UE4 Sockets多線程TCP通信

轉自：https://blog.csdn.net/zilisen/article/details/75007447

一、簡介

UE4引擎是提供了Sockets模塊和Networking模塊的，博主在研究此功能時也是參考的Sockets模塊和Networking模塊的源碼，其中引擎為我們提供了一些實例類很有參考價值，比如Sockets模塊中的MultichannelTcpReceiver.h和MultichannelTcpSender.h，Networking模塊中的UdpSocketReceiver.h和UdpSocketSender.h。博主的例子就是研究參考了以上代碼寫出來的。

編譯與運行環境

UnrealEngine 4.15 ， Visual Studio 2015

實現功能介紹

博主的例子實現的是一個使用Socket多線程TCP通信的客戶端。在主線程中發消息，子線程中收消息。當然也能類似的實現兩個子線程分別收發消息。Socket相關函數都定義在了GameInstance中，以便我們能在不同場景都能調用。

二、代碼實現

服務器代碼

此處使用了一個有簡單收發功能的服務器，用VS2015新建空項目即可：

//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;
    //加載套接字庫
    int err = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (0 != err)
    {
        cout << "WSAStartup failed!" << endl;
        return 1;
    }

    //構造監聽SOCKET，流式SOCKET
    serverSock = socket(AF_INET, SOCK_STREAM, 0);
    //配置監聽地址和端口
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(4399);  //本地監聽端口：4399
    serverAddr.sin_addr.S_un.S_addr = INADDR_ANY;

    //綁定SOCKET
    int retVal = bind(serverSock, (SOCKADDR*)&serverAddr, sizeof(serverAddr));
    if (SOCKET_ERROR == retVal)
    {
        cout << "bind failed!" << endl;
        closesocket(serverSock);
        WSACleanup();
        return -1;
    }

    retVal = listen(serverSock, 5);
    if (SOCKET_ERROR == retVal)
    {
        cout << "listen failed!" << endl;
        closesocket(serverSock);
        WSACleanup();
        return -1;
    }

    char IPdot[20] = { '\0' };
    inet_ntop(AF_INET, (void*)&serverAddr.sin_addr, IPdot, 16);
    printf("Welcome,the Host %s is running!Now Wating for someone comes in!\n", IPdot);

    int addrClientlen = sizeof(clientAddr);
    //等待客戶端連接
    clientSock = accept(serverSock, (SOCKADDR*)&clientAddr, &addrClientlen);
    while (1)
    {
        //發送數據
        char sendBuff[50];
        //sprintf_s(sendBuff, "welcome %s to here", inet_ntoa(clientAddr.sin_addr));
        char IPdotdec[20] = { '\0' };
        inet_ntop(AF_INET, (void*)&clientAddr.sin_addr, IPdotdec, 16);
        sprintf_s(sendBuff, "From Server: welcome %s to here", IPdotdec);
        send(clientSock, sendBuff, strlen(sendBuff) + 1, 0);

        //接收數據
        char recvBuff[50];
        recv(clientSock, recvBuff, 50, 0);
        printf(" %s \n\n", recvBuff);

        Sleep(1000);
    }
    //關閉套接字，關閉加載的套接字庫
    closesocket(serverSock);
    WSACleanup();
    return 0;
}

模塊添加

新建項目，在.Build.cs文件中添加Sockets模塊和Networking模塊：

// 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相關函數定義

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:
    //創建Socket並連接到服務器（主線程）
    UFUNCTION(BlueprintCallable, Category = "MySocket")
    bool SocketCreate(FString IPStr, int32 port);

    //發消息(主線程)
    UFUNCTION(BlueprintCallable, Category = "MySocket")
    bool SocketSend(FString message);

    //收消息(子線程)
    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);     //將傳入的IPStr轉為IPv4地址

    //創建一個addr存放ip地址和端口
    TSharedPtr<FInternetAddr> addr = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateInternetAddr();
    addr->SetIp(ip.Value);
    addr->SetPort(port);

    //創建客戶端socket
    Host = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateSocket(NAME_Stream, TEXT("default"), false);

    //連接成功
    if (Host->Connect(*addr))
    {
        UE_LOG(LogTemp, Warning, TEXT("Connect Succeed!"));
        return true;
    }
    //連接失敗
    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) + 1;
    int32 sent = 0;

    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())));
}

收消息線程

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 0;
        }

        TArray<uint8> ReceiveData;
        uint8 element = 0;
        //接收數據包
        while (!stopping)   //線程計數器控制
        {
            ReceiveData.Init(element, 1024u);
            int32 read = 0;
            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 1;
    }

    virtual void Stop() override
    {
        stopping = true;    //計數器-1
    }

private:
    FSocket* m_Client;  //客戶端套接字
    bool stopping;      //循環控制
    FThreadSafeCounter m_StopTaskCounter;   //線程引用計數器
};

三、運行

在編輯器中，創建我們之前定義的GameInstance的藍圖類，並在Project Setting中設其為默認GameInstance。創建一個GameMode，在他的EventGraph中添加如下藍圖邏輯： 

其中Succe是一個bool類型變量，Index是一個Int類型變量，不改默認值。 
之后將這個GameMode綁定到當前場景中，編譯運行服務器，然后Play，大功告成！博主運行結果如下： 

可以看到，收發消息都成功了。