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move local-state into DatabaseImpl

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Each clone gets an independent local state.
This commit is contained in:
Niko Matsakis 2024-07-28 01:48:20 +00:00
parent 8e9ebbafd3
commit a675810edf
20 changed files with 456 additions and 469 deletions
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32
components/salsa-macro-rules/src/setup_tracked_fn.rs
View file

@ -265,24 +265,26 @@ macro_rules! setup_tracked_fn {
} }
}
let result = $zalsa::macro_if! {
if $needs_interner {
{
let key = $Configuration::intern_ingredient($db).intern_id($db.as_dyn_database(), ($($input_id),*));
$Configuration::fn_ingredient($db).fetch($db, key)
$zalsa::attach($db, || {
let result = $zalsa::macro_if! {
if $needs_interner {
{
let key = $Configuration::intern_ingredient($db).intern_id($db.as_dyn_database(), ($($input_id),*));
$Configuration::fn_ingredient($db).fetch($db, key)
}
} else {
$Configuration::fn_ingredient($db).fetch($db, $zalsa::AsId::as_id(&($($input_id),*)))
}
} else {
$Configuration::fn_ingredient($db).fetch($db, $zalsa::AsId::as_id(&($($input_id),*)))
}
};
};
$zalsa::macro_if! {
if $return_ref {
result
} else {
<$output_ty as std::clone::Clone>::clone(result)
$zalsa::macro_if! {
if $return_ref {
result
} else {
<$output_ty as std::clone::Clone>::clone(result)
}
}
}
})
}
};
}

48
src/accumulator.rs
View file

@ -10,7 +10,7 @@ use crate::{
hash::FxDashMap,
ingredient::{fmt_index, Ingredient, Jar},
key::DependencyIndex,
local_state::{self, LocalState, QueryOrigin},
local_state::{LocalState, QueryOrigin},
storage::IngredientIndex,
Database, DatabaseKeyIndex, Event, EventKind, Id, Revision,
};
@ -80,32 +80,30 @@ impl<A: Accumulator> IngredientImpl<A> {
}
pub fn push(&self, db: &dyn crate::Database, value: A) {
local_state::attach(db, |state| {
let current_revision = db.zalsa().current_revision();
let (active_query, _) = match state.active_query() {
Some(pair) => pair,
None => {
panic!("cannot accumulate values outside of an active query")
}
};
let mut accumulated_values =
self.map.entry(active_query).or_insert(AccumulatedValues {
values: vec![],
produced_at: current_revision,
});
// When we call `push' in a query, we will add the accumulator to the output of the query.
// If we find here that this accumulator is not the output of the query,
// we can say that the accumulated values we stored for this query is out of date.
if !state.is_output_of_active_query(self.dependency_index()) {
accumulated_values.values.truncate(0);
accumulated_values.produced_at = current_revision;
let state = db.zalsa_local();
let current_revision = db.zalsa().current_revision();
let (active_query, _) = match state.active_query() {
Some(pair) => pair,
None => {
panic!("cannot accumulate values outside of an active query")
}
};
state.add_output(self.dependency_index());
accumulated_values.values.push(value);
})
let mut accumulated_values = self.map.entry(active_query).or_insert(AccumulatedValues {
values: vec![],
produced_at: current_revision,
});
// When we call `push' in a query, we will add the accumulator to the output of the query.
// If we find here that this accumulator is not the output of the query,
// we can say that the accumulated values we stored for this query is out of date.
if !state.is_output_of_active_query(self.dependency_index()) {
accumulated_values.values.truncate(0);
accumulated_values.produced_at = current_revision;
}
state.add_output(self.dependency_index());
accumulated_values.values.push(value);
}
pub(crate) fn produced_by(

