Rename NSURLSession queues

Include unique session ID

Author: danieleggert

Foundation/NSURLSession.swift

@@ -158,10 +158,6 @@
 /// timeoutIntervalForRequest even if the request's timeoutInterval has not
 /// been set explicitly?
 ///
-/// - TODO: The queue names are not unique. We might want to use an atomic
-/// counter to give each NSURLSession a unique identifier and add that. Or use
-/// the memory address.
-///
 /// - TODO: We could re-use EasyHandles once they're complete. That'd be a
 /// performance optimization. Not sure how much that'd help. The NSURLSession
 /// would have to keep a pool of unused handles.
@@ -176,18 +172,22 @@ import CoreFoundation
 import Dispatch
 
 
-
+private var sessionCounter = Int32(0)
+private func nextSessionIdentifier() -> Int32 {
+    return OSAtomicIncrement32Barrier(&sessionCounter)
+}
 public let NSURLSessionTransferSizeUnknown: Int64 = -1
 
 public class NSURLSession : NSObject {
     private let _configuration: NSURLSession.Configuration
     private let multiHandle: MultiHandle
     private var nextTaskIdentifier = 1
-    private let workQueue = dispatch_queue_create("NSURLSession", DISPATCH_QUEUE_SERIAL)
+    private let workQueue: dispatch_queue_t
     /// This queue is used to make public attributes on `NSURLSessionTask` instances thread safe.
     /// - Note: It's a **concurrent** queue.
-    private let taskAttributesIsolation = dispatch_queue_create("NSURLSession.taskAttributes", DISPATCH_QUEUE_CONCURRENT)
+    private let taskAttributesIsolation: dispatch_queue_t
     private let taskRegistry = NSURLSession.TaskRegistry()
+    private let identifier: Int32
 
     /*
      * The shared session uses the currently set global NSURLCache,
@@ -204,6 +204,9 @@ public class NSURLSession : NSObject {
      */
     public /*not inherited*/ init(configuration: NSURLSessionConfiguration) {
         initializeLibcurl()
+        identifier = nextSessionIdentifier()
+        self.workQueue = dispatch_queue_create("NSURLSession<\(identifier)>", DISPATCH_QUEUE_SERIAL)
+        self.taskAttributesIsolation = dispatch_queue_create("NSURLSession<\(identifier)>.taskAttributes", DISPATCH_QUEUE_CONCURRENT)
         self.delegateQueue = NSOperationQueue()
         self.delegate = nil
         //TODO: Make sure this one can't be written to?
@@ -216,6 +219,9 @@ public class NSURLSession : NSObject {
     }
     public /*not inherited*/ init(configuration: NSURLSessionConfiguration, delegate: NSURLSessionDelegate?, delegateQueue queue: NSOperationQueue?) {
         initializeLibcurl()
+        identifier = nextSessionIdentifier()
+        self.workQueue = dispatch_queue_create("NSURLSession<\(identifier)>", DISPATCH_QUEUE_SERIAL)
+        self.taskAttributesIsolation = dispatch_queue_create("NSURLSession<\(identifier)>.taskAttributes", DISPATCH_QUEUE_CONCURRENT)
         self.delegateQueue = queue ?? NSOperationQueue()
         self.delegate = delegate
         //TODO: Make sure this one can't be written to?