Enable strict concurrency checks on Basics module (swiftlang#7451)

Also refactored `URLSessionHTTPClient` to remove `weak` references,
which were incompatible with strict concurrency checks.

Author: MaxDesiatov

Package.swift

@@ -81,7 +81,6 @@ let systemSQLitePkgConfig: String? = "sqlite3"
  */
 let autoProducts = [swiftPMProduct, swiftPMDataModelProduct]
 
-
 let packageModelResourcesSettings: [SwiftSetting]
 let packageModelResources: [Resource]
 if ProcessInfo.processInfo.environment["SWIFTPM_USE_LIBRARIES_METADATA"] == nil {
@@ -193,7 +192,10 @@ let package = Package(
                 .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
                 .product(name: "SystemPackage", package: "swift-system"),
             ],
-            exclude: ["CMakeLists.txt", "Vendor/README.md"]
+            exclude: ["CMakeLists.txt", "Vendor/README.md"],
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency"),
+            ]
         ),
 
         .target(
@@ -701,7 +703,7 @@ package.targets.append(contentsOf: [
         name: "FunctionalPerformanceTests",
         dependencies: [
             "swift-package-manager",
-            "SPMTestSupport"
+            "SPMTestSupport",
         ]
     ),
 ])

Sources/Basics/Archiver/Archiver.swift

@@ -13,7 +13,7 @@
 import _Concurrency
 
 /// The `Archiver` protocol abstracts away the different operations surrounding archives.
-public protocol Archiver {
+public protocol Archiver: Sendable {
     /// A set of extensions the current archiver supports.
     var supportedExtensions: Set<String> { get }
 
@@ -27,7 +27,7 @@ public protocol Archiver {
     func extract(
         from archivePath: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Error>) -> Void
     )
 
     /// Asynchronously compress the contents of a directory to a destination archive.
@@ -40,7 +40,7 @@ public protocol Archiver {
     func compress(
         directory: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Error>) -> Void
     )
 
     /// Asynchronously validates if a file is an archive.
@@ -51,7 +51,7 @@ public protocol Archiver {
     @available(*, noasync, message: "Use the async alternative")
     func validate(
         path: AbsolutePath,
-        completion: @escaping (Result<Bool, Error>) -> Void
+        completion: @escaping @Sendable (Result<Bool, Error>) -> Void
     )
 }
 
@@ -65,8 +65,8 @@ extension Archiver {
         from archivePath: AbsolutePath,
         to destinationPath: AbsolutePath
     ) async throws {
-        try await withCheckedThrowingContinuation {
-            self.extract(from: archivePath, to: destinationPath, completion: $0.resume(with:))
+        try await withCheckedThrowingContinuation { continuation in
+            self.extract(from: archivePath, to: destinationPath, completion: { continuation.resume(with: $0) })
         }
     }
 
@@ -79,8 +79,8 @@ extension Archiver {
         directory: AbsolutePath,
         to destinationPath: AbsolutePath
     ) async throws {
-        try await withCheckedThrowingContinuation {
-            self.compress(directory: directory, to: destinationPath, completion: $0.resume(with:))
+        try await withCheckedThrowingContinuation { continuation in
+            self.compress(directory: directory, to: destinationPath, completion: { continuation.resume(with: $0) })
         }
     }
 
@@ -91,8 +91,8 @@ extension Archiver {
     public func validate(
         path: AbsolutePath
     ) async throws -> Bool {
-        try await withCheckedThrowingContinuation {
-            self.validate(path: path, completion: $0.resume(with:))
+        try await withCheckedThrowingContinuation { continuation in
+            self.validate(path: path, completion: { continuation.resume(with: $0) })
         }
     }
 }

Sources/Basics/Archiver/TarArchiver.swift

@@ -47,7 +47,7 @@ public struct TarArchiver: Archiver {
     public func extract(
         from archivePath: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Error>) -> Void
     ) {
         do {
             guard self.fileSystem.exists(archivePath) else {
@@ -84,7 +84,7 @@ public struct TarArchiver: Archiver {
     public func compress(
         directory: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Error>) -> Void
     ) {
         do {
             guard self.fileSystem.isDirectory(directory) else {
@@ -115,7 +115,7 @@ public struct TarArchiver: Archiver {
         }
     }
 
-    public func validate(path: AbsolutePath, completion: @escaping (Result<Bool, Error>) -> Void) {
+    public func validate(path: AbsolutePath, completion: @escaping @Sendable (Result<Bool, Error>) -> Void) {
         do {
             guard self.fileSystem.exists(path) else {
                 throw FileSystemError(.noEntry, path.underlying)

Sources/Basics/Archiver/UniversalArchiver.swift

@@ -73,7 +73,7 @@ public struct UniversalArchiver: Archiver {
     public func extract(
         from archivePath: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Swift.Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Swift.Error>) -> Void
     ) {
         do {
             let archiver = try archiver(for: archivePath)
@@ -86,7 +86,7 @@ public struct UniversalArchiver: Archiver {
     public func compress(
         directory: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Swift.Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Swift.Error>) -> Void
     ) {
         do {
             let archiver = try archiver(for: destinationPath)
@@ -98,7 +98,7 @@ public struct UniversalArchiver: Archiver {
 
     public func validate(
         path: AbsolutePath,
-        completion: @escaping (Result<Bool, Swift.Error>) -> Void
+        completion: @escaping @Sendable (Result<Bool, Swift.Error>) -> Void
     ) {
         do {
             let archiver = try archiver(for: path)