100
src/attach.rs Normal file
View file

@ -0,0 +1,100 @@
use std::{cell::Cell, ptr::NonNull};
use crate::Database;
thread_local! {
/// The thread-local state salsa requires for a given thread
static ATTACHED: Attached = const { Attached::new() }
}
/// State that is specific to a single execution thread.
///
/// Internally, this type uses ref-cells.
///
/// **Note also that all mutations to the database handle (and hence
/// to the local-state) must be undone during unwinding.**
struct Attached {
/// Pointer to the currently attached database.
database: Cell<Option<NonNull<dyn Database>>>,
}
impl Attached {
const fn new() -> Self {
Self {
database: Cell::new(None),
}
}
fn attach<Db, R>(&self, db: &Db, op: impl FnOnce() -> R) -> R
where
Db: ?Sized + Database,
{
struct DbGuard<'s> {
state: Option<&'s Attached>,
}
impl<'s> DbGuard<'s> {
fn new(attached: &'s Attached, db: &dyn Database) -> Self {
if let Some(current_db) = attached.database.get() {
let new_db = NonNull::from(db);
// Already attached? Assert that the database has not changed.
// NOTE: It's important to use `addr_eq` here because `NonNull::eq`
// not only compares the address but also the type's metadata.
if !std::ptr::addr_eq(current_db.as_ptr(), new_db.as_ptr()) {
panic!(
"Cannot change database mid-query. current: {current_db:?}, new: {new_db:?}",
);
}
Self { state: None }
} else {
// Otherwise, set the database.
attached.database.set(Some(NonNull::from(db)));
Self {
state: Some(attached),
}
}
}
}
impl Drop for DbGuard<'_> {
fn drop(&mut self) {
// Reset database to null if we did anything in `DbGuard::new`.
if let Some(attached) = self.state {
attached.database.set(None);
}
}
}
let _guard = DbGuard::new(self, db.as_dyn_database());
op()
}
/// Access the "attached" database. Returns `None` if no database is attached.
/// Databases are attached with `attach_database`.
fn with<R>(&self, op: impl FnOnce(&dyn Database) -> R) -> Option<R> {
if let Some(db) = self.database.get() {
// SAFETY: We always attach the database in for the entire duration of a function,
// so it cannot become "unattached" while this function is running.
Some(op(unsafe { db.as_ref() }))
} else {
None
}
}
}
/// Attach the database to the current thread and execute `op`.
/// Panics if a different database has already been attached.
pub fn attach<R, Db>(db: &Db, op: impl FnOnce() -> R) -> R
where
Db: ?Sized + Database,
{
ATTACHED.with(|a| a.attach(db, op))
}
/// Access the "attached" database. Returns `None` if no database is attached.
/// Databases are attached with `attach_database`.
pub fn with_attached_database<R>(op: impl FnOnce(&dyn Database) -> R) -> Option<R> {
ATTACHED.with(|a| a.with(op))
}

4
src/cycle.rs
View file

@ -1,4 +1,4 @@
use crate::{key::DatabaseKeyIndex, local_state, Database};
use crate::{key::DatabaseKeyIndex, Database};
use std::{panic::AssertUnwindSafe, sync::Arc};
/// Captures the participants of a cycle that occurred when executing a query.
@ -74,7 +74,7 @@ impl Cycle {
impl std::fmt::Debug for Cycle {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
local_state::with_attached_database(|db| {
crate::attach::with_attached_database(|db| {
f.debug_struct("UnexpectedCycle")
.field("all_participants", &self.all_participants(db))
.field("unexpected_participants", &self.unexpected_participants(db))

