# 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 < errno . h >

using namespace std ;

# define MAXLINE 5
# define OPEN_MAX 100
# define LISTENQ 20
# define SERV_PORT 5000
# define INFTIM 1000

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 argc , char * argv [ ] )
{
???? int i , maxi , listenfd , connfd , sockfd , epfd , nfds , portnumber ;
????ssize_t n ;
???? char line [ MAXLINE ] ;
???? socklen_t clilen ;


???? if ( 2 = = argc )
???? {
???????? if ( ( portnumber = atoi ( argv [ 1 ] ) ) < 0 )
???????? {
???????????? fprintf ( stderr , "Usage:%s portnumber/a/n" , argv [ 0 ] ) ;
???????????? return 1 ;
???????? }
???? }
???? else
???? {
???????? fprintf ( stderr , "Usage:%s portnumber/a/n" , argv [ 0 ] ) ;
???????? return 1 ;
???? }



???? //聲明epoll_event結(jié)構(gòu)體的變量,ev用于注冊事件,數(shù)組用于回傳要處理的事件

???? struct epoll_event ev , events [ 20 ] ;
???? //生成用于處理accept的epoll專用的文件描寫敘述符

????epfd = epoll_create ( 256 ) ;
???? struct sockaddr_in clientaddr ;
???? struct sockaddr_in serveraddr ;
????listenfd = socket ( AF_INET , SOCK_STREAM , 0 ) ;
???? //把socket設置為非堵塞方式

???? //setnonblocking(listenfd);

???? //設置與要處理的事件相關的文件描寫敘述符

????ev . data . fd = listenfd ;
???? //設置要處理的事件類型

????ev . events = EPOLLIN | EPOLLET ;
???? //ev.events=EPOLLIN;

???? //注冊epoll事件

????epoll_ctl ( epfd , EPOLL_CTL_ADD , listenfd , & ev ) ;
????bzero ( & serveraddr , sizeof ( serveraddr ) ) ;
????serveraddr . sin_family = AF_INET ;
???? char * local_addr = "127.0.0.1" ;
????inet_aton ( local_addr , & ( serveraddr . sin_addr ) ) ; //htons(portnumber);

????serveraddr . sin_port = htons ( portnumber ) ;
???? bind ( listenfd , ( sockaddr * ) & serveraddr , sizeof ( serveraddr ) ) ;
???? listen ( listenfd , LISTENQ ) ;
????maxi = 0 ;
???? for ( ; ; ) {
???????? //等待epoll事件的發(fā)生

????????nfds = epoll_wait ( epfd , events , 20 , 500 ) ;
???????? //處理所發(fā)生的全部事件

???????? for ( i = 0 ; i < nfds ; + + i )
???????? {
???????????? if ( events [ i ] . data . fd = = listenfd ) //假設新監(jiān)測到一個SOCKET用戶連接到了綁定的SOCKET端口，建立新的連接。

???????????? {
????????????????connfd = accept ( listenfd , ( sockaddr * ) & clientaddr , & clilen ) ;
???????????????? if ( connfd < 0 ) {
???????????????????? perror ( "connfd<0" ) ;
???????????????????? exit ( 1 ) ;
???????????????? }
???????????????? //setnonblocking(connfd);

???????????????? char * str = inet_ntoa ( clientaddr . sin_addr ) ;
???????????????? cout < < "accapt a connection from " < < str < < endl ;
???????????????? //設置用于讀操作的文件描寫敘述符

????????????????ev . data . fd = connfd ;
???????????????? //設置用于注測的讀操作事件

????????????????ev . events = EPOLLIN | EPOLLET ;
???????????????? //ev.events=EPOLLIN;

???????????????? //注冊ev

????????????????epoll_ctl ( epfd , EPOLL_CTL_ADD , connfd , & ev ) ;
???????????? }
???????????? else if ( events [ i ] . events & EPOLLIN ) //假設是已經(jīng)連接的用戶，而且收到數(shù)據(jù)，那么進行讀入。

???????????? {
???????????????? cout < < "EPOLLIN" < < endl ;
???????????????? if ( ( sockfd = events [ i ] . data . fd ) < 0 )
???????????????????? continue ;
???????????????? if ( ( n = read ( sockfd , line , MAXLINE ) ) < 0 ) {
???????????????????? if ( errno = = ECONNRESET ) {
???????????????????????? close ( sockfd ) ;
????????????????????????events [ i ] . data . fd = - 1 ;
???????????????????? } else
???????????????????????? std : : cout < < "readline error" < < std : : endl ;
???????????????? } else if ( n = = 0 ) {
???????????????????? close ( sockfd ) ;
????????????????????events [ i ] . data . fd = - 1 ;
???????????????? }
???????????????? line [ n ] = '/0' ;
???????????????? cout < < "read " < < line < < endl ;
???????????????? //設置用于寫操作的文件描寫敘述符

????????????????ev . data . fd = sockfd ;
???????????????? //設置用于注測的寫操作事件

????????????????ev . events = EPOLLOUT | EPOLLET ;
???????????????? //改動sockfd上要處理的事件為EPOLLOUT

???????????????? //epoll_ctl(epfd,EPOLL_CTL_MOD,sockfd,&ev);

???????????? }
???????????? else if ( events [ i ] . events & EPOLLOUT ) // 假設有數(shù)據(jù)發(fā)送

???????????? {
????????????????sockfd = events [ i ] . data . fd ;
???????????????? write ( sockfd , line , n ) ;
???????????????? //設置用于讀操作的文件描寫敘述符

????????????????ev . data . fd = sockfd ;
???????????????? //設置用于注測的讀操作事件

????????????????ev . events = EPOLLIN | EPOLLET ;
???????????????? //改動sockfd上要處理的事件為EPOLIN

????????????????epoll_ctl ( epfd , EPOLL_CTL_MOD , sockfd , & ev ) ;
???????????? }
???????? }
???? }
???? return 0 ;
}