incubator-nuttx/sched/group/group_suspendchildren.c

131 lines
4.3 KiB
C

/****************************************************************************
* sched/group/group_suspendchildren.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_suspendchildren_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 suspended.
* arg - The PID of the thread to be retained.
*
* Returned Value:
* 0 (OK) always
*
****************************************************************************/
static int group_suspendchildren_handler(pid_t pid, FAR void *arg)
{
FAR struct tcb_s *rtcb;
/* Suspend all threads except for the one specified by the argument */
if (pid != (pid_t)((uintptr_t)arg))
{
/* Suspend this thread if it is still alive. */
rtcb = sched_gettcb(pid);
if (rtcb != NULL)
{
sched_suspend(rtcb);
}
}
/* Always return zero. We need to visit each member of the group. */
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: group_suspendchildren
*
* Description:
* Suspend all children of a task except for the specified task. This is
* SIGSTP/SIGSTOP default signal action logic. When the main task is
* suspended, all of its child pthreads must also be suspended.
*
* Input Parameters:
* tcb - TCB of the task to be retained.
*
* Returned Value:
* None
*
****************************************************************************/
int group_suspendchildren(FAR struct 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->group, group_suspendchildren_handler,
(FAR void *)((uintptr_t)tcb->pid));
sched_unlock();
return ret;
}
#endif /* HAVE_GROUP_MEMBERS */