UE4 Sockets多线程TCP通信

转自：https://blog.****.net/zilisen/article/details/75007447

一、简介

UE4引擎是提供了Sockets模块和Networking模块的，博主在研究此功能时也是参考的Sockets模块和Networking模块的源码，其中引擎为我们提供了一些实例类很有参考价值，比如Sockets模块中的MultichannelTcpReceiver.h和MultichannelTcpSender.h，Networking模块中的UdpSocketReceiver.h和UdpSocketSender.h。博主的例子就是研究参考了以上代码写出来的。

编译与运行环境

UnrealEngine 4.15 ， Visual Studio 2015

实现功能介绍

博主的例子实现的是一个使用Socket多线程TCP通信的客户端。在主线程中发消息，子线程中收消息。当然也能类似的实现两个子线程分别收发消息。Socket相关函数都定义在了GameInstance中，以便我们能在不同场景都能调用。

二、代码实现

服务器代码

此处使用了一个有简单收发功能的服务器，用VS2015新建空项目即可：

//SocketTest.cpp: Defines the entry point for the console application

#include <stdio.h>
#include <string>
#include <iostream>
#include <WinSock2.h>
#include <WS2tcpip.h>
#pragma comment(lib, "WS2_32.lib")

using namespace std;

int main()
{
    WSADATA wsaData;
    SOCKET serverSock;
    SOCKADDR_IN serverAddr;
    SOCKET clientSock;
    SOCKADDR_IN clientAddr;

    cout << "Server Start!" << endl;
    //加载套接字库
    int err = WSAStartup(MAKEWORD(, ), &wsaData);
    if ( != err)
    {
        cout << "WSAStartup failed!" << endl;
        return ;
    }

    //构造监听SOCKET，流式SOCKET
    serverSock = socket(AF_INET, SOCK_STREAM, );
    //配置监听地址和端口
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons();  //本地监听端口：4399
    serverAddr.sin_addr.S_un.S_addr = INADDR_ANY;

    //绑定SOCKET
    int retVal = bind(serverSock, (SOCKADDR*)&serverAddr, sizeof(serverAddr));
    if (SOCKET_ERROR == retVal)
    {
        cout << "bind failed!" << endl;
        closesocket(serverSock);
        WSACleanup();
        return -;
    }

    retVal = listen(serverSock, );
    if (SOCKET_ERROR == retVal)
    {
        cout << "listen failed!" << endl;
        closesocket(serverSock);
        WSACleanup();
        return -;
    }

    char IPdot[] = { '\0' };
    inet_ntop(AF_INET, (void*)&serverAddr.sin_addr, IPdot, );
    printf("Welcome,the Host %s is running!Now Wating for someone comes in!\n", IPdot);

    int addrClientlen = sizeof(clientAddr);
    //等待客户端连接
    clientSock = accept(serverSock, (SOCKADDR*)&clientAddr, &addrClientlen);
    while ()
    {
        //发送数据
        char sendBuff[];
        //sprintf_s(sendBuff, "welcome %s to here", inet_ntoa(clientAddr.sin_addr));
        char IPdotdec[] = { '\0' };
        inet_ntop(AF_INET, (void*)&clientAddr.sin_addr, IPdotdec, );
        sprintf_s(sendBuff, "From Server: welcome %s to here", IPdotdec);
        send(clientSock, sendBuff, strlen(sendBuff) + , );

        //接收数据
        char recvBuff[];
        recv(clientSock, recvBuff, , );
        printf(" %s \n\n", recvBuff);

        Sleep();
    }
    //关闭套接字，关闭加载的套接字库
    closesocket(serverSock);
    WSACleanup();
    return ;
}

模块添加

新建项目，在.Build.cs文件中添加Sockets模块和Networking模块：

// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.

using UnrealBuildTool;

public class SocketThread : ModuleRules
{
    public SocketThread(TargetInfo Target)
    {
        PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "HeadMountedDisplay","Sockets", "Networking" });
    }
}

Socket相关函数定义

STGameInstance.h

//this is the STGameInstance.h

#pragma once

#include "Engine/GameInstance.h"
#include "Networking.h"
#include "ReceiveThread.h"
#include "STGameInstance.generated.h"

UCLASS()
class SOCKETTHREAD_API USTGameInstance : public UGameInstance
{
    GENERATED_BODY()

public:
    //创建Socket并连接到服务器（主线程）
    UFUNCTION(BlueprintCallable, Category = "MySocket")
    bool SocketCreate(FString IPStr, int32 port);

