QuickStone Errors

[mgp104]

Hi,
Since I started playing Simutrans Experimental I've really enjoyed it and loved the new features (to the point that I don't like playing standard Simutrans because it doesn't have features like comfort and vehicle weight), but I've had problems with every game that I have started and it's always something to do with 'QuickStone'.  Usually the problem occurs with a game that I have been playing for a while (and therefore spent a lot of time on), sometimes the problem occurs during the game but mostly it happens when I try to load a save.  I've had the problem with all the versions of Simutrans Experimental (V10.2, 10.3 and 10.4) that I have used (although all of my saved games were games that were started in versions 10.2 or 10.3).
Has anyone else had this problem?  Is it something to do with the settings that I'm using or my machine (64 bit Windows 7)?  I dearly want to play this game but it is so frustrating when you spend a lot of time building up a transport network only to have fatal errors that cause the program to crash.  Can anyone help me?
Mark

[jamespetts]

Mgp,

thank you for your bug report. I am glad that you are enjoying Experimental, and sorry that you are having problems. QuickStone is a smart pointer system implemeted by Standard, but used heavily in Experimental specific features, too. Errors involving QuickStone pointers might occur in many different parts of the code. In order to help to track these issues down, can you be more specific about exactly what error message that you get, and what you do just before it occurs? Uploading a saved game in which the error can be reproduced would be very helpful. Thank you again for your report.

[mgp104]

Hi,
The errors that I have been getting are all:
"FATAL ERROR
quickstone<T>::quickstone_
tpl(T*,unint16)
wants to assign non-null
pointer to null index
PRESS A KEY"
or
"FATAL ERROR
quickstone<T>::quickstone_
tpl(T*,unint16)
slot(2) already taken
PRESS A KEY"
where the number in the brackets after slot is variable.
From a working save I have mostly been improving bus routes to cover more of the expanding cities, tomorrow I will try playing from a working save and saving everytime I change something to try and work out what might be causing the problem.

[jamespetts]

Hmm - I have not seen these errors before. It would be very helpful if you could try to isolate the circumstances in which they occur in order that they might be reproduced; a saved game would be particularly helpful.

[mgp104]

Hi,
I have been working on trying to provoke reproducable errors, I have had no luck so far on reproducing the "Slot already taken" error but I have managed to reproduce the "wants to assign non-null pointer to null index" error.  I have uploaded a .sve file to http://files.simutrans-germany.com as NewerCrashTest2.sve.  Here two goods trains are in one of the platforms at Yendborough Builders Yard Station, both waiting for clearance.  Last night I managed to cause the ""wants to assign non-null pointer to null index" error by saving a game at the beginning of the next month, the error would occur on trying to load this saved game.  However I re-tried this test today and could not reproduce the error!  This is the one time that I have seen this type of error so I believe that it was a chance occurence but it would be interesting to find out why two trains were allowed to enter on platform at once.

[jamespetts]

Thank you for that. That is a most impressive game that you have set up there! I could not reproduce any crash, I am afraid, but I did notice the stuck train. It is very difficult to see another train on top of it, as it is under an elevated way. May I ask - what did you do to that saved game to reproduce the crash? I simply waited (on fast forward) for some time, and no crash appeared. (I also tried, in a different instance of the game, routing the stuck train to go back to its origin, and no crash appeared there, either).

[mgp104]

Yes, I tried the same things today to try and replicate the crash but could not.  I'm sure that it was the stuck trains that caused the crash last night and I'm fairly sure that what I did was wait until at least a month had passed then saved the game, when I tried to load that game it gave the error (all of the fatal errors that I have encountered occur when trying to load a saved game, not during the game).  I have a saved game where this error occurs, although all it does is give an error on loading and crashes.

Incidentally is there a limit on number of vehicles/stops in the game?

[jamespetts]

Hmm - just tried it: can't reproduce on the loading/saving, either (at least, not with my debug build). Might I ask - what platform are you using?

[mgp104]

By platform do you mean hardware or software?
I have a 64 bit Windows 7 OS and use the executable binary for Simutrans Experimental.

[jamespetts]

That answered my question, thank you. I am about to visit my parents for Christmas, so won't be able to do any more debugging until January. If you are able to be more precise about the steps to reproduce in the meantime, I should be very grateful for any information!

[mgp104]

I've been experimenting and have been sporadically encountered various quickstone errors when trying to load a saved game but have been unable to reliably reproduce the error.  My suspicion is that when I either build/alter a route or add/replace vehicles this sometimes causes the error.  I have noticed that in the options - display menu box it shows what appears to be a routing display which shows re-routing data at the beginning of each month; usually the re-routing takes a second or two.  When I have made a change that appears to go on and cause the error this re-routing phase takes 20 or more seconds with the display showing "passenger/re-route".  One point is that I have only noticed this effect when I have a large number of lines, stops and vehicles, could the number of available routes be causing problems?

[jamespetts]

It's very hard to tell what could cause this sort of error, as it is very hard to trap. However, there was a bug in 10.4 that could cause memory corruption, so it is possible that that could be behind any number of otherwise odd bugs. Have you ever had this problem with a game saved in 10.5?

[mgp104]

I've only just downloaded 10.5, the errors still occurs with games saved in 10.4 but so far the error has not occurred in 10.5

[jamespetts]

The error occurs on saving, not loading; perhaps let me know if this recurs with games saved in 10.5?

[jamespetts]

I have recently fixed some Quickstone related errors in my 10.x branch (thanks to Dwachs for assistance with that); hopefully, that will help with this issue.