467 lines
13 KiB
Rust
467 lines
13 KiB
Rust
use std::{
|
|
borrow::{Cow, ToOwned},
|
|
cell::Cell,
|
|
collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList, VecDeque},
|
|
hash::{BuildHasher, Hash},
|
|
marker::PhantomData,
|
|
num::{
|
|
NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroIsize, NonZeroU128,
|
|
NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize,
|
|
},
|
|
path::{Path, PathBuf},
|
|
rc::Rc,
|
|
sync::atomic::{
|
|
AtomicBool, AtomicI16, AtomicI32, AtomicI64, AtomicI8, AtomicIsize, AtomicU16, AtomicU32,
|
|
AtomicU64, AtomicU8, AtomicUsize,
|
|
},
|
|
};
|
|
|
|
/// Substitute for the [`Drop`] trait for garbage collected types.
|
|
pub trait Finalize {
|
|
/// Cleanup logic for a type.
|
|
fn finalize(&self) {}
|
|
}
|
|
|
|
/// The Trace trait, which needs to be implemented on garbage-collected objects.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// - An incorrect implementation of the trait can result in heap overflows, data corruption,
|
|
/// use-after-free, or Undefined Behaviour in general.
|
|
///
|
|
/// - Calling any of the functions marked as `unsafe` outside of the context of the garbage collector
|
|
/// can result in Undefined Behaviour.
|
|
pub unsafe trait Trace: Finalize {
|
|
/// Marks all contained `Gc`s.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// See [`Trace`].
|
|
unsafe fn trace(&self);
|
|
|
|
/// Marks all contained weak references of a `Gc`.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// See [`Trace`].
|
|
unsafe fn weak_trace(&self);
|
|
|
|
/// Increments the root-count of all contained `Gc`s.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// See [`Trace`].
|
|
unsafe fn root(&self);
|
|
|
|
/// Decrements the root-count of all contained `Gc`s.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// See [`Trace`].
|
|
unsafe fn unroot(&self);
|
|
|
|
/// Checks if an ephemeron's key is marked.
|
|
#[doc(hidden)]
|
|
fn is_marked_ephemeron(&self) -> bool {
|
|
false
|
|
}
|
|
|
|
/// Runs [`Finalize::finalize`] on this object and all
|
|
/// contained subobjects.
|
|
fn run_finalizer(&self);
|
|
}
|
|
|
|
/// Utility macro to define an empty implementation of [`Trace`].
|
|
///
|
|
/// Use this for marking types as not containing any `Trace` types.
|
|
#[macro_export]
|
|
macro_rules! empty_trace {
|
|
() => {
|
|
#[inline]
|
|
unsafe fn trace(&self) {}
|
|
#[inline]
|
|
unsafe fn weak_trace(&self) {}
|
|
#[inline]
|
|
unsafe fn root(&self) {}
|
|
#[inline]
|
|
unsafe fn unroot(&self) {}
|
|
#[inline]
|
|
fn run_finalizer(&self) {
|
|
$crate::Finalize::finalize(self)
|
|
}
|
|
};
|
|
}
|
|
|
|
/// Utility macro to manually implement [`Trace`] on a type.
|
|
///
|
|
/// You define a `this` parameter name and pass in a body, which should call `mark` on every
|
|
/// traceable element inside the body. The mark implementation will automatically delegate to the
|
|
/// correct method on the argument.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// Misusing the `mark` function may result in Undefined Behaviour.
|
|
#[macro_export]
|
|
macro_rules! custom_trace {
|
|
($this:ident, $body:expr) => {
|
|
#[inline]
|
|
unsafe fn trace(&self) {
|
|
fn mark<T: $crate::Trace + ?Sized>(it: &T) {
|
|
// SAFETY: The implementor must ensure that `trace` is correctly implemented.
|
|
unsafe {
|
|
$crate::Trace::trace(it);
|
|
}
|
|
}
|
|
let $this = self;
|
|
$body
|
|
}
|
|
#[inline]
|
|
unsafe fn weak_trace(&self) {
|
|
fn mark<T: $crate::Trace + ?Sized>(it: &T) {
|
|
// SAFETY: The implementor must ensure that `weak_trace` is correctly implemented.
