Fix Linux Process deadlocks

Package.resolved

@@ -9,6 +9,24 @@
         "version" : "4.6.1"
       }
     },
+    {
+      "identity" : "async-collections",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/adam-fowler/async-collections.git",
+      "state" : {
+        "revision" : "726af96095a19df6b8053ddbaed0a727aa70ccb2",
+        "version" : "0.1.0"
+      }
+    },
+    {
+      "identity" : "asyncprocess",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/gregcotten/AsyncProcess",
+      "state" : {
+        "revision" : "3a506bb36e4aa54eb3f1b13f15e636c68ee3eb19",
+        "version" : "0.0.5"
+      }
+    },
     {
       "identity" : "jsonutilities",
       "kind" : "remoteSourceControl",
@@ -77,8 +95,17 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-async-algorithms.git",
       "state" : {
-        "revision" : "9cfed92b026c524674ed869a4ff2dcfdeedf8a2a",
-        "version" : "0.1.0"
+        "revision" : "4c3ea81f81f0a25d0470188459c6d4bf20cf2f97",
+        "version" : "1.0.3"
+      }
+    },
+    {
+      "identity" : "swift-atomics",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-atomics.git",
+      "state" : {
+        "revision" : "cd142fd2f64be2100422d658e7411e39489da985",
+        "version" : "1.2.0"
       }
     },
     {
@@ -162,6 +189,15 @@
         "version" : "1.6.1"
       }
     },
+    {
+      "identity" : "swift-nio",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-nio.git",
+      "state" : {
+        "revision" : "c51907a839e63ebf0ba2076bba73dd96436bd1b9",
+        "version" : "2.81.0"
+      }
+    },
     {
       "identity" : "swift-overture",
       "kind" : "remoteSourceControl",

Package.swift

@@ -30,11 +30,13 @@ let package = Package(
     .package(url: "https://github.com/apple/swift-asn1", from: "1.1.0"),
     .package(url: "https://github.com/apple/swift-crypto", from: "3.10.0"),
     .package(url: "https://github.com/CoreOffice/XMLCoder", from: "0.17.1"),
+    .package(url: "https://github.com/adam-fowler/async-collections.git", from: "0.1.0"),
+    .package(url: "https://github.com/gregcotten/AsyncProcess", from: "0.0.5"),
 
     // File watcher dependencies
     .package(url: "https://github.com/sersoft-gmbh/swift-inotify", "0.4.0"..<"0.5.0"),
     .package(url: "https://github.com/apple/swift-system", from: "1.2.0"),
-    .package(url: "https://github.com/apple/swift-async-algorithms", from: "0.1.0"),
+    .package(url: "https://github.com/apple/swift-async-algorithms", from: "1.0.3"),
   ],
   targets: [
     .executableTarget(
@@ -55,6 +57,12 @@ let package = Package(
         .product(name: "SwiftSyntax", package: "swift-syntax"),
         .product(name: "SwiftSyntaxBuilder", package: "swift-syntax"),
         .product(name: "Overture", package: "swift-overture"),
+        .product(name: "AsyncCollections", package: "async-collections"),
+        .product(
+          name: "ProcessSpawnSync",
+          package: "AsyncProcess",
+          condition: .when(platforms: [.linux])
+        ),
 
         // Xcodeproj related dependencies
         .product(
@@ -117,7 +125,13 @@ let package = Package(
 
     .target(
       name: "SwiftBundlerBuilders",
-      dependencies: []
+      dependencies: [
+        .product(
+          name: "ProcessSpawnSync",
+          package: "AsyncProcess",
+          condition: .when(platforms: [.linux])
+        )
+      ]
     ),
 
     .target(

Plugins/SwiftBundlerCommandPlugin/SwiftBundlerCommandPlugin.swift

@@ -4,20 +4,19 @@
 @main
 struct SwiftBundlerCommandPlugin: CommandPlugin {
   /// This entry point is called when operating on a Swift package.
-  func performCommand(context: PluginContext, arguments: [String]) throws {
+  func performCommand(context: PluginContext, arguments: [String]) async throws {
     let bundler = try context.tool(named: "swift-bundler")
 
