怎么提高recv()的速度

[kmij261]

用socket发送文件，局域网，测试文件是大约100k的图片，发送端需要40ms左右，但是接收的时候单是recv（）就需要600ms。。。两边都是阻塞模式。不知道怎么改进。。代码如下

#include"stdafx.h"
#include <stdio.h>
#include <stdlib.h>
//#include <string.h>
#include <WinSock2.h>
#include"iostream"
#include"opencv2/opencv.hpp"

using namespace cv;
using namespace std;
#define PORT 8000
#define SERVER_IP "192.168.1.108"
#define BUFFER_SIZE 4096
#define FILE_NAME_MAX_SIZE 512
#pragma comment(lib, "WS2_32")

double rate = 2.0;//视频帧率
Size videosize(640,480);

int64 startTime ;//开始运行程序时的时钟周期数
double duration;//运行到现在所用时间

const string &filename="objtr";//文件名
const string &ext = ".jpg";//文件后缀名
void recvFile(char file_name[FILE_NAME_MAX_SIZE], SOCKET clientSocket);
double timeCost(int64 beginTime);

int main()
{
	int i=1;
	//创建视频写入实例
	VideoWriter writer("VideoTest.avi", CV_FOURCC('M', 'J', 'P', 'G'), rate,videosize); 
	
	stringstream ss;
	char file_name[FILE_NAME_MAX_SIZE+1];
	memset(file_name,0,FILE_NAME_MAX_SIZE+1);
	
	// 初始化socket dll
	WSADATA wsaData;
	WORD socketVersion = MAKEWORD(2, 0);
	if(WSAStartup(socketVersion, &wsaData) != 0)
	{
		printf("Init socket dll error!");
		exit(1);
	}
	
	//创建socket
	SOCKET clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (SOCKET_ERROR == clientSocket)
	{
		printf("Create Socket Error!");
		system("pause");
		exit(1);
	}
	cout << "创建socket成功" <<endl;
	

	//指定服务端的地址
	sockaddr_in server_addr;
	server_addr.sin_family = AF_INET;
	server_addr.sin_addr.S_un.S_addr = inet_addr(SERVER_IP);
	server_addr.sin_port = htons(PORT);

	if (SOCKET_ERROR == connect(clientSocket, (LPSOCKADDR)&server_addr, sizeof(server_addr)))
	{
		printf("Can Not Connect To Server IP!\n");
		system("pause");
		exit(1);
	}
	cout << "连接服务器成功" <<endl;
	
	while(1)
	{
		startTime = getTickCount();//读取系统周期数

		ss << filename << i << ext ;
		ss >> file_name;

		duration = timeCost(startTime);
		recvFile(file_name,clientSocket);//接收并写入文件
		duration = timeCost(startTime)- duration;
		cout << "文件 "<<file_name<< "接收成功，"<< "接收文件所用时间：" << duration << "s"  <<endl;
		
		Mat frame = imread(file_name);
		if (frame.empty())
			cout<< "图片读取失败" <<endl;
			return -2;

		writer << frame;
		imshow("display",frame);

		send(clientSocket,"~", 1, 0);//服务器接收此标志再发送下一帧
		ss.clear();
		i++;
		duration = timeCost(startTime);
		cout<< "本次用时：" << duration << "s" <<endl<<endl;
		
	}
	closesocket(clientSocket);
	
	//释放winsock库
	WSACleanup();

	return 0;
}

void recvFile(char file_name[FILE_NAME_MAX_SIZE+1], SOCKET clientSocket)
{
	int recvLen=0;//收到的缓冲的长度
    int recvedLen=0;//当前已经收到的长度
    char* buffer;//文件缓冲
    char  recvBuffer[BUFFER_SIZE];//接收缓冲区
	int retval;
	
	
    buffer=new char[1024*300];
	
    while(true)
    {
		recvLen=recv(clientSocket,recvBuffer,BUFFER_SIZE, 0);
        if((recvLen==1)&&(recvBuffer[0]=='#'))//"#"为服务器发送文件结束标志
            break;
		else
		{
        memcpy(buffer+recvedLen,recvBuffer,recvLen);
        recvedLen += recvLen;    
		}
    }
	printf("已经接收%i字节数据\n",recvedLen);
	
	cout << "开始写入" <<endl;
	FILE *fp = NULL;
	if((fp = fopen(file_name,"wb")) == NULL)
	{
		cout << "文件 "<<file_name<< "接收成功" <<endl;
		exit(1);
	}

	retval = fwrite(buffer, recvedLen, 1, fp);
	fclose(fp);
	
}

double timeCost(int64 beginTime)
{
	double duration;	
	duration = (getTickCount()-beginTime)/getTickFrequency();

	return duration ;
}

[56625079]

用非阻塞模式试试？