服务器百万并发实现

1.水平触发  ：buffer里面只要有数据就会一直触发。如果接收的数据比较大， recv函数一次接受不了，就会分几次接收数据。

2.边沿触发 ： buffer里面从没数据到有数据会触发一次。如果接受的数据比较大，recv函数也只会接收一次。

 

EPOLLIN： 水平触发

EPOLLIN | EPOLLET：边沿触发

哪些场景使用边沿触发和水平触发？

答：数据量比较小的使用边沿触发，否则使用水平触发。listenfd使用水平触发，因为使用边沿触发可能会漏掉fd。

tip：分配内存时，建议先分配大的内存，因为分配大的内存更容易失败。

  

命令：ulimit -a  查看一个进程可以打开的fd的数量

设置这个参数：sudo vim /etc/security/limits.conf

 

修改两个地方:fd的数量，2改协议栈的参数

命令：sudo vim /etc/sysctl.conf

修改后命令：sudo sysctl -p

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <arpa/inet.h>

#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>


#define BUFFER_LENGTH        4096
#define MAX_EPOLL_EVENTS    1024
#define SERVER_PORT            8888
#define PORT_COUNT            100

typedef int NCALLBACK(int ,int, void*);

struct ntyevent {
    int fd;
    int events;
    void *arg;
    int (*callback)(int fd, int events, void *arg);
    
    int status;
    char buffer[BUFFER_LENGTH];
    int length;
    long last_active;
};

struct eventblock {

    struct eventblock *next;
    struct ntyevent *events;
    
};

struct ntyreactor {
    int epfd;
    int blkcnt;
    struct eventblock *evblk; //fd --> 100w
};


int recv_cb(int fd, int events, void *arg);
int send_cb(int fd, int events, void *arg);
struct ntyevent *ntyreactor_idx(struct ntyreactor *reactor, int sockfd);


void nty_event_set(struct ntyevent *ev, int fd, NCALLBACK callback, void *arg) {

    ev->fd = fd;
    ev->callback = callback;
    ev->events = 0;
    ev->arg = arg;
    ev->last_active = time(NULL);

    return ;
    
}


int nty_event_add(int epfd, int events, struct ntyevent *ev) {

    struct epoll_event ep_ev = {0, {0}};
    ep_ev.data.ptr = ev;
    ep_ev.events = ev->events = events;

    int op;
    if (ev->status == 1) {
        op = EPOLL_CTL_MOD;
    } else {
        op = EPOLL_CTL_ADD;
        ev->status = 1;
    }

    if (epoll_ctl(epfd, op, ev->fd, &ep_ev) < 0) {
        printf("event add failed [fd=%d], events[%d]\n", ev->fd, events);
        return -1;
    }

    return 0;
}

int nty_event_del(int epfd, struct ntyevent *ev) {

    struct epoll_event ep_ev = {0, {0}};

    if (ev->status != 1) {
        return -1;
    }

    ep_ev.data.ptr = ev;
    ev->status = 0;
    epoll_ctl(epfd, EPOLL_CTL_DEL, ev->fd, &ep_ev);

    return 0;
}

int recv_cb(int fd, int events, void *arg) {

    struct ntyreactor *reactor = (struct ntyreactor*)arg;
    struct ntyevent *ev = ntyreactor_idx(reactor, fd);

    int len = recv(fd, ev->buffer, BUFFER_LENGTH , 0); // 
    nty_event_del(reactor->epfd, ev);

    if (len > 0) {
        
        ev->length = len;
        ev->buffer[len] = '\0';

        printf("C[%d]:%s\n", fd, ev->buffer);

        nty_event_set(ev, fd, send_cb, reactor);
        nty_event_add(reactor->epfd, EPOLLOUT, ev);
        
        
    } else if (len == 0) {

        close(ev->fd);
        //printf("[fd=%d] pos[%ld], closed\n", fd, ev-reactor->events);
         
    } else {

        close(ev->fd);
        printf("recv[fd=%d] error[%d]:%s\n", fd, errno, strerror(errno));
        
