socket.c

bind 9.3结合mysql数据库

	sock = *socketp;
	REQUIRE(VALID_SOCKET(sock));

	LOCK(&sock->lock);
	REQUIRE(sock->references > 0);
	sock->references--;
	if (sock->references == 0)
		kill_socket = ISC_TRUE;
	UNLOCK(&sock->lock);

	if (kill_socket)
		destroy(&sock);

	*socketp = NULL;
}

/*
 * I/O is possible on a given socket.  Schedule an event to this task that
 * will call an internal function to do the I/O.  This will charge the
 * task with the I/O operation and let our select loop handler get back
 * to doing something real as fast as possible.
 *
 * The socket and manager must be locked before calling this function.
 */
static void
dispatch_recv(isc_socket_t *sock) {
	intev_t *iev;
	isc_socketevent_t *ev;

	INSIST(!sock->pending_recv);

	ev = ISC_LIST_HEAD(sock->recv_list);
	if (ev == NULL)
		return;

	sock->pending_recv = 1;
	iev = &sock->readable_ev;

	socket_log(sock, NULL, EVENT, NULL, 0, 0,
		   "dispatch_recv:  event %p -> task %p", ev, ev->ev_sender);

	sock->references++;
	iev->ev_sender = sock;
	iev->ev_action = internal_recv;
	iev->ev_arg = sock;

	isc_task_send(ev->ev_sender, (isc_event_t **)&iev);
}

static void
dispatch_send(isc_socket_t *sock) {
	intev_t *iev;
	isc_socketevent_t *ev;

	INSIST(!sock->pending_send);

	ev = ISC_LIST_HEAD(sock->send_list);
	if (ev == NULL)
		return;

	sock->pending_send = 1;
	iev = &sock->writable_ev;

	socket_log(sock, NULL, EVENT, NULL, 0, 0,
		   "dispatch_send:  event %p -> task %p", ev, ev->ev_sender);

	sock->references++;
	iev->ev_sender = sock;
	iev->ev_action = internal_send;
	iev->ev_arg = sock;

	isc_task_send(ev->ev_sender, (isc_event_t **)&iev);
}

/*
 * Dispatch an internal accept event.
 */
static void
dispatch_accept(isc_socket_t *sock) {
	intev_t *iev;
	isc_socket_newconnev_t *ev;

	INSIST(!sock->pending_accept);

	/*
	 * Are there any done events left, or were they all canceled
	 * before the manager got the socket lock?
	 */
	ev = ISC_LIST_HEAD(sock->accept_list);
	if (ev == NULL)
		return;

	sock->pending_accept = 1;
	iev = &sock->readable_ev;

	sock->references++;  /* keep socket around for this internal event */
	iev->ev_sender = sock;
	iev->ev_action = internal_accept;
	iev->ev_arg = sock;

	isc_task_send(ev->ev_sender, (isc_event_t **)&iev);
}

static void
dispatch_connect(isc_socket_t *sock) {
	intev_t *iev;
	isc_socket_connev_t *ev;

	iev = &sock->writable_ev;

	ev = sock->connect_ev;
	INSIST(ev != NULL); /* XXX */

	INSIST(sock->connecting);

	sock->references++;  /* keep socket around for this internal event */
	iev->ev_sender = sock;
	iev->ev_action = internal_connect;
	iev->ev_arg = sock;

	isc_task_send(ev->ev_sender, (isc_event_t **)&iev);
}

/*
 * Dequeue an item off the given socket's read queue, set the result code
 * in the done event to the one provided, and send it to the task it was
 * destined for.
 *
 * If the event to be sent is on a list, remove it before sending.  If
 * asked to, send and detach from the socket as well.
 *
 * Caller must have the socket locked if the event is attached to the socket.
 */
static void
send_recvdone_event(isc_socket_t *sock, isc_socketevent_t **dev) {
	isc_task_t *task;

	task = (*dev)->ev_sender;

