id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
286	intrusive_ptr may cause dungling ptr access	nobody	Peter Dimov	"{{{
I think intrusive_ptr may cause dungling ptr access in 
multithreaded environment.

Currently, it's constructor is:

    intrusive_ptr(T * p, bool add_ref = true)
    : p_(p)  /* the object may be deleted by other 
thread 
                because this thread does not increment 
reference counter yet. */
    {
        if(p_ != 0 && add_ref)
            intrusive_ptr_add_ref(p_); /* this may occur 
dungling ptr operation. */
    }

We can avoid this problem by ""addref-before-use"" policy.

    intrusive_ptr(T * p, bool add_ref = true)
    {
        if(p != 0 && add_ref)
            intrusive_ptr_add_ref(p_); /* other thread 
never delete the object */
        p_ = p;
    }

}}}"	Bugs	closed		smart_ptr	None		Invalid