almost runs thru miri..?

This commit is contained in:
Janis 2025-06-21 00:28:18 +02:00
parent 8b3ecb1455
commit 3d32569e2f
3 changed files with 76 additions and 79 deletions

View file

@ -5,6 +5,7 @@
cold_path,
fn_align,
box_vec_non_null,
box_as_ptr,
atomic_try_update,
let_chains
)]

View file

@ -432,8 +432,9 @@ mod job {
// for some reason I confused head and tail here and the list is something like this:
// tail <-> job1 <-> job2 <-> ... <-> head
pub struct JobList {
head: Box<Job>,
tail: Box<Job>,
// these cannot be boxes because boxes are noalias.
head: NonNull<Job>,
tail: NonNull<Job>,
}
impl Debug for JobList {
@ -471,73 +472,70 @@ mod job {
impl JobList {
pub fn new() -> JobList {
let head = Box::new(Job::empty());
let tail = Box::new(Job::empty());
let head = Box::into_raw(Box::new(Job::empty()));
let tail = Box::into_raw(Box::new(Job::empty()));
// head and tail point at themselves
unsafe {
(&mut *head.err_or_link.get()).link.next = None;
(&mut *head.err_or_link.get()).link.prev =
Some(NonNull::new_unchecked((&raw const *tail).cast_mut()));
(&mut *(&mut *head).err_or_link.get()).link.next = None;
(&mut *(&mut *head).err_or_link.get()).link.prev =
Some(NonNull::new_unchecked(tail));
(&mut *tail.err_or_link.get()).link.next =
Some(NonNull::new_unchecked((&raw const *head).cast_mut()));
(&mut *tail.err_or_link.get()).link.prev = None;
(&mut *(&mut *tail).err_or_link.get()).link.prev = None;
(&mut *(&mut *tail).err_or_link.get()).link.next =
Some(NonNull::new_unchecked(head));
Self {
head: NonNull::new_unchecked(head),
tail: NonNull::new_unchecked(tail),
}
}
Self { head, tail }
}
fn head_ptr(&self) -> *const Job {
&raw const *self.head
}
fn tail_ptr(&self) -> *const Job {
&raw const *self.tail
}
fn head(&self) -> NonNull<Job> {
unsafe { NonNull::new_unchecked(self.head_ptr().cast_mut()) }
self.head
}
fn tail(&self) -> NonNull<Job> {
unsafe { NonNull::new_unchecked(self.tail_ptr().cast_mut()) }
self.tail
}
/// elem must be valid until it is popped.
pub unsafe fn push_front<T>(&mut self, elem: &Job<T>) {
let head_link = unsafe { self.head.link_mut() };
pub unsafe fn push_front<T>(&mut self, elem: *const Job<T>) {
let head_link = unsafe { self.head.as_ref().link_mut() };
// SAFETY: head will always have a previous element.
let prev = head_link.prev.unwrap();
let prev_link = unsafe { prev.as_ref().link_mut() };
let elem_ptr = unsafe { NonNull::new_unchecked(&*elem as *const Job<T> as *mut Job) };
let elem_ptr = unsafe { NonNull::new_unchecked(elem as _) };
head_link.prev = Some(elem_ptr);
prev_link.next = Some(elem_ptr);
let elem_link = unsafe { elem.link_mut() };
let elem_link = unsafe { (*elem).link_mut() };
elem_link.prev = Some(prev);
elem_link.next = Some(self.head());
}
/// elem must be valid until it is popped.
pub unsafe fn push_back<T>(&mut self, elem: &Job<T>) {
let tail_link = unsafe { self.tail.link_mut() };
pub unsafe fn push_back<T>(&mut self, elem: *const Job<T>) {
let tail_link = unsafe { self.tail.as_ref().link_mut() };
// SAFETY: tail will always have a previous element.
let next = tail_link.next.unwrap();
let next_link = unsafe { next.as_ref().link_mut() };
let elem_ptr = unsafe { NonNull::new_unchecked(&*elem as *const Job<T> as *mut Job) };
let elem_ptr = unsafe { NonNull::new_unchecked(elem as _) };
tail_link.next = Some(elem_ptr);
