Dragon Quest 9 Canvass (also known as Tag or StreetPass)'s crash issue

[MelonGx]

(1) Load DQ9 with melonDS
(2) Start a canvass
(3) Leave it for minutes or hours

The game will crash if I leave it in canvass mode too long (over 15 minutes).
But if I use real DS/DSi/3DS console, the crash will never happen even I leave it in canvass mode 24 hours.

[MelonGx]

BTW is it available to use multi-core for melonDS?
Only single core of my i7-9700K works even I opened 3 or more melonDS processes.

[RSDuck]

can you provide us with a savefile? Also please name the region of the rom.

BTW is it available to use multi-core for melonDS?
Only single core of my i7-9700K works even I opened 3 or more melonDS processes.

melonDS can only utilise a single core per instance, or two if you use the threaded software renderer. That multiple processes don't end up on multiple cores is weird, though there's nothing we can do about it.

[MelonGx]

It happens on every region (JP US EU) and any proper save.
Just go to Stornway’s Inn and start a canvass, then leave it open for over 15 mins. Then this crash issue can be reproduced.

[RSDuck]

I've never played Dragon Quest and I don't want to sit through the first whatever minutes of intro and tutorial to reproduce the bug.

[MelonGx]

I just wanted to say this crash happened on every save regardless of the game progress and whether it was hacked or not.
If you just want to reproduce the issue easier, then every 64KB saves in the following link should be OK.
https://www.woodus.com/den/games/dq9ds/savefiles.php
I’m sorry for the inconvenience.

I know save format other than Raw 64KB will crash. But it’s a crash of save corruption but not a crash during the canvass mode so it’s out of our discussion.

[RSDuck]

thanks for the savefile, I hope my last comment didn't came off as too snarky.

I've been running it for quite some time, but couldn't reproduce it. Maybe it was already fixed since the last stable versions?

[MelonGx]

Oh, I just found that the issue happened on 0.8.2.
Just reproduced this issue on 0.8.2.
I'll try it on 0.8.3 one more time.

[MelonGx]

Uh oh, it's still happening on 0.8.3 here.

I opened 3 processes for making the tag happen (it requires at least 2 processes).
I don't know if it happens on only one process (it's meaningless since we need at least 2 processes to make the tag happen).

BTW I found that when 2 processes are in the canvass mode, they send and receive data every a few seconds.
The issue happens on one of the data transmission and then causes one process die.
Seems that this issue will kill every other processes finally to make only the last one survive.

Process 1
DQ9.NDS + DQ9.sav

Process 2
E_DQ9.NDS + E_DQ9.sav

Process 3
DQ92.NDS + DQ92.sav

All the above use one melonDS program to open.

[RSDuck]

good to know, I only tried it without connecting another game.

Looks like this is an issue with local wireless, which known to be unstable. Though usually it results in connection errors as far as I know.

[ghost]

Kingdom Hearts recoded also had a Tag mode and I think it got similar issues as well.

[KostaSaizo7]

Probably fixed by #1516

I guess the 3rd instance detected only one guest because I use the same savefile in the first two instances.