123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252 |
- /****************************************************************************
- * fs/mqueue/mq_close.c
- *
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership. The
- * ASF licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the
- * License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sched.h>
- #include <mqueue.h>
- #include <assert.h>
- #include <debug.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/sched.h>
- #include <nuttx/mqueue.h>
- #include "inode/inode.h"
- #include "mqueue/mqueue.h"
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: nxmq_close_group
- *
- * Description:
- * This function is used to indicate that all threads in the group are
- * finished with the specified message queue mqdes. The nxmq_close_group()
- * deallocates any system resources allocated by the system for use by
- * this task for its message queue.
- *
- * Input Parameters:
- * mqdes - Message queue descriptor.
- * group - Group that has the open descriptor.
- *
- * Returned Value:
- * Zero (OK) if the message queue is closed successfully. Otherwise, a
- * negated errno value is returned.
- *
- ****************************************************************************/
- int nxmq_close_group(mqd_t mqdes, FAR struct task_group_s *group)
- {
- FAR struct mqueue_inode_s *msgq;
- FAR struct inode *inode;
- int ret = OK;
- DEBUGASSERT(mqdes != NULL && group != NULL);
- /* Verify the inputs */
- if (mqdes)
- {
- sched_lock();
- /* Find the message queue associated with the message descriptor */
- msgq = mqdes->msgq;
- DEBUGASSERT(msgq && msgq->inode);
- /* Close/free the message descriptor */
- ret = nxmq_desclose_group(mqdes, group);
- if (ret >= 0)
- {
- /* Get the inode from the message queue structure */
- inode = msgq->inode;
- DEBUGASSERT(inode->u.i_mqueue == msgq);
- /* Decrement the reference count on the inode, possibly free it */
- mq_inode_release(inode);
- }
- sched_unlock();
- }
- return ret;
- }
- /****************************************************************************
- * Name: nxmq_close
- *
- * Description:
- * This is an internal OS interface. It is functionally equivalent to
- * mq_close() except that:
- *
- * - It is not a cancellation point, and
- * - It does not modify the errno value.
- *
- * See comments with mq_close() for a more complete description of the
- * behavior of this function
- *
- * Input Parameters:
- * mqdes - Message queue descriptor.
- *
- * Returned Value:
- * This is an internal OS interface and should not be used by applications.
- * It follows the NuttX internal error return policy: Zero (OK) is
- * returned on success. A negated errno value is returned on failure.
- *
- ****************************************************************************/
- int nxmq_close(mqd_t mqdes)
- {
- FAR struct tcb_s *rtcb = (FAR struct tcb_s *)nxsched_self();
- int ret;
- /* Lock the scheduler to prevent any asynchronous task delete operation
- * (unlikely).
- */
- sched_lock();
- DEBUGASSERT(mqdes != NULL && rtcb != NULL && rtcb->group != NULL);
- /* Then perform the close operation */
- ret = nxmq_close_group(mqdes, rtcb->group);
- sched_unlock();
- return ret;
- }
- /****************************************************************************
- * Name: mq_close
- *
- * Description:
- * This function is used to indicate that the calling task is finished
- * with the specified message queue mqdes. The mq_close() deallocates
- * any system resources allocated by the system for use by this task for
- * its message queue.
- *
- * If the calling task has attached a notification to the message queue
- * via this mqdes, this attachment will be removed and the message queue
- * is available for another process to attach a notification.
- *
- * Input Parameters:
- * mqdes - Message queue descriptor.
- *
- * Returned Value:
- * 0 (OK) if the message queue is closed successfully,
- * otherwise, -1 (ERROR).
- *
- * Assumptions:
- * - The behavior of a task that is blocked on either a [nx]mq_send() or
- * [nx]mq_receive() is undefined when mq_close() is called.
- * - The results of using this message queue descriptor after a successful
- * return from mq_close() is undefined.
- *
- ****************************************************************************/
- int mq_close(mqd_t mqdes)
- {
- int ret;
- ret = nxmq_close(mqdes);
- if (ret < 0)
- {
- set_errno(-ret);
- ret = ERROR;
- }
- return ret;
- }
- /****************************************************************************
- * Name: mq_inode_release
- *
- * Description:
- * Release a reference count on a message queue inode.
- *
- * Input Parameters:
- * inode - The message queue inode
- *
- * Returned Value:
- * None
- *
- ****************************************************************************/
- void mq_inode_release(FAR struct inode *inode)
- {
- int ret;
- /* Decrement the reference count on the inode */
- do
- {
- ret = inode_semtake();
- /* The only error that is expected is due to thread cancellation.
- * At this point, we must continue to free the mqueue anyway.
- */
- DEBUGASSERT(ret == OK || ret == -ECANCELED);
- }
- while (ret < 0);
- if (inode->i_crefs > 0)
- {
- inode->i_crefs--;
- }
- /* If the message queue was previously unlinked and the reference count
- * has decremented to zero, then release the message queue and delete
- * the inode now.
- */
- if (inode->i_crefs <= 0 && (inode->i_flags & FSNODEFLAG_DELETED) != 0)
- {
- FAR struct mqueue_inode_s *msgq = inode->u.i_mqueue;
- DEBUGASSERT(msgq);
- /* Free the message queue (and any messages left in it) */
- nxmq_free_msgq(msgq);
- inode->u.i_mqueue = NULL;
- /* Release and free the inode container. If it has been properly
- * unlinked, then the peer pointer should be NULL.
- */
- inode_semgive();
- DEBUGASSERT(inode->i_peer == NULL);
- inode_free(inode);
- return;
- }
- inode_semgive();
- }
|