Clearing Quest Globals

[Gonner]

Now while I am unsure of the exact cause of this issue have you tried to set your globals for "temp_level" a bit differ.. Like each level above 70 have a differ number. 71 be temp_level, 2, 5, F then level 72 be temp_level, 3, 5, F It may require a full rewrite of some quests but that may work.

The only reason i say this is your $max_level has the same variable for Undef and for each level. That is just from a quick look at the script and not a full eval of it.

Also quest::deglobal is how you remove gloabls. Had to pound that in my head recently as some of the quest I am working on kind of require it.

[Bulle]

Your post triggered the "WEIRD" warning to me Trevius, so I spent a while today to look into it. I would like my conclusions to be validated by other EQEmu "hackers", so take them with the adequate grain of salt, but here they are.

To make it short I have two news : one good and one bad.
The good one is that there is a solution to your problem : switch from "$max_level" to "$qglobals{max_level}", supposedly the up-to-date way of checking quest globals. For all your variables, no exception.
The bad one is : checking quest globals through the use of "$XXX" variables is bugged. This is especially bad for PEQ quests, because there are a lot that work this way.

I have tried to reproduced your way of working on one NPC (the guard in the room in front of Neriak entrance, DVin L`Crit, who had qglobal set to 1 of course). Here is the code :

my $LevelItemId = 1038; # Tattered Cloth Sandal
my $DefaultMaxLevel = 70;

sub EVENT_SAY
{ print $maxxx_level;

  if(($text=~/65/i) && ($ulevel >= 70))
  { quest::say("Remember, DO NOT lose that trinket ! Welcome to level 65 !");
    quest::summonitem(1038);
    quest::level(65);
  }
  
  if($text=~/make me level 71/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(71);
    quest::setglobal("maxxx_level", 71, 5, "F");
  }
  
  if($text=~/make me level 72/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(72);
    quest::setglobal("maxxx_level", 72, 5, "F");
  }
  
  if($text=~/make me level 73/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(73);
    quest::setglobal("maxxx_level", 73, 5, "F");
  }
  
  if($text=~/make me level 74/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(74);
    quest::setglobal("maxxx_level", 74, 5, "F");
  }
  
  if($text=~/make me level 75/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(75);
    quest::setglobal("maxxx_level", 75, 5, "F");
  }
}


sub EVENT_ITEM
{ if (plugin::check_handin(\%itemcount, $LevelItemId => 1))
  { if(defined($qglobals{maxxx_level}))
    { quest::say("Welcome back to level $qglobals{maxxx_level}, $name");
      quest::level($qglobals{maxxx_level});
    }
    else
    { quest::say("Welcome back to level $DefaultMaxLevel, $name");
      quest::level($DefaultMaxLevel);
    }
  }
  else
  { plugin::return_items(\%itemcount);
    quest::say("I have no use for this item, $name.  Take it back.");
  } 
}

Yeah I have used tattered sandals for the levelling item, I have been a fisher on Live for too long

As it is there is no side-effects across PCs. If you replace the $qglobals{maxxx_level} by $maxxx_level there is a side-effect from one PC to another if the PC has no $maxxx_level set for himself. Basically if your PC already has a maxxx_level (of say 72) Perl will use it. If the PC has never done your quest and set the $maxxx_level, then it uses the one the NPC has seen last, ie the variable is not reset to "undef". May be this is why you tried to "undef" it, but I did not try this, and from your experience it does not work that well. My experience is that the Emu does not "undef" a variable (which answers a question I had a few months ago in fact).

I had a quick look at the C++ code in the server, and it confirmed my suspicions : the "$qglobal" map is created anew each time the NPC evaluates its scripts (in fact for each event), it is a C++ variable globhash that is redeclared, hence reinitialized with each call. This is not the case for the $variables, which are only overwritten with new values. They are not undef'ed first (file embparser.cpp, lines 189+), there is no call to something reinitializing the Perl local/global environment, if it were at all possible anyway.

I see only two ways to address this :
* everybody switches to $qglobals{XXX} and we forget about the old "unperfect" bugged way. It has been hinted at for a long time, but I guess legacy quests slowed this to a halt.
* the C++ code is fixed to clean the Perl environment of all "stale" variables from a previous call to the event before the new one is run. It may be impossible (or very hard and unclean) to do.

As it is though, the problem may impact PEQ quests as it is general. Finding an example of a "broken" behaviour may be tough, but the potential is there. Think "exploit" here.

It would be nice if a developer or a PEQ maintainer could express their views on the subject.

As to me, I will be switching to $qglobals for my generated quest code.

I hope this long diatribe clears it up for you.