|
|
unsafe {
|
|
$crate::Trace::weak_trace(it);
|
|
}
|
|
}
|
|
let $this = self;
|
|
$body
|
|
}
|
|
#[inline]
|
|
unsafe fn root(&self) {
|
|
fn mark<T: $crate::Trace + ?Sized>(it: &T) {
|
|
// SAFETY: The implementor must ensure that `root` is correctly implemented.
|
|
unsafe {
|
|
$crate::Trace::root(it);
|
|
}
|
|
}
|
|
let $this = self;
|
|
$body
|
|
}
|
|
#[inline]
|
|
unsafe fn unroot(&self) {
|
|
fn mark<T: $crate::Trace + ?Sized>(it: &T) {
|
|
// SAFETY: The implementor must ensure that `unroot` is correctly implemented.
|
|
unsafe {
|
|
$crate::Trace::unroot(it);
|
|
}
|
|
}
|
|
let $this = self;
|
|
$body
|
|
}
|
|
#[inline]
|
|
fn run_finalizer(&self) {
|
|
fn mark<T: $crate::Trace + ?Sized>(it: &T) {
|
|
$crate::Trace::run_finalizer(it);
|
|
}
|
|
$crate::Finalize::finalize(self);
|
|
let $this = self;
|
|
$body
|
|
}
|
|
};
|
|
}
|
|
|
|
impl<T: ?Sized> Finalize for &'static T {}
|
|
// SAFETY: 'static references don't need to be traced, since they live indefinitely.
|
|
unsafe impl<T: ?Sized> Trace for &'static T {
|
|
empty_trace!();
|
|
}
|
|
|
|
macro_rules! simple_empty_finalize_trace {
|
|
($($T:ty),*) => {
|
|
$(
|
|
impl Finalize for $T {}
|
|
|
|
// SAFETY:
|
|
// Primitive types and string types don't have inner nodes that need to be marked.
|
|
unsafe impl Trace for $T { empty_trace!(); }
|
|
)*
|
|
}
|
|
}
|
|
|
|
simple_empty_finalize_trace![
|
|
(),
|
|
bool,
|
|
isize,
|
|
usize,
|
|
i8,
|
|
u8,
|
|
i16,
|
|
u16,
|
|
i32,
|
|
u32,
|
|
i64,
|
|
u64,
|
|
i128,
|
|
u128,
|
|
f32,
|
|
f64,
|
|
char,
|
|
String,
|
|
Box<str>,
|
|
Rc<str>,
|
|
Path,
|
|
PathBuf,
|
|
NonZeroIsize,
|
|
NonZeroUsize,
|
|
NonZeroI8,
|
|
NonZeroU8,
|
|
NonZeroI16,
|
|
NonZeroU16,
|
|
NonZeroI32,
|
|
NonZeroU32,
|
|
NonZeroI64,
|
|
NonZeroU64,
|
|
NonZeroI128,
|
|
NonZeroU128,
|
|
AtomicBool,
|
|
AtomicIsize,
|
|
AtomicUsize,
|
|
AtomicI8,
|
|
AtomicU8,
|
|
AtomicI16,
|
|
AtomicU16,
|
|
AtomicI32,
|
|
AtomicU32,
|
|
AtomicI64,
|
|
AtomicU64
|
|
];
|
|
|
|
impl<T: Trace, const N: usize> Finalize for [T; N] {}
|
|
// SAFETY:
|
|
// All elements inside the array are correctly marked.
|
|
unsafe impl<T: Trace, const N: usize> Trace for [T; N] {
|
|
custom_trace!(this, {
|
|
for v in this {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
macro_rules! fn_finalize_trace_one {
|
|
($ty:ty $(,$args:ident)*) => {
|
|
impl<Ret $(,$args)*> Finalize for $ty {}
|
|
// SAFETY:
|
|
// Function pointers don't have inner nodes that need to be marked.