27
src/database.rs
View file

@ -3,7 +3,8 @@ use std::{any::Any, panic::RefUnwindSafe, sync::Arc};
use parking_lot::{Condvar, Mutex};
use crate::{
self as salsa, local_state,
self as salsa,
local_state::{self, LocalState},
storage::{Zalsa, ZalsaImpl},
Durability, Event, EventKind, Revision,
};
@ -16,7 +17,7 @@ use crate::{
/// This trait can only safely be implemented by Salsa's [`DatabaseImpl`][] type.
/// FIXME: Document better the unsafety conditions we guarantee.
#[salsa_macros::db]
pub unsafe trait Database: AsDynDatabase + Any {
pub unsafe trait Database: Send + AsDynDatabase + Any {
/// This function is invoked by the salsa runtime at various points during execution.
/// You can customize what happens by implementing the [`UserData`][] trait.
/// By default, the event is logged at level debug using tracing facade.
@ -45,9 +46,8 @@ pub unsafe trait Database: AsDynDatabase + Any {
/// revision.
fn report_untracked_read(&self) {
let db = self.as_dyn_database();
local_state::attach(db, |state| {
state.report_untracked_read(db.zalsa().current_revision())
})
let zalsa_local = db.zalsa_local();
zalsa_local.report_untracked_read(db.zalsa().current_revision())
}
/// Execute `op` with the database in thread-local storage for debug print-outs.
@ -55,7 +55,7 @@ pub unsafe trait Database: AsDynDatabase + Any {
where
Self: Sized,
{
local_state::attach(self, |_state| op(self))
crate::attach::attach(self, || op(self))
}
/// Plumbing method: Access the internal salsa methods.
@ -68,6 +68,10 @@ pub unsafe trait Database: AsDynDatabase + Any {
/// This can lead to deadlock!
#[doc(hidden)]
fn zalsa_mut(&mut self) -> &mut dyn Zalsa;
/// Access the thread-local state associated with this database
#[doc(hidden)]
fn zalsa_local(&self) -> &LocalState;
}
/// Upcast to a `dyn Database`.
@ -113,6 +117,9 @@ pub struct DatabaseImpl<U: UserData = ()> {
/// Coordination data for cancellation of other handles when `zalsa_mut` is called.
/// This could be stored in ZalsaImpl but it makes things marginally cleaner to keep it separate.
coordinate: Arc<Coordinate>,
/// Per-thread state
zalsa_local: local_state::LocalState,
}
impl<U: UserData + Default> Default for DatabaseImpl<U> {
@ -141,6 +148,7 @@ impl<U: UserData> DatabaseImpl<U> {
clones: Mutex::new(1),
cvar: Default::default(),
}),
zalsa_local: LocalState::new(),
}
}
@ -201,6 +209,10 @@ unsafe impl<U: UserData> Database for DatabaseImpl<U> {
zalsa_mut
}
fn zalsa_local(&self) -> &LocalState {
&self.zalsa_local
}
// Report a salsa event.
fn salsa_event(&self, event: &dyn Fn() -> Event) {
U::salsa_event(self, event)
@ -214,6 +226,7 @@ impl<U: UserData> Clone for DatabaseImpl<U> {
Self {
zalsa_impl: self.zalsa_impl.clone(),
coordinate: Arc::clone(&self.coordinate),
zalsa_local: LocalState::new(),
}
}
}
@ -229,7 +242,7 @@ impl<U: UserData> Drop for DatabaseImpl<U> {
}
}
pub trait UserData: Any + Sized {
pub trait UserData: Any + Sized + Send + Sync {
/// Callback invoked by the [`Database`][] at key points during salsa execution.
/// By overriding this method, you can inject logging or other custom behavior.
///

