Server gets stuck on stop

[tranquvis]

I have the following test in my XCTestCase, which should demonstrate the problem.

let mockServer = MockServer()
mockServer.start()

mockServer.router["/test"] = JSONResponse() { _ -> NSDictionary in
    print("request received")
    return [:]
}

print("Send request")
URLSession(configuration: URLSessionConfiguration.default)
    .dataTask(with: URL(string: "http://localhost:8080/test")!)
    .resume()

sleep(3) // Any action or tear down delay.
print("stop mock server")
mockServer.stop() // Never ends
print("mock server stopped")

MockServer is a wrapper I have made, which handles starting and stopping the server.
I followed your gist about running the server.

class MockServer {
    let router = Router()
    private let server: HTTPServer
    private let serverDispatchQueue = DispatchQueue(label: "com.timr.uitest.serverDispatchQueue", qos: .background)
    private let eventLoop: EventLoop
    private var eventLoopThreadCondition = NSCondition()
    
    init() {
        eventLoop = try! SelectorEventLoop(selector: try! KqueueSelector())
        server = DefaultHTTPServer(
            eventLoop: eventLoop,
            port: 8080,
            app: router.app
        )
    }
    
    func start() {
        try! server.start()
        eventLoopThreadCondition = NSCondition()
        serverDispatchQueue.async() {
            self.eventLoop.runForever()
            self.eventLoopThreadCondition.lock()
            self.eventLoopThreadCondition.signal()
            self.eventLoopThreadCondition.unlock()
        }
    }
    
    func stop() {
        server.stopAndWait()
        eventLoopThreadCondition.lock()
        eventLoop.stop()
        let stopEventLoopTimeout = 10.0
        while eventLoop.running {
            if !eventLoopThreadCondition.wait(until: Date(timeIntervalSinceNow: stopEventLoopTimeout)) {
                fatalError("Join eventLoopThread timeout")
            }
        }
    }
}

The problem is that the test never ends because it gets stuck at server.stopAndWait().
I get this output:

Send request
request received
stop mock server

As I digged a bit deeper I found out that the last event loop round does not finish. So the action awaited in stopAndWait, which is passed to eventLoop.call never gets called.
runOncein EventLoop gets stuck at events = try selector.select(timeout: timeout).

Would be great if you could take a look on this issue @fangpenlin. This problem is a bit too deep for me.

[patricks]

Hi, I had the same problem. You have to disable the swift compiler optimization. see envoy/Embassy#31