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sched: optimize deadlock detection readability

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Use meaningful variable names.

Signed-off-by: xuxingliang <xuxingliang@xiaomi.com>
This commit is contained in:
xuxingliang 2024-08-14 18:05:01 +08:00 committed by Xiang Xiao
parent 97425687cf
commit b7824264f6
1 changed files with 32 additions and 22 deletions
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54
sched/misc/deadlock.c
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@ -33,9 +33,9 @@
struct deadlock_info_s
{
FAR pid_t *pid;
size_t count;
size_t found;
FAR pid_t *holders;
size_t arraylen;
size_t holdercnt;
};
/****************************************************************************
@ -43,7 +43,7 @@ struct deadlock_info_s
****************************************************************************/
/****************************************************************************
* Name: waitmutex
* Name: getmutex
****************************************************************************/
static FAR mutex_t *getmutex(FAR struct tcb_s *tcb)
@ -83,47 +83,57 @@ static void collect_deadlock(FAR struct tcb_s *tcb, FAR void *arg)
return;
}
for (index = 0; index < info->found; index++)
/* Check previous deadlock holder list. */
for (index = 0; index < info->holdercnt; index++)
{
if (info->pid[index] == tcb->pid)
if (info->holders[index] == tcb->pid)
{
return;
}
}
for (index = info->found; index < info->count; index++)
/* Append the holders for this tcb to list. */
for (index = info->holdercnt; index < info->arraylen; index++)
{
pid_t next;
pid_t holder;
size_t i;
next = mutex->holder;
if (next == NXMUTEX_NO_HOLDER)
holder = mutex->holder;
if (holder == NXMUTEX_NO_HOLDER)
{
break;
}
for (i = info->found; i < index; i++)
/* Check if this holder is already held. */
for (i = info->holdercnt; i < index; i++)
{
if (info->pid[i] == next)
if (info->holders[i] == holder)
{
info->found = index;
info->holdercnt = index;
return;
}
}
info->pid[index] = tcb->pid;
tcb = nxsched_get_tcb(next);
/* Add holder to list and continue to holder's holder. */
info->holders[index] = tcb->pid;
tcb = nxsched_get_tcb(holder);
mutex = getmutex(tcb);
if (mutex == NULL)
{
/* If this holder isn't waiting for mutex, it's over. */
break;
}
}
/* if we not find deadlock, clear the pid array */
/* If no deadlock, clear the holders of this tcb. */
memset(&info->pid[info->found], 0,
(info->count - info->found) * sizeof(pid_t));
memset(&info->holders[info->holdercnt], 0,
(info->arraylen - info->holdercnt) * sizeof(pid_t));
}
/****************************************************************************
@ -149,9 +159,9 @@ 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;
info.holders = pid;
info.arraylen = count;
info.holdercnt = 0;
nxsched_foreach(collect_deadlock, &info);
return info.found;
return info.holdercnt;
}