63
src/function/accumulated.rs
View file

@ -1,4 +1,4 @@
use crate::{accumulator, hash::FxHashSet, local_state, Database, DatabaseKeyIndex, Id};
use crate::{accumulator, hash::FxHashSet, Database, DatabaseKeyIndex, Id};
use super::{Configuration, IngredientImpl};
@ -12,44 +12,41 @@ where
where
A: accumulator::Accumulator,
{
local_state::attach(db, |local_state| {
let zalsa = db.zalsa();
let current_revision = zalsa.current_revision();
let zalsa = db.zalsa();
let zalsa_local = db.zalsa_local();
let current_revision = zalsa.current_revision();
let Some(accumulator) = <accumulator::IngredientImpl<A>>::from_db(db) else {
return vec![];
};
let mut output = vec![];
let Some(accumulator) = <accumulator::IngredientImpl<A>>::from_db(db) else {
return vec![];
};
let mut output = vec![];
// First ensure the result is up to date
self.fetch(db, key);
// First ensure the result is up to date
self.fetch(db, key);
let db_key = self.database_key_index(key);
let mut visited: FxHashSet<DatabaseKeyIndex> = FxHashSet::default();
let mut stack: Vec<DatabaseKeyIndex> = vec![db_key];
let db_key = self.database_key_index(key);
let mut visited: FxHashSet<DatabaseKeyIndex> = FxHashSet::default();
let mut stack: Vec<DatabaseKeyIndex> = vec![db_key];
while let Some(k) = stack.pop() {
if visited.insert(k) {
accumulator.produced_by(current_revision, local_state, k, &mut output);
while let Some(k) = stack.pop() {
if visited.insert(k) {
accumulator.produced_by(current_revision, zalsa_local, k, &mut output);
let origin = zalsa
.lookup_ingredient(k.ingredient_index)
.origin(k.key_index);
let inputs = origin.iter().flat_map(|origin| origin.inputs());
// Careful: we want to push in execution order, so reverse order to
// ensure the first child that was executed will be the first child popped
// from the stack.
stack.extend(
inputs
.flat_map(|input| {
TryInto::<DatabaseKeyIndex>::try_into(input).into_iter()
})
.rev(),
);
}
let origin = zalsa
.lookup_ingredient(k.ingredient_index)
.origin(k.key_index);
let inputs = origin.iter().flat_map(|origin| origin.inputs());
// Careful: we want to push in execution order, so reverse order to
// ensure the first child that was executed will be the first child popped
// from the stack.
stack.extend(
inputs
.flat_map(|input| TryInto::<DatabaseKeyIndex>::try_into(input).into_iter())
.rev(),
);
}
}
output
})
output
}
}

37
src/function/fetch.rs
View file

@ -1,9 +1,7 @@
use arc_swap::Guard;
use crate::{
local_state::{self, LocalState},
runtime::StampedValue,
AsDynDatabase as _, Database as _, Id,
local_state::LocalState, runtime::StampedValue, AsDynDatabase as _, Database as _, Id,
};
use super::{Configuration, IngredientImpl};
@ -13,27 +11,26 @@ where
C: Configuration,
{
pub fn fetch<'db>(&'db self, db: &'db C::DbView, key: Id) -> &C::Output<'db> {
local_state::attach(db.as_dyn_database(), |local_state| {
local_state.unwind_if_revision_cancelled(db.as_dyn_database());
let zalsa_local = db.zalsa_local();
zalsa_local.unwind_if_revision_cancelled(db.as_dyn_database());
let StampedValue {
value,
durability,
changed_at,
} = self.compute_value(db, local_state, key);
let StampedValue {
value,
durability,
changed_at,
} = self.compute_value(db, zalsa_local, key);
if let Some(evicted) = self.lru.record_use(key) {
self.evict(evicted);
}
if let Some(evicted) = self.lru.record_use(key) {
self.evict(evicted);
}
local_state.report_tracked_read(
self.database_key_index(key).into(),
durability,
changed_at,
);
zalsa_local.report_tracked_read(
self.database_key_index(key).into(),
durability,
changed_at,
);
value
})
value
}
#[inline]

