fix: allow url async calls to run in parallel (#394)

* fix: allow url async calls to run in parallel

* revert

* add tests

* add changelog

* improve parse url session

* don't test on linux

* fix build on old swift

* revert url session for linux tests

* test not running user tests on linux

* fix test on older linux

* fix session for tests

* fix test session for linux

* test old setup for linux

* working url session for all OS's

* add delegate tests

* add old swift tests

* nit

* extend time

* make delegates sendable

* update test suite

.swiftlint.yml

@@ -5,6 +5,7 @@ disabled_rules:
   - type_body_length
   - inclusive_language
   - comment_spacing
+  - identifier_name
 excluded: # paths to ignore during linting. Takes precedence over `included`.
   - Tests/ParseSwiftTests/ParseEncoderTests
   - DerivedData

CHANGELOG.md

@@ -1,9 +1,14 @@
 # Parse-Swift Changelog
 
 ### main
-[Full Changelog](https://github.com/parse-community/Parse-Swift/compare/4.9.0...main)
+[Full Changelog](https://github.com/parse-community/Parse-Swift/compare/4.9.1...main)
 * _Contributing to this repo? Add info about your change here to be included in the next release_
 
+### 4.9.1
+[Full Changelog](https://github.com/parse-community/Parse-Swift/compare/4.9.0...4.9.1)
+__Fixes__
+- Corrects a memory leak where multiple Parse URLSessions can get created. Use an actor for the url session delegates to ensure thread safety when making async calls in parallel ([#394](https://github.com/parse-community/Parse-Swift/pull/394)), thanks to [Corey Baker](https://github.com/cbaker6).
+
 ### 4.9.0
 [Full Changelog](https://github.com/parse-community/Parse-Swift/compare/4.8.0...4.9.0)
 

Sources/ParseSwift/API/API+Command.swift

@@ -60,10 +60,18 @@ internal extension API {
             case .success(let urlRequest):
                 if method == .POST || method == .PUT || method == .PATCH {
                     let task = URLSession.parse.uploadTask(withStreamedRequest: urlRequest)
-                    ParseSwift.sessionDelegate.uploadDelegates[task] = uploadProgress
                     ParseSwift.sessionDelegate.streamDelegates[task] = stream
+                    #if compiler(>=5.5.2) && canImport(_Concurrency)
+                    Task {
+                        await ParseSwift.sessionDelegate.delegates.updateUpload(task, callback: uploadProgress)
+                        await ParseSwift.sessionDelegate.delegates.updateTask(task, queue: callbackQueue)
+                        task.resume()
+                    }
+                    #else
+                    ParseSwift.sessionDelegate.uploadDelegates[task] = uploadProgress
                     ParseSwift.sessionDelegate.taskCallbackQueues[task] = callbackQueue
                     task.resume()
+                    #endif
                     return
                 }
             case .failure(let error):

Sources/ParseSwift/API/ParseURLSessionDelegate.swift

@@ -11,16 +11,56 @@ import Foundation
 import FoundationNetworking
 #endif
 
-class ParseURLSessionDelegate: NSObject, URLSessionDelegate, URLSessionDataDelegate, URLSessionDownloadDelegate
+class ParseURLSessionDelegate: NSObject
 {
     var callbackQueue: DispatchQueue
     var authentication: ((URLAuthenticationChallenge,
                           (URLSession.AuthChallengeDisposition,
                            URLCredential?) -> Void) -> Void)?
+    var streamDelegates = [URLSessionTask: InputStream]()
+    #if compiler(>=5.5.2) && canImport(_Concurrency)
+    actor SessionDelegate: Sendable {
+        var downloadDelegates = [URLSessionDownloadTask: ((URLSessionDownloadTask, Int64, Int64, Int64) -> Void)]()
+        var uploadDelegates = [URLSessionTask: ((URLSessionTask, Int64, Int64, Int64) -> Void)]()
+        var taskCallbackQueues = [URLSessionTask: DispatchQueue]()
+
+        func updateDownload(_ task: URLSessionDownloadTask,
+                            callback: ((URLSessionDownloadTask, Int64, Int64, Int64) -> Void)?) {
+            downloadDelegates[task] = callback
+        }
+
+        func removeDownload(_ task: URLSessionDownloadTask) {
+            downloadDelegates.removeValue(forKey: task)
+            taskCallbackQueues.removeValue(forKey: task)
+        }
+
+        func updateUpload(_ task: URLSessionTask,
+                          callback: ((URLSessionTask, Int64, Int64, Int64) -> Void)?) {
+            uploadDelegates[task] = callback
+        }
+
+        func removeUpload(_ task: URLSessionTask) {
+            uploadDelegates.removeValue(forKey: task)
+            taskCallbackQueues.removeValue(forKey: task)
+        }
+
+        func updateTask(_ task: URLSessionTask,
+                        queue: DispatchQueue) {
+            taskCallbackQueues[task] = queue
+        }
+
+        func removeTask(_ task: URLSessionTask) {
+            taskCallbackQueues.removeValue(forKey: task)
+        }
+    }
+
+    var delegates = SessionDelegate()
+
+    #else
     var downloadDelegates = [URLSessionDownloadTask: ((URLSessionDownloadTask, Int64, Int64, Int64) -> Void)]()
     var uploadDelegates = [URLSessionTask: ((URLSessionTask, Int64, Int64, Int64) -> Void)]()
-    var streamDelegates = [URLSessionTask: InputStream]()
     var taskCallbackQueues = [URLSessionTask: DispatchQueue]()
+    #endif
 
     init (callbackQueue: DispatchQueue,
           authentication: ((URLAuthenticationChallenge,
@@ -30,7 +70,9 @@ class ParseURLSessionDelegate: NSObject, URLSessionDelegate, URLSessionDataDeleg
         self.authentication = authentication
         super.init()
     }
+}
 