    }

    return len;
}


int send_cb(int fd, int events, void *arg) {

    struct ntyreactor *reactor = (struct ntyreactor*)arg;
    struct ntyevent *ev = ntyreactor_idx(reactor, fd);

    int len = send(fd, ev->buffer, ev->length, 0);
    if (len > 0) {
        printf("send[fd=%d], [%d]%s\n", fd, len, ev->buffer);

        nty_event_del(reactor->epfd, ev);
        nty_event_set(ev, fd, recv_cb, reactor);
        nty_event_add(reactor->epfd, EPOLLIN, ev);
        
    } else {

        close(ev->fd);

        nty_event_del(reactor->epfd, ev);
        printf("send[fd=%d] error %s\n", fd, strerror(errno));

    }

    return len;
}

int accept_cb(int fd, int events, void *arg) {

    struct ntyreactor *reactor = (struct ntyreactor*)arg;
    if (reactor == NULL) return -1;

    struct sockaddr_in client_addr;
    socklen_t len = sizeof(client_addr);

    int clientfd;

    if ((clientfd = accept(fd, (struct sockaddr*)&client_addr, &len)) == -1) {
        if (errno != EAGAIN && errno != EINTR) {
            
        }
        printf("accept: %s\n", strerror(errno));
        return -1;
    }

    

    int flag = 0;
    if ((flag = fcntl(clientfd, F_SETFL, O_NONBLOCK)) < 0) {
        printf("%s: fcntl nonblocking failed, %d\n", __func__, MAX_EPOLL_EVENTS);
        return -1;
    }

    struct ntyevent *event = ntyreactor_idx(reactor, clientfd);
    
    nty_event_set(event, clientfd, recv_cb, reactor);
    nty_event_add(reactor->epfd, EPOLLIN, event);

    
    printf("new connect [%s:%d], pos[%d]\n", 
        inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), clientfd);

    return 0;

}

int init_sock(short port) {

    int fd = socket(AF_INET, SOCK_STREAM, 0);
    fcntl(fd, F_SETFL, O_NONBLOCK);

    struct sockaddr_in server_addr;
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(port);

    bind(fd, (struct sockaddr*)&server_addr, sizeof(server_addr));

    if (listen(fd, 20) < 0) {
        printf("listen failed : %s\n", strerror(errno));
    }

    return fd;
}


int ntyreactor_alloc(struct ntyreactor *reactor) {

    if (reactor == NULL) return -1;
    if (reactor->evblk == NULL) return -1;

    struct eventblock *blk = reactor->evblk;
    while (blk->next != NULL) {
        blk = blk->next;
    }

    struct ntyevent *evs = (struct ntyevent*)malloc((MAX_EPOLL_EVENTS) * sizeof(struct ntyevent));
    if (evs == NULL) {
        printf("ntyreactor_alloc ntyevents failed\n");
        return -2;
    }
    memset(evs, 0, (MAX_EPOLL_EVENTS) * sizeof(struct ntyevent));

    struct eventblock *block = (struct eventblock *)malloc(sizeof(struct eventblock));
    if (block == NULL) {
        printf("ntyreactor_alloc eventblock failed\n");
        return -2;
    }
    memset(block, 0, sizeof(struct eventblock));

    block->events = evs;
    block->next = NULL;

    blk->next = block;
    reactor->blkcnt ++; //

    return 0;
}

struct ntyevent *ntyreactor_idx(struct ntyreactor *reactor, int sockfd) {

    int blkidx = sockfd / MAX_EPOLL_EVENTS;

    while (blkidx >= reactor->blkcnt) {
        ntyreactor_alloc(reactor);
    }

    int i = 0;
    struct eventblock *blk = reactor->evblk;
    while(i ++ < blkidx && blk != NULL) {
        blk = blk->next;
    }

    return &blk->events[sockfd % MAX_EPOLL_EVENTS];
}


int ntyreactor_init(struct ntyreactor *reactor) {

    if (reactor == NULL) return -1;
    memset(reactor, 0, sizeof(struct ntyreactor));

    reactor->epfd = epoll_create(1);
    if (reactor->epfd <= 0) {
        printf("create epfd in %s err %s\n", __func__, strerror(errno));
        return -2;
    }

