetworking in an iOS app that downloads thousands of images. This is implemented via NSMutableURLRequest, AFHTTPRequestOperation (with a AFHTTPResponseSerializer), NSOperationQueue (The maxConcurrentOperationCount on the NSOperationQueue is set to 8 btw).

what i'm seeing is that while these images are downloading from the server, the memory footprint of my app goes up significantly. Using allocations in instruments (XCode5), it looks like a lot of the memory goes to CFData in HTTPProtocol::bytesAvailable in CFNetwork.

While i don't know anything about CFNetwork, i am just speculating that while images are downloading, some CFData is not being released, which leads to the temporary accumulation of a lot of memory.

Just to be clear, this memory is eventually released, somewhere, somehow, as i see the memory footprint go down in Instruments after a while, but what I'm concerned abut is whats going on while the images download.

The strange things is that with maxConcurrentOperationCount=8, you would think that no more than 8 images are downloaded at any one time...

Is this an issue that others have come across and if so, how to fix it? can AFNetworking be configured in a way so this doesn't happen?

Thanks.

Answer 1

AFNetworking具有操作队列，您可以如下设置最大并发操作数：

[[requestOperationManager operationQueue] setMaxConcurrentOperationCount:5];