C++基于reactor的服務(wù)器百萬并發(fā)實(shí)現(xiàn)與講解
更新時(shí)間：2022年07月01日 14:09:52 作者：恒者走天下
這篇文章主要介紹了C++基于reactor的服務(wù)器百萬并發(fā)實(shí)現(xiàn)與講解，本文通過實(shí)例圖文相結(jié)合給大家介紹的非常詳細(xì)，對大家的學(xué)習(xí)或工作具有一定的參考借鑒價(jià)值,需要的朋友可以參考下
reactor實(shí)現(xiàn)的原理請參考：
http://dhdzp.com/article/253794.htm
本次百萬并發(fā)的代碼實(shí)現(xiàn)也是基于上面代碼進(jìn)行更改而來
并發(fā)量和承載的概念
并發(fā)量：一個(gè)服務(wù)器能同時(shí)承載客戶端的數(shù)量
承載：客戶端發(fā)送給服務(wù)器的請求(http或tcp等)在200ms內(nèi)可以返回正確的結(jié)果
一、服務(wù)器的代碼實(shí)現(xiàn)與講解
結(jié)構(gòu)體代碼主要構(gòu)建的結(jié)構(gòu)如圖所示
鏈表結(jié)構(gòu)，每個(gè)eventblock結(jié)點(diǎn)，包括一個(gè)ntyevent數(shù)組，數(shù)組中存儲fd
/*結(jié)構(gòu)體定義鏈表數(shù)組*/
struct ntyevent {
int fd;//要監(jiān)聽的文件描述符
int events;//對應(yīng)的監(jiān)聽事件， EPOLLIN和EPOLLOUT（不同的事件，走不同的回調(diào)函數(shù)）
void *arg;//指向自己結(jié)構(gòu)體指針
int (*callback)(int fd, int events, void *arg);
int status;//是否在監(jiān)聽：1->在紅黑樹上（監(jiān)聽），0->不在（不監(jiān)聽）
char buffer[BUFFER_LENGTH];
int length;
long last_active;
};
struct eventblock {
struct eventblock *next;
struct ntyevent *events;//數(shù)組
};
struct ntyreactor {
//句柄
int epfd;
//結(jié)點(diǎn)個(gè)數(shù)
int blkcnt;
struct eventblock *evblk; //fd --> 100w
};初始化fd 上樹、下樹代碼
//nty_event_set(event, sockfd, acceptor, reactor);
//初始化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 ;
}
//nty_event_add(reactor->epfd, EPOLLIN, event);
//對監(jiān)聽的epoll紅黑樹上的結(jié)點(diǎn)的修改
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;
}
回調(diào)函數(shù)代碼的書寫
注意看recv_cb的回調(diào)函數(shù)中，recv之后，立馬下樹，然后又重新初始化fd，上樹。這樣做的目的是因?yàn)榇a邏輯是recv收到數(shù)據(jù)后，立即原樣send,所以需要對fd的屬性進(jìn)行更改，需要重新初始化賦值，然后上樹
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;
}
/*存儲*/
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;
}
鏈表的初始化與銷毀
//初始化鏈表
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;
}
找到fd應(yīng)在鏈表數(shù)組中存儲的位置并返回
//新增塊數(shù)(eventblock結(jié)點(diǎn)個(gè)數(shù))
//ntyreactor_alloc(reactor);
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 *event = ntyreactor_idx(reactor, sockfd);
struct ntyevent *ntyreactor_idx(struct ntyreactor *reactor, int sockfd) {
int blkidx = sockfd / MAX_EPOLL_EVENTS;
//如果塊數(shù)(eventblock結(jié)點(diǎn)個(gè)數(shù))不能滿足新的sockfd的存放
while (blkidx >= reactor->blkcnt) {
//新增塊數(shù)(eventblock結(jié)點(diǎn)個(gè)數(shù))
ntyreactor_alloc(reactor);
}
//找到存放sockfd的塊(eventblock對應(yīng)的結(jié)點(diǎn))
int i = 0;
struct eventblock *blk = reactor->evblk;
while(i ++ < blkidx && blk != NULL) {
blk = blk->next;
}
//返回對應(yīng)塊(eventblock對應(yīng)的結(jié)點(diǎn))的存放sockfd數(shù)組的那個(gè)具體位置
return &blk->events[sockfd % MAX_EPOLL_EVENTS];
}
上樹，并初始化鏈表數(shù)組上對應(yīng)的fd
//ntyreactor_addlistener(reactor, sockfds[i], accept_cb);
//上樹，并初始化鏈表數(shù)組上對應(yīng)的fd
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];
//找到sock所在的具體位置
struct ntyevent *event = ntyreactor_idx(reactor, sockfd);
初始化sockfd
nty_event_set(event, sockfd, acceptor, reactor);
//對監(jiān)聽的epoll紅黑樹上的結(jié)點(diǎn)的修改