next_link.prev = Some(elem_ptr);
let elem_link = unsafe { elem.link_mut() };
let elem_link = unsafe { (*elem).link_mut() };
elem_link.next = Some(next);
elem_link.prev = Some(self.tail());
}
#[allow(dead_code)]
pub fn pop_front(&mut self) -> Option<NonNull<Job>> {
let head_link = unsafe { self.head.link_mut() };
let head_link = unsafe { self.head.as_ref().link_mut() };
// SAFETY: head will always have a previous element.
let elem = head_link.prev.unwrap();
@ -554,7 +552,7 @@ mod job {
pub fn pop_back(&mut self) -> Option<NonNull<Job>> {
// TODO: next and elem might be the same
let tail_link = unsafe { self.tail.link_mut() };
let tail_link = unsafe { self.tail.as_ref().link_mut() };
// SAFETY: head will always have a previous element.
let elem = tail_link.next.unwrap();
@ -570,6 +568,16 @@ mod job {
}
}
impl Drop for JobList {
fn drop(&mut self) {
// Need to drop the head and tail, which were allocated on the heap.
// elements of the list are managed externally.
unsafe {
drop((Box::from_non_null(self.head), Box::from_non_null(self.tail)));
};
}
}
union ValueOrThis<T> {
uninit: (),
value: ManuallyDrop<SmallBox<T>>,
@ -912,7 +920,7 @@ mod job {
}
#[allow(dead_code)]
pub fn into_boxed_job<T>(self: Box<Self>) -> Box<Job<()>>
pub fn into_boxed_job<T>(self: Box<Self>) -> *mut Job<()>
where
F: FnOnce() -> T + Send,
T: Send,
@ -923,10 +931,12 @@ mod job {
F: FnOnce() -> T + Send,
T: Sized + Send,
{
eprintln!("heapjob harness");
let job = job.cast_mut();
// turn `this`, which was allocated at (2), into box.
// miri complains this is a use-after-free, but it isn't? silly miri...
let this = unsafe { Box::from_raw(this.cast::<HeapJob<F>>().cast_mut()) };
let f = this.f;
let f = this.into_inner();
_ = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| f()));
@ -938,9 +948,10 @@ mod job {
}
// (1) allocate box for job
Box::new(Job::new(harness::<F, T>, unsafe {
Box::into_raw(Box::new(Job::new(harness::<F, T>, unsafe {
// (2) convert self into a pointer
NonNull::new_unchecked(Box::into_raw(self)).cast()
}))
})))
}
}
@ -1027,7 +1038,7 @@ use std::{
future::Future,
hint::cold_path,
marker::PhantomData,
mem::{self, MaybeUninit},
mem::MaybeUninit,
ptr::{self, NonNull},
sync::{
atomic::{AtomicBool, AtomicPtr, AtomicUsize, Ordering},
@ -1179,13 +1190,13 @@ impl WorkerThread {
unsafe { (*WORKER.with(UnsafeCell::get)).map(|ptr| ptr.as_ref()) }
}
fn push_front<T>(&self, job: &Job<T>) {
fn push_front<T>(&self, job: *const Job<T>) {
unsafe {
self.queue.as_mut_unchecked().push_front(job);
}
}
#[allow(dead_code)]
fn push_back<T>(&self, job: &Job<T>) {
fn push_back<T>(&self, job: *const Job<T>) {
unsafe {
self.queue.as_mut_unchecked().push_back(job);
}
@ -1534,8 +1545,8 @@ impl<'scope> Scope<'scope> {
tracing::trace!("allocated heapjob");
worker.push_front(&job);
Box::leak(job);
worker.push_front(job);
tracing::trace!("leaked heapjob");
});
}
@ -1564,13 +1575,13 @@ impl<'scope> Scope<'scope> {
Runnable::<()>::from_raw(NonNull::new_unchecked(this.cast_mut()));
runnable.run();
// SAFETY: job was turned into raw
drop(Box::from_raw(job.cast_mut()));
}
let job = Box::new(Job::<T>::new(harness::<T>, runnable.into_raw()));
worker.push_front(job.as_ref());
mem::forget(job);
worker.push_front(Box::into_raw(job));
};
let (runnable, task) = unsafe { async_task::spawn_unchecked(future, schedule) };

