MC-23105Exception in Server when exiting
When exiting a freshly created minecraft Server with Ctrl+C on the linux console, I got a lot of console spam. The messages all were
java.util.ConcurrentModificationException
at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1115)
at java.util.TreeMap$KeyIterator.next(TreeMap.java:1169)
at jr.a(SourceFile:454)
at aed.a(SourceFile:217)
at aed.a(SourceFile:91)
at jq.b(SourceFile:154)
at jq.a(SourceFile:183)
at jr.a(SourceFile:602)
at net.minecraft.server.MinecraftServer.a(SourceFile:263)
at net.minecraft.server.MinecraftServer.m(SourceFile:283)
at hg.run(SourceFile:566)
Being able to code a little bit in Java, this seems to be a severe bug (race condition or missing synchronization or something).
After restarting the server some chunks looked as if they were not saved correctly.
This is reproducible.
Can attach additional files like server.properties if necessary.
Environment
Linux Server 1.6.2 (Ubuntu), x64 Java (OpenJDK)
Linked Issues
Created Issue:
Exception in Server when exiting
When exiting a freshly created minecraft Server with Ctrl+C on the linux console, I got a lot of console spam. The messages all were
java.util.ConcurrentModificationException at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1115) at java.util.TreeMap$KeyIterator.next(TreeMap.java:1169) at jr.a(SourceFile:454) at aed.a(SourceFile:217) at aed.a(SourceFile:91) at jq.b(SourceFile:154) at jq.a(SourceFile:183) at jr.a(SourceFile:602) at net.minecraft.server.MinecraftServer.a(SourceFile:263) at net.minecraft.server.MinecraftServer.m(SourceFile:283) at hg.run(SourceFile:566)Being able to code a little bit in Java, this seems to be a severe bug (race condition or missing synchronization or something).
After restarting the server some chunks looked as if they were not saved correctly.
This is reproducible.
Can attach additional files like server.properties if necessary.
Environment
Linux Server 1.6.2 (Ubuntu), x64 Java (OpenJDK)
relates to
Are you using any plugins?
No, just a fresh vanilla server.
I guess this is caused by generating the chunks at the same time as saving them.
Note that this bug only occurs when you exit a server you just created/started a few seconds ago with a fresh world. As I said, it's probably happening because the initial chunk generation is still happening while the server is already exiting.
What version of java do you have installed?
Also, is this a problem for server 1.7.4?
I'm using
java version "1.7.0_25"
OpenJDK Runtime Environment (IcedTea 2.3.10) (7u25-2.3.10-1ubuntu0.12.04.2)
OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)
Still in 1.7.4. Will test snapshot when I have time to update.
Problem encountered often in snapshot 14w30c:
After this happens, the same command may work immediately after the error.
@Anthony Martin: That's something different.
vs.
java.util.ConcurrentModificationException at java.util.TreeMap$PrivateEntryIterator.nextEntryConcurrentModificationException means that one thread cannot get a lock on a resource because some other thread has it already (If I do interpret that correctly), but the causes for both exceptions are different.
It's usually a race condition. This report mentions race conditions. So, rather than risk a duplicate report, I just commented here.
I believe this situation now triggers the watchdog thread, by default:
MC-63590Is this still a concern in the current Minecraft version 1.8.1 Prerelease 3 / Launcher version 1.5.3 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
No response for over a year.