nty_event_add(reactor->epfd, EPOLLIN, event);
return 0;
}
epollwait
//ntyreactor_run(reactor);
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;
//看fd連接是否發(fā)生變化
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);
}
}
}
}
main函數(shù)；此服務(wù)器代碼開設(shè)了100個(gè)監(jiān)聽的端口，目的是因?yàn)榭蛻舳藴y試程序也是運(yùn)行在虛擬機(jī)的Ubuntu上，通過開三臺來充當(dāng)客戶端來進(jìn)行測試。有因?yàn)橐慌_Ubuntu最多有6w個(gè)端口，3臺有18w端口。如果服務(wù)器只開設(shè)一個(gè)監(jiān)聽端口，則最多有18w端口。因此要達(dá)到100w并發(fā)則應(yīng)多開設(shè)端口
// 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]);//把參數(shù) str 所指向的字符串轉(zhuǎn)換為一個(gè)整數(shù)（類型為 int 型）
}
struct ntyreactor *reactor = (struct ntyreactor*)malloc(sizeof(struct ntyreactor));
/*初始化三個(gè)結(jié)構(gòu)體，建立鏈表*/
ntyreactor_init(reactor);
int i = 0;
int sockfds[PORT_COUNT] = {0};
for (i = 0;i < PORT_COUNT;i ++) {
//端口號的監(jiān)聽
sockfds[i] = init_sock(port+i);
//上樹
ntyreactor_addlistener(reactor, sockfds[i], accept_cb);
}
// epoll_wait
ntyreactor_run(reactor);
//
ntyreactor_destory(reactor);
for (i = 0;i < PORT_COUNT;i ++) {
close(sockfds[i]);
}
free(reactor);
return 0;
}
完整服務(wù)器代碼展示
/*鏈表存儲數(shù)組，把epoll變成對事件的管理,用鏈表數(shù)組的目的就是為了回調(diào)函數(shù)*/
/*recv寫法：代碼邏輯是收到數(shù)據(jù)后，立即原樣返回所以才那樣寫*/
#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 *evs = (struct ntyevent*)malloc((MAX_EPOLL_EVENTS) * sizeof(struct ntyevent));
struct ntyevent {
int fd;//要監(jiān)聽的文件描述符
int events;//對應(yīng)的監(jiān)聽事件， EPOLLIN和EPOLLOUT（不同的事件，走不同的回調(diào)函數(shù)）
void *arg;//指向自己結(jié)構(gòu)體指針
int (*callback)(int fd, int events, void *arg);
int status;//是否在監(jiān)聽：1->在紅黑樹上（監(jiān)聽），0->不在（不監(jiān)聽）
char buffer[BUFFER_LENGTH];
int length;
long last_active;
};
struct eventblock {
struct eventblock *next;
struct ntyevent *events;//數(shù)組
};
struct ntyreactor {
//句柄
int epfd;
//結(jié)點(diǎn)個(gè)數(shù)
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);
//nty_event_set(event, sockfd, acceptor, reactor);
//初始化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 ;
}
//nty_event_add(reactor->epfd, EPOLLIN, event);
//對監(jiān)聽的epoll紅黑樹上的結(jié)點(diǎn)的修改
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;
}
/*存儲*/
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;
}
//新增塊數(shù)(eventblock結(jié)點(diǎn)個(gè)數(shù))
//ntyreactor_alloc(reactor);
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 *event = ntyreactor_idx(reactor, sockfd);
struct ntyevent *ntyreactor_idx(struct ntyreactor *reactor, int sockfd) {
int blkidx = sockfd / MAX_EPOLL_EVENTS;
//如果塊數(shù)(eventblock結(jié)點(diǎn)個(gè)數(shù))不能滿足新的sockfd的存放
while (blkidx >= reactor->blkcnt) {
//新增塊數(shù)(eventblock結(jié)點(diǎn)個(gè)數(shù))
ntyreactor_alloc(reactor);
}
//找到存放sockfd的塊(eventblock對應(yīng)的結(jié)點(diǎn))
int i = 0;
struct eventblock *blk = reactor->evblk;
while(i ++ < blkidx && blk != NULL) {
blk = blk->next;
}
//返回對應(yīng)塊(eventblock對應(yīng)的結(jié)點(diǎn))的存放sockfd數(shù)組的那個(gè)具體位置