    //发消息(主线程)
    UFUNCTION(BlueprintCallable, Category = "MySocket")
    bool SocketSend(FString message);

    //收消息(子线程)
    UFUNCTION(BlueprintCallable, Category = "MySocket")
    bool SocketReceive();

    UFUNCTION(BlueprintCallable, Category = "MySocket")
    bool ThreadEnd();

    FString StringFromBinaryArray(TArray<uint8> BinaryArray);

public:
    FSocket *Host;
    FIPv4Address ip;
    FRunnableThread* m_RecvThread;
};

STGameInstance.cpp

//this is the STGameInstance.cpp

#include "SocketThread.h"
#include "STGameInstance.h"

bool USTGameInstance::SocketCreate(FString IPStr, int32 port)
{
    FIPv4Address::Parse(IPStr, ip);     //将传入的IPStr转为IPv4地址

    //创建一个addr存放ip地址和端口
    TSharedPtr<FInternetAddr> addr = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateInternetAddr();
    addr->SetIp(ip.Value);
    addr->SetPort(port);

    //创建客户端socket
    Host = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateSocket(NAME_Stream, TEXT("default"), false);

    //连接成功
    if (Host->Connect(*addr))
    {
        UE_LOG(LogTemp, Warning, TEXT("Connect Succeed!"));
        return true;
    }
    //连接失败
    else
    {
        UE_LOG(LogTemp, Warning, TEXT("Connect Failed!"));
        return false;
    }
}

bool USTGameInstance::SocketSend(FString message)
{
    TCHAR *seriallizedChar = message.GetCharArray().GetData();
    int32 size = FCString::Strlen(seriallizedChar) + ;
    int32 sent = ;

    if (Host->Send((uint8*)TCHAR_TO_UTF8(seriallizedChar), size, sent))
    {
        UE_LOG(LogTemp, Warning, TEXT("___Send Succeed!"));
        return true;
    }
    else
    {
        UE_LOG(LogTemp, Warning, TEXT("___Send Failed!"));
        return false;
    }
}

bool USTGameInstance::SocketReceive()
{
    m_RecvThread = FRunnableThread::Create(new FReceiveThread(Host), TEXT("RecvThread"));
    return true;
}

bool USTGameInstance::ThreadEnd()
{
    if (m_RecvThread != nullptr)
    {
        m_RecvThread->Kill(true);
        delete m_RecvThread;
    }
    return true;
}

FString USTGameInstance::StringFromBinaryArray(TArray<uint8> BinaryArray)
{
    return FString(ANSI_TO_TCHAR(reinterpret_cast<const char*>(BinaryArray.GetData())));
}

收消息线程

ReceiveThread.h

//this is the ReceiveThread.h
#pragma once

#include "ThreadingBase.h"
#include "Networking.h"

class SOCKETTHREAD_API FReceiveThread : public FRunnable
{
public:
    FReceiveThread(FSocket* client): m_Client(client)
    {}
    ~FReceiveThread()
    {
        stopping = true;
    }

    virtual bool Init() override
    {
        stopping = false;
        return true;
    }

    virtual uint32 Run() override
    {
        if (!m_Client)
        {
            return ;
        }

        TArray<uint8> ReceiveData;
        uint8 element = ;
        //接收数据包
        while (!stopping)   //线程计数器控制
        {
            ReceiveData.Init(element, 1024u);
            int32 read = ;
            m_Client->Recv(ReceiveData.GetData(), ReceiveData.Num(), read);
            const FString ReceivedUE4String = FString(ANSI_TO_TCHAR(reinterpret_cast<const char*>(ReceiveData.GetData())));
            FString log = "Server:" + ReceivedUE4String;
            UE_LOG(LogTemp, Warning, TEXT("*** %s"), *log);

            FPlatformProcess::Sleep(0.01f);
        }

        return ;
    }

    virtual void Stop() override
    {
        stopping = true;    //计数器-1
    }

private:
    FSocket* m_Client;  //客户端套接字
    bool stopping;      //循环控制
    FThreadSafeCounter m_StopTaskCounter;   //线程引用计数器
};

三、运行

在编辑器中，创建我们之前定义的GameInstance的蓝图类，并在Project Setting中设其为默认GameInstance。创建一个GameMode，在他的EventGraph中添加如下蓝图逻辑：

其中Succe是一个bool类型变量，Index是一个Int类型变量，不改默认值。 
之后将这个GameMode绑定到当前场景中，编译运行服务器，然后Play，大功告成！博主运行结果如下：

可以看到，收发消息都成功了。