nuttx/sched/group/group_killchildren.c

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/****************************************************************************
* sched/group/group_killchildren.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 <assert.h>
#include <debug.h>
#include <pthread.h>
#include <sched.h>
#include <stdint.h>
#include <sys/types.h>
#include <nuttx/sched.h>
#include <nuttx/signal.h>
#include "sched/sched.h"
#include "group/group.h"
#ifdef HAVE_GROUP_MEMBERS
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: group_kill_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 signaled.
* arg - The PID of the thread to be retained.
*
* Returned Value:
* 0 (OK) always
*
****************************************************************************/
#if defined(CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS) && \
CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS != 0
static int group_kill_children_handler(pid_t pid, FAR void *arg)
{
/* Cancel all threads except for the one specified by the argument */
if (pid != (pid_t)((uintptr_t)arg))
{
pthread_kill(pid, SIGTERM);
}
return OK;
}
#endif
/****************************************************************************
* Name: group_cancel_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 signaled.
* arg - The PID of the thread to be retained.
*
* Returned Value:
* 0 (OK) always
*
****************************************************************************/
static int group_cancel_children_handler(pid_t pid, FAR void *arg)
{
FAR struct tcb_s *rtcb;
int ret;
/* Cancel all threads except for the one specified by the argument */
if (pid != (pid_t)((uintptr_t)arg))
{
/* Cancel this thread. This is a forced cancellation. Make sure that
* cancellation is not disabled by the task/thread. That bit will
* prevent pthread_cancel() or nxtask_delete() from doing what they
* need to do.
*/
rtcb = nxsched_get_tcb(pid);
if (rtcb != NULL)
{
/* This is a forced cancellation. Make sure that cancellation is
* not disabled by the task/thread. That bit would prevent
* pthread_cancel() or task_delete() from doing what they need
* to do.
*/
rtcb->flags &= ~TCB_FLAG_NONCANCELABLE;
/* 'pid' could refer to the main task of the thread. That pid
* will appear in the group member list as well!
*/
if ((rtcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
{
ret = pthread_cancel(pid);
}
else
{
ret = nxtask_delete(pid);
}
if (ret < 0)
{
serr("ERROR: Failed to kill %d: %d\n", ret, pid);
}
}
}
/* Always return zero. We need to visit each member of the group. */
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: group_kill_children
*
* Description:
* Delete all children of a task except for the specified task. This is
* used by the task restart logic and by the default signal handling
* abnormal termination logic. When the main task is restarted or killed,
* all of its child pthreads must be terminated.
*
* Input Parameters:
* tcb - TCB of the task to be retained.
*
* Returned Value:
* None
*
****************************************************************************/
int group_kill_children(FAR struct tcb_s *tcb)
{
int ret;
DEBUGASSERT(tcb->group);
if (tcb->group->tg_flags & GROUP_FLAG_EXITING)
{
return 0;
}
#ifdef CONFIG_SMP
/* NOTE: sched_lock() is not enough for SMP
* because tcb->group will be accessed from the child tasks
*/
irqstate_t flags = enter_critical_section();
#else
/* Lock the scheduler so that there this thread will not lose priority
* until all of its children are suspended.
*/
sched_lock();
#endif
/* Tell the children that this group has started exiting */
tcb->group->tg_flags |= GROUP_FLAG_EXITING;
#if defined(CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS) && \
CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS != 0
/* Send SIGTERM for each first */
group_foreachchild(tcb->group, group_kill_children_handler,
(FAR void *)((uintptr_t)tcb->pid));
/* Wait a bit for child exit */
ret = CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS;
while (1)
{
if (tcb->group->tg_nmembers <= 1)
{
break;
}
nxsig_usleep(USEC_PER_MSEC);
# if CONFIG_GROUP_KILL_CHILDREN_TIMEOUT_MS > 0
if (--ret < 0)
{
break;
}
# endif
}
#endif
/* Force cancel/delete again */
ret = group_foreachchild(tcb->group, group_cancel_children_handler,
(FAR void *)((uintptr_t)tcb->pid));
#ifdef CONFIG_SMP
leave_critical_section(flags);
#else
sched_unlock();
#endif
return ret;
}
#endif /* HAVE_GROUP_MEMBERS */