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Respect VcCellMode in TraitRef::cell
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bgw committed Aug 5, 2024
1 parent ef8e4e5 commit 86a1e41
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144 changes: 144 additions & 0 deletions turbopack/crates/turbo-tasks-memory/tests/trait_ref_cell_mode.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,144 @@
#![feature(arbitrary_self_types)]

use anyhow::Result;
use turbo_tasks::{IntoTraitRef, State, TraitRef, Upcast, Vc};
use turbo_tasks_testing::{register, run, Registration};

static REGISTRATION: Registration = register!();

// Test that with `cell = "shared"`, the cell will be re-used as long as the
// value is equal.
#[tokio::test]
async fn test_trait_ref_shared_cell_mode() {
run(&REGISTRATION, async {
let input = CellIdSelector {
value: 42,
cell_idx: State::new(0),
}
.cell();

// create the task and compute it
let counter_value_vc = shared_value_from_input(input);
let trait_ref_a = counter_value_vc.into_trait_ref().await.unwrap();

// invalidate the task, and pick a different cell id for the next execution
input.await.unwrap().cell_idx.set_unconditionally(1);

// recompute the task
let trait_ref_b = counter_value_vc.into_trait_ref().await.unwrap();

for trait_ref in [&trait_ref_a, &trait_ref_b] {
assert_eq!(
*TraitRef::cell(trait_ref.clone()).get_value().await.unwrap(),
42
);
}

// because we're using `cell = "shared"`, these trait refs must use the same
// underlying Arc/SharedRef (by identity)
assert!(TraitRef::ptr_eq(&trait_ref_a, &trait_ref_b));
})
.await
}

// Test that with `cell = "new"`, the cell will is never re-used, even if the
// value is equal.
#[tokio::test]
async fn test_trait_ref_new_cell_mode() {
run(&REGISTRATION, async {
let input = CellIdSelector {
value: 42,
cell_idx: State::new(0),
}
.cell();

// create the task and compute it
let counter_value_vc = new_value_from_input(input);
let trait_ref_a = counter_value_vc.into_trait_ref().await.unwrap();

// invalidate the task, and pick a different cell id for the next execution
input.await.unwrap().cell_idx.set_unconditionally(1);

// recompute the task
let trait_ref_b = counter_value_vc.into_trait_ref().await.unwrap();

for trait_ref in [&trait_ref_a, &trait_ref_b] {
assert_eq!(
*TraitRef::cell(trait_ref.clone()).get_value().await.unwrap(),
42
);
}

// because we're using `cell = "new"`, these trait refs must use different
// underlying Arc/SharedRefs (by identity)
assert!(!TraitRef::ptr_eq(&trait_ref_a, &trait_ref_b));
})
.await
}

#[turbo_tasks::value_trait]
trait ValueTrait {
fn get_value(&self) -> Vc<usize>;
}

#[turbo_tasks::value(transparent, cell = "shared")]
struct SharedValue(usize);

#[turbo_tasks::value(transparent, cell = "new")]
struct NewValue(usize);

#[turbo_tasks::value_impl]
impl ValueTrait for SharedValue {
#[turbo_tasks::function]
fn get_value(&self) -> Vc<usize> {
Vc::cell(self.0)
}
}

#[turbo_tasks::value_impl]
impl ValueTrait for NewValue {
#[turbo_tasks::function]
fn get_value(&self) -> Vc<usize> {
Vc::cell(self.0)
}
}

#[turbo_tasks::value]
struct CellIdSelector {
value: usize,
cell_idx: State<usize>,
}

async fn value_from_input<T>(
input: Vc<CellIdSelector>,
mut cell_fn: impl FnMut(usize) -> Vc<T>,
) -> Result<Vc<Box<dyn ValueTrait>>>
where
T: ValueTrait + Upcast<Box<dyn ValueTrait>>,
{
let input = input.await?;

// create multiple cells so that we can pick from them, simulating a function
// with non-deterministic ordering that returns a "random" cell that happens to
// contain the same value
let mut upcast_vcs = Vec::new();
for _idx in 0..2 {
upcast_vcs.push(Vc::upcast((cell_fn)(input.value)));
}

// pick a different cell idx upon each invalidation/execution
let picked_vc = upcast_vcs[*input.cell_idx.get()];

// round-trip through `TraitRef::cell`
Ok(TraitRef::cell(picked_vc.into_trait_ref().await?))
}

#[turbo_tasks::function]
async fn shared_value_from_input(input: Vc<CellIdSelector>) -> Result<Vc<Box<dyn ValueTrait>>> {
value_from_input::<SharedValue>(input, Vc::<SharedValue>::cell).await
}

#[turbo_tasks::function]
async fn new_value_from_input(input: Vc<CellIdSelector>) -> Result<Vc<Box<dyn ValueTrait>>> {
value_from_input::<NewValue>(input, Vc::<NewValue>::cell).await
}
19 changes: 11 additions & 8 deletions turbopack/crates/turbo-tasks/src/trait_ref.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4,10 +4,10 @@ use anyhow::Result;
use serde::{Deserialize, Serialize};

use crate::{
manager::find_cell_by_type,
registry::get_value_type,
task::shared_reference::TypedSharedReference,
vc::{cast::VcCast, ReadVcFuture, VcValueTraitCast},
RawVc, Vc, VcValueTrait,
Vc, VcValueTrait,
};

/// Similar to a [`ReadRef<T>`][crate::ReadRef], but contains a value trait
Expand Down Expand Up @@ -90,6 +90,10 @@ where
_t: PhantomData,
}
}

pub fn ptr_eq(this: &Self, other: &Self) -> bool {
triomphe::Arc::ptr_eq(&this.shared_reference.1 .0, &other.shared_reference.1 .0)
}
}

impl<T> TraitRef<T>
Expand All @@ -99,12 +103,11 @@ where
/// Returns a new cell that points to a value that implements the value
/// trait `T`.
pub fn cell(trait_ref: TraitRef<T>) -> Vc<T> {
// See Safety clause above.
let TypedSharedReference(ty, shared_ref) = trait_ref.shared_reference;
let local_cell = find_cell_by_type(ty);
local_cell.update_with_shared_reference(shared_ref);
let raw_vc: RawVc = local_cell.into();
raw_vc.into()
let TraitRef {
shared_reference, ..
} = trait_ref;
let value_type = get_value_type(shared_reference.0);
(value_type.raw_cell)(shared_reference).into()
}
}

Expand Down

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