	(*dev)->ev_sender = sock;

	if (ISC_LINK_LINKED(*dev, ev_link))
		ISC_LIST_DEQUEUE(sock->recv_list, *dev, ev_link);

	if (((*dev)->attributes & ISC_SOCKEVENTATTR_ATTACHED)
	    == ISC_SOCKEVENTATTR_ATTACHED)
		isc_task_sendanddetach(&task, (isc_event_t **)dev);
	else
		isc_task_send(task, (isc_event_t **)dev);
}

/*
 * See comments for send_recvdone_event() above.
 *
 * Caller must have the socket locked if the event is attached to the socket.
 */
static void
send_senddone_event(isc_socket_t *sock, isc_socketevent_t **dev) {
	isc_task_t *task;

	INSIST(dev != NULL && *dev != NULL);

	task = (*dev)->ev_sender;
	(*dev)->ev_sender = sock;

	if (ISC_LINK_LINKED(*dev, ev_link))
		ISC_LIST_DEQUEUE(sock->send_list, *dev, ev_link);

	if (((*dev)->attributes & ISC_SOCKEVENTATTR_ATTACHED)
	    == ISC_SOCKEVENTATTR_ATTACHED)
		isc_task_sendanddetach(&task, (isc_event_t **)dev);
	else
		isc_task_send(task, (isc_event_t **)dev);
}

/*
 * Call accept() on a socket, to get the new file descriptor.  The listen
 * socket is used as a prototype to create a new isc_socket_t.  The new
 * socket has one outstanding reference.  The task receiving the event
 * will be detached from just after the event is delivered.
 *
 * On entry to this function, the event delivered is the internal
 * readable event, and the first item on the accept_list should be
 * the done event we want to send.  If the list is empty, this is a no-op,
 * so just unlock and return.
 */
static void
internal_accept(isc_task_t *me, isc_event_t *ev) {
	isc_socket_t *sock;
	isc_socketmgr_t *manager;
	isc_socket_newconnev_t *dev;
	isc_task_t *task;
	ISC_SOCKADDR_LEN_T addrlen;
	int fd;
	isc_result_t result = ISC_R_SUCCESS;
	char strbuf[ISC_STRERRORSIZE];

	UNUSED(me);

	sock = ev->ev_sender;
	INSIST(VALID_SOCKET(sock));

	LOCK(&sock->lock);
	socket_log(sock, NULL, TRACE,
		   isc_msgcat, ISC_MSGSET_SOCKET, ISC_MSG_ACCEPTLOCK,
		   "internal_accept called, locked socket");

	manager = sock->manager;
	INSIST(VALID_MANAGER(manager));

	INSIST(sock->listener);
	INSIST(sock->pending_accept == 1);
	sock->pending_accept = 0;

	INSIST(sock->references > 0);
	sock->references--;  /* the internal event is done with this socket */
	if (sock->references == 0) {
		UNLOCK(&sock->lock);
		destroy(&sock);
		return;
	}

	/*
	 * Get the first item off the accept list.
	 * If it is empty, unlock the socket and return.
	 */
	dev = ISC_LIST_HEAD(sock->accept_list);
	if (dev == NULL) {
		UNLOCK(&sock->lock);
		return;
	}

	/*
	 * Try to accept the new connection.  If the accept fails with
	 * EAGAIN or EINTR, simply poke the watcher to watch this socket
	 * again.  Also ignore ECONNRESET, which has been reported to
	 * be spuriously returned on Linux 2.2.19 although it is not
	 * a documented error for accept().  ECONNABORTED has been
	 * reported for Solaris 8.  The rest are thrown in not because
	 * we have seen them but because they are ignored by other
	 * deamons such as BIND 8 and Apache.
	 */

	addrlen = sizeof(dev->newsocket->address.type);
	memset(&dev->newsocket->address.type.sa, 0, addrlen);
	fd = accept(sock->fd, &dev->newsocket->address.type.sa,
		    (void *)&addrlen);

