Strict concurrency is ready

Demo/Demo/Kingfisher-Demo/ViewControllers/ProgressiveJPEGViewController.swift

@@ -84,7 +84,7 @@ class ProgressiveJPEGViewController: UIViewController {
                 processorIdentifier: self.processor.identifier,
                 callbackQueue: .mainAsync,
                 completionHandler: {
-                    self.loadImage()
+                    Task { @MainActor in self.loadImage() }
                 }
             )
         }

Demo/Demo/Kingfisher-Demo/ViewControllers/TextAttachmentViewController.swift

@@ -46,10 +46,11 @@ class TextAttachmentViewController: UIViewController {
         attributedText.replaceCharacters(in: NSRange(), with: NSAttributedString(attachment: textAttachment))
         label.attributedText = attributedText
 
+        let label = getLabel()
         KF.url(URL(string: "https://onevcat.com/assets/images/avatar.jpg")!)
             .resizing(referenceSize: CGSize(width: 30, height: 30))
             .roundCorner(radius: .point(15))
-            .set(to: textAttachment, attributedView: self.getLabel())
+            .set(to: textAttachment, attributedView: label)
     }
 
     func getLabel() -> UILabel {

Demo/Demo/Kingfisher-watchOS-Demo Extension/InterfaceController.swift

@@ -48,9 +48,9 @@ class InterfaceController: WKInterfaceController {
     func refreshImage() {
         let url = URL(string: "https://raw.githubusercontent.com/onevcat/Kingfisher/master/images/kingfisher-\(currentIndex! + 1).jpg")!
         print("Start loading... \(url)")
-        interfaceImage.kf.setImage(with: url) { r in
+        interfaceImage.kf.setImage(with: url, completionHandler:  { r in
             print(r)
-        }
+        })
     }
 
     override func willActivate() {

Kingfisher.xcodeproj/project.pbxproj

@@ -1125,6 +1125,7 @@
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
 				SWIFT_INSTALL_OBJC_HEADER = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				TARGETED_DEVICE_FAMILY = "1,2,3,4,7";
 				VERSIONING_SYSTEM = "apple-generic";
 			};
@@ -1185,6 +1186,7 @@
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SWIFT_INSTALL_OBJC_HEADER = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
+				SWIFT_STRICT_CONCURRENCY = complete;
 				TARGETED_DEVICE_FAMILY = "1,2,3,4,7";
 				VERSIONING_SYSTEM = "apple-generic";
 			};

Sources/Cache/DiskStorage.swift

@@ -43,12 +43,18 @@ public enum DiskStorage {
     /// ``DiskStorage/Config`` value or by modifying the ``DiskStorage/Backend/config`` property after it has been
     /// created. The ``DiskStorage/Backend`` will use the file's attributes to keep track of a file for its expiration
     /// or size limitation.
-    public class Backend<T: DataTransformable> {
+    public class Backend<T: DataTransformable>: @unchecked Sendable {
 
+        private let propertyQueue = DispatchQueue(label: "com.onevcat.kingfisher.DiskStorage.Backend.propertyQueue")
+
+        private var _config: Config
         /// The configuration used for this disk storage.
         ///
         /// It is a value you can set and use to configure the storage as needed.
-        public var config: Config
+        public var config: Config {
+            get { propertyQueue.sync { _config } }
+            set { propertyQueue.sync { _config = newValue } }
+        }
 
         /// The final storage URL on disk of the disk storage ``DiskStorage/Backend``, considering the
         /// ``DiskStorage/Config/name`` and the  ``DiskStorage/Config/cachePathBlock``.
@@ -83,7 +89,7 @@ public enum DiskStorage {
 
             // Break any possible retain cycle set by outside.
             config.cachePathBlock = nil
-            self.config = config
+            _config = config
 
             metaChangingQueue = DispatchQueue(label: creation.cacheName)
             setupCacheChecking()
@@ -255,7 +261,7 @@ public enum DiskStorage {
                 let data = try Data(contentsOf: fileURL)
                 let obj = try T.fromData(data)
                 metaChangingQueue.async {
-                    meta.extendExpiration(with: fileManager, extendingExpiration: extendingExpiration)
+                    meta.extendExpiration(with: self.config.fileManager, extendingExpiration: extendingExpiration)
                 }
                 return obj
             } catch {
@@ -463,7 +469,7 @@ public enum DiskStorage {
 extension DiskStorage {
 
     /// Represents the configuration used in a ``DiskStorage/Backend``.
-    public struct Config {
+    public struct Config: @unchecked Sendable {
 
         /// The file size limit on disk of the storage in bytes. 
         ///
@@ -496,7 +502,7 @@ extension DiskStorage {
         /// A closure that takes in the initial directory path and generates the final disk cache path.
         ///
         /// You can use it to fully customize your cache path.
-        public var cachePathBlock: ((_ directory: URL, _ cacheName: String) -> URL)! = {
+        public var cachePathBlock: (@Sendable (_ directory: URL, _ cacheName: String) -> URL)! = {
             (directory, cacheName) in
             return directory.appendingPathComponent(cacheName, isDirectory: true)
         }