[trevius]

AHHH, so if I am understanding you correctly, it is saving the qglobal as a variable and that is why it is being carried over when other PCs do the quest if they don't have a global already defined? That explains why it only does it 1 time per PC instead of everytime they repeat the de-level and turn in process to re-level. That makes sense to me now, so thanks for the explanation! I didn't realize I was doing it the old way and that there are problems with doing it that way.

Now I have a whole new way to attempt to get this working flawlessly. So far my players seem to like the variety that being able to de-level adds in. This problem has been a thorn in my side for a while now lol. The fix you presented is a fairly simple one for me, since I only have maybe 10 or so qglobals in use on my server. Though, if PEQ had to change all of it's quests involving globals, that might present more of a problem.

[trevius]

Originally Posted by Gonner

Now while I am unsure of the exact cause of this issue have you tried to set your globals for "temp_level" a bit differ.. Like each level above 70 have a differ number. 71 be temp_level, 2, 5, F then level 72 be temp_level, 3, 5, F It may require a full rewrite of some quests but that may work.

The only reason i say this is your $max_level has the same variable for Undef and for each level. That is just from a quick look at the script and not a full eval of it.

Also quest::deglobal is how you remove gloabls. Had to pound that in my head recently as some of the quest I am working on kind of require it.

Didn't see this post at first. The temp_level global is for another quest and is unrelated to the problem I have been having. I have some fairly tricky globals in use for de-leveling and access to my de-level zone to ensure there are no possible exploits to gain access to the zone.

[Bulle]

To explain it with more rigor, here is how it seems to work :
- before you enter a Perl script, the individual qglobals $XXX variables are loaded in the Perl interpreter for this zone server. Any variable defined in qglobals is set with its value from the DB, for this character (accounting for timestamps, NPC-specific variables etc)
- the $qglobals map is also initialized ANEW, at the same time (the ANEW is important here, the $qglobals starts from scratch for each script interpretation)
- there is a good chance that the Perl interpreter is reused as-is in the next script, to reduce CPU-load. The qglobals for the new PC/NPC are simply reloaded FOR THE VALUES DEFINED, but nothing is undefined as it is a complex problem to know what variables need to be undefined in the global store.

The real problem is "stale" variables from the previous PC. They are not undefined in the Perl interpreter before switching to the next PC/NPC. The $qglobals variable is not undefined either, but as it is overwritten each time with the full qglobals map (which is computed from an empty map for each script) it does not have any noticeable effect. This is why the $qglobals map is more reliable.

One test you could make to validate this assumption is : have two PCs of different levels (say 72 and 74) do the delevel quest. Their $max_level will be set to the appropriate value. If they do the turn-in they will both return to their proper level, because the variable is defined for them. Then have a level 70 character do the delevel-relevel. As its $max_level will not be set (you can see it in the DB), it should use the $max_level of the previous PC for this zone server.

Doing a #reloadquest reinitializes the Perl interpreter so the "stale" variables are removed (and the problem hidden).

I had a similar problem with temporary variables that were not erased unless I undefined them forcefully. Looks like using $qglobals will avoid this forceful deletion. I will try it when I am back to that point in my tools

Validating that (on another server than mine) would be a clear indication that $qglobals is a must from now on.

[trevius]

So, to make sure I understand this clearly, if I want to check for a certain global variable, I would use something like this:

if (defined($qglobals{max_level}) == 75)

?

[trevius]

Or maybe it should be:

if (defined($qglobals{max_level} == 75))

I guess I will need to test them both out when I get home and see which one works. Hopefully one of them does.

[Bulle]

No

You need just remember that $qglobals{max_level} is the replacement for $max_level.

So you could use :

if(defined($qglobals{max_level}))

to check that the variable is defined, in the same way you could have used if(defined($max_level))

Or you could use :

if($qglobals{max_level}) == 75)

to check if the variable is equal to 75 (after you have ensured it is defined !), in the same way you could have used if($max_level == 75)

If you want the safe solution in one "if" :

if(defined($qglobals{max_level}) && $qglobals{max_level} == 75)

With cascading "if"s :

if(!defined($qglobals{max_level}))
{ # Here you assume Max Level is 70 I guess
}
elsif($qglobals{max_level} == 71)
{ # Max Level is 71
}
elsif($qglobals{max_level} == 72)
{ # Max Level is 72
}
elsif($qglobals{max_level} == 73)
{ # Max Level is 73
}
elsif($qglobals{max_level} == 74)
{ # Max Level is 74
}
elsif($qglobals{max_level} == 75)
{ # Max Level is 75
}
else
{ # Damnit ! A super-hero !
}

