nuttx/sched/sched/sched_continue.c
Gregory Nutt a7265d71c6 This commit adds support for default signal actions for SIGSTOP, SIGSTP, and SIGCONT.
Squashed commit of the following:

    Add procfs support to show stopped tasks.  Add nxsig_action() to solve a chicken and egg problem:  We needed to use sigaction to set default actions, but sigaction() would refuse to set actions if the default actions could not be caught or ignored.

    sched/signal:  Add configuration option to selectively enabled/disable default signal actions for SIGSTOP/SIGSTP/SIGCONT and SIGKILL/SIGINT.  Fix some compilation issues.

    sched/sched:  Okay.. I figured out a way to handle state changes that may occur while they were stopped. If a task/thread was already blocked when SIGSTOP/SIGSTP was received, it will restart in the running state.  I will appear that to the task/thread that the blocked condition was interrupt by a signal and returns the EINTR error.

    sched/group and sched/sched:  Finish framework for continue/resume logic.

    sched/signal:  Roughing out basic structure to support task suspend/resume
2018-08-30 10:27:18 -06:00

82 lines
3.0 KiB
C

/****************************************************************************
* sched/sched/sched_continue.c
*
* Copyright (C) 2018 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 <assert.h>
#include <nuttx/irq.h>
#include <nuttx/sched.h>
#include <nuttx/arch.h>
#include "sched/sched.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sched_continue
*
* Description:
* Resume the specified thread. This is normally calling indirectly
* via group_continue();
*
****************************************************************************/
void sched_continue(FAR struct tcb_s *tcb)
{
irqstate_t flags;
DEBUGASSERT(tcb != NULL && tcb->task_state == TSTATE_TASK_STOPPED);
flags = enter_critical_section();
/* Simply restart the thread. If is was blocked before, it will awaken
* with pterrno = EINTR and will appears as if it were awakened by a
* signal. If pre-emption is not disabled this action could block this
* task here!
*/
up_unblock_task(tcb);
leave_critical_section(flags);
}