Fix Concurrency Warnings in Swift 6

Source/AwsCommonRuntimeKit/auth/credentials/Credentials.swift

@@ -4,7 +4,9 @@
 import AwsCAuth
 import Foundation
 
-public final class Credentials {
+// We can't mutate this class after initialization. Swift can not verify the sendability due to OpaquePointer,
+// So mark it unchecked Sendable
+public final class Credentials: @unchecked Sendable {
 
     let rawValue: OpaquePointer
 

Source/AwsCommonRuntimeKit/auth/credentials/CredentialsProvider.swift

@@ -10,7 +10,9 @@ public protocol CredentialsProviding {
     func getCredentials() async throws -> Credentials
 }
 
-public class CredentialsProvider: CredentialsProviding {
+// We can't mutate this class after initialization. Swift can not verify the sendability due to pointer,
+// So mark it unchecked Sendable
+public class CredentialsProvider: CredentialsProviding, @unchecked Sendable {
 
     let rawValue: UnsafeMutablePointer<aws_credentials_provider>
 
@@ -590,7 +592,7 @@ private func onGetCredentials(credentials: OpaquePointer?,
 // We need to share this pointer to C in a task block but Swift compiler complains
 // that Pointer does not conform to Sendable. Wrap the pointer in a @unchecked Sendable block
 // for Swift compiler to stop complaining.
-struct SendablePointer: @unchecked Sendable {
+struct SendableRawPointer: @unchecked Sendable {
     let pointer: UnsafeMutableRawPointer
 }
 
@@ -600,12 +602,13 @@ private func getCredentialsDelegateFn(_ delegatePtr: UnsafeMutableRawPointer!,
                                                         Int32,
                                                         UnsafeMutableRawPointer?) -> Void)!,
                                       _ userData: UnsafeMutableRawPointer!) -> Int32 {
-    let delegate = Unmanaged<Box<CredentialsProviding>>
-        .fromOpaque(delegatePtr)
-        .takeUnretainedValue().contents
-    let userData = SendablePointer(pointer: userData)
+    let userData = SendableRawPointer(pointer: userData)
+    let delegatePtr = SendableRawPointer(pointer: delegatePtr)
     Task {
         do {
+            let delegate = Unmanaged<Box<CredentialsProviding>>
+                .fromOpaque(delegatePtr.pointer)
+                .takeUnretainedValue().contents
             let credentials = try await delegate.getCredentials()
             callbackFn(credentials.rawValue, AWS_OP_SUCCESS, userData.pointer)
         } catch CommonRunTimeError.crtError(let crtError) {

Source/AwsCommonRuntimeKit/auth/imds/IAMProfile.swift

@@ -4,7 +4,7 @@
 import AwsCAuth
 import Foundation
 
-public struct IAMProfile {
+public struct IAMProfile: Sendable {
     public let lastUpdated: Date
     public let profileArn: String
     public let profileId: String

Source/AwsCommonRuntimeKit/auth/imds/IMDSClient.swift

@@ -4,7 +4,9 @@
 import AwsCAuth
 
 // swiftlint:disable type_body_length
-public class IMDSClient {
+// We can't mutate this class after initialization. Swift can not verify the sendability due to OpaquePointer,
+// So mark it unchecked Sendable
+public class IMDSClient: @unchecked Sendable {
     let rawValue: OpaquePointer
 
     /// Creates an IMDSClient that always uses IMDSv2

Source/AwsCommonRuntimeKit/auth/imds/IMDSInstanceInfo.swift

@@ -4,7 +4,7 @@
 import AwsCAuth
 import Foundation
 
-public struct IMDSInstanceInfo {
+public struct IMDSInstanceInfo: Sendable {
     public let marketPlaceProductCodes: [String]
     public let availabilityZone: String
     public let privateIp: String

