WarcMutex

Description

The WarcMutex crate is a Rust library that provides a macro attribute for mods, structs, and impls. The purpose of this library is to generate a wrapper that allows the struct to be used with the asynchronous reference control called Arc and the Mutex for asynchronous mutation control.

Installation

To use the WarcMutex crate, add the following dependency to your Cargo.toml:

[dependencies]
warcmutex = "1.0.0"

Example Usage

Here's a simple example of using WarcMutex:

#[warcmutex]
pub struct MyStruct {
    value: usize,
}

#[warcmutex]
impl MyStruct {
    pub fn new() -> Self {
        Self {
            value: 0,
        }
    }

    pub fn reset(&mut self) {
        self.value = 0;
    }

    pub fn value_mut(&mut self) -> &mut usize {
        &mut self.value
    }

    pub fn get_value(&self) -> usize {
        self.value
    }
}

After applying the #[warcmutex] attribute, the code is transformed into:

pub struct MyStructBase {
    value: usize,
}

impl MyStructBase {
    pub fn new() -> Self {
        Self {
            value: 0,
        }
    }

    fn reset(&mut self) {
        self.value = 0;
    }

    pub fn value_mut(&mut self) -> &mut usize {
        &mut self.value
    }

    fn get_value(&self) -> usize {
        self.value
    }
}

pub struct MyStruct {
    base: Arc<Mutex<MyStructBase>>,
}

impl MyStruct {
    pub fn new() -> Self {
        Self {
            base: Arc::new(Mutex::new(MyStructBase::new())),
        }
    }

    pub fn reset(&mut self) {
        self.base.lock().unwrap().reset();
    }

    pub fn get_value(&self) -> usize {
        self.base.lock().unwrap().get_value()
    }
}

impl MyStruct {
    pub fn lock(&mut self) -> LockResult<MutexGuard<'_, MyStructBase>> {
        self.base.lock()
    }
}

impl Clone for MyStruct {
    fn clone(&self) -> Self {
        Self {
            base: self.base.clone(),
        }
    }
}

unsafe impl Send for MyStruct {}
unsafe impl Sync for MyStruct {}

After using the #[warcmutex] attribute, the MyStruct will be automatically rewritten with the addition of a base field containing an Arc<Mutex<MyStructBase>>. The functions of MyStruct will then be implemented to safely access the base field.

Method lock

Similar to the method in Mutex<T>, this function is used to lock the usage and gain access to functions that return references as shown in the example below:

fn main() {
    use my_module::MyStruct;
    let mut a = MyStruct::new();
    *a.lock().unwrap().value_mut() = 10;
    assert_eq!(a.get_value(), 10);
}

Modules

You can simplify the use of #[warcmutex] by placing it as an attribute for the module, which will have the same effect as in the previous example:

use warcmutex::warcmutex;

#[warcmutex]
mod my_module {
    /// other mods, structs, and/or impls...
}

When used on a module, all structs, impls, and mods will be included, with exceptions.

The use of the attribute may not work well with other attributes.

Contribution

The WarcMutex project is mainly maintained by a single developer known as PFP but welcomes contributions from the community. However, it's essential that contributions stay within the scope of the project's main function.

License

This project is licensed under the MIT License. See the LICENSE file for more details.