48
src/function/maybe_changed_after.rs
View file

@ -2,7 +2,7 @@ use arc_swap::Guard;
use crate::{
key::DatabaseKeyIndex,
local_state::{self, ActiveQueryGuard, EdgeKind, LocalState, QueryOrigin},
local_state::{ActiveQueryGuard, EdgeKind, LocalState, QueryOrigin},
runtime::StampedValue,
storage::Zalsa,
AsDynDatabase as _, Database, Id, Revision,
@ -20,36 +20,32 @@ where
key: Id,
revision: Revision,
) -> bool {
local_state::attach(db.as_dyn_database(), |local_state| {
let zalsa = db.zalsa();
local_state.unwind_if_revision_cancelled(db.as_dyn_database());
let zalsa_local = db.zalsa_local();
let zalsa = db.zalsa();
zalsa_local.unwind_if_revision_cancelled(db.as_dyn_database());
loop {
let database_key_index = self.database_key_index(key);
loop {
let database_key_index = self.database_key_index(key);
tracing::debug!(
"{database_key_index:?}: maybe_changed_after(revision = {revision:?})"
);
tracing::debug!("{database_key_index:?}: maybe_changed_after(revision = {revision:?})");
// Check if we have a verified version: this is the hot path.
let memo_guard = self.memo_map.get(key);
if let Some(memo) = &memo_guard {
if self.shallow_verify_memo(db, zalsa, database_key_index, memo) {
return memo.revisions.changed_at > revision;
}
drop(memo_guard); // release the arc-swap guard before cold path
if let Some(mcs) = self.maybe_changed_after_cold(db, local_state, key, revision)
{
return mcs;
} else {
// We failed to claim, have to retry.
}
} else {
// No memo? Assume has changed.
return true;
// Check if we have a verified version: this is the hot path.
let memo_guard = self.memo_map.get(key);
if let Some(memo) = &memo_guard {
if self.shallow_verify_memo(db, zalsa, database_key_index, memo) {
return memo.revisions.changed_at > revision;
}
drop(memo_guard); // release the arc-swap guard before cold path
if let Some(mcs) = self.maybe_changed_after_cold(db, zalsa_local, key, revision) {
return mcs;
} else {
// We failed to claim, have to retry.
}
} else {
// No memo? Assume has changed.
return true;
}
})
}
}
fn maybe_changed_after_cold<'db>(

