Re: *ugh* Backtracking..

From: Mark A. Heilpern (
Date: 01/24/00

At 02:20 PM 1/24/00 +0100, you wrote:
>Hiya all..
>I'm currently fighting a very weird random hitting bug. The problem arises
>when someone tries to Redit a room, and *boom* the mud crashes with
>coredump and everything.

Since your backtrace has nothing whatsoever relating to room editing in it...
are you certain that redit wasn't just a coincidence? Read on for more info...

>Apparently it comes from DG_Scripts.c (Yes, I run with DG_Scripts :)
>GDB tells me the following:
>a Backtrack shows:
>#0  0x80c306b in script_driver (go=0x4013bed8, trig=0x8241220, type=2,
>     at dg/dg_scripts.c:2862
>#1  0x80bd9c8 in trig_wait_event (info=0x8554ad0) at dg/dg_scripts.c:483
>#2  0x80b9752 in process_events () at dg/dg_event.c:81

This indicates that the crash happened when trying to continue a script that
paused itself (via the "wait" command). I expect the problem is the owner of
the script (mob/object) no longer exists; either it was purged, killed, junked,
eaten, etc. There is a bug in the event system that DG Scripts uses by
default that will cause this.

I haven't put a fix into what will probably be called pl8 yet. However, in
my own
mud, in dg_scripts.c, I've made the following changes:

      * all of this is MailerCode(tm)

1) in the struct wait_event_data definition, I've added a member "id" of
type long.

2) in process_wait():
     after the three existing wait_event_obj->MEMBER assignments, I have the

   if (type == MOB_TRIGGER)
     wait_event_obj->id = GET_ID((struct char_data *)go);
   else if (type == OBJ_TRIGGER)
     wait_event_obj->id = GET_ID((struct obj_data *)go);
   else wait_event_obj->id = 0;

3)    in the trig_wait_event function [  EVENT(trig_wait_event) ], add:

    long id = wait_event_obj->id;

    free(wait_event_obj); /* should already exist */

    /* if the char/obj no longer exists, abort */
    if (id &&
        (((type == MOB_TRIGGER) && (find_char(id)==NULL)) ||
        ((type == OBJ_TRIGGER) && (find_obj(id)==NULL)))) return;

     | Ensure that you have read the CircleMUD Mailing List FAQ:  |
     |  |

This archive was generated by hypermail 2b30 : 04/10/01 PDT