Add async version of wait, add run and asyncRun (#243)

* Add async version of wait, add run and asyncRun `wait` stalls the thread it is running on. If that thread is used by the task executor it will mean running Tasks could stall. Added `asyncWait` to run application on a separate DispatchQueue. Also added a `run` and `asyncRun` which is a combination of `start` and `wait` * Update Sources/Hummingbird/Application.swift Co-authored-by: Joannis Orlandos <[email protected]> * Update Sources/Hummingbird/Application.swift Co-authored-by: Joannis Orlandos <[email protected]> * PR changes requested --------- Co-authored-by: Joannis Orlandos <[email protected]>
hummingbird-project · Oct 6, 2023 · 3c7f440 · 3c7f440
1 parent 0adb5e6
commit 3c7f440
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Showing 2 changed files with 51 additions and 5 deletions.
diff --git a/Sources/Hummingbird/Application.swift b/Sources/Hummingbird/Application.swift
@@ -174,7 +174,26 @@ public final class HBApplication: HBExtensible {
 
     // MARK: Methods
 
-    /// Run application
+    /// Start application and wait for it to stop
+    ///
+    /// This function can only be called from a non async context as it stalls
+    /// the current thread waiting for the application to finish
+    @available(*, noasync, message: "Use HBApplication.asyncRun instead.")
+    public func run() throws {
+        try self.start()
+        self.wait()
+    }
+
+    /// Start application and wait for it to stop
+    ///
+    /// Version of `run` that can be called from asynchronous context
+    @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+    public func asyncRun() async throws {
+        try self.start()
+        await self.asyncWait()
+    }
+
+    /// Start application
     public func start() throws {
         var startError: Error?
         let startSemaphore = DispatchSemaphore(value: 0)
@@ -187,11 +206,25 @@ public final class HBApplication: HBExtensible {
         try startError.map { throw $0 }
     }
 
-    /// wait while server is running
+    /// Wait until server has stopped running
+    ///
+    /// This function can only be called from a non async context as it stalls
+    /// the current thread waiting for the application to finish
+    @available(*, noasync, message: "Use HBApplication.asyncWait instead.")
     public func wait() {
         self.lifecycle.wait()
     }
 
+    /// Wait until server has stopped running
+    ///
+    /// Version of `wait`` that can be called from asynchronous context
+    @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+    public func asyncWait() async {
+        await self.onExecutionQueue { app in
+            app.wait()
+        }
+    }
+
     /// Shutdown application
     public func stop() {
         let stopSemaphore = DispatchSemaphore(value: 0)
@@ -218,4 +251,18 @@ public final class HBApplication: HBExtensible {
             try self.eventLoopGroup.syncShutdownGracefully()
         }
     }
+
+    /// Run closure on private execution queue
+    @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+    private func onExecutionQueue(_ process: @Sendable @escaping (HBApplication) -> Void) async {
+        let unsafeApp = HBUnsafeTransfer(self)
+        await withCheckedContinuation { continuation in
+            HBApplication.executionQueue.async {
+                process(unsafeApp.wrappedValue)
+                continuation.resume()
+            }
+        }
+    }
+
+    private static let executionQueue = DispatchQueue(label: "hummingbird.execution")
 }
diff --git a/Sources/PerformanceTest/main.swift b/Sources/PerformanceTest/main.swift
@@ -18,7 +18,7 @@ import NIOPosix
 
 // get environment
 let hostname = HBEnvironment.shared.get("SERVER_HOSTNAME") ?? "127.0.0.1"
-let port = HBEnvironment.shared.get("SERVER_PORT", as: Int.self) ?? 8080
+let port = HBEnvironment.shared.get("SERVER_PORT", as: Int.self) ?? 8081
 
 // create app
 let elg = MultiThreadedEventLoopGroup(numberOfThreads: 2)
@@ -54,5 +54,4 @@ app.router.get("json") { _ in
 }
 
 // run app
-try app.start()
-app.wait()
+try app.run()