typedef struct epoll_event { uint32_t events;      // Epoll events  epoll_data_t data;      // User data variable ep_callback  callback;    /* 這跟linux內核不一樣 ？ */}EPOLL_PACK; /*在添加epoll事件的時候就多了一個回調函數注冊，這個十分方便了，回調函數可以用一個全局變量搞定，一個框架搭好，隨后添加就大大的簡單多了*/

typedef union epoll_data {  void *ptr;  int fd;  uint32_t u32;  uint64_t u64;  } epoll_data_t;struct epoll_event { uint32_t events;      // Epoll events  epoll_data_t data;      // User data variable  };  

extern int epoll_create(int  size);extern int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);extern int epoll_wait(int epfd, struct epoll_event* events, int maxevents, int timeout);

/*Example for suggested usageWhile  the  usage  of  epoll when employed as a level-triggered interface does have the same semantics as poll(2), the edge-triggered usage requires moreclarification to avoid stalls in the application event loop.  In this example, listener is a nonblocking socket on which listen(2) has been called.   Thefunction  do_use_fd()  uses the new ready file descriptor until EAGAIN is returned by either read(2) or write(2).  An event-driven state machine applica‐tion should, after having received EAGAIN, record its current state so that at the next call to do_use_fd() it will continue to read(2) or write(2)  fromwhere it stopped before.*/#define MAX_EVENTS 10struct epoll_event ev, events[MAX_EVENTS];int listen_sock, conn_sock, nfds, epollfd;/* Code to set up listening socket, 'listen_sock',(socket(), bind(), listen()) omitted */static Epoll_Case(){epollfd = epoll_create1(0);if (epollfd == -1) {perror("epoll_create1");exit(EXIT_FAILURE);}ev.events = EPOLLIN;ev.data.fd = listen_sock;if (epoll_ctl(epollfd, EPOLL_CTL_ADD, listen_sock, &ev) == -1) {perror("epoll_ctl: listen_sock");exit(EXIT_FAILURE);}for (;;) {nfds = epoll_wait(epollfd, events, MAX_EVENTS, -1);if (nfds == -1) {perror("epoll_wait");exit(EXIT_FAILURE);}for (n = 0; n < nfds; ++n) {if (events[n].data.fd == listen_sock) {conn_sock = accept(listen_sock,(struct sockaddr *) &local, &addrlen);if (conn_sock == -1) {perror("accept");exit(EXIT_FAILURE);}setnonblocking(conn_sock);ev.events = EPOLLIN | EPOLLET;ev.data.fd = conn_sock;if (epoll_ctl(epollfd, EPOLL_CTL_ADD, conn_sock,&ev) == -1) {perror("epoll_ctl: conn_sock");exit(EXIT_FAILURE);}} else {do_use_fd(events[n].data.fd);}}}}/*           When  used  as an edge-triggered interface, for performance reasons, it is possible to add the file descriptor inside the epoll interface (EPOLL_CTL_ADD)once by specifying (EPOLLIN|EPOLLOUT).  This allows you  to  avoid  continuously  switching  between  EPOLLIN  and  EPOLLOUT  calling  epoll_ctl(2)  withEPOLL_CTL_MOD.*/

