Epoll封装：Epoller

epoller.h

#ifndef EPOLLER_H_
#define EPOLLER_H_

#include <sys/epoll.h> //epoll_ctl()
#include <fcntl.h> //fcntl()
#include <unistd.h> //close()
#include <vector>
#include <errno.h>

class Epoller{
public:
    explicit Epoller(int maxEvent =1024);
    ~Epoller();

    // 核心操作：添加、修改、删除文件描述符及其事件
    bool AddFd(int fd,uint32_t events);
    bool ModFd(int fd,uint32_t events);
    bool DelFd(int fd);

    // 等待事件就绪
    int Wait(int timeoutMs=-1);

    // 获取就绪事件的文件描述符和事件类型
    int GetEventFd(size_t i) const;
    uint32_t GetEvents(size_t i) const;

private:
    int epollFd_;   // epoll实例的文件描述符
    std::vector<struct epoll_event> events_;// 存储就绪事件的数组



};



#endif

epoller.cpp

#include "epoller.h"

// 创建epoll对象 epoll_create(512)
Epoller::Epoller(int maxEvent):epollFd_(epoll_create(512)), events_(maxEvent){
    assert(epollFd_ >= 0 && events_.size() > 0);
}

Epoller::~Epoller() {
    close(epollFd_);
}

// 添加文件描述符到epoll中进行管理
bool Epoller::AddFd(int fd, uint32_t events) {
    if(fd < 0) return false;
    epoll_event ev = {0};
    ev.data.fd = fd;
    ev.events = events;
    return 0 == epoll_ctl(epollFd_, EPOLL_CTL_ADD, fd, &ev);
}

// 修改
bool Epoller::ModFd(int fd, uint32_t events) {
    if(fd < 0) return false;
    epoll_event ev = {0};
    ev.data.fd = fd;
    ev.events = events;
    return 0 == epoll_ctl(epollFd_, EPOLL_CTL_MOD, fd, &ev);  // 此时修改了事件的模式如EPOLLOUT
}

// 删除
bool Epoller::DelFd(int fd) {
    if(fd < 0) return false;
    epoll_event ev = {0};
    return 0 == epoll_ctl(epollFd_, EPOLL_CTL_DEL, fd, &ev);
}

// 调用epoll_wait()进行事件检测
int Epoller::Wait(int timeoutMs) {
    return epoll_wait(epollFd_, &events_[0], static_cast<int>(events_.size()), timeoutMs);  // events == &events[0]
}

// 获取产生事件的文件描述符
int Epoller::GetEventFd(size_t i) const {
    assert(i < events_.size() && i >= 0);
    return events_[i].data.fd;
}

// 获取事件
uint32_t Epoller::GetEvents(size_t i) const {
    assert(i < events_.size() && i >= 0);
    return events_[i].events;
}