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Diffstat (limited to 'nuttx/sched/mq_close.c')
| -rw-r--r-- | nuttx/sched/mq_close.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/nuttx/sched/mq_close.c b/nuttx/sched/mq_close.c new file mode 100644 index 000000000..57780a8e6 --- /dev/null +++ b/nuttx/sched/mq_close.c @@ -0,0 +1,187 @@ +/**************************************************************************** + * sched/mq_close.c + * + * Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 <nuttx/config.h> + +#include <mqueue.h> +#include <sched.h> + +#include "os_internal.h" +#include "mq_internal.h" + +/**************************************************************************** + * Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: mq_desfree + * + * Description: + * Deallocate a message queue descriptor but returning it to the free list + * + * Inputs: + * mqdes - message queue descriptor to free + * + ****************************************************************************/ + +#define mq_desfree(mqdes) sq_addlast((FAR sq_entry_t*)mqdes, &g_desfree) + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: mq_close + * + * Description: + * This function is used to indicate that the calling task is finished + * with the specified message queued 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. + * + * Parameters: + * mqdes - Message queue descriptor. + * + * Return 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 mq_send() or + * 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 _TCB *rtcb = (FAR _TCB*)g_readytorun.head; + FAR msgq_t *msgq; + irqstate_t saved_state; + int ret = ERROR; + + /* Verify the inputs */ + + if (mqdes) + { + sched_lock(); + + /* Remove the message descriptor from the current task's + * list of message descriptors. + */ + + sq_rem((FAR sq_entry_t*)mqdes, &rtcb->msgdesq); + + /* Find the message queue associated with the message descriptor */ + + msgq = mqdes->msgq; + + /* Check if the calling task has a notification attached to + * the message queue via this mqdes. + */ + +#ifndef CONFIG_DISABLE_SIGNALS + if (msgq->ntmqdes == mqdes) + { + msgq->ntpid = INVALID_PROCESS_ID; + msgq->ntsigno = 0; + msgq->ntvalue.sival_int = 0; + msgq->ntmqdes = NULL; + } +#endif + + /* Decrement the connection count on the message queue. */ + + if (msgq->nconnect) + { + msgq->nconnect--; + } + + /* If it is no longer connected to any message descriptor and if the + * message queue has already been unlinked, then we can discard the + * message queue. + */ + + if (!msgq->nconnect && msgq->unlinked) + { + /* Remove the message queue from the list of all + * message queues + */ + + saved_state = irqsave(); + (void)sq_rem((FAR sq_entry_t*)msgq, &g_msgqueues); + irqrestore(saved_state); + + /* Then deallocate it (and any messages left in it) */ + + mq_msgqfree(msgq); + } + + /* Deallocate the message descriptor */ + + mq_desfree(mqdes); + + sched_unlock(); + ret = OK; + } + + return ret; +} + |