Source/AwsCommonRuntimeKit/auth/signing/Signer.swift

@@ -164,9 +164,11 @@ public class Signer {
     }
 }
 
-class SignRequestCore {
+// After signing, we mutate the request and resume the continuation, which may result in a thread change.
+// We won't modify it after continuation.resume is called. So we can mark it @unchecked Sendable
+class SignRequestCore: @unchecked Sendable {
     let request: HTTPRequestBase
-    var continuation: CheckedContinuation<HTTPRequestBase, Error>
+    let continuation: CheckedContinuation<HTTPRequestBase, Error>
     let shouldSignHeader: ((String) -> Bool)?
     init(request: HTTPRequestBase,
          continuation: CheckedContinuation<HTTPRequestBase, Error>,
@@ -207,6 +209,7 @@ private func onRequestSigningComplete(signingResult: UnsafeMutablePointer<aws_si
     } else {
         signRequestCore.continuation.resume(throwing: CommonRunTimeError.crtError(.makeFromLastError()))
     }
+    // It's not thread-safe to modify `signingRequestCore.request` after continuation.resume
 }
 
 private func onSigningComplete(signingResult: UnsafeMutablePointer<aws_signing_result>?,
@@ -220,9 +223,10 @@ private func onSigningComplete(signingResult: UnsafeMutablePointer<aws_signing_r
 
     // Success
     var awsStringPointer: UnsafeMutablePointer<aws_string>!
+    let signature = AWSString("signature")
     guard aws_signing_result_get_property(
             signingResult!,
-            g_aws_signature_property_name,
+            signature.rawValue,
             &awsStringPointer) == AWS_OP_SUCCESS else {
         chunkSignerCore.continuation.resume(throwing: CommonRunTimeError.crtError(.makeFromLastError()))
         return

Source/AwsCommonRuntimeKit/crt/Allocator.swift

@@ -2,11 +2,17 @@
 //  SPDX-License-Identifier: Apache-2.0.
 import AwsCCommon
 
-/**
- The default allocator.
- You are probably looking to use `allocator` instead.
+/*
+ * The default allocator.
+ * We need to declare `allocator` as mutable (`var`) instead of `let` because we override it with a tracing allocator in tests. This is not mutated anywhere else apart from the start of tests.
+ * Swift compiler doesn't let us compile this code in Swift 6 due to global shared mutable state without locks, and complains that this is not safe. Disable the safety here since we won't modify it.
+ * Remove the Ifdef once our minimum supported Swift version reaches 5.10
  */
+#if swift(>=5.10)
+nonisolated(unsafe) var allocator = aws_default_allocator()!
+#else
 var allocator = aws_default_allocator()!
+#endif
 
 /// An allocator is used to allocate memory on the heap.
 protocol Allocator {

Source/AwsCommonRuntimeKit/crt/CommonRuntimeError.swift

@@ -8,7 +8,7 @@ public enum CommonRunTimeError: Error {
     case crtError(CRTError)
 }
 
-public struct CRTError: Equatable {
+public struct CRTError: Equatable, Sendable {
     public let code: Int32
     public let message: String
     public let name: String

Source/AwsCommonRuntimeKit/crt/Logger.swift

@@ -10,7 +10,7 @@ public enum LogTarget {
     case filePath(String) 
 }
 
-public struct Logger {
+public actor Logger {
     private static var logger: aws_logger?
     private static let lock = NSLock()
 
@@ -55,7 +55,7 @@ public struct Logger {
     }
 }
 
-public enum LogLevel {
+public enum LogLevel: Sendable {
     case none
     case fatal
     case error

Source/AwsCommonRuntimeKit/http/HTTP1Stream.swift

@@ -3,8 +3,10 @@
 import AwsCHttp
 import Foundation
 
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
 /// An HTTP1Stream represents a single HTTP/1.1 specific Http Request/Response.
-public class HTTP1Stream: HTTPStream {
+public class HTTP1Stream: HTTPStream, @unchecked Sendable {
     /// Stream keeps a reference to HttpConnection to keep it alive
     private let httpConnection: HTTPClientConnection
 

Source/AwsCommonRuntimeKit/http/HTTP2ClientConnection.swift

@@ -5,7 +5,9 @@ import AwsCHttp
 import AwsCIo
 import Foundation
 
-public class HTTP2ClientConnection: HTTPClientConnection {
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
+public class HTTP2ClientConnection: HTTPClientConnection, @unchecked Sendable {
 
     /// Creates a new http2 stream from the `HTTPRequestOptions` given.
     /// - Parameter requestOptions: An `HTTPRequestOptions` struct containing callbacks on

Source/AwsCommonRuntimeKit/http/HTTP2Stream.swift

@@ -4,8 +4,10 @@
 import AwsCHttp
 import Foundation
 
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
 /// An HTTP2Stream represents a single HTTP/2 specific HTTP Request/Response.
-public class HTTP2Stream: HTTPStream {
+public class HTTP2Stream: HTTPStream, @unchecked Sendable {
     private let httpConnection: HTTPClientConnection?
 