-    try run(command: bundler.path, with: arguments)
+    try await run(command: bundler.path, with: arguments)
   }
 }
 
 extension SwiftBundlerCommandPlugin {
   /// Run a command with the given arguments.
-  func run(command: Path, with arguments: [String]) throws {
+  func run(command: Path, with arguments: [String]) async throws {
     let exec = URL(fileURLWithPath: command.string)
 
-    let process = try Process.run(exec, arguments: arguments)
-    process.waitUntilExit()
+    let process = try await Process.runAndWait(exec, arguments: arguments)
 
     // Check whether the subprocess invocation was successful.
     if process.terminationReason == .exit,
@@ -30,3 +29,17 @@
     }
   }
 }
+
+extension Process {
+  class func runAndWait(_ url: URL, arguments: [String]) async throws -> Process {
+    try await withCheckedThrowingContinuation { c in
+      do {
+        _ = try Process.run(url, arguments: arguments) {
+          c.resume(returning: $0)
+        }
+      } catch {
+        c.resume(throwing: error)
+      }
+    }
+  }
+}

Sources/SwiftBundlerBuilders/Builder.swift

@@ -3,7 +3,7 @@ import Foundation
 /// A project builder.
 public protocol Builder {
   /// Builds the project defined by the given context.
-  static func build(_ context: some BuilderContext) throws -> BuilderResult
+  static func build(_ context: some BuilderContext) async throws -> BuilderResult
 }
 
 private enum BuilderError: LocalizedError {
@@ -19,20 +19,46 @@ private enum BuilderError: LocalizedError {
 
 extension Builder {
   /// Default builder entrypoint. Parses builder context from stdin.
-  public static func main() {
+  public static func main() async {
     do {
-      guard let input = readLine(strippingNewline: true) else {
-        throw BuilderError.noInput
-      }
+      let input = try await readLineAsync()
 
       let context = try JSONDecoder().decode(
         _BuilderContextImpl.self, from: Data(input.utf8)
       )
 
-      _ = try build(context)
+      _ = try await build(context)
     } catch {
       print(error)
       Foundation.exit(1)
     }
   }
 }
+
+func readLineAsync(strippingNewline: Bool = true) async throws -> String {
+  let readBytesStream = AsyncStream.makeStream(of: Data.self)
+
+  FileHandle.standardInput.readabilityHandler = { handle in
+    readBytesStream.continuation.yield(handle.availableData)
+  }
+
+  defer { FileHandle.standardInput.readabilityHandler = nil }
+
+  var accumulatedData = Data()
+  for await data in readBytesStream.stream {
+    accumulatedData.append(data)
+    if let stringData = String(data: accumulatedData, encoding: .utf8),
+      stringData.contains(where: { $0.isNewline }),
+      let firstLine = stringData.components(separatedBy: .newlines).first
+    {
+      readBytesStream.continuation.finish()
+      if strippingNewline {
+        return firstLine
+      } else {
+        return firstLine + "\n"
+      }
+    }
+  }
+
+  throw BuilderError.noInput
+}

Sources/SwiftBundlerBuilders/BuilderContextImpl.swift

@@ -1,7 +1,12 @@
 import Foundation
 
+#if os(Linux)
+  import ProcessSpawnSync
+  typealias Process = PSProcess
+#endif
+
 //swiftlint:disable type_name
 // TODO: Use `package` access level when we bump to Swift 5.9
 /// Implementation detail, may have breaking changes from time to time.
 /// "Hidden" from users to avoid exposing implementation details such as
 /// the ``Codable`` conformance, since the builder API has to be pretty
@@ -14,10 +19,11 @@
   }
 
   enum Error: LocalizedError {
+    case commandNotFound
     case nonZeroExitStatus(Int)
   }
 
-  public func run(_ command: String, _ arguments: [String]) throws {
+  public func run(_ command: String, _ arguments: [String]) async throws {
     let process = Process()
     #if os(Windows)
       process.executableURL = URL(fileURLWithPath: "C:\\Windows\\System32\\cmd.exe")
@@ -27,8 +33,7 @@
       process.arguments = [command] + arguments
     #endif
 