#ifdef F_DUPFD
        /*
         * Leave a space for stdio to work in.
         */
        if (fd >= 0 && fd < 20) {
                int new, tmp;
                new = fcntl(fd, F_DUPFD, 20);
                tmp = errno;
                (void)close(fd);
                errno = tmp;
                fd = new;
        }
#endif

	if (fd < 0) {
		if (SOFT_ERROR(errno))
			goto soft_error;
		switch (errno) {
		case ENOBUFS:
		case ENFILE:
		case ENOMEM:
		case ECONNRESET:
		case ECONNABORTED:
		case EHOSTUNREACH:
		case EHOSTDOWN:
		case ENETUNREACH:
		case ENETDOWN:
		case ECONNREFUSED:
#ifdef EPROTO
		case EPROTO:
#endif
#ifdef ENONET
		case ENONET:
#endif
			goto soft_error;
		default:
			break;
		}
		isc__strerror(errno, strbuf, sizeof(strbuf));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "internal_accept: accept() %s: %s",
				 isc_msgcat_get(isc_msgcat,
						ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED,
						"failed"),
				 strbuf);
		fd = -1;
		result = ISC_R_UNEXPECTED;
	} else {
		if (addrlen == 0) {
			UNEXPECTED_ERROR(__FILE__, __LINE__,
					 "internal_accept(): "
					 "accept() failed to return "
					 "remote address");

			(void)close(fd);
			goto soft_error;
		} else if (dev->newsocket->address.type.sa.sa_family !=
			   sock->pf)
		{
			UNEXPECTED_ERROR(__FILE__, __LINE__,
					 "internal_accept(): "
					 "accept() returned peer address "
					 "family %u (expected %u)", 
					 dev->newsocket->address.
					 type.sa.sa_family,
					 sock->pf);
			(void)close(fd);
			goto soft_error;
		} else if (fd >= (int)FD_SETSIZE) {
			isc_log_iwrite(isc_lctx, ISC_LOGCATEGORY_GENERAL,
				       ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
				       isc_msgcat, ISC_MSGSET_SOCKET,
				       ISC_MSG_TOOMANYFDS,
				       "%s: too many open file descriptors",
				       "accept");
			(void)close(fd);
			goto soft_error;
		}
	}

	if (fd != -1) {
		dev->newsocket->address.length = addrlen;
		dev->newsocket->pf = sock->pf;
	}

	/*
	 * Pull off the done event.
	 */
	ISC_LIST_UNLINK(sock->accept_list, dev, ev_link);

	/*
	 * Poke watcher if there are more pending accepts.
	 */
	if (!ISC_LIST_EMPTY(sock->accept_list))
		select_poke(sock->manager, sock->fd, SELECT_POKE_ACCEPT);

	UNLOCK(&sock->lock);

	if (fd != -1 && (make_nonblock(fd) != ISC_R_SUCCESS)) {
		(void)close(fd);
		fd = -1;
		result = ISC_R_UNEXPECTED;
	}

	/*
	 * -1 means the new socket didn't happen.
	 */
	if (fd != -1) {
		LOCK(&manager->lock);
		ISC_LIST_APPEND(manager->socklist, dev->newsocket, link);

		dev->newsocket->fd = fd;
		dev->newsocket->bound = 1;
		dev->newsocket->connected = 1;

		/*
		 * Save away the remote address
		 */
		dev->address = dev->newsocket->address;

		manager->fds[fd] = dev->newsocket;
		manager->fdstate[fd] = MANAGED;
		if (manager->maxfd < fd)
			manager->maxfd = fd;

		socket_log(sock, &dev->newsocket->address, CREATION,
			   isc_msgcat, ISC_MSGSET_SOCKET, ISC_MSG_ACCEPTEDCXN,
			   "accepted connection, new socket %p",
			   dev->newsocket);

		UNLOCK(&manager->lock);
	} else {
		dev->newsocket->references--;
		free_socket(&dev->newsocket);
	}
	
