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- /****************************************************************************
- * fs/mqueue/mq_unlink.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 <stdbool.h>
- #include <stdio.h>
- #include <mqueue.h>
- #include <assert.h>
- #include <errno.h>
- #include <nuttx/mqueue.h>
- #include "inode/inode.h"
- #include "mqueue/mqueue.h"
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: mq_inode_release
- *
- * Description:
- * Release a reference count on a message queue inode.
- *
- * Input Parameters:
- * inode - The message queue inode
- *
- * Returned Value:
- * None
- *
- ****************************************************************************/
- static void mq_inode_release(FAR struct inode *inode)
- {
- if (inode->i_crefs <= 1)
- {
- FAR struct mqueue_inode_s *msgq = inode->i_private;
- if (msgq)
- {
- nxmq_free_msgq(msgq);
- inode->i_private = NULL;
- }
- }
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: file_mq_unlink
- *
- * Description:
- * This is an internal OS interface. It is functionally equivalent to
- * mq_unlink() except that:
- *
- * - It is not a cancellation point, and
- * - It does not modify the errno value.
- *
- * See comments with mq_unlink() for a more complete description of the
- * behavior of this function
- *
- * Input Parameters:
- * mq_name - Name of the message queue
- *
- * 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 file_mq_unlink(FAR const char *mq_name)
- {
- FAR struct inode *inode;
- struct inode_search_s desc;
- char fullpath[MAX_MQUEUE_PATH];
- int ret;
- /* Get the full path to the message queue */
- snprintf(fullpath, MAX_MQUEUE_PATH, CONFIG_FS_MQUEUE_MPATH "/%s", mq_name);
- /* Get the inode for this message queue. */
- SETUP_SEARCH(&desc, fullpath, false);
- sched_lock();
- ret = inode_find(&desc);
- if (ret < 0)
- {
- /* There is no inode that includes in this path */
- goto errout_with_search;
- }
- /* Get the search results */
- inode = desc.node;
- DEBUGASSERT(inode != NULL);
- /* Verify that what we found is, indeed, a message queue */
- if (!INODE_IS_MQUEUE(inode))
- {
- ret = -ENXIO;
- goto errout_with_inode;
- }
- /* Refuse to unlink the inode if it has children. I.e., if it is
- * functioning as a directory and the directory is not empty.
- */
- ret = inode_semtake();
- if (ret < 0)
- {
- goto errout_with_inode;
- }
- if (inode->i_child != NULL)
- {
- ret = -ENOTEMPTY;
- goto errout_with_semaphore;
- }
- /* Remove the old inode from the tree. Because we hold a reference count
- * on the inode, it will not be deleted now. This will set the
- * FSNODEFLAG_DELETED bit in the inode flags.
- */
- ret = inode_remove(fullpath);
- /* inode_remove() should always fail with -EBUSY because we hae a reference
- * on the inode. -EBUSY means that the inode was, indeed, unlinked but
- * thatis could not be freed because there are references.
- */
- DEBUGASSERT(ret >= 0 || ret == -EBUSY);
- /* Now we do not release the reference count in the normal way (by calling
- * inode release. Rather, we call mq_inode_release(). mq_inode_release
- * will decrement the reference count on the inode. But it will also free
- * the message queue if that reference count decrements to zero. Since we
- * hold one reference, that can only occur if the message queue is not
- * in-use.
- */
- inode_semgive();
- mq_inode_release(inode);
- RELEASE_SEARCH(&desc);
- sched_unlock();
- return OK;
- errout_with_semaphore:
- inode_semgive();
- errout_with_inode:
- inode_release(inode);
- errout_with_search:
- RELEASE_SEARCH(&desc);
- sched_unlock();
- return ret;
- }
- /****************************************************************************
- * Name: nxmq_unlink
- *
- * Description:
- * This is an internal OS interface. It is functionally equivalent to
- * mq_unlink() except that:
- *
- * - It is not a cancellation point, and
- * - It does not modify the errno value.
- *
- * See comments with mq_unlink() for a more complete description of the
- * behavior of this function
- *
- * Input Parameters:
- * mq_name - Name of the message queue
- *
- * 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_unlink(FAR const char *mq_name)
- {
- return file_mq_unlink(mq_name);
- }
- /****************************************************************************
- * Name: mq_unlink
- *
- * Description:
- * This function removes the message queue named by "mq_name." If one
- * or more tasks have the message queue open when mq_unlink() is called,
- * removal of the message queue is postponed until all references to the
- * message queue have been closed.
- *
- * Input Parameters:
- * mq_name - Name of the message queue
- *
- * Returned Value:
- * None
- *
- * Assumptions:
- *
- ****************************************************************************/
- int mq_unlink(FAR const char *mq_name)
- {
- int ret;
- ret = nxmq_unlink(mq_name);
- if (ret < 0)
- {
- set_errno(-ret);
- return ERROR;
- }
- return OK;
- }
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