nuttx/sched/group/group_killchildren.c
Ville Juven 2cdba4a0a2 task/task_cancelpt: Kill the child if it is not in a cancel point
Do not allow a deferred cancellation if the group is exiting, it is too
dangerous to allow the threads to execute any user space code after the
exit has started.

If the cancelled thread is not inside a cancellation point, just kill it
immediately via asynchronous cancellation. This will create far less
problems than allowing it to continue running user code.
2023-02-17 22:57:36 +08:00

167 lines
4.9 KiB
C

/****************************************************************************
* 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 <sys/types.h>
#include <stdint.h>
#include <sched.h>
#include <pthread.h>
#include <debug.h>
#include <nuttx/sched.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
*
****************************************************************************/
static int group_kill_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);
#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;
ret = group_foreachchild(tcb->group, group_kill_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 */