| /* Generic write queue implementation */ |
| /* |
| * (C) 2010-2016 by Holger Hans Peter Freyther |
| * (C) 2010 by On-Waves |
| * |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| */ |
| |
| #include <errno.h> |
| #include <osmocom/core/write_queue.h> |
| #include <osmocom/core/logging.h> |
| |
| /*! \addtogroup write_queue |
| * @{ |
| * \brief write queue for writing \ref msgb to sockets/fd's |
| */ |
| |
| /*! \file write_queue.c */ |
| |
| /*! \brief Select loop function for write queue handling |
| * \param[in] fd osmocom file descriptor |
| * \param[in] what bit-mask of events that have happened |
| * \returns 0 on success; negative on error |
| * |
| * This function is provided so that it can be registered with the |
| * select loop abstraction code (\ref osmo_fd::cb). |
| */ |
| int osmo_wqueue_bfd_cb(struct osmo_fd *fd, unsigned int what) |
| { |
| struct osmo_wqueue *queue; |
| int rc; |
| |
| queue = container_of(fd, struct osmo_wqueue, bfd); |
| |
| if (what & BSC_FD_READ) { |
| rc = queue->read_cb(fd); |
| if (rc == -EBADF) |
| goto err_badfd; |
| } |
| |
| if (what & BSC_FD_EXCEPT) { |
| rc = queue->except_cb(fd); |
| if (rc == -EBADF) |
| goto err_badfd; |
| } |
| |
| if (what & BSC_FD_WRITE) { |
| struct msgb *msg; |
| |
| fd->when &= ~BSC_FD_WRITE; |
| |
| /* the queue might have been emptied */ |
| if (!llist_empty(&queue->msg_queue)) { |
| --queue->current_length; |
| |
| msg = msgb_dequeue(&queue->msg_queue); |
| rc = queue->write_cb(fd, msg); |
| msgb_free(msg); |
| |
| if (rc == -EBADF) |
| goto err_badfd; |
| |
| if (!llist_empty(&queue->msg_queue)) |
| fd->when |= BSC_FD_WRITE; |
| } |
| } |
| |
| err_badfd: |
| /* Return value is not checked in osmo_select_main() */ |
| return 0; |
| } |
| |
| /*! \brief Initialize a \ref osmo_wqueue structure |
| * \param[in] queue Write queue to operate on |
| * \param[in] max_length Maximum length of write queue |
| */ |
| void osmo_wqueue_init(struct osmo_wqueue *queue, int max_length) |
| { |
| queue->max_length = max_length; |
| queue->current_length = 0; |
| queue->read_cb = NULL; |
| queue->write_cb = NULL; |
| queue->except_cb = NULL; |
| queue->bfd.cb = osmo_wqueue_bfd_cb; |
| INIT_LLIST_HEAD(&queue->msg_queue); |
| } |
| |
| /*! \brief Enqueue a new \ref msgb into a write queue |
| * \param[in] queue Write queue to be used |
| * \param[in] data to-be-enqueued message buffer |
| * \returns 0 on success; negative on error |
| */ |
| int osmo_wqueue_enqueue(struct osmo_wqueue *queue, struct msgb *data) |
| { |
| if (queue->current_length >= queue->max_length) { |
| LOGP(DLGLOBAL, LOGL_ERROR, |
| "wqueue(%p) is full. Rejecting msgb\n", queue); |
| return -ENOSPC; |
| } |
| |
| ++queue->current_length; |
| msgb_enqueue(&queue->msg_queue, data); |
| queue->bfd.when |= BSC_FD_WRITE; |
| |
| return 0; |
| } |
| |
| /*! \brief Clear a \ref osmo_wqueue |
| * \param[in] queue Write queue to be cleared |
| * |
| * This function will clear (remove/release) all messages in it. |
| */ |
| void osmo_wqueue_clear(struct osmo_wqueue *queue) |
| { |
| while (!llist_empty(&queue->msg_queue)) { |
| struct msgb *msg = msgb_dequeue(&queue->msg_queue); |
| msgb_free(msg); |
| } |
| |
| queue->current_length = 0; |
| queue->bfd.when &= ~BSC_FD_WRITE; |
| } |
| |
| /*! @} */ |