/**************************************************************************** * fs/mqueue/mq_close.c * * Copyright (C) 2007, 2009, 2013-2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #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 freeing it */ mq_inode_release(inode); } 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) { FAR struct tcb_s *rtcb = (FAR struct tcb_s *)sched_self(); int ret; /* Lock the scheduler to prevent any asynchronous task delete operation * (unlikely). */ sched_lock(); rtcb = (FAR struct tcb_s *)sched_self(); DEBUGASSERT(mqdes != NULL && rtcb != NULL && rtcb->group != NULL); /* Then perform the close operation */ ret = nxmq_close_group(mqdes, rtcb->group); #if 0 if (ret < 0) /* Currently, nxmq_close_group() only returns OK */ { set_errno(-ret); ret = ERROR; } #endif sched_unlock(); 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) { /* Decrement the reference count on the inode */ inode_semtake(); 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(); }