[C/C++] An instance of using EPoll

epolltest.cpp :

#include <stdio.h>#include <stdlib.h>#include <time.h>#include <unistd.h>#include <fcntl.h>#include <sys/socket.h>#include <sys/ioctl.h>#include <arpa/inet.h>#include <sys/epoll.h>#define MAX_EPOLL_FD_NUM 20000 #define SEND_BUFFER_LEN 1024#define RECV_BUFFER_LEN 1024int nb_socket(int domain, int type, int protocol){ int sfd = socket(domain, type, protocol), flags = 1; if (sfd == -1) return -1; if(ioctl(sfd, FIONBIO, &flags) && ((flags = fcntl(sfd, F_GETFL, 0)) < 0 || fcntl(sfd, F_SETFL, flags | O_NONBLOCK) < 0)) { close(sfd); return -1; } return sfd;}int main(){int epollfd;int triggered;int i;struct epoll_event *events;struct epoll_event *cevents;struct epoll_event ev;unsigned short port = 8008;struct sockaddr_in addr;int listenfd, flags = 1;struct linger ling = {0, 0};int socks;time_t now; char recvbuffer[1024];int bytes;unsigned int pkgs;printf("程序开始执行....创建侦听套接字../n");if ((listenfd = nb_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {printf("失败。。。。呜呜..!");return 3;}setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &flags, sizeof(flags));setsockopt(listenfd, SOL_SOCKET, SO_KEEPALIVE, &flags, sizeof(flags));setsockopt(listenfd, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling));printf("侦听套接字ID:%d/n",listenfd);addr.sin_family = AF_INET;addr.sin_port = htons(port);addr.sin_addr.s_addr = htonl(INADDR_ANY);if(bind(listenfd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {close(listenfd);return 4;}listen(listenfd, 1024);printf("准备创建EPoll端口...../n");if((epollfd = epoll_create(MAX_EPOLL_FD_NUM)) < 0) {perror("epoll_create");close(listenfd);return -1;}printf("EPoll端口创建完成...端口号:%d/n",epollfd);events = (struct epoll_event *)malloc(MAX_EPOLL_FD_NUM * sizeof(struct epoll_event));printf("将侦听套接字绑定到EPoll端口..../n");ev.data.fd = listenfd;ev.events = EPOLLIN | EPOLLERR | EPOLLHUP;if(epoll_ctl(epollfd, EPOLL_CTL_ADD, listenfd, &ev) < 0){printf("epoll set insertion error: listen socket fd=%d/n", listenfd);free(events);close(epollfd);close(listenfd);return 5;}printf("侦听套接字绑定到EPoll端口完成...进入事件触发等待/n");socks = 1;for(int k = 0 ; k < 100; k ++){triggered = epoll_wait(epollfd, events, MAX_EPOLL_FD_NUM, -1);printf("事件数:%d/n",triggered);for(i=0; i<triggered; i++){cevents = events + i;if(cevents->events & (EPOLLERR | EPOLLHUP)){printf("POLLERR | POLLHUP fd = %d/r/n", cevents->data.fd);epoll_ctl(epollfd, EPOLL_CTL_DEL, cevents->data.fd, NULL);close(cevents->data.fd);socks--;continue ;}if(cevents->events & EPOLLIN){if(cevents->data.fd == listenfd){ struct sockaddr_in addr; int len; int sfd; len = sizeof(addr); if((sfd = accept(listenfd, (struct sockaddr*)&addr, (socklen_t*)&len)) == -1) {perror("accept");continue; } ev.data.fd = sfd; ev.events = EPOLLIN | EPOLLERR | EPOLLHUP; epoll_ctl(epollfd, EPOLL_CTL_ADD, sfd, &ev); socks++; printf("accpet a connection %s:%d/r/n", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port)); continue;}bytes = read(cevents->data.fd, recvbuffer, sizeof(recvbuffer));if(bytes > 0){printf("套接字:%d,收到字符:%s/t对它注册发送事件./n",cevents->data.fd,recvbuffer);ev.data.fd = cevents->data.fd;ev.events = EPOLLOUT;if(epoll_ctl(epollfd, EPOLL_CTL_MOD, cevents->data.fd, &ev) == -1){perror("对方有数据到来时，这边添加发送事件出错../n");printf("对套接字:%d,注册发送事件失败.../n",cevents->data.fd);continue ;}}else{printf("套接字:%d,被关闭，注销事件。/n",cevents->data.fd);ev.data.fd = cevents->data.fd;ev.events = EPOLLOUT|EPOLLIN|EPOLLERR|EPOLLHUP;if(epoll_ctl(epollfd, EPOLL_CTL_DEL, cevents->data.fd, &ev) == -1){perror("对方关闭时，这边注销事件出错../n");printf("对套接字:%d,注销所有事件失败.../n",cevents->data.fd);close(cevents->data.fd);continue ;}printf("关闭该套接字..");close(cevents->data.fd);}}if(cevents->events & EPOLLOUT){printf("套接字：%d,有发送事件...现在将该套接字发送事件删除。/n",cevents->data.fd);send(cevents->data.fd,recvbuffer,bytes,0);ev.data.fd = cevents->data.fd;ev.events = EPOLLIN|EPOLLERR|EPOLLHUP;if(epoll_ctl(epollfd, EPOLL_CTL_MOD, cevents->data.fd, &ev) == -1){perror("可以对套接字发送数据时，这边删除发送事件出错../n");printf("对套接字:%d,注册发送事件失败.../n",cevents->data.fd);continue ;}}}} return 0;} 

makefile :

#------------------------------------------------------------------------------# 路径#------------------------------------------------------------------------------# includeINC_BOOST= -I/usr/local/include/boost-1_32INC_POLLER= -I./includeINC_SYS= -I/usr/include#------------------------------------------------------------------------------# libLIB_BOOST= -L/usr/local/lib -lboost_thread-gcc-mt -lboost_date_time-gcc-mtLIB_LOG4CPLUS= -L/usr/local/lib -llog4cplus#------------------------------------------------------------------------------# 开发环境的定义C_FLAGS= -g -Wall -pthread -ftemplate-depth-20 -DDEBUG #-DUSE_LOG4CPLUSLD_FLAGS=CC= gccCXX= g++RANLIB= ranlibAR= arINC= $(INC_POLLER) #$(INC_BOOST) LIB= $(LIB_LOG4CPLUS) #$(LIB_BOOST)BINNAME= epolltestSRCS = $(wildcard *.cpp)OBJS = $(patsubst %.cpp,%.o,$(SRCS))all:$(BINNAME)$(BINNAME):$(OBJS)$(CXX) $(C_FLAGS) -o $(BINNAME) *.o%.o:%.cpp$(CXX) $(C_FLAGS)$(INC) $(INC_SYS) -o $@ -c $<clean:rm -fr *.o $(BINNAME)