+extension ParseURLSessionDelegate: URLSessionDelegate {
     func urlSession(_ session: URLSession,
                     didReceive challenge: URLAuthenticationChallenge,
                     completionHandler: @escaping (URLSession.AuthChallengeDisposition,
@@ -43,60 +85,95 @@ class ParseURLSessionDelegate: NSObject, URLSessionDelegate, URLSessionDataDeleg
             completionHandler(.performDefaultHandling, nil)
         }
     }
+}
 
+extension ParseURLSessionDelegate: URLSessionDataDelegate {
     func urlSession(_ session: URLSession,
                     task: URLSessionTask,
                     didSendBodyData bytesSent: Int64,
                     totalBytesSent: Int64,
                     totalBytesExpectedToSend: Int64) {
-        if let callBack = uploadDelegates[task],
+        #if compiler(>=5.5.2) && canImport(_Concurrency)
+        Task {
+            if let callback = await delegates.uploadDelegates[task],
+               let queue = await delegates.taskCallbackQueues[task] {
+                queue.async {
+                    callback(task, bytesSent, totalBytesSent, totalBytesExpectedToSend)
+                }
+            }
+        }
+        #else
+        if let callback = uploadDelegates[task],
            let queue = taskCallbackQueues[task] {
-
             queue.async {
-                callBack(task, bytesSent, totalBytesSent, totalBytesExpectedToSend)
+                callback(task, bytesSent, totalBytesSent, totalBytesExpectedToSend)
+            }
+        }
+        #endif
+    }
 
-                if totalBytesSent == totalBytesExpectedToSend {
-                    self.uploadDelegates.removeValue(forKey: task)
-                }
+    func urlSession(_ session: URLSession,
+                    task: URLSessionTask,
+                    needNewBodyStream completionHandler: @escaping (InputStream?) -> Void) {
+        if let stream = streamDelegates[task] {
+            completionHandler(stream)
+        }
+    }
+
+    func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
+        streamDelegates.removeValue(forKey: task)
+        #if compiler(>=5.5.2) && canImport(_Concurrency)
+        Task {
+            await delegates.removeUpload(task)
+            if let downloadTask = task as? URLSessionDownloadTask {
+                await delegates.removeDownload(downloadTask)
             }
         }
+        #else
+        uploadDelegates.removeValue(forKey: task)
+        taskCallbackQueues.removeValue(forKey: task)
+        if let downloadTask = task as? URLSessionDownloadTask {
+            downloadDelegates.removeValue(forKey: downloadTask)
+        }
+        #endif
     }
+}
 
+extension ParseURLSessionDelegate: URLSessionDownloadDelegate {
     func urlSession(_ session: URLSession,
                     downloadTask: URLSessionDownloadTask,
                     didWriteData bytesWritten: Int64,
                     totalBytesWritten: Int64,
                     totalBytesExpectedToWrite: Int64) {
-
-        if let callBack = downloadDelegates[downloadTask],
+        #if compiler(>=5.5.2) && canImport(_Concurrency)
+        Task {
+            if let callback = await delegates.downloadDelegates[downloadTask],
+               let queue = await delegates.taskCallbackQueues[downloadTask] {
+                queue.async {
+                    callback(downloadTask, bytesWritten, totalBytesWritten, totalBytesExpectedToWrite)
+                }
+            }
+        }
+        #else
+        if let callback = downloadDelegates[downloadTask],
            let queue = taskCallbackQueues[downloadTask] {
             queue.async {
-                callBack(downloadTask, bytesWritten, totalBytesWritten, totalBytesExpectedToWrite)
-                if totalBytesWritten == totalBytesExpectedToWrite {
-                    self.downloadDelegates.removeValue(forKey: downloadTask)
-                }
+                callback(downloadTask, bytesWritten, totalBytesWritten, totalBytesExpectedToWrite)
             }
         }
+        #endif
     }
 
     func urlSession(_ session: URLSession,
                     downloadTask: URLSessionDownloadTask,
                     didFinishDownloadingTo location: URL) {
+        #if compiler(>=5.5.2) && canImport(_Concurrency)
+        Task {
+            await delegates.removeDownload(downloadTask)
+        }
+        #else
         downloadDelegates.removeValue(forKey: downloadTask)
         taskCallbackQueues.removeValue(forKey: downloadTask)
-    }
-
-    func urlSession(_ session: URLSession,
-                    task: URLSessionTask,
-                    needNewBodyStream completionHandler: @escaping (InputStream?) -> Void) {
-        if let stream = streamDelegates[task] {
-            completionHandler(stream)
-        }
-    }
-
-    func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
-        uploadDelegates.removeValue(forKey: task)
-        streamDelegates.removeValue(forKey: task)
-        taskCallbackQueues.removeValue(forKey: task)
+        #endif
     }
 }

