F-Stack 之 kqueue 封装为 epoll 介绍

int 
ff_epoll_ctl(int epfd, int op, int fd, struct epoll_event *event)
{
	if (!event && op != EPOLL_CTL_DEL) {
        ff_os_errno(ff_EINVAL);
		return -1;
	}

	struct kevent kev[3];
	if (op == EPOLL_CTL_ADD){
		EV_SET(&kev[0], fd, EVFILT_READ,
			EV_ADD | (event->events & EPOLLIN ? 0 : EV_DISABLE), 0, 0, NULL);
		EV_SET(&kev[1], fd, EVFILT_WRITE,
			EV_ADD | (event->events & EPOLLOUT ? 0 : EV_DISABLE), 0, 0, NULL);
		EV_SET(&kev[2], fd, EVFILT_USER, EV_ADD,
			    event->events & EPOLLRDHUP ? 1 : 0, 0, NULL);		
	} else if (op == EPOLL_CTL_DEL) {
		EV_SET(&kev[0], fd, EVFILT_READ, EV_DELETE, 0, 0, NULL);
		EV_SET(&kev[1], fd, EVFILT_WRITE, EV_DELETE, 0, 0, NULL);
		EV_SET(&kev[2], fd, EVFILT_USER, EV_DELETE, 0, 0, NULL);
	} else if (op == EPOLL_CTL_MOD) {
		EV_SET(&kev[0], fd, EVFILT_READ,
		    event->events & EPOLLIN ? EV_ENABLE : EV_DISABLE, 0, 0, NULL);
		EV_SET(&kev[1], fd, EVFILT_WRITE,
		    event->events & EPOLLOUT ? EV_ENABLE : EV_DISABLE, 0, 0, NULL);
		EV_SET(&kev[2], fd, EVFILT_USER, 0,
		    NOTE_FFCOPY | (event->events & EPOLLRDHUP ? 1 : 0), 0, NULL);		
	} else {
		ff_os_errno(ff_EINVAL);
		return -1;
	}

	return ff_kevent(epfd, kev, 3, NULL, 0, NULL);
}

int 
ff_epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout)
{
	if (!events || maxevents < 1) {
		ff_os_errno(ff_EINVAL);
		return -1;
	}
	
	struct kevent *evlist = malloc(sizeof(struct kevent)*maxevents, M_DEVBUF, M_ZERO|M_NOWAIT);
	if(NULL == evlist){
		ff_os_errno(ff_EINVAL);
		return -1;		
	}
	memset(evlist, 0, sizeof(struct kevent)*maxevents);
	
	int ret = ff_kevent(epfd, NULL, 0, evlist, maxevents, NULL);
	if (ret == -1) {
		free(evlist, M_DEVBUF);
		return ret;
	}

	unsigned int event_one = 0;
	for (int i = 0; i < ret; ++i) {
		event_one = 0;
		if (evlist[i].filter & EVFILT_READ) {
			event_one |= EPOLLIN;
		} 
		if (evlist[i].filter & EVFILT_WRITE) {
			event_one |= EPOLLOUT;
		}

		if (evlist[i].flags & EV_ERROR) {
			event_one |= EPOLLERR;
		}

		if (evlist[i].flags & EV_EOF) {
			event_one |= EPOLLIN;		
		}
		events[i].events   = event_one;
		events[i].data.fd  = evlist[i].ident;
	}
	
	free(evlist, M_DEVBUF);
	return ret;
}

int loop(void *arg)
{
    /* Wait for events to happen */

    int nevents = ff_epoll_wait(epfd,  events, MAX_EVENTS, 0);
    int i;

    for (i = 0; i < nevents; ++i) {	
        /* Handle new connect */
        if (events[i].data.fd == sockfd) {
            int nclientfd = ff_accept(sockfd, NULL, NULL);
            assert(nclientfd > 0);
            /* Add to event list */
    	    ev.data.fd = nclientfd;
    	    ev.events  = EPOLLIN;
    	    assert(ff_epoll_ctl(epfd, EPOLL_CTL_ADD, nclientfd, &ev) == 0);
            //fprintf(stderr, "A new client connected to the server..., fd:%d\n", nclientfd);
        } else { 
            if (events[i].events & EPOLLERR ) {
                /* Simply close socket */
        	ff_epoll_ctl(epfd, EPOLL_CTL_DEL,  events[i].data.fd, NULL);
                ff_close(events[i].data.fd);
                //fprintf(stderr, "A client has left the server...,fd:%d\n", events[i].data.fd);
            } else if (events[i].events & EPOLLIN) {
                char buf[256];
                size_t readlen = ff_read( events[i].data.fd, buf, sizeof(buf));
                //fprintf(stderr, "bytes are available to read..., readlen:%d, fd:%d\n", readlen,  events[i].data.fd);
        	if(readlen > 0){
                    ff_write( events[i].data.fd, html, sizeof(html));
        	} else {
        	    ff_epoll_ctl(epfd, EPOLL_CTL_DEL,  events[i].data.fd, NULL);
                    ff_close( events[i].data.fd);
                    //fprintf(stderr, "A client has left the server...,fd:%d\n", events[i].data.fd);		
        	}
            } else {
                fprintf(stderr, "unknown event: %8.8X\n", events[i].events);
            }
        }
    }
}