-    try process.run()
-    process.waitUntilExit()
+    try await process.runAndWait()
 
     let exitStatus = Int(process.terminationStatus)
     guard exitStatus == 0 else {
@@ -36,4 +41,20 @@
     }
   }
 }
 //swiftlint:enable type_name
+
+extension Process {
+  func runAndWait() async throws {
+    try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
+      terminationHandler = { _ in
+        continuation.resume()
+      }
+
+      do {
+        try run()
+      } catch {
+        continuation.resume(throwing: error)
+      }
+    }
+  }
+}

Sources/SwiftBundlerBuilders/Context.swift

@@ -8,5 +8,5 @@ public protocol BuilderContext {
 
   /// Runs the given command (either a path or a tool name) with the given
   /// arguments.
-  func run(_ command: String, _ arguments: [String]) throws
+  func run(_ command: String, _ arguments: [String]) async throws
 }

Sources/swift-bundler/Bundler/AppImageBundler.swift

@@ -33,13 +33,13 @@ enum AppImageBundler: Bundler {
   static func bundle(
     _ context: BundlerContext,
     _ additionalContext: Context
-  ) -> Result<BundlerOutputStructure, AppImageBundlerError> {
+  ) async -> Result<BundlerOutputStructure, AppImageBundlerError> {
     let outputStructure = intendedOutput(in: context, additionalContext)
     let appDir = context.outputDirectory
       .appendingPathComponent("\(context.appName).AppDir")
     let bundleName = outputStructure.bundle.lastPathComponent
 
-    return GenericLinuxBundler.bundle(
+    return await GenericLinuxBundler.bundle(
       context,
       GenericLinuxBundler.Context(cosmeticBundleName: bundleName)
     )
@@ -69,7 +69,7 @@ enum AppImageBundler: Bundler {
     }
     .andThenDoSideEffect { structure in
       log.info("Converting '\(context.appName).AppDir' to '\(bundleName)'")
-      return AppImageTool.bundle(appDir: appDir, to: outputStructure.bundle)
+      return await AppImageTool.bundle(appDir: appDir, to: outputStructure.bundle)
         .mapError { .failedToBundleAppDir($0) }
     }
     .replacingSuccessValue(with: outputStructure)

Sources/swift-bundler/Bundler/AppImageTool.swift

@@ -3,9 +3,9 @@ import Foundation
 /// A swifty interface for the `appimagetool` command-line tool for converting AppDirs to
 /// AppImages.
 enum AppImageTool {
-  static func bundle(appDir: URL, to appImage: URL) -> Result<Void, AppImageToolError> {
+  static func bundle(appDir: URL, to appImage: URL) async -> Result<Void, AppImageToolError> {
     let arguments = [appDir.path, appImage.path]
-    return Process.runAppImage("appimagetool", arguments: arguments)
+    return await Process.runAppImage("appimagetool", arguments: arguments)
       .mapError { error in
         .failedToRunAppImageTool(
           command: "appimagetool \(arguments.joined(separator: " "))",

Sources/swift-bundler/Bundler/ArchiveTool.swift

@@ -6,10 +6,10 @@ enum ArchiveTool {
   static func createTarGz(
     of directory: URL,
     at outputFile: URL
-  ) -> Result<Void, ArchiveToolError> {
+  ) async -> Result<Void, ArchiveToolError> {
     let arguments = ["--create", "--file", outputFile.path, directory.lastPathComponent]
     let workingDirectory = directory.deletingLastPathComponent()
-    return Process.create("tar", arguments: arguments, directory: workingDirectory)
+    return await Process.create("tar", arguments: arguments, directory: workingDirectory)
       .runAndWait()
       .mapError { error in
         .failedToCreateTarGz(directory: directory, outputFile: outputFile, error)

Sources/swift-bundler/Bundler/Bundler.swift

@@ -33,7 +33,7 @@ protocol Bundler {
   static func bundle(
     _ context: BundlerContext,
     _ additionalContext: Context
-  ) -> Result<BundlerOutputStructure, Error>
+  ) async -> Result<BundlerOutputStructure, Error>
 
   /// Returns a description of the files that would be produced if
   /// ``Bundler/bundle(_:_:)`` were to get called with the provided context.