     // Called by Connection Manager

Source/AwsCommonRuntimeKit/http/HTTP2StreamManager.swift

@@ -2,8 +2,10 @@
 //  SPDX-License-Identifier: Apache-2.0.
 import AwsCHttp
 
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
 /// Manages a Pool of HTTP/2 Streams. Creates and manages HTTP/2 connections under the hood.
-public class HTTP2StreamManager {
+public class HTTP2StreamManager: @unchecked Sendable {
     let rawValue: UnsafeMutablePointer<aws_http2_stream_manager>
 
     public init(options: HTTP2StreamManagerOptions) throws {

Source/AwsCommonRuntimeKit/http/HTTPClientConnection.swift

@@ -6,7 +6,9 @@ import AwsCIo
 import Foundation
 
 // swiftlint:disable force_try
-public class HTTPClientConnection {
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
+public class HTTPClientConnection: @unchecked Sendable {
     let rawValue: UnsafeMutablePointer<aws_http_connection>
     /// This will keep the connection manager alive until connection is alive
     let manager: HTTPClientConnectionManager

Source/AwsCommonRuntimeKit/http/HTTPStream.swift

@@ -3,9 +3,11 @@
 import AwsCHttp
 import Foundation
 
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
 /// An base abstract class that represents a single Http Request/Response for both HTTP/1.1 and HTTP/2.
 /// Can be used to update the Window size, and get status code.
-public class HTTPStream {
+public class HTTPStream: @unchecked Sendable {
     let rawValue: UnsafeMutablePointer<aws_http_stream>
     var callbackData: HTTPStreamCallbackCore
 

Source/AwsCommonRuntimeKit/io/HostAddress.swift

@@ -4,7 +4,7 @@
 import AwsCIo
 
 /// Represents a single HostAddress resolved by the Host Resolver
-public struct HostAddress: CStruct {
+public struct HostAddress: CStruct, Sendable {
 
     /// Address type is ipv4 or ipv6
     public let addressType: HostAddressType

Source/AwsCommonRuntimeKit/io/HostAddressType.swift

@@ -4,7 +4,7 @@
 import AwsCIo
 
 /// Type of Host Address (ipv4 or ipv6)
-public enum HostAddressType {
+public enum HostAddressType: Sendable {
     case A
     case AAAA
 }

Source/AwsCommonRuntimeKit/io/HostResolver.swift

@@ -23,8 +23,10 @@ public protocol HostResolverProtocol {
     func purgeCache() async
 }
 
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
 /// CRT Host Resolver which performs async DNS lookups
-public class HostResolver: HostResolverProtocol {
+public class HostResolver: HostResolverProtocol, @unchecked Sendable {
     let rawValue: UnsafeMutablePointer<aws_host_resolver>
     let maxTTL: Int
 

Source/AwsCommonRuntimeKit/io/retryer/RetryToken.swift

@@ -3,8 +3,10 @@
 
 import AwsCIo
 
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
 /// This is just a wrapper for aws_retry_token which user can not create themself but pass around once acquired.
-public class RetryToken {
+public class RetryToken: @unchecked Sendable {
     let rawValue: UnsafeMutablePointer<aws_retry_token>
 
