incubator-nuttx/fs/event/event_close.c

98 lines
3.1 KiB
C

/****************************************************************************
* fs/event/event_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 <assert.h>
#include <errno.h>
#include <nuttx/event.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
#include "notify/notify.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxevent_close
*
* Description:
* This function is called to indicate that the calling task is finished
* with the specified named event group. The event_close() deallocates
* any system resources allocated by the system for this named event.
*
* Input Parameters:
* event - event descriptor
*
* Returned Value:
* 0 (OK), or negated errno if unsuccessful.
*
* Assumptions:
* - Care must be taken to avoid risking the deletion of a event that
* another calling task has already locked.
* - event_close must not be called for an un-named event
*
****************************************************************************/
int nxevent_close(FAR nxevent_t *event)
{
FAR struct nevent_inode_s *nevent;
struct inode *inode;
DEBUGASSERT(event);
/* Upcast to get back to out internal representation */
nevent = (FAR struct nevent_inode_s *)event;
DEBUGASSERT(nevent->ne_inode);
inode = nevent->ne_inode;
/* If the event group was previously unlinked and the reference count has
* decremented to zero, then release the event group and delete the inode
* now.
*/
if (atomic_fetch_sub(&inode->i_crefs, 1) <= 1)
{
nxevent_destroy(&nevent->ne_event);
group_free(NULL, nevent);
/* Release and free the inode container. If it has been properly
* unlinked, then the peer pointer should be NULL.
*/
#ifdef CONFIG_FS_NOTIFY
notify_close2(inode);
#endif
DEBUGASSERT(inode->i_peer == NULL);
inode_free(inode);
}
return OK;
}