MC-159315Chunks generate in a non-threadsafe manner after special conditions
note: this MAY duplicate MC-315, however, the conditions to replicate this bug and crash are very different.
Chunk generation is not thread-safe on linux (ubuntu 18.4) under certain conditions, leading to crashes. Steps to reproduce: Can occur at random, but this is very rare and requires teleportation, a slow ticks-per-second, or other strange conditions. Otherwise, create a virtual partition of small size. mount it, move minecraft inside this partion, create a world, generate enough world-space that the partition becomes full and the game crashes. Move minecraft out of the virtual partition and load up the game file again. go to the part of the world where the crash occurred. Here, new chunks will generate in the wrong location (you can clearly see where they should have generated, but they are in the wrong position) and the game will likely crash after a minute or so. May be reproducible on windows, but I haven't tested, because virtual partitions are a lot less friendly on windows.
See these screenshots I took after spending a while filling up a 500mb virtual partition, the moving the save to a different directory:
Clearly, the chunks have generated in the wrong positions; the correct position can be seen in the other screenshots.
after getting these screenshots, the game crashed. log file is attached.
The savefile may keep producing these errors, so, if necessary, I can provide it via dropbox; the player should appear in a village that is quite far from spawn; fly a few more chunks away from spawn and the glitch will begin to occur as new chunks are generated.
Environment
Minecraft Version: 1.14.4
Minecraft Version ID: 1.14.4
Operating System: Linux (amd64) version 4.15.0-58-generic
Java Version: 1.8.0_222, Private Build
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Private Build
Memory: 917588672 bytes (875 MB) / 2013265920 bytes (1920 MB) up to 2147483648 bytes (2048 MB)
CPUs: 4
JVM Flags: 8 total; -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
Player Count: 1 / 8; [vl['DrSeussTheDoctor'/98, l='threadtest', x=-3808.93, y=103.40, z=156.07]]
Data Packs: vanilla
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.
Linked Issues
duplicates1
Created Issue:
Chunks generate in a non-threadsafe manner after special conditions
note: this MAY duplicate
MC-315, however, the conditions to replicate this bug and crash are very different.Chunk generation is not thread-safe on linux (ubuntu 18.4) under certain conditions, leading to crashes. Steps to reproduce: Can occur at random, but this is very rare and requires teleportation, a slow ticks-per-second, or other strange conditions. Otherwise, create a virtual partition of small size. mount it, move minecraft inside this partion, create a world, generate enough world-space that the partition becomes full and the game crashes. Move minecraft out of the virtual partition and load up the game file again. go to the part of the world where the crash occurred. Here, new chunks will generate in the wrong location (you can clearly see where they should have generated, but they are in the wrong position) and the game will likely crash after a minute or so. May be reproducible on windows, but I haven't tested, because virtual partitions are a lot less friendly on windows.
See these screenshots I took after spending a while filling up a 500mb virtual partition, the moving the save to a different directory:
Clearly, the chunks have generated in the wrong positions; the correct position can be seen in the other screenshots.
after getting these screenshots, the game crashed. log file is attached.
The savefile may keep producing these errors, so, if necessary, I can provide it via dropbox; the player should appear in a village that is quite far from spawn; fly a few more chunks away from spawn and the glitch will begin to occur as new chunks are generated.
Environment
Minecraft Version: 1.14.4
Minecraft Version ID: 1.14.4
Operating System: Linux (amd64) version 4.15.0-58-generic
Java Version: 1.8.0_222, Private Build
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Private Build
Memory: 917588672 bytes (875 MB) / 2013265920 bytes (1920 MB) up to 2147483648 bytes (2048 MB)
CPUs: 4
JVM Flags: 8 total; -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
Player Count: 1 / 8; [vl['DrSeussTheDoctor'/98, l='threadtest', x=-3808.93, y=103.40, z=156.07]]
Data Packs: vanilla
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.
Attachments4
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duplicates
Does
MC-150202describe your issue?This seems related to, if not duplicating these three reports:
MC-150202,MC-158988,MC-74762.Note these have all been fixed for a future release.
MC-74762makes note of the full disk null-pointer-error that caused my issue. Seems I was barking up the wrong tree when I was looking atMC-315. Thanks, I think this should be marked as a duplicate of that issue