incubator-nuttx/sched/group/group_suspendchildren.c

116 lines
3.5 KiB
C

/****************************************************************************
* sched/group/group_suspendchildren.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* 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_suspend_children_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_suspend_children_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 = nxsched_get_tcb(pid);
if (rtcb != NULL)
{
nxsched_suspend(rtcb);
}
}
/* Always return zero. We need to visit each member of the group. */
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: group_suspend_children
*
* 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_suspend_children(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_suspend_children_handler,
(FAR void *)((uintptr_t)tcb->pid));
sched_unlock();
return ret;
}
#endif /* HAVE_GROUP_MEMBERS */