多线程网络服务.md

• 一、多线程网络服务
• 二、代码实现
  • 2.1、utili.h
  • 2.2、ser.c
  • 2.3、cli.c
  • 2.4、运行结果
• 三、分析总结

一、多线程网络服务

多线程网络模式类似于多进程网络模式；不同的是：新客户端到来时，启动的是一个线程(每来一个客户，将创建一个线程)。

模型分析

二、代码实现

同样用处理整数运算来模拟多线程的并发处理。

2.1、utili.h

#include<unistd.h>
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<pthread.h>

#define SERVER_PORT  9090
#define SERVER_IP    "127.0.0.1"
#define LISTEN_QUEUE  5
#define BUFFER_SIZE   255


typedef enum{ADD,SUB,MUL,DIV,MOD, QUIT}OPER_TYPE;

typedef struct OperStruct{
    int op1;
    int op2;
    OPER_TYPE oper;
}OperStruct;

2.2、ser.c

#include"../utili.h"

void* Thread_Handler(void *arg);

void* Thread_Handler(void *arg){
    int sockConn = *(int *)arg;
    OperStruct op; 
    int result;
    while(1){
        int res = recv(sockConn, &op, sizeof(op), 0); 
        if(res == -1){
            printf("recv data fail.\n");
            continue;
        }   
        if(op.oper == ADD){
            result = op.op1 + op.op2;
        }else if(op.oper == SUB){
            result = op.op1 - op.op2;
        }else if(op.oper == MUL){
            result = op.op1 * op.op2;
        }else if(op.oper == DIV){
            result = op.op1 / op.op2;
        }else if(op.oper == QUIT){
            break;
        }   

        res = send(sockConn, &result, sizeof(result), 0); 
        if(res == -1){
            printf("send data fail.\n");
            continue;
        }
    }
    close(sockConn);
    pthread_exit(0);
}

int main(void){
    int sockSer = socket(AF_INET, SOCK_STREAM, 0);
    if(sockSer == -1){
        perror("socket");
        return -1;
    }
    struct sockaddr_in addrSer, addrCli;
    addrSer.sin_family = AF_INET;
    addrSer.sin_port = htons(SERVER_PORT);
    addrSer.sin_addr.s_addr = inet_addr(SERVER_IP);

    socklen_t len = sizeof(struct sockaddr);
    int res = bind(sockSer, (struct sockaddr*)&addrSer, len);
    if(res == -1){
        perror("bind");
        close(sockSer);
        return -1;        
   }

    listen(sockSer, LISTEN_QUEUE);

    int sockConn;
    while(1){
        printf("Server Wait Client Connect.......\n");
        sockConn = accept(sockSer, (struct sockaddr*)&addrCli, &len);
        if(sockConn == -1){
            printf("Server Accept Client Connect Fail.\n");
            continue;
        }else{
            printf("Server Accept Client Connect Success.\n");
            printf("Client IP:>%s\n", inet_ntoa(addrCli.sin_addr));
            printf("Client Port:>%d\n",ntohs(addrCli.sin_port));
        }

        pthread_t tid;
        pthread_create(&tid, NULL, Thread_Handler, &sockConn);        
    }
    close(sockSer);
    return 0;
}

2.3、cli.c

#include"utili.h"

void InputData(OperStruct *pt);

void InputData(OperStruct *pt){
    printf("please input op1 and op2 : ");
    scanf("%d %d", &(pt->op1), &(pt->op2));
}

//Cli
int main(void){
    int sockCli = socket(AF_INET, SOCK_STREAM, 0); 
    if(sockCli == -1){
        perror("socket");
        return -1; 
    }   
    struct sockaddr_in addrSer;
    addrSer.sin_family = AF_INET;
    addrSer.sin_port = htons(SERVER_PORT);
    addrSer.sin_addr.s_addr = inet_addr(SERVER_IP);

    socklen_t len = sizeof(struct sockaddr);
    int res = connect(sockCli, (struct sockaddr*)&addrSer, len);
    if(res == -1){
        perror("connect");
        close(sockCli);
        return -1; 
    }else{
        printf("Client Connect Server Success.\n");
    }

    char cmd[2];
    OperStruct  op;
    int result;
    while(1){
        printf("Please input operator : ");
        scanf("%s",cmd);
        if(strcmp(cmd, "+") == 0){
            op.oper = ADD;
            InputData(&op);
        }else if(strcmp(cmd,"-") == 0){
            op.oper = SUB;
            InputData(&op);
        }else if(strcmp(cmd,"*") == 0){
            op.oper = MUL;
            InputData(&op);
        }else if(strcmp(cmd,"/") == 0){
            op.oper = DIV;
            InputData(&op);
        }else if(strcmp(cmd, "quit") == 0){
            op.oper = QUIT;
        }else{
            printf("Cmd invalid.\n");        
        }

        res = send(sockCli, &op, sizeof(op), 0);
        if(res == -1){
            printf("send data fail.\n");
            continue;
        }
        if(op.oper == QUIT)
            break;
        res = recv(sockCli, &result, sizeof(result), 0);
        if(res == -1){
            printf("recv data fail.\n");
            continue;
        }
        printf("result = %d\n", result);
    }
    close(sockCli);
    return 0;
}

2.4、运行结果

服务器端：

客户1：

客户2：

三、分析总结

多线程网络服务也存在线程的动态申请与释放，还是有一定的开销，若存在大量用户在线，很可能带来线程间切换开销。