You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
helix/helix-event/src/runtime.rs

89 lines
3.0 KiB
Rust

//! The event system makes use of global to decouple different systems.
//! However, this can cause problems for the integration test system because
//! it runs multiple helix applications in parallel. Making the globals
//! thread-local does not work because a applications can/does have multiple
//! runtime threads. Instead this crate implements a similar notion to a thread
//! local but instead of being local to a single thread, the statics are local to
//! a single tokio-runtime. The implementation requires locking so it's not exactly efficient.
//!
//! Therefore this function is only enabled during integration tests and behaves like
//! a normal static otherwise. I would prefer this module to be fully private and to only
//! export the macro but the macro still need to construct these internals so it's marked
//! `doc(hidden)` instead
use std::ops::Deref;
#[cfg(not(feature = "integration_test"))]
pub struct RuntimeLocal<T: 'static> {
/// inner API used in the macro, not part of public API
#[doc(hidden)]
pub __data: T,
}
#[cfg(not(feature = "integration_test"))]
impl<T> Deref for RuntimeLocal<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.__data
}
}
#[cfg(not(feature = "integration_test"))]
#[macro_export]
macro_rules! runtime_local {
($($(#[$attr:meta])* $vis: vis static $name:ident: $ty: ty = $init: expr;)*) => {
$($(#[$attr])* $vis static $name: $crate::runtime::RuntimeLocal<$ty> = $crate::runtime::RuntimeLocal {
__data: $init
};)*
};
}
#[cfg(feature = "integration_test")]
pub struct RuntimeLocal<T: 'static> {
data:
parking_lot::RwLock<hashbrown::HashMap<tokio::runtime::Id, &'static T, ahash::RandomState>>,
init: fn() -> T,
}
#[cfg(feature = "integration_test")]
impl<T> RuntimeLocal<T> {
/// inner API used in the macro, not part of public API
#[doc(hidden)]
pub const fn __new(init: fn() -> T) -> Self {
Self {
data: parking_lot::RwLock::new(hashbrown::HashMap::with_hasher(
ahash::RandomState::with_seeds(423, 9978, 38322, 3280080),
)),
init,
}
}
}
#[cfg(feature = "integration_test")]
impl<T> Deref for RuntimeLocal<T> {
type Target = T;
fn deref(&self) -> &T {
let id = tokio::runtime::Handle::current().id();
let guard = self.data.read();
match guard.get(&id) {
Some(res) => res,
None => {
drop(guard);
let data = Box::leak(Box::new((self.init)()));
let mut guard = self.data.write();
guard.insert(id, data);
data
}
}
}
}
#[cfg(feature = "integration_test")]
#[macro_export]
macro_rules! runtime_local {
($($(#[$attr:meta])* $vis: vis static $name:ident: $ty: ty = $init: expr;)*) => {
$($(#[$attr])* $vis static $name: $crate::runtime::RuntimeLocal<$ty> = $crate::runtime::RuntimeLocal::__new(|| $init);)*
};
}