View file

@ -1,5 +1,5 @@
use std::{
mem::MaybeUninit,
mem::{self, MaybeUninit},
pin::{pin, Pin},
};
@ -42,14 +42,14 @@ fn job_list_pop_back() {
let c = pin!(Job::empty());
unsafe {
list.push_front(&a);
list.push_front(&b);
list.push_back(&c);
list.push_front(&*a);
list.push_front(&*b);
list.push_back(&*c);
}
assert_eq!(list.pop_back(), Some(pin_ptr(&c)));
unsafe {
list.push_front(&c);
list.push_front(&*c);
}
assert_eq!(list.pop_back(), Some(pin_ptr(&a)));
assert_eq!(list.pop_back(), Some(pin_ptr(&b)));
@ -66,14 +66,14 @@ fn job_list_pop_front() {
let c = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&b);
list.push_back(&c);
list.push_front(&*a);
list.push_front(&*b);
list.push_back(&*c);
}
assert_eq!(list.pop_front(), Some(pin_ptr(&b)));
unsafe {
list.push_back(&b);
list.push_back(&*b);
}
assert_eq!(list.pop_front(), Some(pin_ptr(&a)));
assert_eq!(list.pop_front(), Some(pin_ptr(&c)));
@ -90,9 +90,9 @@ fn unlink_job_middle() {
let c = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&b);
list.push_front(&c);
list.push_front(&*a);
list.push_front(&*b);
list.push_front(&*c);
}
unsafe {
@ -113,9 +113,9 @@ fn unlink_job_front() {
let c = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&b);
list.push_front(&c);
list.push_front(&*a);
list.push_front(&*b);
list.push_front(&*c);
}
unsafe {
@ -136,9 +136,9 @@ fn unlink_job_back() {
let c = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&b);
list.push_front(&c);
list.push_front(&*a);
list.push_front(&*b);
list.push_front(&*c);
}
unsafe {
@ -157,7 +157,7 @@ fn unlink_job_single() {
let a = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&*a);
}
unsafe {
@ -347,7 +347,7 @@ fn job_list_pop_back_emptied() {
let a = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&*a);
}
assert_eq!(list.pop_back(), Some(pin_ptr(&a)));
@ -362,7 +362,7 @@ fn job_list_pop_front_emptied() {
let a = pin!(Job::<()>::empty());
unsafe {
list.push_front(&a);
list.push_front(&*a);
}
assert_eq!(list.pop_front(), Some(pin_ptr(&a)));
@ -372,7 +372,6 @@ fn job_list_pop_front_emptied() {
}
#[test]
#[tracing_test::traced_test]
fn spawn() {
let pool = ThreadPool::new();
@ -390,19 +389,6 @@ fn spawn() {
eprintln!("x: {x}");
}
#[test]
fn rayon_spawn() {
let pool = rayon::ThreadPoolBuilder::new().build().unwrap();
let mut x = 0;
pool.scope(|s| {
s.spawn(|_| {
x += 1;
});
});
eprintln!("x: {x}");
}
#[test]
fn spawn_borrow() {
let pool = ThreadPool::new();
@ -449,13 +435,12 @@ fn join() {
}
#[test]
#[traced_test]
fn join_many() {
use crate::util::tree::Tree;
let pool = ThreadPool::new();
let tree = Tree::new(16, 1u32);
let tree = Tree::new(4, 1u32);
fn sum(tree: &Tree<u32>, node: usize, scope: &Scope) -> u32 {
let node = tree.get(node);