如何计算在 Kotlin 中创建的线程数？

Posted 2023-04-18

【中文标题】如何计算在 Kotlin 中创建的线程数？

【英文标题】：How to count number of threads created in Kotlin?

【发布时间】：2022-01-17 19:06:44

【问题描述】：

我有套接字编程，我正在为每个客户端创建新线程并使用具有多线程的应用程序，如下所示。

fun ClientHandler() 
        try 
            var count = 0
            var serverSocket = ServerSocket(5000)

            while (true) 
                val socket: Socket = serverSocket!!.accept()
                count++
                socket.reuseAddress = true
                _log("$socket.remoteSocketAddress Client Connected. Connected client count is $count")
                Thread(ServerThread(socket)).start() //Here i'm creating Threads. 
            
         catch (e: ConnectException) 
            _logEx("UnExpected connection error", e)
         catch (ex: IOException) 
            _logEx("ClientHandler", ex)
         catch (e: Exception) 
            _logEx("ServerSocketHandler ", e)
        



internal inner class ServerThread(socket: Socket) : Runnable  
    private val client: Socket = socket
    private val reader: Scanner = Scanner(client.getInputStream())
    private val writer = PrintStream(client.getOutputStream())
    private var receiveString: String = ""
    override fun run() 
        try 
            while(reader.hasNextLine())
                receiveString = reader.nextLine() ?: ""
                _log("Message received: " + receiveString)
                if (receiveString != null && receiveString != "") 
                    checkMessage(receiveString, writer,client)
                
            
         catch (ex: Exception) 
            _log("Cannot read the message. Please try again")
            //_log(ex.localizedMessage)
            val spReq = Error()
            spReq.sendErrorMsg(writer, "Cannot read the message. Please try again",client)
        
    

更新 我也添加了 ServerThread 代码部分。

如何关注他们并获得他们的状态？

【问题讨论】：

跟踪他们是什么意思？定期检查他们的状态？检查他们是否被杀？

@DiegoMarcher 是的，我想获得他们的状态？（活着、睡觉或被杀）以及他们有多少？

然后我只需创建一个包含所有已创建线程的 Map 以供进一步参考

@DiegoMarcher 你能举个例子吗？我是 Kotlin 的新手

我会把它作为答案发布

【参考方案1】：

您可以通过 Map 来跟踪线程及其状态以供进一步参考

fun ClientHandler() 
    try 
        var count = 0
        val serverSocket = ServerSocket(5000)

        while (true) 
            val socket: Socket = serverSocket.accept()
            count++
            socket.reuseAddress = true
            threads["thread name here"] = ServerThread(socket)
        
     catch (e: ConnectException) 
        e.printStackTrace()
     catch (e: IOException) 
        e.printStackTrace()
     catch (e: Exception) 
        e.printStackTrace()
    


fun stopServerThread(threadName: String) 
    threads[threadName]?.interrupt()


internal inner class ServerThread(private val client: Socket) : Thread()  
    private val reader = Scanner(client.getInputStream())
    private val writer = PrintStream(client.getOutputStream())
    private var receiveString: String = ""
    
    init 
        start()
    
    
    override fun run() 
        try 
            while(reader.hasNextLine())
                if (isInterrupted) 
                    break
                
                receiveString = reader.nextLine() ?: ""
                if (receiveString != "") 
                    checkMessage(receiveString, writer, client)
                
            
         catch (ex: Exception) 
            _log("Cannot read the message. Please try again")
            //_log(ex.localizedMessage)
            val spReq = Error()
            spReq.sendErrorMsg(writer, "Cannot read the message. Please try again",client)
        
    

【讨论】：

好的，但是 checkSocketThred 应该是可运行的，对吧？你写的是正常的功能。

看你想在哪里调用它，你可以在一个单独的线程中进行这个检查，你可以让线程进行自检。我不确定你想在这里实现什么......

我正在尝试创建线程，在该线程中我正在打开套接字接收和发送消息，然后关闭套接字......但线程保持打开并在应用程序上休眠（我在 Profiler android Studio 上观看) 我担心会炸毁内存....

能否贴出原题中的ServerThread代码内容？

发布的ServerThread