[Question] Memory concerns?

Hi all, thanks for the great library.

I am trying to diagnose what appears to be a memory leak in one of our applications, and I am wanting to make sure I am not misusing or overlooking something with Handlebars. After running our application, which will dynamically load up Handlebars templates, for a long time, generating many templates, I see memory usage continue to grow.

There’s many other pieces to this, so I didn’t even consider Handlebars until I used Visual Studio’s memory profiler and found this:

Where we have (this is a diff) over 200 MB of these ReaderWriterLockSlim objects, and they’re all referenced from HandlebarsDotNet objects.

Our usage of Handlebars is as follows:

string OnEachRequest(...)
{
    var handlebars = Handlebars.Create();

    //Register custom helpers
    ...
    
    return handlebars.Compile(someTemplate)(someData);
}

Is there some sort of cleanup I’m forgetting to do?

Thanks! I will continue to dig into this further but figure it doesn’t hurt to ask in case I’m missing something obvious.

[Zulu-Inuoe]

@zjklee I think this should be marked as a bug. Running Handlebars 2.0.7, the following eats up all my RAM:

            while(true)
            {
                Handlebars.Compile("Hello, world!");
            }

I haven’t dug down exactly what’s happening but each call to Compile ends up throwing more things into that ObservableList that is ultimately referenced by the HandlebarsEnvironment held in that static variable, creating a memory leak.

I know most people (should) be using a fresh environment, but this is definitely a regression from v1.x

[Zulu-Inuoe]

@zjklee Apologies - I just tested this and you are totally correct. I was misremembering the codebase