#include <netdb.h>#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <sys/socket.h>#include <arpa/inet.h>#include <string.h>#include <netinet/in.h>#include <sys/epoll.h>#include <poll.h>#include <assert.h>#include <unistd.h>#include <fcntl.h>#include "basetype.h"static int g_Main_Epoll_Fd = -1;#define MAX_EPOLL_EVENT_COUNT 64#define MAX_LISTEN_NUM  10#define MAX_BUFF_LEN 512/*#define BIT_TEST(a, b)          ((a) & (b))#define BIT_RESET(a, b)         ((a) ~= (b))#define BIT_SET(a, b)           ((a) |= (b))#define BIT_MATCH(a,b)          ((a)&(b) = (b))#define BIT_COMPARE(a, b, c)    ((a)&(b) == (c))*/static void print_socket_info(struct addrinfo *ai){char ipstr[INET6_ADDRSTRLEN];uint16_t port;void *addr  = NULL;char *ipver = NULL;struct sockaddr_in *ipv4 = NULL;struct sockaddr_in6 *ipv6 = NULL;assert(NULL != ai);if (ai->ai_family == AF_INET) { // IPv4ipv4 = (struct sockaddr_in *)ai->ai_addr;addr = &(ipv4->sin_addr);ipver = "IPv4";port =ntohs(((struct sockaddr_in*)ai->ai_addr)->sin_port);} else { // IPv6ipv6 = (struct sockaddr_in6 *)ai->ai_addr;addr = &(ipv6->sin6_addr);ipver = "IPv6";port =ntohs(((struct sockaddr_in6*)ai->ai_addr)->sin6_port);}// convert the IP to a string and print it:(void)inet_ntop(ai->ai_family, addr, ipstr, sizeof ipstr);printf(" server initing... AF: %s IP: %s,PORT: %un", ipver, ipstr,port);return ;}static int SetSocketNoblocking(const int sockfd){int flags = 0;int iret  = 0;flags = fcntl (sockfd, F_GETFL, 0);if (flags == -1){perror ("fcntl");return -1;}flags |= O_NONBLOCK;iret = fcntl (sockfd, F_SETFL, flags);if (iret == -1){perror ("fcntl");return -1;}return 0;}static int Epoll_Control(const int sockfd, const int oper, const int events){struct epoll_event ep_event;int iret = 0;memset(&ep_event, 0, sizeof(ep_event));ep_event.events = events;ep_event.data.fd = sockfd;iret = epoll_ctl(g_Main_Epoll_Fd, oper, sockfd, &ep_event);if (0 > iret){perror("epoll_ctl error.");printf("epoll_ctl error opt:%dn", oper);return -1;}return 0;}static int CreateServerScoket(const char *host, const char *port){struct addrinfo hints;struct addrinfo*ailist= NULL; struct addrinfo *ai= NULL;int iret;int sockfd = 0;int sockoptval = 1;memset(&hints, 0, sizeof(hints));hints.ai_family = AF_UNSPEC; // AF_INET 或 AF_INET6 hints.ai_socktype = SOCK_STREAM;hints.ai_flags = AI_PASSIVE;     /* All interfaces */iret = getaddrinfo(host, port, &hints, &ailist);if (0 != iret){fprintf(stderr, "getaddrinfo: %sn", gai_strerror(iret));return -1;}for(ai = ailist;ai != NULL; ai = ai->ai_next) {sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);if (0 > sockfd){continue;}/* set reuse addr */iret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &sockoptval, sizeof(sockoptval));if (0 > iret){perror("setsockopt errorn");freeaddrinfo(ailist);return -1;}iret = bind(sockfd, ai->ai_addr, ai->ai_addrlen);/*sizeof(struct sockaddr)*/if (0 == iret){print_socket_info(ai);break;}else{close(sockfd);}}if (NULL == ai){fprintf(stderr, "get server socket error.n");return -1;}freeaddrinfo(ailist); /* set no-block mode */iret = SetSocketNoblocking(sockfd);if (0 != iret){return -1;}/* listen socket */iret = listen(sockfd, MAX_LISTEN_NUM);if (0  > iret){perror("listen socket error.n");return -1;}printf("server socket init success. listenning...n");return sockfd;}static void HandleAccept(const int listen_scok, int Event){struct sockaddr_in addr;socklen_t  len = sizeof(addr);int client_sock  = -1;if (BIT_TEST(EPOLLIN, Event)){client_sock = accept(listen_scok, (struct sockaddr *)&addr, &len);if(client_sock < 0 ){perror("accept infd error");return;}(void)Epoll_Control(client_sock, EPOLL_CTL_ADD, EPOLLIN);}return ;}static void ProcRecvMsg(int sockfd){ssize_t recvlen = 0;char recvBuf[MAX_BUFF_LEN];//read ev  ready;recvlen = recv(sockfd, recvBuf, sizeof(recvBuf), 0);if(recvlen < 0){perror("recv error.");return ;}else if(recvlen == 0){printf("client quitn");	(void)Epoll_Control(sockfd, EPOLL_CTL_DEL, 0);close(sockfd);}else{(void)Epoll_Control(sockfd, EPOLL_CTL_MOD, EPOLLOUT);printf("recv msg fprom client:msg#:%sn",recvBuf);}return ;}static void SendMsg2Client(const int sockfd){ssize_t sendlen = 0;char sendBuf[MAX_BUFF_LEN];int event = 0;sprintf(sendBuf, "HTTP/1.0 200 OKrnrn<html><h1>Hello Epoll! [client_fd:%d]</h1></html>", sockfd);  int sendsize = send(sockfd, sendBuf, strlen(sendBuf)+1, 0);  if(sendsize <= 0)  {  perror("send error.");(void)Epoll_Control(sockfd, EPOLL_CTL_DEL, 0);close(sockfd);}  else {  printf("Server reply msg ok! data: %sn", sendBuf);  event = EPOLLIN | EPOLLERR | EPOLLHUP;(void)Epoll_Control(sockfd, EPOLL_CTL_MOD, event);}  return ;}int main(int argc, char *argv[]){int listenfd =0;int epfd = 0;int iret = 0;int event = 0;struct epoll_event ep_events[MAX_EPOLL_EVENT_COUNT];int ev_num = 0;int in_sockfd = 0;int loop = 0;if (3 > argc){printf("Usage: %s [ip_addr] [port]n",argv[0]);return -1;}listenfd = CreateServerScoket(argv[1], argv[2]);if (0 > listenfd){return -1;}epfd = epoll_create(1);if (-1 == epfd){perror("create epoll error.n");return -1;}else{g_Main_Epoll_Fd = epfd;}event = EPOLLIN;iret = Epoll_Control(listenfd, EPOLL_CTL_ADD, event);if (0 != iret){return -1;}/* proc epoll event regined */printf("server init success, epoll wait now.n");for(;;){memset(ep_events, 0, sizeof(ep_events));ev_num = epoll_wait(g_Main_Epoll_Fd, ep_events, MAX_EPOLL_EVENT_COUNT, -1);switch (ev_num){case 0:{printf("epoll_wait timeout.n");break;}case -1:{perror("epoll_wait error.n");break;}default:{for (loop = 0; loop < ev_num; loop++){in_sockfd = ep_events[loop].data.fd;event = ep_events[loop].events;if (in_sockfd == listenfd){HandleAccept(in_sockfd, event);}else{if (BIT_TEST(EPOLLIN, event)){/* have data to read */ProcRecvMsg(in_sockfd);}else if (BIT_TEST(EPOLLOUT, event)){SendMsg2Client(in_sockfd);}}}break;}}}return 0;}