|
|
unsafe impl<Ret $(,$args)*> Trace for $ty { empty_trace!(); }
|
|
}
|
|
}
|
|
macro_rules! fn_finalize_trace_group {
|
|
() => {
|
|
fn_finalize_trace_one!(extern "Rust" fn () -> Ret);
|
|
fn_finalize_trace_one!(extern "C" fn () -> Ret);
|
|
fn_finalize_trace_one!(unsafe extern "Rust" fn () -> Ret);
|
|
fn_finalize_trace_one!(unsafe extern "C" fn () -> Ret);
|
|
};
|
|
($($args:ident),*) => {
|
|
fn_finalize_trace_one!(extern "Rust" fn ($($args),*) -> Ret, $($args),*);
|
|
fn_finalize_trace_one!(extern "C" fn ($($args),*) -> Ret, $($args),*);
|
|
fn_finalize_trace_one!(extern "C" fn ($($args),*, ...) -> Ret, $($args),*);
|
|
fn_finalize_trace_one!(unsafe extern "Rust" fn ($($args),*) -> Ret, $($args),*);
|
|
fn_finalize_trace_one!(unsafe extern "C" fn ($($args),*) -> Ret, $($args),*);
|
|
fn_finalize_trace_one!(unsafe extern "C" fn ($($args),*, ...) -> Ret, $($args),*);
|
|
}
|
|
}
|
|
|
|
macro_rules! tuple_finalize_trace {
|
|
() => {}; // This case is handled above, by simple_finalize_empty_trace!().
|
|
($($args:ident),*) => {
|
|
impl<$($args),*> Finalize for ($($args,)*) {}
|
|
// SAFETY:
|
|
// All elements inside the tuple are correctly marked.
|
|
unsafe impl<$($args: $crate::Trace),*> Trace for ($($args,)*) {
|
|
custom_trace!(this, {
|
|
#[allow(non_snake_case, unused_unsafe)]
|
|
fn avoid_lints<$($args: $crate::Trace),*>(&($(ref $args,)*): &($($args,)*)) {
|
|
// SAFETY: The implementor must ensure a correct implementation.
|
|
unsafe { $(mark($args);)* }
|
|
}
|
|
avoid_lints(this)
|
|
});
|
|
}
|
|
}
|
|
}
|
|
|
|
macro_rules! type_arg_tuple_based_finalize_trace_impls {
|
|
($(($($args:ident),*);)*) => {
|
|
$(
|
|
fn_finalize_trace_group!($($args),*);
|
|
tuple_finalize_trace!($($args),*);
|
|
)*
|
|
}
|
|
}
|
|
|
|
type_arg_tuple_based_finalize_trace_impls![
|
|
();
|
|
(A);
|
|
(A, B);
|
|
(A, B, C);
|
|
(A, B, C, D);
|
|
(A, B, C, D, E);
|
|
(A, B, C, D, E, F);
|
|
(A, B, C, D, E, F, G);
|
|
(A, B, C, D, E, F, G, H);
|
|
(A, B, C, D, E, F, G, H, I);
|
|
(A, B, C, D, E, F, G, H, I, J);
|
|
(A, B, C, D, E, F, G, H, I, J, K);
|
|
(A, B, C, D, E, F, G, H, I, J, K, L);
|
|
];
|
|
|
|
impl<T: Trace + ?Sized> Finalize for Box<T> {}
|
|
// SAFETY: The inner value of the `Box` is correctly marked.
|
|
unsafe impl<T: Trace + ?Sized> Trace for Box<T> {
|
|
custom_trace!(this, {
|
|
mark(&**this);
|
|
});
|
|
}
|
|
|
|
impl<T: Trace> Finalize for Box<[T]> {}
|
|
// SAFETY: All the inner elements of the `Box` array are correctly marked.
|
|
unsafe impl<T: Trace> Trace for Box<[T]> {
|
|
custom_trace!(this, {
|
|
for e in this.iter() {
|
|
mark(e);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Trace> Finalize for Vec<T> {}
|
|
// SAFETY: All the inner elements of the `Vec` are correctly marked.
|
|
unsafe impl<T: Trace> Trace for Vec<T> {
|
|
custom_trace!(this, {
|
|
for e in this {
|
|
mark(e);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Trace> Finalize for Option<T> {}
|
|
// SAFETY: The inner value of the `Option` is correctly marked.
