[유니티 네트워크] 비동기 UdpSender, UdpReceiver 구조체 전송 (UdpClient)

1. 내용

 (1) 권장 포트 번호 : 49152 ~ 65535

 

포트 번호	내용
0	사용하지 않음.
1 ~1023	잘 알려진 포트(Well-known port)
1024 ~ 49151	등록된 포트(Registered port)
49152 ~ 65535	동적 포트(Dynamic port)

 

 (2) 전송 패키지 사이즈

 Udp는 이론상으로는 65507 byte까지 보낼수 있지만, 내부 통신이 아닌 경우 1024 byte이내를 권장합니다.

 

 (3) 소스 내용

  - 유니티와 유니티, 또는 C#과의 통신, 또는 C++와의 통신

  - 클래스 : UdpClient

  - 개체 직렬화 : Marshal

  - 전송 패킷 : 구조체 ↔ 바이트 배열

 

2. 소스

2.1 Receiver.cs 

using UnityEngine;
using System;
using System.Net;
using System.Net.Sockets;
using System.Runtime.InteropServices;

public class Receiver : MonoBehaviour
{
    private UdpClient m_Receive;
    public int m_Port = 50001;
    public Packet m_ReceivePacket = new Packet();
    private byte[] m_ReceiveBytes;


    void Awake()
    {
        InitReceiver();
    }

    void OnApplicationQuit()
    {
        CloseReceiver();
    }

    void InitReceiver()
    {
        try
        {
            if (m_Receive == null)
            {
                m_Receive = new UdpClient(m_Port);
                m_Receive.BeginReceive(new AsyncCallback(DoBeginReceive), null);
            }
        }
        catch (SocketException e)
        {
            Debug.Log(e.Message);
        }
    }

    void DoBeginReceive(IAsyncResult ar)
    {
        IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Any, m_Port);


        if (m_Receive != null)
        {
            m_ReceiveBytes = m_Receive.EndReceive(ar, ref ipEndPoint);
        }

        else
        {
            return;
        }

        m_Receive.BeginReceive(new AsyncCallback(DoBeginReceive), null);
        DoReceive();
    }

    void DoReceive()
    {
        m_ReceivePacket = ByteArrayToStruct<Packet>(m_ReceiveBytes);

        // 받은 값 처리 ... 
        Debug.LogFormat($"BoolVariable = {m_ReceivePacket.m_BoolVariable} " +
            $"IntlVariable = {m_ReceivePacket.m_IntVariable} " +
            $"m_IntArray[0] = {m_ReceivePacket.m_IntArray[0]} " +
            $"m_IntArray[1] = {m_ReceivePacket.m_IntArray[1] } " +
            $"FloatlVariable = {m_ReceivePacket.m_FloatlVariable} " +
            $"StringlVariable = {m_ReceivePacket.m_StringlVariable}");
        //출력: BoolVariable = True IntlVariable = 2941 m_IntArray[0] = 0 m_IntArray[1] = 1 FloatlVariable = 34.06423 StringlVariable = CoderZero 코더제로 
    }

    void CloseReceiver()
    {
        if (m_Receive != null)
        {
            m_Receive.Close();
            m_Receive = null;
        }
    }

    T ByteArrayToStruct<T>(byte[] buffer) where T : struct
    {
        int size = Marshal.SizeOf(typeof(T));
        if (size > buffer.Length)
        {
            throw new Exception();
        }

        IntPtr ptr = Marshal.AllocHGlobal(size);
        Marshal.Copy(buffer, 0, ptr, size);
        T obj = (T)Marshal.PtrToStructure(ptr, typeof(T));
        Marshal.FreeHGlobal(ptr);
        return obj;
    }
}

 

2.2 Sender.cs

using UnityEngine;
using System;
using System.Net;
using System.Net.Sockets;
using System.Runtime.InteropServices;

public class Sender : MonoBehaviour
{
    private UdpClient m_Sender;
    public string m_ReceiverIp = "127.0.0.1";
    public int m_Port = 50001;
    public Packet m_SendPacket = new Packet();
    private byte[] m_SendBytes;

    void Start()
    {
        InitSender();
    }

    void Update()
    {
        SetSendPacket();
        DoBeginSend(m_SendBytes);
    }

    void OnApplicationQuit()
    {
        CloseSender();
    }

    void InitSender()
    {
        m_Sender = new UdpClient();
        m_Sender.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
        m_Sender.Connect(IPAddress.Parse(m_ReceiverIp), m_Port);
    }

    void SetSendPacket()
    {
        m_SendPacket.m_BoolVariable = !m_SendPacket.m_BoolVariable;
        m_SendPacket.m_IntVariable++;
        if (m_SendPacket.m_IntVariable >= int.MaxValue - 1)
            m_SendPacket.m_IntVariable = default(int);

        m_SendPacket.m_IntArray = new int[2];
        m_SendPacket.m_IntArray[0] = 0;
        m_SendPacket.m_IntArray[1] = 1;
        m_SendPacket.m_FloatlVariable = UnityEngine.Random.Range(0f, 100.0f);
        m_SendPacket.m_StringlVariable = "CoderZero 코더제로";

        m_SendBytes = StructToByteArray(m_SendPacket);
    }

    void DoBeginSend(byte[] packets)
    {
        m_Sender.BeginSend(packets, packets.Length, new AsyncCallback(SendCallback), m_Sender);
    }

    void SendCallback(IAsyncResult ar)
    {
        UdpClient udpClient = (UdpClient)ar.AsyncState;
    }

    void CloseSender()
    {
        if (m_Sender != null)
        {
            m_Sender.Close();
            m_Sender = null;
        }
    }

    byte[] StructToByteArray(object obj)
    {
        int size = Marshal.SizeOf(obj);
        byte[] arr = new byte[size];
        IntPtr ptr = Marshal.AllocHGlobal(size);

        Marshal.StructureToPtr(obj, ptr, true);
        Marshal.Copy(ptr, arr, 0, size);
        Marshal.FreeHGlobal(ptr);
        return arr;
    }
}

 

2.3 Packets.cs

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
[Serializable]
public struct Packet
{
    [MarshalAs(UnmanagedType.Bool)]
    public bool m_BoolVariable;
    public int m_IntVariable;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
    public int[] m_IntArray;
    public float m_FloatlVariable;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
    public string m_StringlVariable;
}