How to access lua.used_memory() from lua.set_interrupt() callback?

[33KK]

I need to cap memory usage of the lua context, so I am trying to check current memory usage in interrupt handler since set_memory_limit is not available with Luau. Using an Arc<Mutex<Lua>> doesn't work either since it doesn't drop the lock while executing code.

EDIT: also i'm not quite sure what is the right way to stop execution, return Err(mlua::Error::RuntimeError("script took too long to execute".to_owned())); seems to work but doesn't feel right

[33KK]

It seems that set_memory_limit works fine with luau, any reason it is not enabled for luau feature?

[khvzak]

any reason it is not enabled for luau feature?

Same reason as #119

Using an Arc<Mutex> doesn't work either since it doesn't drop the lock while executing code.

You probably don't need Mutex here, and just can try Arc/Rc instead... Unfortunately Luau does not provide fully defined semantics for interrupts (but checking memory should be ok).

also i'm not quite sure what is the right way to stop execution, return Err(mlua::Error::RuntimeError("script took too long to execute".to_owned())); seems to work but doesn't feel right

More elegant way is to trigger VmState::Yield to force return execution back to Rust. Generating an exception is also fine.
An example: https://github.com/khvzak/mlua/blob/v0.8.3/tests/luau.rs#L176

[33KK]

Using an Arc doesn't seem to work, I do have the send feature enabled

[khvzak]

Seems the only way is to use ReentrantMutex from parking_lot :(
I see how inconvenient it is! I probably change interrupts interface in a next major release.

[33KK]

I see, I guess I'll convert this into an issue for now