     init(rawValue: UnsafeMutablePointer<aws_retry_token>) {

Source/Elasticurl/CommandLine.swift

@@ -3,7 +3,6 @@
 
 import Foundation
 import AwsCCommon
-// swiftlint:disable trailing_whitespace
 
 struct CommandLineParser {
     /// A function to parse command line arguments
@@ -27,8 +26,8 @@ struct CommandLineParser {
                 break
             }
             if let char = UnicodeScalar(Int(opt)) {
-                if aws_cli_optarg != nil {
-                    argumentsDict[String(char)] = String(cString: aws_cli_optarg)
+                if aws_get_cli_optarg() != nil {
+                    argumentsDict[String(char)] = String(cString: aws_get_cli_optarg())
                 } else {
                     // if argument doesnt have a value just mark it as present in the dictionary
                     argumentsDict[String(char)] = true
@@ -60,7 +59,9 @@ extension CLIHasArg: RawRepresentable, CaseIterable {
     }
 }
 
-class AWSCLIOption {
+// Swift cannot verify the sendability due to a pointer, and thread safety is handled in the C layer.
+// So mark it as unchecked Sendable.
+class AWSCLIOption: @unchecked Sendable {
     let rawValue: aws_cli_option
     let name: UnsafeMutablePointer<CChar>
     init(name: String, hasArg: CLIHasArg, flag: UnsafeMutablePointer<Int32>? = nil, val: String) {

Source/Elasticurl/Elasticurl.swift

@@ -6,7 +6,7 @@ import AwsCommonRuntimeKit
 import Foundation
 
 // swiftlint:disable cyclomatic_complexity function_body_length
-struct Context {
+struct Context: @unchecked Sendable {
     // args
     public var logLevel: LogLevel = .trace
     public var verb: String = "GET"
@@ -29,9 +29,8 @@ struct Context {
 @main
 struct Elasticurl {
     private static let version = "0.1.0"
-    private static var context = Context()
 
-    static func parseArguments() {
+    static func parseArguments() -> Context {
         let optionString = "a:b:c:e:f:H:d:g:j:l:m:M:GPHiko:t:v:VwWh"
         let options = [ElasticurlOptions.caCert.rawValue,
                        ElasticurlOptions.caPath.rawValue,
@@ -63,6 +62,7 @@ struct Elasticurl {
                                                              arguments: CommandLine.unsafeArgv,
                                                              optionString: optionString, options: options)
 
+        var context = Context()
         if let caCert = argumentsDict["a"] as? String {
             context.caCert = caCert
         }
@@ -176,6 +176,7 @@ struct Elasticurl {
             exit(-1)
         }
         context.url = url
+        return context
     }
 
     static func showHelp() {
@@ -202,22 +203,24 @@ struct Elasticurl {
         print("  -h, --help: Display this message and quit.")
     }
 
-    static func createOutputFile() {
+    static func createOutputFile(context: Context) -> Context {
+        var context = context
         if let fileName = context.outputFileName {
             let fileManager = FileManager.default
             let path = FileManager.default.currentDirectoryPath + "/" + fileName
             fileManager.createFile(atPath: path, contents: nil, attributes: nil)
             context.outputStream = FileHandle(forWritingAtPath: fileName) ?? FileHandle.standardOutput
         }
+        return context
     }
 
-    static func writeData(data: Data) {
+    static func writeData(data: Data, context: Context) {
         context.outputStream.write(data)
     }
 
     static func main() async {
-        parseArguments()
-        createOutputFile()
+        var context = parseArguments()
+        context = createOutputFile(context: context)
         if let traceFile = context.traceFile {
             print("enable logging with trace file")
             try? Logger.initialize(target: .filePath(traceFile), level: context.logLevel)
@@ -226,10 +229,10 @@ struct Elasticurl {
             try? Logger.initialize(target: .standardOutput, level: context.logLevel)
         }
 
-        await run()
+        await run(context)
     }
 
-    static func run() async {
+    static func run(_ context: Context) async {
         do {
             guard let host = context.url.host else {
                 print("no proper host was parsed from the url. quitting.")
@@ -291,7 +294,7 @@ struct Elasticurl {
                 }
 
                 let onBody: HTTPRequestOptions.OnIncomingBody = { bodyChunk in
-                    writeData(data: bodyChunk)
+                    writeData(data: bodyChunk, context: context)
                 }
 
                 let onComplete: HTTPRequestOptions.OnStreamComplete = { result in