    struct ntyevent *evs = (struct ntyevent*)malloc((MAX_EPOLL_EVENTS) * sizeof(struct ntyevent));
    if (evs == NULL) {
        printf("ntyreactor_alloc ntyevents failed\n");
        return -2;
    }
    memset(evs, 0, (MAX_EPOLL_EVENTS) * sizeof(struct ntyevent));

    struct eventblock *block = (struct eventblock *)malloc(sizeof(struct eventblock));
    if (block == NULL) {
        printf("ntyreactor_alloc eventblock failed\n");
        return -2;
    }
    memset(block, 0, sizeof(struct eventblock));

    block->events = evs;
    block->next = NULL;

    reactor->evblk = block;
    reactor->blkcnt = 1;

    return 0;
}

int ntyreactor_destory(struct ntyreactor *reactor) {

    close(reactor->epfd);
    //free(reactor->events);

    struct eventblock *blk = reactor->evblk;
    struct eventblock *blk_next = NULL;

    while (blk != NULL) {

        blk_next = blk->next;

        free(blk->events);
        free(blk);

        blk = blk_next;

    }
    
    return 0;
}



int ntyreactor_addlistener(struct ntyreactor *reactor, int sockfd, NCALLBACK *acceptor) {

    if (reactor == NULL) return -1;
    if (reactor->evblk == NULL) return -1;

    //reactor->evblk->events[sockfd];
    struct ntyevent *event = ntyreactor_idx(reactor, sockfd);

    nty_event_set(event, sockfd, acceptor, reactor);
    nty_event_add(reactor->epfd, EPOLLIN, event);

    return 0;
}



int ntyreactor_run(struct ntyreactor *reactor) {
    if (reactor == NULL) return -1;
    if (reactor->epfd < 0) return -1;
    if (reactor->evblk == NULL) return -1;
    
    struct epoll_event events[MAX_EPOLL_EVENTS+1];
    
    int checkpos = 0, i;

    while (1) {
/*
        long now = time(NULL);
        for (i = 0;i < 100;i ++, checkpos ++) {
            if (checkpos == MAX_EPOLL_EVENTS) {
                checkpos = 0;
            }

            if (reactor->events[checkpos].status != 1) {
                continue;
            }

            long duration = now - reactor->events[checkpos].last_active;

            if (duration >= 60) {
                close(reactor->events[checkpos].fd);
                printf("[fd=%d] timeout\n", reactor->events[checkpos].fd);
                nty_event_del(reactor->epfd, &reactor->events[checkpos]);
            }
        }
*/

        int nready = epoll_wait(reactor->epfd, events, MAX_EPOLL_EVENTS, 1000);
        if (nready < 0) {
            printf("epoll_wait error, exit\n");
            continue;
        }

        for (i = 0;i < nready;i ++) {

            struct ntyevent *ev = (struct ntyevent*)events[i].data.ptr;

            if ((events[i].events & EPOLLIN) && (ev->events & EPOLLIN)) {
                ev->callback(ev->fd, events[i].events, ev->arg);
            }
            if ((events[i].events & EPOLLOUT) && (ev->events & EPOLLOUT)) {
                ev->callback(ev->fd, events[i].events, ev->arg);
            }
            
        }

    }
}

// 3, 6w, 1, 100 == 
// <remoteip, remoteport, localip, localport>
int main(int argc, char *argv[]) {

    unsigned short port = SERVER_PORT; // listen 8888
    if (argc == 2) {
        port = atoi(argv[1]);
    }
    struct ntyreactor *reactor = (struct ntyreactor*)malloc(sizeof(struct ntyreactor));
    ntyreactor_init(reactor);

    int i = 0;
    int sockfds[PORT_COUNT] = {0};
    for (i = 0;i < PORT_COUNT;i ++) {
        sockfds[i] = init_sock(port+i);
        ntyreactor_addlistener(reactor, sockfds[i], accept_cb);
    }

    
    ntyreactor_run(reactor);

    ntyreactor_destory(reactor);

    for (i = 0;i < PORT_COUNT;i ++) {
        close(sockfds[i]);
    }

    free(reactor);

    return 0;
}

 

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标签：reactor,int,struct,并发,fd,服务器,ev,events,百万
来源： https://www.cnblogs.com/cuijy1/p/16327194.html