使用CocoaMQTT开发命令行客户端无法完成MQTT 3.1.1 Broker连接的问题求助

各位好，我现在用CocoaMQTT开发一个命令行客户端，连接MQTT 3.1.1协议的Broker时遇到了棘手的问题，想请大家帮忙排查下。

环境信息 #

• 系统：macOS 15.5
• Xcode版本：16.2
• CocoaMQTT版本：2.1.19
• Broker：Mosquitto 2.0.21

问题现象 #

我调用connect()方法时返回了true，但实际连接状态始终是断开的。Broker的日志里能检测到新连接建立，但客户端一直显示为<unknown>，直到我关闭App，Broker才会记录连接关闭的日志。比如Broker的关键日志片段：

1748772860: New connection from 127.0.0.1:53415 on port 1883.
1748772873: Client <unknown> closed its connection.
1748772894: New connection from 127.0.0.1:53416 on port 1883.
1748772904: Client <unknown> closed its connection.

同时，Delegate类里的didConnectAck回调从来没有触发过，命令行的输出如下：

Status is disconnected
CocoaMQTT(error): socket connect error: Error Domain=MGCDAsyncSocketErrorDomain Code=1 "Attempting to connect while connected or accepting connections. Disconnect first." UserInfo={NSLocalizedDescription=Attempting to connect while connected or accepting connections. Disconnect first.}
Program ended with exit code: 0

另外我做了一个带UI的测试App，里面有连接、断开、订阅按钮，这个版本是完全正常的——我猜是因为UI程序自带主RunLoop处理异步事件，但命令行程序不知道该怎么处理这种异步逻辑。

我的代码 #

主程序代码：

import Foundation
import CocoaMQTT

let delegate = Delegate()
let defaultHost = "localhost"
let clientID = "CocoaMQTT-" + String(ProcessInfo().processIdentifier)
let mqtt = CocoaMQTT(clientID: clientID, host: defaultHost, port: 1883)
mqtt.logLevel = .debug
mqtt.username = ""
mqtt.password = ""
mqtt.willMessage = CocoaMQTTMessage(topic: "/will", string: "dieout")
mqtt.keepAlive = 60
mqtt.delegate = delegate

var state = mqtt.connect()
while state {
    print("Status is \(mqtt.connState)")
    sleep(5)
    if mqtt.connState == .connected {
        mqtt.subscribe("test/#")
    } else {
        state = mqtt.connect()
    }
}

Delegate类代码：

import Foundation
import CocoaMQTT

class Delegate: CocoaMQTTDelegate {
    func mqtt(_ mqtt: CocoaMQTT, didConnectAck ack: CocoaMQTTConnAck) {
        print("didConnectAck: \(ack)")
    }
    
    func mqtt(_ mqtt: CocoaMQTT, didPublishMessage message: CocoaMQTTMessage, id: UInt16) {
        print("didPublishMessage: \(message)")
    }
    
    func mqtt(_ mqtt: CocoaMQTT, didPublishAck id: UInt16) {
        print("didPublishAck: \(id)")
    }
    
    func mqtt(_ mqtt: CocoaMQTT, didReceiveMessage message: CocoaMQTTMessage, id: UInt16) {
        print("didReceiveMessage: \(message)")
    }
    
    func mqtt(_ mqtt: CocoaMQTT, didSubscribeTopics success: NSDictionary, failed: [String]) {
        print("didSubscribeTopics: \(success), \(failed)")
    }
    
    func mqtt(_ mqtt: CocoaMQTT, didUnsubscribeTopics topics: [String]) {
        print("didUnsubscribeTopics: \(topics)")
    }
    
    func mqttDidPing(_ mqtt: CocoaMQTT) {
        print("didPing")
    }
    
    func mqttDidReceivePong(_ mqtt: CocoaMQTT) {
        print("didReceivePong")
    }
    
    func mqttDidDisconnect(_ mqtt: CocoaMQTT, withError err: (any Error)?) {
        print("didDisconnect: \(err)")
    }
}

我想请教的问题 #

有没有大佬能告诉我，命令行程序里该怎么处理CocoaMQTT的异步连接逻辑？怎样才能让连接流程正常走完，触发Delegate的回调，并且让Broker正确识别我的客户端ID？

内容来源于stack exchange