126
src/function/specify.rs
View file

@ -1,7 +1,7 @@
use crossbeam::atomic::AtomicCell;
use crate::{
local_state::{self, QueryOrigin, QueryRevisions},
local_state::{QueryOrigin, QueryRevisions},
tracked_struct::TrackedStructInDb,
AsDynDatabase as _, Database, DatabaseKeyIndex, Id,
};
@ -18,76 +18,74 @@ where
where
C::Input<'db>: TrackedStructInDb,
{
local_state::attach(db.as_dyn_database(), |state| {
let (active_query_key, current_deps) = match state.active_query() {
Some(v) => v,
None => panic!("can only use `specify` inside a tracked function"),
};
let zalsa_local = db.zalsa_local();
// `specify` only works if the key is a tracked struct created in the current query.
//
// The reason is this. We want to ensure that the same result is reached regardless of
// the "path" that the user takes through the execution graph.
// If you permit values to be specified from other queries, you can have a situation like this:
// * Q0 creates the tracked struct T0
// * Q1 specifies the value for F(T0)
// * Q2 invokes F(T0)
// * Q3 invokes Q1 and then Q2
// * Q4 invokes Q2 and then Q1
//
// Now, if We invoke Q3 first, We get one result for Q2, but if We invoke Q4 first, We get a different value. That's no good.
let database_key_index = <C::Input<'db>>::database_key_index(db.as_dyn_database(), key);
let dependency_index = database_key_index.into();
if !state.is_output_of_active_query(dependency_index) {
panic!(
"can only use `specify` on salsa structs created during the current tracked fn"
);
}
let (active_query_key, current_deps) = match zalsa_local.active_query() {
Some(v) => v,
None => panic!("can only use `specify` inside a tracked function"),
};
// Subtle: we treat the "input" to a set query as if it were
// volatile.
//
// The idea is this. You have the current query C that
// created the entity E, and it is setting the value F(E) of the function F.
// When some other query R reads the field F(E), in order to have obtained
// the entity E, it has to have executed the query C.
//
// This will have forced C to either:
//
// - not create E this time, in which case R shouldn't have it (some kind of leak has occurred)
// - assign a value to F(E), in which case `verified_at` will be the current revision and `changed_at` will be updated appropriately
// - NOT assign a value to F(E), in which case we need to re-execute the function (which typically panics).
//
// So, ruling out the case of a leak having occurred, that means that the reader R will either see:
//
// - a result that is verified in the current revision, because it was set, which will use the set value
// - a result that is NOT verified and has untracked inputs, which will re-execute (and likely panic)
// `specify` only works if the key is a tracked struct created in the current query.
//
// The reason is this. We want to ensure that the same result is reached regardless of
// the "path" that the user takes through the execution graph.
// If you permit values to be specified from other queries, you can have a situation like this:
// * Q0 creates the tracked struct T0
// * Q1 specifies the value for F(T0)
// * Q2 invokes F(T0)
// * Q3 invokes Q1 and then Q2
// * Q4 invokes Q2 and then Q1
//
// Now, if We invoke Q3 first, We get one result for Q2, but if We invoke Q4 first, We get a different value. That's no good.
let database_key_index = <C::Input<'db>>::database_key_index(db.as_dyn_database(), key);
let dependency_index = database_key_index.into();
if !zalsa_local.is_output_of_active_query(dependency_index) {
panic!("can only use `specify` on salsa structs created during the current tracked fn");
}
let revision = db.zalsa().current_revision();
let mut revisions = QueryRevisions {
changed_at: current_deps.changed_at,
durability: current_deps.durability,
origin: QueryOrigin::Assigned(active_query_key),
};
// Subtle: we treat the "input" to a set query as if it were
// volatile.
//
// The idea is this. You have the current query C that
// created the entity E, and it is setting the value F(E) of the function F.
// When some other query R reads the field F(E), in order to have obtained
// the entity E, it has to have executed the query C.
//
// This will have forced C to either:
//
// - not create E this time, in which case R shouldn't have it (some kind of leak has occurred)
// - assign a value to F(E), in which case `verified_at` will be the current revision and `changed_at` will be updated appropriately
// - NOT assign a value to F(E), in which case we need to re-execute the function (which typically panics).
//
// So, ruling out the case of a leak having occurred, that means that the reader R will either see:
//
// - a result that is verified in the current revision, because it was set, which will use the set value
// - a result that is NOT verified and has untracked inputs, which will re-execute (and likely panic)
if let Some(old_memo) = self.memo_map.get(key) {
self.backdate_if_appropriate(&old_memo, &mut revisions, &value);
self.diff_outputs(db, database_key_index, &old_memo, &revisions);
}
let revision = db.zalsa().current_revision();
let mut revisions = QueryRevisions {
changed_at: current_deps.changed_at,
durability: current_deps.durability,
origin: QueryOrigin::Assigned(active_query_key),
};
let memo = Memo {
value: Some(value),
verified_at: AtomicCell::new(revision),
revisions,
};
if let Some(old_memo) = self.memo_map.get(key) {
self.backdate_if_appropriate(&old_memo, &mut revisions, &value);
self.diff_outputs(db, database_key_index, &old_memo, &revisions);
}
tracing::debug!("specify: about to add memo {:#?} for key {:?}", memo, key);
self.insert_memo(db, key, memo);
let memo = Memo {
value: Some(value),
verified_at: AtomicCell::new(revision),
revisions,
};
// Record that the current query *specified* a value for this cell.
let database_key_index = self.database_key_index(key);
state.add_output(database_key_index.into());
})
tracing::debug!("specify: about to add memo {:#?} for key {:?}", memo, key);
self.insert_memo(db, key, memo);
// Record that the current query *specified* a value for this cell.
let database_key_index = self.database_key_index(key);
zalsa_local.add_output(database_key_index.into());
}
/// Invoked when the query `executor` has been validated as having green inputs

