What exactly is a memory leak and how do i fix it?

[brandon3055]

I just discovered a problem with my packet system and im hoping someone here can help figure out how to fix it.

 

First off what exactly dose this mean?

[06:46:21] [server thread/ERROR] [FML]: Detected ongoing potential memory leak. 100 packets have leaked. Top offenders
[06:46:21] [server thread/ERROR] [FML]: 	 DraconicEvolution : 100
[06:47:33] [server thread/ERROR] [FML]: Detected ongoing potential memory leak. 200 packets have leaked. Top offenders
[06:47:33] [server thread/ERROR] [FML]: 	 DraconicEvolution : 200
[06:47:49] [server thread/ERROR] [FML]: Detected ongoing potential memory leak. 300 packets have leaked. Top offenders
[06:47:49] [server thread/ERROR] [FML]: 	 DraconicEvolution : 300
[06:48:03] [server thread/ERROR] [FML]: Detected ongoing potential memory leak. 400 packets have leaked. Top offenders
[06:48:03] [server thread/ERROR] [FML]: 	 DraconicEvolution : 400
[06:48:43] [server thread/ERROR] [FML]: Detected ongoing potential memory leak. 500 packets have leaked. Top offenders
[06:48:43] [server thread/ERROR] [FML]: 	 DraconicEvolution : 500

It pops up whenever i click a button in one of my guis 100 times (so for every 100 packets sent)

 

I am using SanAndreasP's packet handling system (it was suggested by SanAndreasP not sure who came up with it)

 

 

[Eternaldoom]

Use IMessages. Diesieben07 has a tutorial in the tutorials section.

[brandon3055]

I am not using the Diesieben07's system the system i am using is very similar to this tutorial.

http://www.minecraftforge.net/wiki/Netty_Packet_Handling

 

I did some checking and that system is still used by CofhCore and Tinkerers Construct so it cant be that bad can it?

 

The difference with the version i am using is it uses an interface instead of the abstract packet.

 

Is there any reason i cant keep using this system? because i really dont want to have to re write my entire packet system again.

[Eternaldoom]

There's a message from cpw at the top saying its no good and can cause memory leaks. You don't need to write a new system, FML already has one. Diesieben's tutorial is on how to use it.

[brandon3055]

I ment i dont want to have to re write my mod to use a different system. But after looking at Diesieben's tutorial it looks like the packet classes are very similar to the ones i am currently using so hopefully i wont have to change much to switch to the new system.

 

Thanks for your help.

[jabelar]

By the way, a memory leak occurs with the software program continues to allocate memory for use without ever freeing it up again.  So the amount of memory used by the program grows until the system can't handle it anymore and crashes.

 

Memory leaks are often a result of poor buffer management.  For example, if you're doing file I/O operations and keep opening up stream buffers for reading without ever closing them, or similarly with networking that usually uses buffers for the message payloads.  I'm not really certain how the memory leak occurred in that problematic packet system that we all used for a while, but it likely was similar issue with buffer allocations not being freed up.

[TheGreyGhost]

Hi

 

THat message isn't actually a memory leak error.  It tells you that you are receiving a message but don't have a handler registered for it on that side.

 

If you search the Forge code for that error message string, and put a breakpoint there, you can inspect the packet (IMessage) it's currently processing to find out which IMessage has the missing handler.

 

-TGG