return &blk->events[sockfd % MAX_EPOLL_EVENTS];
}
//初始化鏈表
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;
}
//ntyreactor_addlistener(reactor, sockfds[i], accept_cb);
//上樹，并初始化鏈表數(shù)組上對應(yīng)的fd
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];
//找到sock所在的具體位置
struct ntyevent *event = ntyreactor_idx(reactor, sockfd);
初始化sockfd
nty_event_set(event, sockfd, acceptor, reactor);
//對監(jiān)聽的epoll紅黑樹上的結(jié)點(diǎn)的修改
nty_event_add(reactor->epfd, EPOLLIN, event);
return 0;
}
//ntyreactor_run(reactor);
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;
//看fd連接是否發(fā)生變化
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]);//把參數(shù) str 所指向的字符串轉(zhuǎn)換為一個(gè)整數(shù)（類型為 int 型）
}
struct ntyreactor *reactor = (struct ntyreactor*)malloc(sizeof(struct ntyreactor));
/*初始化三個(gè)結(jié)構(gòu)體，建立鏈表*/
ntyreactor_init(reactor);
int i = 0;
int sockfds[PORT_COUNT] = {0};
for (i = 0;i < PORT_COUNT;i ++) {
//端口號的監(jiān)聽
sockfds[i] = init_sock(port+i);
//上樹
ntyreactor_addlistener(reactor, sockfds[i], accept_cb);
}
// epoll_wait
ntyreactor_run(reactor);
//
ntyreactor_destory(reactor);
for (i = 0;i < PORT_COUNT;i ++) {
close(sockfds[i]);
}
free(reactor);
return 0;
}reactor的寫法感覺和epoll的普通寫法，感覺差別就是reactor多了個(gè)回調(diào)函數(shù)，具體沒啥優(yōu)點(diǎn)？
epoll是針對io的管理。 reactor對針對事件的管理
不同的事件，針對不同的回調(diào)函數(shù)
性能上沒啥差異，但提高了代碼的復(fù)用性。具體需要自己慢慢體會體會，嗚嗚嗚嗚還有體會到，編程思想不過關(guān)。
二、環(huán)境設(shè)置
限制是fd的限制，系統(tǒng)默認(rèn)fd最多有1024個(gè)，按照一個(gè)連接一個(gè)fd的做法，那就需要百萬個(gè)fd。這里有兩種修改方法，一是使用ulimit -n命令，這個(gè)命令重啟就失效；二是修改/etc/security/limits.conf文件，這是永久有效的，重啟或sysctl -p生效。
* hard nofile 1048576 * soft nofile 1048576
hard是硬限制，不能超過該值，soft是軟限制，可以超過，超過后就開始回收。
這個(gè)文件里還有一些其他的參數(shù)可以了解一下，fs.file_max是fd可取到的最大值，注意與fd最大個(gè)數(shù)區(qū)分。
突破這兩個(gè)限制后，還會遇到一個(gè)問題，客戶端會報(bào)錯：connection timedout。連接超時(shí)，即是客戶端未收到服務(wù)器對客戶端connect()的回應(yīng)包。這里有兩種可能，客戶端為收到服務(wù)器的包或是服務(wù)器未收到客戶端的connect包。事實(shí)上，是因?yàn)橄到y(tǒng)有個(gè)防火墻iotables，這個(gè)防火墻是基于網(wǎng)卡和協(xié)議棧之間的過濾機(jī)制netfilter實(shí)現(xiàn)的。netfilter當(dāng)連接數(shù)到達(dá)一定程度時(shí)，會不允許再向外發(fā)送connect包。修改也是通過/etc/security/limits.conf文件
net.nf_conntrack_max=1048576
突破這些限制，就可以實(shí)現(xiàn)百萬并發(fā)了。
這里再介紹/etc/security/limits.conf中幾個(gè)參數(shù)
net.ipv4.tcp_mem=262144 524288 786432是所有TCP協(xié)議棧所占空間的大小，單位是頁（4KB）。介紹一下后面寫的三個(gè)值，當(dāng)所占空間大小超過第二個(gè)值時(shí)，系統(tǒng)會進(jìn)行優(yōu)化，此時(shí)如果占用空間降到第一個(gè)值以下，不再優(yōu)化，第三個(gè)值是上限，不允許分配超過比大小的空間。
net.ipv4.tcp_wmem=2048 2048 4096是每個(gè)socket對應(yīng)的寫緩沖區(qū)大小，三個(gè)值分別是最小值、默認(rèn)值、最大值，單位是B。
net.ipv4.tcp_rmem=2048 2048 4096是每個(gè)socket對應(yīng)的讀緩沖區(qū)大小，三個(gè)值分別是最小值、默認(rèn)值、最大值，單位是B。
做百萬并發(fā)時(shí)，如果內(nèi)存不大，可以相應(yīng)調(diào)小。在實(shí)際應(yīng)用中，如果傳輸大文件，調(diào)大；如果傳輸?shù)亩际亲址{(diào)小，就可以接收更多fd。
到此這篇關(guān)于C++基于reactor的服務(wù)器百萬并發(fā)實(shí)現(xiàn)的文章就介紹到這了,更多相關(guān)reactor服務(wù)器百萬并發(fā)內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
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