> On Wed, 31 Mar 2010, Mathieu Desnoyers wrote:
>
> > * Thomas Gleixner (
tglx@linutronix.de) wrote:
> > > On Mon, 29 Mar 2010, Mathieu Desnoyers wrote:
> > >
> > > > Implement a basic state machine checker in the debugobjects.
> > >
> > > Can you please add some real explanation how that checker works and
> > > why we want to have it ?
> >
> > We can add this to the changelog. Is it worth it to create a Documentation file
> > for it ?
>
> I meant the changelog. The "Implement ...." line was not really helpful :)
>
> >
> > This state machine checker detects races and inconsistencies within the "active"
> > life of a debugobject. The checker only keeps track of the current state; all
> > the state machine logic is kept at the object instance level.
> >
> > The checker works by adding a supplementary "unsigned int astate" field to the
> > debug_obj structure. It keeps track of the current "active state" of the object.
> >
> > The only constraints that are imposed on the states by the debugobjects system
> > is that:
> >
> > - activation of an object sets the current active state to 0,
> > - deactivation of an object expects the current active state to be 0.
> >
> > For the rest of the states, the state mapping is determined by the specific
> > object instance. Therefore, the logic keeping track of the state machine is
> > within the specialized instance, without any need to know about it at the
> > debugobject level.
> >
> > The current object active state is changed by calling:
> >
> > debug_object_active_state(addr, descr, expect, next)
> >
> > where "expect" is the expected state and "next" is the next state to move to if
> > the expected state is found. A warning is generated if the expected is not
> > found.
>
> Does it only warn or is there a callback to fixup things as well ?