|
|
unsafe impl<T: Trace> Trace for Option<T> {
|
|
custom_trace!(this, {
|
|
if let Some(ref v) = *this {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Trace, E: Trace> Finalize for Result<T, E> {}
|
|
// SAFETY: Both inner values of the `Result` are correctly marked.
|
|
unsafe impl<T: Trace, E: Trace> Trace for Result<T, E> {
|
|
custom_trace!(this, {
|
|
match *this {
|
|
Ok(ref v) => mark(v),
|
|
Err(ref v) => mark(v),
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Ord + Trace> Finalize for BinaryHeap<T> {}
|
|
// SAFETY: All the elements of the `BinaryHeap` are correctly marked.
|
|
unsafe impl<T: Ord + Trace> Trace for BinaryHeap<T> {
|
|
custom_trace!(this, {
|
|
for v in this.iter() {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<K: Trace, V: Trace> Finalize for BTreeMap<K, V> {}
|
|
// SAFETY: All the elements of the `BTreeMap` are correctly marked.
|
|
unsafe impl<K: Trace, V: Trace> Trace for BTreeMap<K, V> {
|
|
custom_trace!(this, {
|
|
for (k, v) in this {
|
|
mark(k);
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Trace> Finalize for BTreeSet<T> {}
|
|
// SAFETY: All the elements of the `BTreeSet` are correctly marked.
|
|
unsafe impl<T: Trace> Trace for BTreeSet<T> {
|
|
custom_trace!(this, {
|
|
for v in this {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<K: Eq + Hash + Trace, V: Trace, S: BuildHasher> Finalize for HashMap<K, V, S> {}
|
|
// SAFETY: All the elements of the `HashMap` are correctly marked.
|
|
unsafe impl<K: Eq + Hash + Trace, V: Trace, S: BuildHasher> Trace for HashMap<K, V, S> {
|
|
custom_trace!(this, {
|
|
for (k, v) in this.iter() {
|
|
mark(k);
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Eq + Hash + Trace, S: BuildHasher> Finalize for HashSet<T, S> {}
|
|
// SAFETY: All the elements of the `HashSet` are correctly marked.
|
|
unsafe impl<T: Eq + Hash + Trace, S: BuildHasher> Trace for HashSet<T, S> {
|
|
custom_trace!(this, {
|
|
for v in this.iter() {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Eq + Hash + Trace> Finalize for LinkedList<T> {}
|
|
// SAFETY: All the elements of the `LinkedList` are correctly marked.
|
|
unsafe impl<T: Eq + Hash + Trace> Trace for LinkedList<T> {
|
|
custom_trace!(this, {
|
|
for v in this.iter() {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T> Finalize for PhantomData<T> {}
|
|
// SAFETY: A `PhantomData` doesn't have inner data that needs to be marked.
|
|
unsafe impl<T> Trace for PhantomData<T> {
|
|
empty_trace!();
|
|
}
|
|
|
|
impl<T: Trace> Finalize for VecDeque<T> {}
|
|
// SAFETY: All the elements of the `VecDeque` are correctly marked.
|
|
unsafe impl<T: Trace> Trace for VecDeque<T> {
|
|
custom_trace!(this, {
|
|
for v in this.iter() {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: ToOwned + Trace + ?Sized> Finalize for Cow<'static, T> {}
|
|
// SAFETY: 'static references don't need to be traced, since they live indefinitely, and the owned
|
|
// variant is correctly marked.
|
|
unsafe impl<T: ToOwned + Trace + ?Sized> Trace for Cow<'static, T>
|
|
where
|
|
T::Owned: Trace,
|
|
{
|
|
custom_trace!(this, {
|
|
if let Cow::Owned(ref v) = this {
|
|
mark(v);
|
|
}
|
|
});
|
|
}
|
|
|
|
impl<T: Trace> Finalize for Cell<Option<T>> {
|
|
fn finalize(&self) {
|
|
if let Some(t) = self.take() {
|
|
t.finalize();
|
|
self.set(Some(t));
|
|
}
|
|
}
|
|
}
|
|
|
|
unsafe impl<T: Trace> Trace for Cell<Option<T>> {
|
|
custom_trace!(this, {
|
|
if let Some(t) = this.take() {
|
|
mark(&t);
|
|
this.set(Some(t));
|
|
}
|
|
});
|
|
}
|