awesomeness

This commit is contained in:
nora 2022-01-25 09:07:56 +01:00
parent ea28dc4f4c
commit 860c44707a

View file

@ -1,3 +1,7 @@
//! This crate provides a `GLock<T>`, that is globally locked. Every `GLock<T>` uses the same
//! global lock, so locking on will lock all. Sounds like a dumb idea? One of the most popular
//! programming implementations does it, so it must be smart.
use parking_lot::lock_api::{MutexGuard, RawMutex};
use parking_lot::Mutex;
use std::cell::UnsafeCell;
@ -5,30 +9,44 @@ use std::ops::{Deref, DerefMut};
static LOCK: Mutex<()> = Mutex::const_new(RawMutex::INIT, ());
/// A global lock that locks every `GLock` using the same global lock (like the GIL in cpython lmao)
pub struct GLock<T> {
inner: UnsafeCell<T>,
}
impl<T> GLock<T> {
pub fn lock(&self) -> GLockGuard<T> {
let mutex_guard = LOCK.lock();
// SAFETY: We have the global lock
let value = unsafe { &mut *self.inner.get() };
GLockGuard { value, mutex_guard }
/// Creates a new GLock
pub const fn new(value: T) -> Self {
Self {
inner: UnsafeCell::new(value),
}
}
pub fn get_mut(&mut self) -> &mut T {
/// Lock the global lock, not allowing any other `GLock` to be locked during the locked duration
pub fn lock(&self) -> GLockGuard<T> {
let global_guard = LOCK.lock();
// SAFETY: We took the global lock above,
// so no other one is allowed to get to this critical section here
let value = unsafe { &mut *self.inner.get() };
GLockGuard {
value,
global_guard,
}
}
pub const fn get_mut(&mut self) -> &mut T {
self.inner.get_mut()
}
pub fn into_inner(self) -> T {
pub const fn into_inner(self) -> T {
self.inner.into_inner()
}
}
/// A guard that guards a globally locked value
struct GLockGuard<'a, T> {
value: &'a mut T,
mutex_guard: MutexGuard<'a, parking_lot::RawMutex, ()>,
global_guard: MutexGuard<'a, parking_lot::RawMutex, ()>,
}
impl<'a, T> Deref for GLockGuard<'a, T> {