nuttx/sched/misc/deadlock.c
anjiahao 4ae17a6f7b sched:Automatically find deadlocks when assert
When asserting, automatically analyze whether
there is a deadlock in the thread, and if there
is a deadlock, print out the deadlocked thread.

The principle is to analyze whether there is
a lock ring through the tcb holder.

Signed-off-by: anjiahao <anjiahao@xiaomi.com>
2023-06-22 16:08:03 +08:00

116 lines
3.5 KiB
C

/****************************************************************************
* sched/misc/deadlock.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/mutex.h>
#include <nuttx/sched.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
struct deadlock_info_s
{
FAR pid_t *pid;
size_t count;
size_t found;
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name:find_circular_lock
****************************************************************************/
static void collect_deadlock(FAR struct tcb_s *tcb, FAR void *arg)
{
FAR struct deadlock_info_s *info = arg;
size_t index;
for (index = 0; index < info->found; index++)
{
if (info->pid[index] == tcb->pid)
{
return;
}
}
for (index = info->found; index < info->count; index++)
{
FAR sem_t *sem = tcb->waitobj;
pid_t next;
size_t i;
if (tcb->task_state != TSTATE_WAIT_SEM || sem == NULL ||
!(sem->flags & SEM_TYPE_MUTEX))
{
return;
}
next = ((FAR mutex_t *)sem)->holder;
for (i = info->found; i < index; i++)
{
if (info->pid[i] == next)
{
info->found = index;
return;
}
}
info->pid[index] = tcb->pid;
tcb = nxsched_get_tcb(next);
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsched_collect_deadlock
*
* Description:
* Check if there is a deadlock and get the thread pid of the deadlock.
*
* Input parameters:
* pid - The array to store the thread pid of the deadlock.
* count - The size of the pid array.
*
* Returned Value:
* The number of thread deadlocks.
*
****************************************************************************/
size_t nxsched_collect_deadlock(FAR pid_t *pid, size_t count)
{
struct deadlock_info_s info;
info.pid = pid;
info.count = count;
info.found = 0;
nxsched_foreach(collect_deadlock, &info);
return info.found;
}