Re: [CODE] Events - My ch pointer has been violated! :)

From: Sammy (samedi@DHC.NET)
Date: 05/07/98

On Thu, 7 May 1998, George wrote:

> >void call_timed_dt(struct char_data *ch)
> >{
> >   struct death_trap_type *dt;
> >
> >   CREATE(dt, struct death_trap_type, 1);
> >   dt->ch = ch;
> >   GET_TIMED_DT(ch) = event_create(timed_dt, dt, 4);
> >
> >}
> CREATE() will zero out the 'dt' structure.


> Trying to take 'dt->ch' will give you your NULL reference.


dt is now a pointer to a struct containing a single char_data pointer.
The memory it points to exists and is useable at this point (assuming the
CREATE didn't fail), so assigning dt->ch shouldn't cause problems.

I didn't see anything wrong with the rest of the posted code, but the
symptom mentioned (dereferenced ch) is a little vague.  Since this is
something which causes death, make sure there's no way any code tries to
access ch after the character is killed.

This would be a good time to learn how to use your debugger's
single-stepping feature, since it's such a small amount of code to step


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