Finally you can use a temporary variable (for a briefer notation), I just hope you won't get a warning in case the quest global is not defined, Perl's subtleties sometimes evade me :

$MaxLevel = $qglobals{max_level};
if(defined($MaxLevel) && $MaxLevel  == 75)

Notice how I propose a temporary variable different from max_level, to avoid any new weirdness

Note that to undefine a Perl variable I normally use this, instead of $XXX = undef :

undef($XXX);

I do not know whether both are equivalent. To delete a quest global from the DB the function to use is quest::delglobal as Gonner mentioned, which probably does NOT "undef" the associated variable. I have no idea whether the $qglobals map is updated at the same time, or only on next call to the script. This will have to be tested. it is the best way to know. In fact this should be tested for both delglobal and setglobal, and I hope they behave in a consistent way.

[Bulle]

I have made a few more tests with the following quest script. It is a bit long but it prints the variables at the start and end of the script :

my $LevelItemId = 1038; # Tattered Cloth Sandal
my $DefaultMaxLevel = 70;


sub EVENT_SAY
{ if(defined($maxxx_level))
  { print "maxxx_level($name) begin = $maxxx_level"; }
  else
  { print "maxxx_level($name) begin is not defined"; }
  
  if(defined($qglobals{maxxx_level}))
  { print "qglobals{maxxx_level}($name) begin = $qglobals{maxxx_level}"; }
  else
  { print "qglobals{maxxx_level}($name) begin is not defined"; }
  
  if(($text=~/65/i) && ($ulevel >= 70))
  { quest::say("Remember, DO NOT lose that trinket ! Welcome to level 65 !");
    quest::summonitem(1038);
    quest::level(65);
  }
  
  if($text=~/make me a newb/i)
  { quest::say("Arrr Arrr Arrr, my pleasure !");
    quest::level(1);
    quest::delglobal("maxxx_level"); undef($qglobals{maxxx_level});
  }
  if($text=~/make me level 73/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(73);
    quest::setglobal("maxxx_level", 73, 5, "F"); $qglobals{maxxx_level} = 73;
  }
  if($text=~/make me level 75/i)
  { quest::say("OK, you're the boss after all *sigh*");
    quest::level(75);
    quest::setglobal("maxxx_level", 75, 5, "F"); $qglobals{maxxx_level} = 75;
  }

  if(defined($maxxx_level))
  { print "maxxx_level($name) end = $maxxx_level"; }
  else
  { print "maxxx_level($name) end is not defined"; }
  
  if(defined($qglobals{maxxx_level}))
  { print "qglobals{maxxx_level}($name) end = $qglobals{maxxx_level}"; }
  else
  { print "qglobals{maxxx_level}($name) end is not defined"; }
}


sub EVENT_ITEM
{ if(defined($maxxx_level))
  { print "maxxx_level($name) begin = $maxxx_level"; }
  else
  { print "maxxx_level($name) begin is not defined"; }
  
  if(defined($qglobals{maxxx_level}))
  { print "qglobals{maxxx_level}($name) begin = $qglobals{maxxx_level}"; }
  else
  { print "qglobals{maxxx_level}($name) begin is not defined"; }
  
  if(plugin::check_handin(\%itemcount, $LevelItemId => 1))
  { if(defined($qglobals{maxxx_level}))
    { quest::say("Welcome back to level $qglobals{maxxx_level}, $name");
      quest::level($qglobals{maxxx_level});
    }
    else
    { quest::say("Welcome back to level $DefaultMaxLevel, $name");
      quest::level($DefaultMaxLevel);
    }
  }
  else
  { plugin::return_items(\%itemcount);
    quest::say("I have no use for this item, $name.  Take it back.");
  } 

  if(defined($maxxx_level))
  { print "maxxx_level($name) end = $maxxx_level"; }
  else
  { print "maxxx_level($name) end is not defined"; }
  
  if(defined($qglobals{maxxx_level}))
  { print "qglobals{maxxx_level}($name) end = $qglobals{maxxx_level}"; }
  else
  { print "qglobals{maxxx_level}($name) end is not defined"; }
}

I have removed some level choices for simplicity.

Currently quest::...global do not update the $qglobals map to keep it in sync with DB changes done in the script so you have to update $qglobals explicitly.

As it is the script works fine : it updates the DB globals with quest::...global, and at the same time updates the $qglobals map for consistency, to keep them in sync.
If you code this way you can even re-read the $qglobals in the same sub, and it is consistent with what has been entered in the DB. It could be a nice "coding rule" for script writing. Best would be if the Emu server did that synchronization in quest::...global itself, I will have to look into that.