	/*
	 * Fill in the done event details and send it off.
	 */
	dev->result = result;
	task = dev->ev_sender;
	dev->ev_sender = sock;

	isc_task_sendanddetach(&task, ISC_EVENT_PTR(&dev));
	return;

 soft_error:
	select_poke(sock->manager, sock->fd, SELECT_POKE_ACCEPT);
	UNLOCK(&sock->lock);
	return;
}

static void
internal_recv(isc_task_t *me, isc_event_t *ev) {
	isc_socketevent_t *dev;
	isc_socket_t *sock;

	INSIST(ev->ev_type == ISC_SOCKEVENT_INTR);

	sock = ev->ev_sender;
	INSIST(VALID_SOCKET(sock));

	LOCK(&sock->lock);
	socket_log(sock, NULL, IOEVENT,
		   isc_msgcat, ISC_MSGSET_SOCKET, ISC_MSG_INTERNALRECV,
		   "internal_recv: task %p got event %p", me, ev);

	INSIST(sock->pending_recv == 1);
	sock->pending_recv = 0;

	INSIST(sock->references > 0);
	sock->references--;  /* the internal event is done with this socket */
	if (sock->references == 0) {
		UNLOCK(&sock->lock);
		destroy(&sock);
		return;
	}

	/*
	 * Try to do as much I/O as possible on this socket.  There are no
	 * limits here, currently.
	 */
	dev = ISC_LIST_HEAD(sock->recv_list);
	while (dev != NULL) {
		switch (doio_recv(sock, dev)) {
		case DOIO_SOFT:
			goto poke;

		case DOIO_EOF:
			/*
			 * read of 0 means the remote end was closed.
			 * Run through the event queue and dispatch all
			 * the events with an EOF result code.
			 */
			do {
				dev->result = ISC_R_EOF;
				send_recvdone_event(sock, &dev);
				dev = ISC_LIST_HEAD(sock->recv_list);
			} while (dev != NULL);
			goto poke;

		case DOIO_SUCCESS:
		case DOIO_HARD:
			send_recvdone_event(sock, &dev);
			break;
		}

		dev = ISC_LIST_HEAD(sock->recv_list);
	}

 poke:
	if (!ISC_LIST_EMPTY(sock->recv_list))
		select_poke(sock->manager, sock->fd, SELECT_POKE_READ);

	UNLOCK(&sock->lock);
}

static void
internal_send(isc_task_t *me, isc_event_t *ev) {
	isc_socketevent_t *dev;
	isc_socket_t *sock;

	INSIST(ev->ev_type == ISC_SOCKEVENT_INTW);

	/*
	 * Find out what socket this is and lock it.
	 */
	sock = (isc_socket_t *)ev->ev_sender;
	INSIST(VALID_SOCKET(sock));

	LOCK(&sock->lock);
	socket_log(sock, NULL, IOEVENT,
		   isc_msgcat, ISC_MSGSET_SOCKET, ISC_MSG_INTERNALSEND,
		   "internal_send: task %p got event %p", me, ev);

	INSIST(sock->pending_send == 1);
	sock->pending_send = 0;

	INSIST(sock->references > 0);
	sock->references--;  /* the internal event is done with this socket */
	if (sock->references == 0) {
		UNLOCK(&sock->lock);
		destroy(&sock);
		return;
	}

	/*
	 * Try to do as much I/O as possible on this socket.  There are no
	 * limits here, currently.
	 */
	dev = ISC_LIST_HEAD(sock->send_list);
	while (dev != NULL) {
		switch (doio_send(sock, dev)) {
		case DOIO_SOFT:
			goto poke;

		case DOIO_HARD:
		case DOIO_SUCCESS:
			send_senddone_event(sock, &dev);
			break;
		}

		dev = ISC_LIST_HEAD(sock->send_list);
	}

 poke:
	if (!ISC_LIST_EMPTY(sock->send_list))
		select_poke(sock->manager, sock->fd, SELECT_POKE_WRITE);

	UNLOCK(&sock->lock);
}

static void
process_fds(isc_socketmgr_t *manager, int maxfd,
	    fd_set *readfds, fd_set *writefds)