C++ (Cpp) epoll_recalcの例

コード例 #1

ファイル: epoll.c プロジェクト: qingliudao/libevent_ana

static int
epoll_add(void *arg, struct event *ev)
{
	struct epollop *epollop = arg;
	struct epoll_event epev = {0, {0}};
	struct evepoll *evep;
	int fd, op, events;

    /*
     * x信号的原理
     * 1 设置信号处理函数，保存原来的信号处理函数到event的ev_base->sh_old中去
     * 2 如果是首次添加信号，那么需要为所有信号追加一个信号事件来源自event->ev_base->ev_signal
     *   同时设置event->ev_base->ev_signal->ev_signal_added,表示信号回调事件已经设置了
     * 3 同时把事件追加到event->ev_base->ev_signal->evsigevents[signno]链表中去
     */
	if (ev->ev_events & EV_SIGNAL)  //如果是加入的信号
		return (evsignal_add(ev));

	fd = ev->ev_fd;
	if (fd >= epollop->nfds) {
		/* Extent the file descriptor array as necessary */
        //如果说当前的epoll中已经满足不了新加入的句柄
		if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
			return (-1);
	}

	evep = &epollop->fds[fd];
	op = EPOLL_CTL_ADD;
	events = 0;
    //如果事件之前是可读
	if (evep->evread != NULL) {
		events |= EPOLLIN;
		op = EPOLL_CTL_MOD;
	}
    //如果事件之前是可写
	if (evep->evwrite != NULL) {
		events |= EPOLLOUT;
		op = EPOLL_CTL_MOD;
	}

    //新加入事件设置的是可读事件
	if (ev->ev_events & EV_READ)
		events |= EPOLLIN;
    //新加入事件设置的是可写事件
	if (ev->ev_events & EV_WRITE)
		events |= EPOLLOUT;

	epev.data.ptr = evep;
	epev.events = events;
	if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
			return (-1);

	/* Update events responsible */
	if (ev->ev_events & EV_READ)
		evep->evread = ev;
	if (ev->ev_events & EV_WRITE)
		evep->evwrite = ev;

	return (0);
}

コード例 #2

ファイル: epoll.c プロジェクト: kevin-gjm/libevent-1.4.13

static int
epoll_add(void *arg, struct event *ev)
{
	struct epollop *epollop = arg;
	struct epoll_event epev = {0, {0}};
	struct evepoll *evep;
	int fd, op, events;
	//signal 的添加部分，直接调用signal添加函数
	if (ev->ev_events & EV_SIGNAL)
		return (evsignal_add(ev));

	fd = ev->ev_fd;
	//fd总是系统中空闲的最小fd，判断fds是否够，不够扩大
	if (fd >= epollop->nfds) {
		/* Extent the file descriptor array as necessary */
		if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
			return (-1);
	}
	//fds 和 events数组的索引是一致的都是fd
	evep = &epollop->fds[fd];
	op = EPOLL_CTL_ADD;
	events = 0;
	//若相应的fd已经添加了相应的event
	//再次添加回覆盖evepoll中的event指针
	if (evep->evread != NULL) {
		events |= EPOLLIN;
		op = EPOLL_CTL_MOD;
	}
	if (evep->evwrite != NULL) {
		events |= EPOLLOUT;
		op = EPOLL_CTL_MOD;
	}

	if (ev->ev_events & EV_READ)
		events |= EPOLLIN;
	if (ev->ev_events & EV_WRITE)
		events |= EPOLLOUT;

	epev.data.fd = fd;
	epev.events = events;
	if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
			return (-1);

