text: /****************************************************************************
   *  sched/mqueue/mq_msgfree.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 <queue.h>
  
  #include <nuttx/irq.h>
  #include <nuttx/arch.h>
  #include <nuttx/kmalloc.h>
  
  #include "mqueue/mqueue.h"
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: nxmq_free_msg
   *
   * Description:
   *   The nxmq_free_msg function will return a message to the free pool of
   *   messages if it was a pre-allocated message. If the message was
   *   allocated dynamically it will be deallocated.
   *
   * Input Parameters:
   *   mqmsg - message to free
   *
   * Returned Value:
   *   None
   *
   ****************************************************************************/
  
  void nxmq_free_msg(FAR struct mqueue_msg_s *mqmsg)
  {
    irqstate_t flags;
  
    /* If this is a generally available pre-allocated message,
     * then just put it back in the free list.
     */
  
    if (mqmsg->type == MQ_ALLOC_FIXED)
      {
        /* Make sure we avoid concurrent access to the free
         * list from interrupt handlers.
         */
  
        flags = enter_critical_section();
        sq_addlast((FAR sq_entry_t *)mqmsg, &g_msgfree);
        leave_critical_section(flags);
      }
  
    /* If this is a message pre-allocated for interrupts,
     * then put it back in the correct  free list.
     */
  
    else if (mqmsg->type == MQ_ALLOC_IRQ)
      {
        /* Make sure we avoid concurrent access to the free
         * list from interrupt handlers.
         */
  
        flags = enter_critical_section();
        sq_addlast((FAR sq_entry_t *)mqmsg, &g_msgfreeirq);
        leave_critical_section(flags);
      }
  
    /* Otherwise, deallocate it.  Note:  interrupt handlers
     * will never deallocate messages because they will not
     * received them.
     */
  
    else if (mqmsg->type == MQ_ALLOC_DYN)
      {
        sched_kfree(mqmsg);
      }
    else
      {
        DEBUGPANIC();
      }
  }
  