2022-4-19 LT模式和ET模式《Linux高性能服务器》笔记

服务端

#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<assert.h>
#include<stdio.h>
#include<unistd.h>
#include<errno.h>
#include<string.h>
#include<fcntl.h>
#include<stdlib.h>
#include<sys/epoll.h>
#include<pthread.h>
#define MAX_EVENT_NUMBER 1024
#define BUFFER_SIZE 10
int setnonblocking(int fd){
    
    
    int old_option = fcntl(fd,F_GETFL);
    int new_option = old_option|O_NONBLOCK;
    fcntl(fd,F_SETFL,new_option);
    return old_option;
}
void addfd(int epollfd,int fd,bool enable_et){
    
    
    struct epoll_event event;
    event.data.fd = fd;
    event.events = EPOLLIN;
    if(enable_et){
    
    
        event.events |= EPOLLET;
    }
    epoll_ctl(epollfd,EPOLL_CTL_ADD,fd,&event);
    setnonblocking(fd);
}
void lt(epoll_event*events,int number,int epollfd,int listenfd){
    
    
    char buf[BUFFER_SIZE];
    for(int i = 0;i < number;i++){
    
    
        int sockfd = events[i].data.fd;
        if(sockfd == listenfd){
    
    
            struct sockaddr_in client_address;
            socklen_t client_addrlength = sizeof(client_address);
            int connfd = accept(listenfd,(struct sockaddr*)&client_address,&client_addrlength);
            addfd(epollfd,connfd,false);
        }
        else if(events[i].events & EPOLLIN){
    
    
            printf("event trigger once\n");
            memset(buf,'\0',BUFFER_SIZE);
            int ret = recv(sockfd,buf,BUFFER_SIZE-1,0);
            if(ret == -1){
    
    
                close(sockfd);
                continue;
            }
            printf("get %d bytes of content: %s\n",ret,buf);
        }else {
    
    
            printf("something else happened\n");
        }
    }
}
void et(epoll_event*events,int number,int epollfd,int listenfd){
    
    
    char buf[BUFFER_SIZE];
    for(int i = 0;i < number;i++){
    
    
        int sockfd = events[i].data.fd;
        if(sockfd == listenfd){
    
    
            struct sockaddr_in client_address;
            socklen_t client_addrlenght = sizeof(client_address);
            int connfd = accept(listenfd,(struct sockaddr*)&client_address,&client_addrlenght);
            addfd(epollfd,connfd,true);
        }else if(events[i].events & EPOLLIN){
    
    
            printf("event trigger once\n");
            while(1){
    
    
                memset(buf,'\0',BUFFER_SIZE-1);
                int ret = recv(sockfd,buf,BUFFER_SIZE-1,0);
                if(ret == -1){
    
    
                    if((errno == EAGAIN) ||(errno == EWOULDBLOCK)){
    
    
                        printf("read later\n");
                        break;
                    }
                    close(sockfd);
                    break;
                }else if(ret == 0){
    
    
                    close(sockfd);
                }else {
    
    
                    printf("get %d bytes of content:%s\n",ret,buf);
                }
            }
        }
        else{
    
    
            printf("something else happened\n");
        }
    }
}
int main(void){
    
    
    int ret = 0;
    struct sockaddr_in address;
    bzero(&address,sizeof(address));
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_family = AF_INET;
    address.sin_port = htons(9999);
    int listenfd = socket(AF_INET,SOCK_STREAM,0);
    if(listenfd == -1){
    
    
        perror("socket");
        return -1;
    }
    ret = bind(listenfd,(struct sockaddr*)&address,sizeof(address));
    if(ret == -1){
    
    
        perror("bind");
        return -1;
    }
    ret = listen(listenfd,5);
    if(ret == -1){
    
    
        perror("listen");
        return -1;
    }
    epoll_event events[MAX_EVENT_NUMBER];
    int epollfd = epoll_create(5);
    if(epollfd == -1){
    
    
        perror("epoll_create");
        return -1;
        
    }
    addfd(epollfd,listenfd,true);
    while(1){
    
    
        int ret = epoll_wait(epollfd,events,MAX_EVENT_NUMBER,-1);
        if(ret == -1){
    
    
            perror("epoll_wait");
            break;
        }
        lt(events,ret,epollfd,listenfd);
        //et(events,ret,epollfd,listenfd);
    }
    close(listenfd);
    return 0;
}

客户端

//tcp 通信客户端
#include<stdio.h>
#include<arpa/inet.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>

int main(void){
    
    
    //1.创建套接字
    int fd = socket(AF_INET,SOCK_STREAM,0);
    if(fd == -1){
    
    
        perror("socket");
        exit(0);
    }

    //2.连接服务器端
    struct sockaddr_in serveraddr;
    serveraddr.sin_family = AF_INET;
    inet_pton(AF_INET,"192.168.131.138",&serveraddr.sin_addr.s_addr);
    serveraddr.sin_port = htons(9999);
    int ret = connect(fd,(struct sockaddr*)&serveraddr,sizeof(serveraddr));
    if(ret == -1){
    
    
        perror("connect");
        exit(0);
    }

    
    char *data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
    
    write(fd,data,strlen(data));

    char recvBuf[1024] = {
    
    0}; 
    while(read(fd,recvBuf,sizeof(recvBuf)) > 0){
    
    
        printf("recv data :%s\n",recvBuf);
    }

    close(fd);
    return 0;
}

lt模式

ET模式
同样是读取，但是只有一次触发