简单封装一下epoll

按照lighttpd的方式封装了一下epoll，打算以后就直接这么用了，虽然简陋了点，不过很容易修改
event.h头文件

#include <sys/epoll.h>

#define BV(x) (1 << x)
#define FDEVENT_IN     BV(0)
#define FDEVENT_PRI    BV(1)
#define FDEVENT_OUT    BV(2)
#define FDEVENT_ERR    BV(3)
#define FDEVENT_HUP    BV(4)
#define FDEVENT_NVAL   BV(5)

typedef void (*fdevent_handler)(int fd,void *ctx, int revents);
typedef struct _fdnode{
	fdevent_handler handler;
	int fd;
	void *ctx;
	int status;
}fdnode;

typedef struct fdevents{
	fdnode **fdarray;
	size_t maxfds;

	int epoll_fd;
	struct epoll_event *epoll_events;
}fdevents;

fdevents *fdevent_init(size_t maxfds);
void fdevent_free(fdevents *ev);
int fdevent_register(fdevents *ev,int fd,fdevent_handler handler,void *ctx);
int fdevent_unregister(fdevents *ev,int fd);
int fdevent_event_add(fdevents *ev,int fd,int events);
int fdevent_event_del(fdevents *ev,int fd);
int fdevent_poll(fdevents *ev, int timeout_ms);

event.c实现

#include<stdio.h>
#include<unistd.h>
#include<sys/types.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<errno.h>
#include<fcntl.h>
#include<netinet/in.h>
#include<sys/resource.h>
#include "event.h"
//foward declaration
static fdnode *fdnode_init();
static void fdnode_free(fdnode *fdn);


fdevents *fdevent_init(size_t maxfds){
	fdevents *ev;

	ev = calloc(1,sizeof(*ev));
	ev->fdarray = calloc(maxfds , sizeof(*ev->fdarray));
	ev->maxfds = maxfds;
	
	ev->epoll_fd=epoll_create(maxfds);
	if(-1==ev->epoll_fd){
		fprintf(stderr,"epoll create failed,%s\n",strerror(errno));
		return NULL;
	}

	ev->epoll_events=malloc(maxfds * sizeof(*ev->epoll_events));

	return ev;
}
void fdevent_free(fdevents *ev){
	size_t i;
	if(!ev) return ;

	close(ev->epoll_fd);
	free(ev->epoll_events);
	
	for(i=0;i<ev->maxfds;i++){
		if(ev->fdarray[i]) free(ev->fdarray[i]);		
	}

	free(ev->fdarray);
	free(ev);

}

int fdevent_register(fdevents *ev,int fd,fdevent_handler handler,void *ctx){
	fdnode *fdn;
	fdn=fdnode_init();
	fdn->handler=handler;
	fdn->fd=fd;
	fdn->ctx=ctx;

	ev->fdarray[fd]=fdn;

	return 0;
}

int fdevent_unregister(fdevents *ev,int fd){
	if(!ev) return 0;

	fdnode *fdn=ev->fdarray[fd];
	fdnode_free(fdn);
	ev->fdarray[fd]=NULL;

	return 0;
}

int fdevent_event_add(fdevents *ev,int fd,int events){
	struct epoll_event ep;
	int add=0;

	fdnode *fdn=ev->fdarray[fd];
	add = (fdn->status == -1 ? 1 : 0);
	
	memset(&ep,0,sizeof(ep));
	ep.events = 0;

	if(events & FDEVENT_IN) ep.events |=EPOLLIN;
	if(events & FDEVENT_OUT) ep.events |=EPOLLOUT;

	ep.data.ptr=NULL;
	ep.data.fd=fd;

	if(0 != epoll_ctl(ev->epoll_fd,add ? EPOLL_CTL_ADD : EPOLL_CTL_MOD,fd,&ep)){
		fprintf(stderr,"epoll_ctl failed %s\n",strerror(errno));
		return -1;
	}
	
	if(add){
		fdn->status=1;
	}
	return 0;

}
int fdevent_event_del(fdevents *ev,int fd){
	struct epoll_event ep;
	fdnode *fdn=ev->fdarray[fd];	
	if(-1==fdn->status){
		return 0;
	}
	memset(&ep,0,sizeof(ep));

	ep.data.ptr=NULL;
	ep.data.fd=fd;

	if(0 != epoll_ctl(ev->epoll_fd,EPOLL_CTL_DEL,fd,&ep)){
		fprintf(stderr,"epoll del failed %s\n",strerror(errno));
		return -1;
	}

	fdn->status=-1;
	return 0;
}
int fdevent_poll(fdevents *ev, int timeout_ms){
	int n,i;
	for(;;){
		n=0;
		if((n=epoll_wait(ev->epoll_fd,ev->epoll_events,ev->maxfds,timeout_ms))>0){
			for(i=0;i<n;i++){
				fdevent_handler handler;
				void *context;
				int events = 0, e,fd;
				fdnode *fdn;
				
				e=ev->epoll_events[i].events;
				if (e & EPOLLIN) events |= FDEVENT_IN;
				if (e & EPOLLOUT) events |= FDEVENT_OUT;
				
				fd=ev->epoll_events[i].data.fd;

				fdn = ev->fdarray[fd];
				context = fdn->ctx;
				fdn->handler(fd,context,events);
			}	
		}
	}
}
static fdnode *fdnode_init(){
	fdnode *fdn;

	fdn=calloc(1,sizeof(*fdn));
	fdn->fd=-1;
	fdn->status=-1;

	return fdn;
}
static void fdnode_free(fdnode *fdn){
	free(fdn);
}

简单调用流程就是下面这几个接口

fdevents *fdevent_init(size_t maxfds);
int fdevent_register(fdevents *ev,int fd,fdevent_handler handler,void *ctx);
int fdevent_event_add(fdevents *ev,int fd,int events);
int fdevent_poll(fdevents *ev, int timeout_ms);

评论

1 楼 laier903 2012-03-13  

请问这句的作用是？如何理解呢？if(events & FDEVENT_IN) ep.events |=EPOLLIN;