No OpenGL context found in the current thread

[charsmud]

I am attempting to run mc.launchIntegratedServer, but I keep getting the following error:

 

2014-07-10 13:48:18 [iNFO] [sTDERR] java.lang.RuntimeException: No OpenGL context found in the current thread.
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at org.lwjgl.opengl.GLContext.getCapabilities(GLContext.java:124)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at org.lwjgl.opengl.GL11.glClear(GL11.java:585)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.client.gui.LoadingScreenRenderer.setLoadingProgress(LoadingScreenRenderer.java:81)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.client.gui.LoadingScreenRenderer.resetProgresAndWorkingMessage(LoadingScreenRenderer.java:62)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.client.Minecraft.loadWorld(Minecraft.java:2097)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.client.Minecraft.loadWorld(Minecraft.java:2063)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.client.Minecraft.launchIntegratedServer(Minecraft.java:1981)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at timeTraveler.mechanics.FutureTravelMechanics.launchWorld(FutureTravelMechanics.java:287)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at timeTraveler.network.TimeTravelerPacketHandler.onPacketData(TimeTravelerPacketHandler.java:88)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at cpw.mods.fml.common.network.NetworkRegistry.handlePacket(NetworkRegistry.java:255)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at cpw.mods.fml.common.network.NetworkRegistry.handleCustomPacket(NetworkRegistry.java:245)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at cpw.mods.fml.common.network.FMLNetworkHandler.handlePacket250Packet(FMLNetworkHandler.java:85)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.network.NetServerHandler.handleCustomPayload(NetServerHandler.java:1130)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.network.packet.Packet250CustomPayload.processPacket(Packet250CustomPayload.java:61)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.network.MemoryConnection.processReadPackets(MemoryConnection.java:89)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.network.NetServerHandler.networkTick(NetServerHandler.java:141)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.network.NetworkListenThread.networkTick(NetworkListenThread.java:54)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.server.integrated.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:109)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:691)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:587)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
2014-07-10 13:48:18 [iNFO] [sTDERR] 	at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:583)

 

This is the affected method:

    public static void launchWorld(String folderName, String worldName, WorldSettings ws)
    {
    	if(FMLClientHandler.instance().getClient().isSingleplayer())
    	{
    		FMLClientHandler.instance().getClient().launchIntegratedServer(folderName, worldName, ws);
    	}
    }

 

And here is where I am calling this method:

 

		        if(future.exists())
	        {
	        	try
	        	{
			        System.out.println("THIS FUTURE EXISTS, MOVING THE FUTURE IN");
			        mc.displayGuiScreen(null);
			        	
				    mc.statFileWriter.readStat(StatList.leaveGameStat, 1);
					mc.theWorld.sendQuittingDisconnectingPacket();
					ms.stopServer();
					// mc.loadWorld((WorldClient)null);

					Thread.sleep(3000);

					CopyFile.moveMultipleFiles(future, worldFile);
					FutureTravelMechanics.launchWorld(folderName, worldName, (WorldSettings)null);
					//ms.startServerThread();
					//mc.launchIntegratedServer(folderName, worldName, (WorldSettings) null);

	        	}
	        	catch(Exception ex)
	        	{
	        		ex.printStackTrace();
	        	}
	        }

 

This is inside of a class that implements IPacketHandler.  I'm guessing that this error is occuring because this is run on the server, which does not have an OpenGL instance.  However, this code needs to run serverside;  any suggestions? 

[Elyon]

Wow, this is an interesting issue. Or rather, an interesting context (or lack thereof).

 

I am not sure, but I think you will want to have a look at what

launchIntegratedServer

does, and replicate parts of it (starting a new thread, etc.) without replicating others (drawing to the screen, etc.).

 

Best of luck, and colour me curious.

[charsmud]

Thanks for the input!  I also was thinking of doing this as well, but wanted to check here to make sure I'm not just over-looking something. 

[Rainfur]

Adding onto Elyon said, try overriding the launchIntegratedServer method, in your own IntegratedServer class. (@Override in the class). Remove what you need.

[TheGreyGhost]

Hi

 

You're calling client side code (including OpenGL) from the server side, which is an extremely bad idea because it will cause random crashes.  You must make sure that your server-side code doesn't run any client-side code.

 

Perhaps you could explain what exactly you want to run on the server side; certainly not the GUI? 

 

-TGG

 

 

 

[charsmud]

What I want the server-side to do is to exit the world, then reload it after I move around files in the world folder.

[Elyon]

Define exit the world, please. Oh, and what shall happen to the connected clients while the server doesn't have a world?

 

 

Also, moving around files in the world folder directly? To what effect?

 

Surely there must be a better approach to what you want to do than to move around files in the world folder directly

[TheGreyGhost]

Hi

 

If all you really want to do is copy/backup some files, you can force the server to stop saving to disk for a short time.  See the save-off command.

 

I think your current approach of relaunching the server thread from within the server thread is asking for trouble. 

Perhaps you could describe in more detail what you're trying to achieve by moving files around?

 

-TGG

 

[charsmud]

I've attempted to implement that, but the world files appear to still be in use.  Here's the modified code block:

	        if(future.exists())
	        {
	        	try
	        	{
			        System.out.println("THIS FUTURE EXISTS, MOVING THE FUTURE IN");
			        //mc.displayGuiScreen(null);
			        MinecraftServer allServers = MinecraftServer.getServer();
			        for (int i = 0; i < allServers.worldServers.length; ++i)
			        {
			            if (allServers.worldServers[i] != null)
			            {
			                WorldServer wServer = allServers.worldServers[i];
			                wServer.canNotSave = true;
							System.out.println(wServer.canNotSave);

			            }
			        }
			        	
				    //mc.statFileWriter.readStat(StatList.leaveGameStat, 1);
					//mc.theWorld.sendQuittingDisconnectingPacket();
					//ms.stopServer();
					// mc.loadWorld((WorldClient)null);

					Thread.sleep(3000);

					CopyFile.moveMultipleFiles(future, worldFile);

					for(int i = 0; i < allServers.worldServers.length; ++i)
					{
						if(allServers.worldServers[i] != null)
						{
							WorldServer wServer = allServers.worldServers[i];
							wServer.canNotSave = false;
						}
					}
					//FutureTravelMechanics.launchWorld(folderName, worldName, (WorldSettings)null);
					//ms.startServerThread();
					//mc.launchIntegratedServer(folderName, worldName, (WorldSettings) null);

	        	}
	        	catch(Exception ex)
	        	{
	        		ex.printStackTrace();
	        	}
	        }

 

What I'm trying to achieve is load in a version of the world file that I had previously modified.  However, because the world files are in use, they cannot be moved unless minecraft is not using them.  Is it possible that Minecraft is still reading from the world file, and thus why the files aren't moving? 

[TheGreyGhost]

Hi

 

Yeah I imagine that Minecraft maintains a read lock on the world files even if it's not saving, so you won't be able move the files.  You would need to force minecraft to detach itself from the files, move the files, and then reattach and reload all the chunks again.  See ChunkProviderServer and IChunkLoader / AnvilChunkLoader.  I'm sure it's possible with enough poking around in the guts of vanilla but I suspect it wouldn't be very robust.

 

Perhaps you can achieve the effect you want a different way-

for example, instead of copying new data into the existing world, you could put everything in a new (parallel) dimension and then "invisibly" teleport players there when you want to "update" the world.  No need to mess around with files at all then. 

 

-TGG

[charsmud]

Thanks, I'll look into that!  I might end up making a dummy dimension so I can do the file manipulation, but if I can't I'll just create a dynamic dimension.