Sources/Basics/Archiver/ZipArchiver.swift

@@ -37,7 +37,7 @@ public struct ZipArchiver: Archiver, Cancellable {
     public func extract(
         from archivePath: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Error>) -> Void
     ) {
         do {
             guard self.fileSystem.exists(archivePath) else {
@@ -77,7 +77,7 @@ public struct ZipArchiver: Archiver, Cancellable {
     public func compress(
         directory: AbsolutePath,
         to destinationPath: AbsolutePath,
-        completion: @escaping (Result<Void, Error>) -> Void
+        completion: @escaping @Sendable (Result<Void, Error>) -> Void
     ) {
         do {
             guard self.fileSystem.isDirectory(directory) else {
@@ -125,7 +125,7 @@ public struct ZipArchiver: Archiver, Cancellable {
         }
     }
 
-    public func validate(path: AbsolutePath, completion: @escaping (Result<Bool, Error>) -> Void) {
+    public func validate(path: AbsolutePath, completion: @escaping @Sendable (Result<Bool, Error>) -> Void) {
         do {
             guard self.fileSystem.exists(path) else {
                 throw FileSystemError(.noEntry, path.underlying)

Sources/Basics/Cancellator.swift

@@ -18,9 +18,9 @@ import class TSCBasic.Thread
 import WinSDK
 #endif
 
-public typealias CancellationHandler = (DispatchTime) throws -> Void
+public typealias CancellationHandler = @Sendable (DispatchTime) throws -> Void
 
-public final class Cancellator: Cancellable {
+public final class Cancellator: Cancellable, Sendable {
     public typealias RegistrationKey = String
 
     private let observabilityScope: ObservabilityScope?
@@ -119,7 +119,7 @@ public final class Cancellator: Cancellable {
     }
 
     @discardableResult
-    public func register(name: String, handler: @escaping () throws -> Void) -> RegistrationKey? {
+    public func register(name: String, handler: @escaping @Sendable () throws -> Void) -> RegistrationKey? {
         self.register(name: name, handler: { _ in try handler() })
     }
 

Sources/Basics/Concurrency/ConcurrencyHelpers.swift

@@ -64,7 +64,7 @@ public func safe_async<T, ErrorType: Error>(
 }
 
 /// Bridges between potentially blocking methods that take a result completion closure and async/await
-public func safe_async<T>(_ body: @escaping (@escaping (Result<T, Never>) -> Void) -> Void) async -> T {
+public func safe_async<T>(_ body: @escaping @Sendable (@escaping (Result<T, Never>) -> Void) -> Void) async -> T {
     await withCheckedContinuation { continuation in
         // It is possible that body make block indefinitely on a lock, semaphore,
         // or similar then synchronously call the completion handler. For full safety

Sources/Basics/Concurrency/TokenBucket.swift

@@ -30,7 +30,7 @@ public actor TokenBucket {
     /// invocations of `withToken` will suspend until a "free" token is available.
     /// - Parameter body: The closure to invoke when a token is available.
     /// - Returns: Resulting value returned by `body`.
-    public func withToken<ReturnType>(
+    public func withToken<ReturnType: Sendable>(
         _ body: @Sendable () async throws -> ReturnType
     ) async rethrows -> ReturnType {
         await self.getToken()

Sources/Basics/FileSystem/FileSystem+Extensions.swift

@@ -25,7 +25,7 @@ import var TSCBasic.localFileSystem
 import protocol TSCBasic.WritableByteStream
 
 public typealias FileSystem = TSCBasic.FileSystem
-public var localFileSystem = TSCBasic.localFileSystem
+public let localFileSystem = TSCBasic.localFileSystem
 
 // MARK: - Custom path
 

Sources/Basics/FileSystem/TemporaryFile.swift

@@ -72,7 +72,7 @@ public func withTemporaryDirectory<Result>(
     dir: AbsolutePath? = nil,
     prefix: String = "TemporaryDirectory",
     removeTreeOnDeinit: Bool = false,
-    _ body: @escaping (AbsolutePath) async throws -> Result
+    _ body: @escaping @Sendable (AbsolutePath) async throws -> Result
 ) throws -> Task<Result, Error> {
     try withTemporaryDirectory(fileSystem: fileSystem, dir: dir, prefix: prefix) { path, cleanup in
         defer { if removeTreeOnDeinit { cleanup(path) } }

Sources/Basics/HTTPClient/LegacyHTTPClient.swift

@@ -25,7 +25,7 @@ public final class LegacyHTTPClient: Cancellable {
     public typealias Configuration = LegacyHTTPClientConfiguration
     public typealias Request = LegacyHTTPClientRequest
     public typealias Response = HTTPClientResponse
-    public typealias Handler = (Request, ProgressHandler?, @escaping (Result<Response, Error>) -> Void) -> Void
+    public typealias Handler = (Request, ProgressHandler?, @escaping @Sendable (Result<Response, Error>) -> Void) -> Void
     public typealias ProgressHandler = @Sendable (_ bytesReceived: Int64, _ totalBytes: Int64?) throws -> Void
     public typealias CompletionHandler = @Sendable (Result<HTTPClientResponse, Error>) -> Void