nuttx/sched/group/group_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

129 lines
4.1 KiB
C

/****************************************************************************
* sched/group/group_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 <stdint.h>
#include <sched.h>
#include <pthread.h>
#include <nuttx/sched.h>
#include "sched/sched.h"
#include "group/group.h"
#ifdef HAVE_GROUP_MEMBERS
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: group_continue_handler
*
* Description:
* Callback from group_foreachchild that handles one member of the group.
*
* Input Parameters:
* pid - The ID of the group member that may be resumed.
* arg - Unused
*
* Returned Value:
* 0 (OK) on success; a negated errno value on failure.
*
****************************************************************************/
static int group_continue_handler(pid_t pid, FAR void *arg)
{
FAR struct tcb_s *rtcb;
int ret;
/* Resume all threads */
rtcb = sched_gettcb(pid);
if (rtc != NULL)
{
ret = sched_resume(rtcb);
if (ret < 0)
{
serr("ERROR: Failed to resume %d: %d\n", ret, pid);
}
}
/* Always return zero. We need to visit each member of the group*/
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: group_continue
*
* Description:
* Resume all members of the task group. This is SIGCONT default signal
* action logic.
*
* Input Parameters:
* tcb - TCB of the task to be retained.
*
* Returned Value:
* None
*
****************************************************************************/
int group_continue(FAR struct task_tcb_s *tcb)
{
int ret;
/* Lock the scheduler so that there this thread will not lose priority
* until all of its children are suspended.
*/
sched_lock();
ret = group_foreachchild(tcb->cmn.group, group_continue_handler, NULL);
sched_unlock();
return ret;
}
#endif /* HAVE_GROUP_MEMBERS */