NSURLConnection leak in Swift - ios

Question

I've found several other articles about memory issues with NSURLConnection however none of them related to projects using ARC. My problem is that I make NSURLConnections every 0.5s (yes I know it would be better with sockets, but I don't have control over the API). When I open the debug inspector of xCode I could clearly see my used memory rising:
When I profile my application with instruments however - no leaks, no persistent storage across mark generations, simply nothing:
I've purposely decoupled all my other logic and created simple application to show my problem.
This is the main(and only) ViewController
import UIKit
class ViewController: UIViewController {
private var timer: NSTimer!
private var requests = [ServerRequest]()
override func viewDidAppear(animated: Bool)
{
self.timer = NSTimer(timeInterval: 0.5, target: self, selector: "refresh", userInfo: nil, repeats: true)
NSRunLoop.mainRunLoop().addTimer(self.timer, forMode: NSRunLoopCommonModes)
}
#objc private func refresh()
{
let urlRequest = NSURLRequest(URL: NSURL(string: "https://api.stackexchange.com/2.2/questions?order=desc&sort=activity&site=stackoverflow")!)
let serverRequest = ServerRequest(request: urlRequest){
[unowned self] result, error, request in
println("yaba daba duu")
self.requests.removeAll(keepCapacity: false)
}
requests.append(serverRequest)
serverRequest.send()
}
}
And here's my async connection delegate:
import Foundation
class ServerRequest: NSObject
{
private var request: NSURLRequest!
typealias completionType = (NSData?, NSError?, ServerRequest) -> ()
private var completion: completionType!
private var receivedData: NSMutableData?
private var connection: NSURLConnection?
init(request: NSURLRequest, completion: (NSData?, NSError?, ServerRequest) -> ())
{
super.init()
self.request = request
self.completion = completion
self.connection = NSURLConnection(request: self.request, delegate: self, startImmediately:false)
//this line will help connection is fired even while tere are touch events
self.connection?.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSRunLoopCommonModes)
NSURLCache.sharedURLCache().removeAllCachedResponses()
}
func send()
{
receivedData = NSMutableData()
self.connection?.start()
}
func abort()
{
self.connection?.cancel()
}
}
extension ServerRequest: NSURLConnectionDataDelegate, NSURLConnectionDelegate
{
func connection(connection: NSURLConnection, didReceiveResponse response: NSURLResponse)
{
self.receivedData?.length = 0
}
func connection(connection: NSURLConnection, didReceiveData data: NSData)
{
self.receivedData?.appendData(data)
}
func connection(connection: NSURLConnection, didFailWithError error: NSError)
{
self.connection = nil
self.completion(nil, error, self)
}
func connectionDidFinishLoading(connection: NSURLConnection)
{
self.connection = nil
self.completion(receivedData, nil, self)
}
//MARK: https specific(canAuthenticateAgainstProtectionSpace is depraceted first in iOS 8)
func connection(connection: NSURLConnection, canAuthenticateAgainstProtectionSpace protectionSpace: NSURLProtectionSpace) -> Bool
{
return protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust
}
func connection(connection: NSURLConnection, willSendRequestForAuthenticationChallenge challenge: NSURLAuthenticationChallenge)
{
challenge.sender.useCredential(NSURLCredential(forTrust: challenge.protectionSpace.serverTrust), forAuthenticationChallenge: challenge)
challenge.sender.continueWithoutCredentialForAuthenticationChallenge(challenge)
}
func connection(connection: NSURLConnection, willCacheResponse cachedResponse: NSCachedURLResponse) -> NSCachedURLResponse? {
return nil
}
}
Please note that I need to connect to https server, so I need corresponding delegate methods. Also I've implemented cache methods because of some suggestions in SO that caching responses in NSURLConnection may cause my issues. Finally request is scheduled in "NSRunLoopCommonModes" mode because I need it alive while scrolling(although removing this line doesn't affect the issue anyway).
UPDATE
I've jut tried even without custom class with delegate and the result is pretty much the same. Just copy-paste following:
import UIKit
class ViewController: UIViewController {
private var timer: NSTimer!
override func viewDidAppear(animated: Bool)
{
self.timer = NSTimer(timeInterval: 0.5, target: self, selector: "refresh", userInfo: nil, repeats: true)
NSRunLoop.mainRunLoop().addTimer(self.timer, forMode: NSRunLoopCommonModes)
}
#objc private func refresh()
{
let urlRequest = NSURLRequest(URL: NSURL(string: "https://api.stackexchange.com/2.2/questions?order=desc&sort=activity&site=stackoverflow")!)
NSURLConnection.sendAsynchronousRequest(urlRequest, queue: NSOperationQueue.mainQueue())
{
response, data, error in
println("yaba daba duu")
}
}
}
And my memory pressure is again rising: