i initiated mutex in the main thread and acquire at the same context, is
it wrong?
Should i lock it in the main thread and acquire it in another thread
with a timeout?
i will try.
/Song
在 2021/5/24 下午5:20, chensong_2000--- via Xenomai 写道:
hi,
i'm working on mutex_timedlock64, the call stack roughly is supposed to be:
CoBaLt_mutex_timedlock64 -- __cobalt_mutex_timedlock_break --
xnsynch_acquire -- xnthread_suspend
however, it doesn't go to xnthread_suspend as expected, turns out it
returns from here:
h = atomic_cmpxchg(lockp, XN_NO_HANDLE,
get_owner_handle(currh, synch));
if (likely(h == XN_NO_HANDLE)) {
set_current_owner(synch, curr);
xnthread_get_resource(curr);
return 0;
}
atomic_cmpxchg returns 0.
i printed some information by
printk("%s, 1, curr handle: 0x%x, status: 0x%x, lockp: 0x%x\n",
__FUNCTION__, currh, synch->status, lockp);
printk("curr: 0x%x, name:%s, owner: 0x%x\n ", curr, curr->name,
synch->owner);
got these:
xnsynch_acquire, 1, curr handle: 0x20, status: 0xb, lockp: 0xb810e40
curr: 0x6c4408, name:lt-smokey, owner: 0x0
As far as my understanding, atomic_cmpxchg is supposed to assign curr
handle (0x20) to lockp->v, is my unserstanding correct and is there
anything i can do to dig into atomic_cmpxchg?
Any tips would be appreciated, many thanks.
BR
Song
