linux 2.6内核epoll用法举例说明(续)--给echo服务器增加读线程池

#include <iostream>#include <sys/socket.h>#include <sys/epoll.h>#include <netinet/in.h>#include <arpa/inet.h>#include <fcntl.h>#include <unistd.h>#include <stdio.h>#include <pthread.h>#define MAXLINE 10#define OPEN_MAX 100#define LISTENQ 20#define SERV_PORT 5555#define INFTIM 1000//线程池任务队列结构体struct task{ int fd; //需要读写的文件描述符 struct task *next; //下一个任务};//用于读写两个的两个方面传递参数struct user_data{ int fd; unsigned int n_size; char line[MAXLINE];};//线程的任务函数void * readtask(void *args);void * writetask(void *args);//声明epoll_event结构体的变量,ev用于注册事件,数组用于回传要处理的事件struct epoll_event ev,events[20];int epfd;pthread_mutex_t mutex;pthread_cond_t cond1;struct task *readhead=NULL,*readtail=NULL,*writehead=NULL;void setnonblocking(int sock){
int opts; opts=fcntl(sock,F_GETFL); if(opts<0) {
perror("fcntl(sock,GETFL)"); exit(1); } opts = opts|O_NONBLOCK; if(fcntl(sock,F_SETFL,opts)<0) {
perror("fcntl(sock,SETFL,opts)"); exit(1); } }int main(){
int i, maxi, listenfd, connfd, sockfd,nfds; pthread_t tid1,tid2; struct task *new_task=NULL; struct user_data *rdata=NULL; socklen_t clilen;
pthread_mutex_init(&mutex,NULL); pthread_cond_init(&cond1,NULL); //初始化用于读线程池的线程 pthread_create(&tid1,NULL,readtask,NULL); pthread_create(&tid2,NULL,readtask,NULL); //生成用于处理accept的epoll专用的文件描述符 epfd=epoll_create(256); struct sockaddr_in clientaddr; struct sockaddr_in serveraddr; listenfd = socket(AF_INET, SOCK_STREAM, 0); //把socket设置为非阻塞方式 setnonblocking(listenfd); //设置与要处理的事件相关的文件描述符 ev.data.fd=listenfd; //设置要处理的事件类型 ev.events=EPOLLIN|EPOLLET; //注册epoll事件 epoll_ctl(epfd,EPOLL_CTL_ADD,listenfd,&ev); bzero(&serveraddr, sizeof(serveraddr)); serveraddr.sin_family = AF_INET; char *local_addr="200.200.200.222"; inet_aton(local_addr,&(serveraddr.sin_addr));//htons(SERV_PORT); serveraddr.sin_port=htons(SERV_PORT); bind(listenfd,(sockaddr *)&serveraddr, sizeof(serveraddr)); listen(listenfd, LISTENQ);

maxi = 0; for ( ; ; ) { //等待epoll事件的发生 nfds=epoll_wait(epfd,events,20,500); //处理所发生的所有事件 for(i=0;i<nfds;++i) {
if(events[i].data.fd==listenfd) {
connfd = accept(listenfd,(sockaddr *)&clientaddr, &clilen); if(connfd<0){ perror("connfd<0"); exit(1); }
setnonblocking(connfd);

char *str = inet_ntoa(clientaddr.sin_addr); std::cout<<"connec_ from >>"<<str<<std::endl; //设置用于读操作的文件描述符 ev.data.fd=connfd; //设置用于注测的读操作事件 ev.events=EPOLLIN|EPOLLET; //注册ev epoll_ctl(epfd,EPOLL_CTL_ADD,connfd,&ev); } else if(events[i].events&EPOLLIN) {
printf("reading!/n"); if ( (sockfd = events[i].data.fd) < 0) continue; new_task=new task(); new_task->fd=sockfd; new_task->next=NULL; //添加新的读任务 pthread_mutex_lock(&mutex); if(readhead==NULL) {
readhead=new_task; readtail=new_task;
} else {
readtail->next=new_task; readtail=new_task; } //唤醒所有等待cond1条件的线程 pthread_cond_broadcast(&cond1); pthread_mutex_unlock(&mutex); } else if(events[i].events&EPOLLOUT) { rdata=(struct user_data *)events[i].data.ptr; sockfd = rdata->fd; write(sockfd, rdata->line, rdata->n_size); delete rdata; //设置用于读操作的文件描述符 ev.data.fd=sockfd; //设置用于注测的读操作事件 ev.events=EPOLLIN|EPOLLET; //修改sockfd上要处理的事件为EPOLIN epoll_ctl(epfd,EPOLL_CTL_MOD,sockfd,&ev); }
}
}
}void * readtask(void *args){
int fd=-1; unsigned int n; //用于把读出来的数据传递出去 struct user_data *data = NULL; while(1){

pthread_mutex_lock(&mutex); //等待到任务队列不为空 while(readhead==NULL) pthread_cond_wait(&cond1,&mutex); fd=readhead->fd; //从任务队列取出一个读任务 struct task *tmp=readhead; readhead = readhead->next; delete tmp; pthread_mutex_unlock(&mutex); data = new user_data(); data->fd=fd; if ( (n = read(fd, data->line, MAXLINE)) < 0) { if (errno == ECONNRESET) { close(fd);

} else std::cout<<"readline error"<<std::endl; if(data!=NULL)delete data; } else if (n == 0) { close(fd); printf("Client close connect!/n"); if(data!=NULL)delete data; } else{

data->n_size=n;
//设置需要传递出去的数据 ev.data.ptr=data; //设置用于注测的写操作事件 ev.events=EPOLLOUT|EPOLLET; //修改sockfd上要处理的事件为EPOLLOUT epoll_ctl(epfd,EPOLL_CTL_MOD,fd,&ev); } }}