异步TCP读取期间的Stackoverflow

Question

最后一个适合这个网站的问题。

    public class Client {

        public TcpClient tcpClient;

        public NetworkStream stream;

        public CancellationTokenSource cts = new CancellationTokenSource();

        private byte[] readBuffer = new byte[1024];

        private StringBuilder receiveString = new StringBuilder();


        public Client(TcpClient tcpClient) {
            this.tcpClient = tcpClient;
            this.stream = this.tcpClient.GetStream();
        }

        public void StartReadAsync(){
            ReadAsync(cts.Token);
        }

        private async Task ReadAsync(CancellationToken ct) {
          // Stackoverflow exception occurs on next line after 20-30 mins
            int amountRead = await stream.ReadAsync(readBuffer, 0, readBuffer.Length, ct);
            if (amountRead > 0) {
                string message = Encoding.UTF8.GetString(readBuffer, 0, amountRead);
                receiveString.Append(message);
                Console.WriteLine("Client " + name + " sent: " + message);

                if (receiveString.ToString().IndexOf(eof) > -1) {
                    // Full message received, otherwise keep reading
                    if (OnClientRead != null)
                        OnClientRead(this, new SocketEventArgs(this, receiveString.ToString()));
                    receiveString.Clear();
                }
            }
            ReadAsync(ct);
        }
    }

Answer 1

您正在执行一个重入调用，ReadAsync再次调用ReadAsync，所以是的，您将结束一个StackOverflow异常。

将代码更改为：

public class Client 
{

    public TcpClient tcpClient;

    public NetworkStream stream;

    public CancellationTokenSource cts = new CancellationTokenSource();

    private byte[] readBuffer = new byte[1024];

    private StringBuilder receiveString = new StringBuilder();


    public Client(TcpClient tcpClient) {
        this.tcpClient = tcpClient;
        this.stream = this.tcpClient.GetStream();
    }

    public async void StartReadAsync(){

        while(await ReadAsync(cts.Token));
    }

    private async Task<bool> ReadAsync(CancellationToken ct) 
    {

        try
        {
            int amountRead = await stream.ReadAsync(readBuffer, 0, readBuffer.Length, ct);
            if (amountRead > 0)
            {
                string message = Encoding.UTF8.GetString(readBuffer, 0, amountRead);
                receiveString.Append(message);
                Console.WriteLine("Client " + name + " sent: " + message);

                if (receiveString.ToString().IndexOf(eof) > -1)
                {
                    // Full message received, otherwise keep reading
                    if (OnClientRead != null)
                        OnClientRead(this, new SocketEventArgs(this, receiveString.ToString()));
                    receiveString.Clear();
                }

                return true;
            }

            return false;
        }
        catch { return false; }

    }
}