Simplify scheduler

Package.swift

@@ -20,7 +20,7 @@ let package = Package(
         .package(url: "https://github.com/christophhagen/ClairvoyantBinaryCodable", from: "0.3.1"),
     ],
     targets: [
-        .target(
+        .executableTarget(
             name: "App",
             dependencies: [
                 .product(name: "Fluent", package: "fluent"),
@@ -30,18 +30,7 @@ let package = Package(
                 .product(name: "Clairvoyant", package: "Clairvoyant"),
                 .product(name: "ClairvoyantVapor", package: "ClairvoyantVapor"),
                 .product(name: "ClairvoyantBinaryCodable", package: "ClairvoyantBinaryCodable"),
-            ],
-            swiftSettings: [
-                // Enable better optimizations when building in Release configuration. Despite the use of
-                // the `.unsafeFlags` construct required by SwiftPM, this flag is recommended for Release
-                // builds. See <https://github.com/swift-server/guides/blob/main/docs/building.md#building-for-production> for details.
-                .unsafeFlags(["-cross-module-optimization"], .when(configuration: .release))
             ]
-        ),
-        .executableTarget(name: "Run", dependencies: [.target(name: "App")]),
-//        .testTarget(name: "AppTests", dependencies: [
-//            .target(name: "App"),
-//            .product(name: "XCTVapor", package: "vapor"),
-//        ])
+        )
     ]
 )

Sources/App/EventLoopScheduler.swift

@@ -1,34 +1,10 @@
 import Foundation
-import Clairvoyant
 import Vapor
-import NIOCore
+import Clairvoyant
 
-final class EventLoopScheduler {
+extension MultiThreadedEventLoopGroup: AsyncScheduler {
 
-    private let backgroundGroup: EventLoopGroup
-
-    init(numberOfThreads: Int = 2) {
-        backgroundGroup = MultiThreadedEventLoopGroup(numberOfThreads: numberOfThreads)
-    }
-
-    func next() -> EventLoop {
-        backgroundGroup.next()
-    }
-
-    func provider() -> NIOEventLoopGroupProvider {
-        return .shared(backgroundGroup)
-    }
-
-    func shutdown() {
-        backgroundGroup.shutdownGracefully { _ in
-
-        }
-    }
-}
-
-extension EventLoopScheduler: AsyncScheduler {
-
-    func schedule(asyncJob: @escaping @Sendable () async throws -> Void) {
-        _ = backgroundGroup.any().makeFutureWithTask(asyncJob)
+    public func schedule(asyncJob: @escaping @Sendable () async throws -> Void) {
+        _ = any().makeFutureWithTask(asyncJob)
     }
 }

Sources/App/configure.swift

@@ -8,26 +8,10 @@ var server: SQLiteDatabase!
 
 private var provider: VaporMetricProvider! = nil
 private var status: Metric<ServerStatus>!
-private let scheduler = EventLoopScheduler()
+private let scheduler = MultiThreadedEventLoopGroup(numberOfThreads: 2)
 private var configurationError: Error? = nil
 
-public func configure(_ app: Application) throws {
-    let semaphore = DispatchSemaphore(value: 0)
-    scheduler.schedule {
-        do {
-            try await configureAsync(app)
-        } catch {
-            configurationError = error
-        }
-        semaphore.signal()
-    }
-    semaphore.wait()
-    if let configurationError {
-        throw configurationError
-    }
-}
-
-private func configureAsync(_ app: Application) async throws {
+func configure(_ app: Application) async throws {
     let storageFolder = URL(fileURLWithPath: app.directory.resourcesDirectory)
     
     let configPath = URL(fileURLWithPath: app.directory.resourcesDirectory)
@@ -45,7 +29,7 @@ private func configureAsync(_ app: Application) async throws {
         name: "Status",
         description: "The main status of the server")
     
-    _ = try? await status.update(.initializing)
+    try await status.update(.initializing)
 
     app.http.server.configuration.port = configuration.serverPort
 
@@ -69,7 +53,7 @@ private func configureAsync(_ app: Application) async throws {
         try await app.autoMigrate()
     } catch {
         await monitor.log("Failed to migrate database: \(error)")
-        _ = try? await status.update(.initializationFailure)
+        try await status.update(.initializationFailure)
         return
     }
 
@@ -79,15 +63,6 @@ private func configureAsync(_ app: Application) async throws {
     let db = app.databases.database(.sqlite, logger: .init(label: "Init"), on: app.databases.eventLoopGroup.next())!
     server = try await SQLiteDatabase(database: db, mail: configuration.mail)
     
-    // Gracefully shut down by closing potentially open socket
-    DispatchQueue.global(qos: .utility).asyncAfter(deadline: .now() + .seconds(5)) {
-        _ = app.server.onShutdown.always { _ in
-            scheduler.schedule {
-                await server.disconnectAllSockets()
-            }
-        }
-    }
-
     // register routes
     routes(app)
 
@@ -96,7 +71,14 @@ private func configureAsync(_ app: Application) async throws {
     provider.asyncScheduler = scheduler
     provider.registerRoutes(app)
 
-    _ = try? await status.update(.nominal)
+    try await status.update(.nominal)
+}
+
+func shutdown() {
+    scheduler.schedule {
+        await server.disconnectAllSockets()
+        try await scheduler.shutdownGracefully()
+    }
 }
 
 func log(_ message: String) {

Sources/App/entrypoint.swift

@@ -0,0 +1,43 @@
+import Vapor
+import Dispatch
+import Logging
+
+/// This extension is temporary and can be removed once Vapor gets this support.
+private extension Vapor.Application {
+    static let baseExecutionQueue = DispatchQueue(label: "vapor.codes.entrypoint")
+    
+    func runFromAsyncMainEntrypoint() async throws {
+        try await withCheckedThrowingContinuation { continuation in
+            Vapor.Application.baseExecutionQueue.async { [self] in
+                do {
+                    try self.run()
+                    continuation.resume()
+                } catch {
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+    }
+}
+
+@main
+enum Entrypoint {
+    static func main() async throws {
+        var env = try Environment.detect()
+        try LoggingSystem.bootstrap(from: &env)
+        
+        let app = Application(env)
+        defer {
+            shutdown()
+            app.shutdown()
+        }
+        
+        do {
+            try await configure(app)
+        } catch {
+            app.logger.report(error: error)
+            throw error
+        }
+        try await app.runFromAsyncMainEntrypoint()
+    }
+}

Sources/Run/main.swift

@@ -1,10 +0,0 @@
-import App
-import Vapor
-
-var env = try Environment.detect()
-try LoggingSystem.bootstrap(from: &env)
-let app = Application(env)
-defer { app.shutdown() }
-
-try configure(app)
-try app.run()

Tests/AppTests/AppTests.swift

@@ -1,15 +0,0 @@
-@testable import App
-import XCTVapor
-
-final class AppTests: XCTestCase {
-    func testHelloWorld() throws {
-        let app = Application(.testing)
-        defer { app.shutdown() }
-        try configure(app)
-
-        try app.test(.GET, "hello", afterResponse: { res in
-            XCTAssertEqual(res.status, .ok)
-            XCTAssertEqual(res.body.string, "Hello, world!")
-        })
-    }
-}