linux 2.6内核epoll用法举例说明(续)--给echo服务器增加读线程池
上篇文章使用linux内核2.6提供的epoll机制实现了一个反应式echo服务器，使用反应式服务器的最大好处就是可以按cpu的数量来配置线程池 内线程的线程数而不是根据客户端的并发量配置线程池。我是第一次使用pthread库来写线程池，使用的是工作队列方式的线程池。我感觉作队列方式的线程 池可以当成一种设计模式来用的，在很多平台上都是可以按这种方式来实现线程池，从win32 ,unix到jvm都是适用的
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#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>
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#define MAXLINE 10
#define OPEN_MAX 100
#define LISTENQ 20
#define SERV_PORT 5555
#define INFTIM 1000
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//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
};
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//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];
};
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//线程的任务函数
void * readtask(void *args);
void * writetask(void *args);
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//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;
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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);
???? }???
}
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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);
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???? 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
????????{
???? ???? ???? 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><</str>
???? ???? ???? ???? //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"<
???? ???? ?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);
???? ??}
???}
}