	/* Update events responsible */
	if (ev->ev_events & EV_READ)
		evep->evread = ev;
	if (ev->ev_events & EV_WRITE)
		evep->evwrite = ev;

	return (0);
}

コード例 #3

ファイル: epoll.c プロジェクト: Akin-Net/mozilla-central

static int
epoll_add(void *arg, struct event *ev)
{
	struct epollop *epollop = arg;
	struct epoll_event epev = {0, {0}};
	struct evepoll *evep;
	int fd, op, events;

	if (ev->ev_events & EV_SIGNAL)
		return (evsignal_add(ev));

	fd = ev->ev_fd;
	if (fd >= epollop->nfds) {
		/* Extent the file descriptor array as necessary */
		if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
			return (-1);
	}
	evep = &epollop->fds[fd];
	op = EPOLL_CTL_ADD;
	events = 0;
	if (evep->evread != NULL) {
		events |= EPOLLIN;
		op = EPOLL_CTL_MOD;
	}
	if (evep->evwrite != NULL) {
		events |= EPOLLOUT;
		op = EPOLL_CTL_MOD;
	}

	if (ev->ev_events & EV_READ)
		events |= EPOLLIN;
	if (ev->ev_events & EV_WRITE)
		events |= EPOLLOUT;

	epev.data.ptr = evep;
	epev.events = events;
	if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
			return (-1);

	/* Update events responsible */
	if (ev->ev_events & EV_READ)
		evep->evread = ev;
	if (ev->ev_events & EV_WRITE)
		evep->evwrite = ev;

	return (0);
}

コード例 #4

ファイル: epoll.c プロジェクト: qtekfun/htcDesire820Kernel

static int
epoll_add(void *arg, struct event *ev)
{
	struct epollop *epollop = arg;
	struct epoll_event epev = {0, {0}};
	struct evepoll *evep;
	int fd, op, events;

	if (ev->ev_events & EV_SIGNAL)
		return (evsignal_add(ev));

	fd = ev->ev_fd;
	if (fd >= epollop->nfds) {
		
		if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
			return (-1);
	}
	evep = &epollop->fds[fd];
	op = EPOLL_CTL_ADD;
	events = 0;
	if (evep->evread != NULL) {
		events |= EPOLLIN;
		op = EPOLL_CTL_MOD;
	}
	if (evep->evwrite != NULL) {
		events |= EPOLLOUT;
		op = EPOLL_CTL_MOD;
	}

	if (ev->ev_events & EV_READ)
		events |= EPOLLIN;
	if (ev->ev_events & EV_WRITE)
		events |= EPOLLOUT;

	epev.data.fd = fd;
	epev.events = events;
	if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
			return (-1);

	
	if (ev->ev_events & EV_READ)
		evep->evread = ev;
	if (ev->ev_events & EV_WRITE)
		evep->evwrite = ev;

	return (0);
}

コード例 #5

ファイル: epoll.c プロジェクト: hzsunzixiang/programming

int
epoll_add(void *arg, struct event *ev)
{
	struct epollop *epollop = arg;
	struct epoll_event epev;
	struct evepoll *evep;
	int fd, op, events;

	if (ev->ev_events & EV_SIGNAL)
		return (evsignal_add(&epollop->evsigmask, ev));

	fd = ev->ev_fd;
	if (fd >= epollop->nfds) {
		/* Extent the file descriptor array as necessary */
		if (epoll_recalc(epollop, fd) == -1)
			return (-1);
	}
	evep = &epollop->fds[fd];  // NOTE: 以fd作为下标 的一个指针，指向数组, 
	op = EPOLL_CTL_ADD;
	events = 0;
	if (evep->evread != NULL) {
		events |= EPOLLIN;
		op = EPOLL_CTL_MOD;
	}
	if (evep->evwrite != NULL) {
		events |= EPOLLOUT;
		op = EPOLL_CTL_MOD;
	}

	if (ev->ev_events & EV_READ)
		events |= EPOLLIN;
	if (ev->ev_events & EV_WRITE)
		events |= EPOLLOUT;

	epev.data.ptr = evep;  // NOTE: 这里作为一个指针
	epev.events = events;  // NOTE 疑问， epev是局部变量，可以直接传指针？ 应该是没问题，内核复制一份
	if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
			return (-1);

	/* Update events responsible */
	if (ev->ev_events & EV_READ)
		evep->evread = ev;    // 在这里真正复制了 对应的事件  返回的时候就能看到
	if (ev->ev_events & EV_WRITE)
		evep->evwrite = ev;

	return (0);
}