px4-firmware/nuttx/sched/task_deletecurrent.c

141 lines
5.2 KiB
C

/****************************************************************************
* sched/task_deletecurrent.c
*
* Copyright (C) 2008-2009, 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 <sched.h>
#include "os_internal.h"
#ifndef CONFIG_DISABLE_SIGNALS
# include "sig_internal.h"
#endif
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: task_delete
*
* Description:
* This function causes the currently running task (i.e., the task at the
* head of the ready-to-run list) to cease to exist. This is a part of
* the logic used to implement _exit(). The full implementation of _exit()
* is architecture-dependent. This function should never be called from
* normal user code, but only from the architecture-specific implementation
* of exit.
*
* Inputs:
* None
*
* Return Value:
* OK on success; or ERROR on failure
*
****************************************************************************/
int task_deletecurrent(void)
{
FAR _TCB *dtcb = (FAR _TCB*)g_readytorun.head;
FAR _TCB *rtcb;
/* Remove the TCB of the current task from the ready-to-run list. A context
* switch will definitely be necessary -- that must be done by the
* architecture-specific logic.
*
* sched_removereadytorun will mark the task at the head of the ready-to-run
* with state == TSTATE_TASK_RUNNING
*/
(void)sched_removereadytorun(dtcb);
rtcb = (FAR _TCB*)g_readytorun.head;
/* We are not in a bad state -- the head of the ready to run task list
* does not correspond to the thread that is running. Disabling pre-
* emption on this TCB and marking the new ready-to-run task as not
* running (see, for example, get_errno_ptr()).
*/
sched_lock();
rtcb->task_state = TSTATE_TASK_READYTORUN;
/* Move the TCB to the specified blocked task list and delete it */
sched_addblocked(dtcb, TSTATE_TASK_INACTIVE);
task_delete(dtcb->pid);
rtcb->task_state = TSTATE_TASK_RUNNING;
/* If there are any pending tasks, then add them to the ready-to-run
* task list now
*/
if (g_pendingtasks.head)
{
(void)sched_mergepending();
}
/* Now calling sched_unlock() should have no effect */
sched_unlock();
return OK;
}