px4-firmware/nuttx/sched/sched_free.c

115 lines
4.3 KiB
C

/************************************************************************
* sched/sched_free.c
*
* Copyright (C) 2007, 2009, 2012 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 <queue.h>
#include <assert.h>
#include <nuttx/kmalloc.h>
#include <nuttx/arch.h>
#include <nuttx/wqueue.h>
#include "os_internal.h"
/************************************************************************
* Definitions
************************************************************************/
/************************************************************************
* Private Type Declarations
************************************************************************/
/************************************************************************
* Global Variables
************************************************************************/
/************************************************************************
* Private Variables
************************************************************************/
/************************************************************************
* Private Function Prototypes
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: sched_free
*
* Description:
* This function performs deallocations that the operating system may
* need to make. This special interface to free is used to handling
* corner cases where the operating system may have to perform
* deallocations from within an interrupt handler.
*
************************************************************************/
void sched_free(FAR void *address)
{
/* Check if this is an attempt to deallocate memory from an exception
* handler. If this function is called from the IDLE task, then we
* must have exclusive access to the memory manager to do this.
*/
if (up_interrupt_context() || kmm_trysemaphore() != 0)
{
/* Yes.. Delay the deallocation until a more appropriate time. */
irqstate_t saved_state = irqsave();
sq_addlast((FAR sq_entry_t*)address, (sq_queue_t*)&g_delayeddeallocations);
/* Signal the worker thread that is has some clean up to do */
#ifdef CONFIG_SCHED_WORKQUEUE
work_signal(LPWORK);
#endif
irqrestore(saved_state);
}
else
{
/* No.. just deallocate the memory now. */
kfree(address);
kmm_givesemaphore();
}
}