Sources/ParseSwift/Extensions/URLSession.swift

@@ -13,7 +13,10 @@ import FoundationNetworking
 #endif
 
 internal extension URLSession {
-    static let parse: URLSession = {
+    #if !os(Linux) && !os(Android) && !os(Windows)
+    static var parse = URLSession.shared
+    #else
+    static var parse: URLSession = /* URLSession.shared */ {
         if !ParseSwift.configuration.isTestingSDK {
             let configuration = URLSessionConfiguration.default
             configuration.urlCache = URLCache.parse
@@ -25,9 +28,32 @@ internal extension URLSession {
         } else {
             let session = URLSession.shared
             session.configuration.urlCache = URLCache.parse
-            return URLSession.shared
+            session.configuration.requestCachePolicy = ParseSwift.configuration.requestCachePolicy
+            session.configuration.httpAdditionalHeaders = ParseSwift.configuration.httpAdditionalHeaders
+            return session
         }
     }()
+    #endif
+
+    static func updateParseURLSession() {
+        #if !os(Linux) && !os(Android) && !os(Windows)
+        if !ParseSwift.configuration.isTestingSDK {
+            let configuration = URLSessionConfiguration.default
+            configuration.urlCache = URLCache.parse
+            configuration.requestCachePolicy = ParseSwift.configuration.requestCachePolicy
+            configuration.httpAdditionalHeaders = ParseSwift.configuration.httpAdditionalHeaders
+            Self.parse = URLSession(configuration: configuration,
+                                    delegate: ParseSwift.sessionDelegate,
+                                    delegateQueue: nil)
+        } else {
+            let session = URLSession.shared
+            session.configuration.urlCache = URLCache.parse
+            session.configuration.requestCachePolicy = ParseSwift.configuration.requestCachePolicy
+            session.configuration.httpAdditionalHeaders = ParseSwift.configuration.httpAdditionalHeaders
+            Self.parse = session
+        }
+        #endif
+    }
 
     static func reconnectInterval(_ maxExponent: Int) -> Int {
         let min = NSDecimalNumber(decimal: Swift.min(30, pow(2, maxExponent) - 1))
@@ -220,9 +246,17 @@ internal extension URLSession {
             completion(.failure(ParseError(code: .unknownError, message: "data and file both cannot be nil")))
         }
         if let task = task {
+            #if compiler(>=5.5.2) && canImport(_Concurrency)
+            Task {
+                await ParseSwift.sessionDelegate.delegates.updateUpload(task, callback: progress)
+                await ParseSwift.sessionDelegate.delegates.updateTask(task, queue: notificationQueue)
+                task.resume()
+            }
+            #else
             ParseSwift.sessionDelegate.uploadDelegates[task] = progress
             ParseSwift.sessionDelegate.taskCallbackQueues[task] = notificationQueue
             task.resume()
+            #endif
         }
     }
 
@@ -255,9 +289,17 @@ internal extension URLSession {
             }
             completion(result)
         }
+        #if compiler(>=5.5.2) && canImport(_Concurrency)
+        Task {
+            await ParseSwift.sessionDelegate.delegates.updateDownload(task, callback: progress)
+            await ParseSwift.sessionDelegate.delegates.updateTask(task, queue: notificationQueue)
+            task.resume()
+        }
+        #else
         ParseSwift.sessionDelegate.downloadDelegates[task] = progress
         ParseSwift.sessionDelegate.taskCallbackQueues[task] = notificationQueue
         task.resume()
+        #endif
     }
 
     func downloadTask<U>(

Sources/ParseSwift/Parse.swift

@@ -267,6 +267,7 @@ public struct ParseSwift {
         Self.configuration = configuration
         Self.sessionDelegate = ParseURLSessionDelegate(callbackQueue: .main,
                                                        authentication: configuration.authentication)
+        URLSession.updateParseURLSession()
         deleteKeychainIfNeeded()
 
         #if !os(Linux) && !os(Android) && !os(Windows)
@@ -626,6 +627,7 @@ public struct ParseSwift {
                                                           URLCredential?) -> Void) -> Void)?) {
         Self.sessionDelegate = ParseURLSessionDelegate(callbackQueue: .main,
                                                        authentication: authentication)
+        URLSession.updateParseURLSession()
     }
 
     #if !os(Linux) && !os(Android) && !os(Windows)

Sources/ParseSwift/ParseConstants.swift

@@ -10,7 +10,7 @@ import Foundation
 
 enum ParseConstants {
     static let sdk = "swift"
-    static let version = "4.9.0"
+    static let version = "4.9.1"
     static let fileManagementDirectory = "parse/"
     static let fileManagementPrivateDocumentsDirectory = "Private Documents/"
     static let fileManagementLibraryDirectory = "Library/"