px4-firmware/nuttx/sched/sched_releasetcb.c

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/************************************************************************
* sched/sched_releasetcb.c
*
* Copyright (C) 2007, 2009, 2012-2013 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 <sys/types.h>
#include <sched.h>
#include <errno.h>
#include <nuttx/arch.h>
#include "os_internal.h"
#include "group_internal.h"
#include "timer_internal.h"
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Name: sched_releasepid
*
* Description: When a task is destroyed, this function must
* be called to make its process ID available for re-use.
************************************************************************/
static void sched_releasepid(pid_t pid)
{
int hash_ndx = PIDHASH(pid);
/* Make any pid associated with this hash available. Note:
* no special precautions need be taken here because the
* following action is atomic
*/
g_pidhash[hash_ndx].tcb = NULL;
g_pidhash[hash_ndx].pid = INVALID_PROCESS_ID;
}
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: sched_releasetcb
*
* Description:
* Free all resources contained in a TCB
*
* Parameters:
* None
*
* Return Value:
* OK on success; ERROR on failure
*
* Assumptions:
* Interrupts are disabled.
*
************************************************************************/
int sched_releasetcb(FAR _TCB *tcb)
{
int ret = OK;
int i;
if (tcb)
{
/* Relase any timers that the task might hold. We do this
* before release the PID because it may still be trying to
* deliver signals (although interrupts are should be
* disabled here).
*/
#ifndef CONFIG_DISABLE_POSIX_TIMERS
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (timer_deleteall != NULL)
#endif
{
timer_deleteall(tcb->pid);
}
#endif
/* Release the task's process ID if one was assigned. PID
* zero is reserved for the IDLE task. The TCB of the IDLE
* task is never release so a value of zero simply means that
* the process ID was never allocated to this TCB.
*/
if (tcb->pid)
{
sched_releasepid(tcb->pid);
}
/* Delete the thread's stack if one has been allocated */
#ifndef CONFIG_CUSTOM_STACK
if (tcb->stack_alloc_ptr)
{
up_release_stack(tcb);
}
#endif
/* Delete the tasks's allocated DSpace region (external modules only) */
#ifdef CONFIG_PIC
if (tcb->dspace)
{
if (tcb->dspace->crefs <= 1)
{
sched_free(tcb->dspace);
}
else
{
tcb->dspace->crefs--;
}
}
#endif
/* Release command line arguments that were allocated for task
* start/re-start.
*/
if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK)
{
for (i = 1; i < CONFIG_MAX_TASK_ARGS+1 && tcb->argv[i]; i++)
{
sched_free((FAR void*)tcb->argv[i]);
}
}
/* Release this thread's reference to the address environment */
#ifdef CONFIG_ADDRENV
ret = up_addrenv_release(tcb);
#endif
/* Leave the group (if we did not already leady in task_exithook.c) */
#ifdef HAVE_TASK_GROUP
group_leave(tcb);
#endif
/* And, finally, release the TCB itself */
sched_free(tcb);
}
return ret;
}