31
src/input.rs
View file

@ -17,7 +17,7 @@ use crate::{
id::{AsId, FromId},
ingredient::{fmt_index, Ingredient},
key::{DatabaseKeyIndex, DependencyIndex},
local_state::{self, QueryOrigin},
local_state::QueryOrigin,
plumbing::{Jar, Stamp},
storage::IngredientIndex,
Database, Durability, Id, Revision,
@ -152,21 +152,20 @@ impl<C: Configuration> IngredientImpl<C> {
id: C::Struct,
field_index: usize,
) -> &'db C::Fields {
local_state::attach(db, |state| {
let field_ingredient_index = self.ingredient_index.successor(field_index);
let id = id.as_id();
let value = self.struct_map.get(id);
let stamp = &value.stamps[field_index];
state.report_tracked_read(
DependencyIndex {
ingredient_index: field_ingredient_index,
key_index: Some(id),
},
stamp.durability,
stamp.changed_at,
);
&value.fields
})
let zalsa_local = db.zalsa_local();
let field_ingredient_index = self.ingredient_index.successor(field_index);
let id = id.as_id();
let value = self.struct_map.get(id);
let stamp = &value.stamps[field_index];
zalsa_local.report_tracked_read(
DependencyIndex {
ingredient_index: field_ingredient_index,
key_index: Some(id),
},
stamp.durability,
stamp.changed_at,
);
&value.fields
}
/// Peek at the field values without recording any read dependency.

73
src/interned.rs
View file

@ -9,7 +9,7 @@ use crate::durability::Durability;
use crate::id::AsId;
use crate::ingredient::fmt_index;
use crate::key::DependencyIndex;
use crate::local_state::{self, QueryOrigin};
use crate::local_state::QueryOrigin;
use crate::plumbing::Jar;
use crate::storage::IngredientIndex;
use crate::{Database, DatabaseKeyIndex, Id};
@ -136,46 +136,45 @@ where
db: &'db dyn crate::Database,
data: C::Data<'db>,
) -> C::Struct<'db> {
local_state::attach(db, |state| {
state.report_tracked_read(
DependencyIndex::for_table(self.ingredient_index),
Durability::MAX,
self.reset_at,
);
let zalsa_local = db.zalsa_local();
zalsa_local.report_tracked_read(
DependencyIndex::for_table(self.ingredient_index),
Durability::MAX,
self.reset_at,
);
// Optimisation to only get read lock on the map if the data has already
// been interned.
let internal_data = unsafe { self.to_internal_data(data) };
if let Some(guard) = self.key_map.get(&internal_data) {
let id = *guard;
drop(guard);
return self.interned_value(id);
// Optimisation to only get read lock on the map if the data has already
// been interned.
let internal_data = unsafe { self.to_internal_data(data) };
if let Some(guard) = self.key_map.get(&internal_data) {
let id = *guard;
drop(guard);
return self.interned_value(id);
}
match self.key_map.entry(internal_data.clone()) {
// Data has been interned by a racing call, use that ID instead
dashmap::mapref::entry::Entry::Occupied(entry) => {
let id = *entry.get();
drop(entry);
self.interned_value(id)
}
match self.key_map.entry(internal_data.clone()) {
// Data has been interned by a racing call, use that ID instead
dashmap::mapref::entry::Entry::Occupied(entry) => {
let id = *entry.get();
drop(entry);
self.interned_value(id)
}
// We won any races so should intern the data
dashmap::mapref::entry::Entry::Vacant(entry) => {
let next_id = self.counter.fetch_add(1);
let next_id = crate::id::Id::from_u32(next_id);
let value = self.value_map.entry(next_id).or_insert(Alloc::new(Value {
id: next_id,
fields: internal_data,
}));
let value_raw = value.as_raw();
drop(value);
entry.insert(next_id);
// SAFETY: Items are only removed from the `value_map` with an `&mut self` reference.
unsafe { C::struct_from_raw(value_raw) }
}
// We won any races so should intern the data
dashmap::mapref::entry::Entry::Vacant(entry) => {
let next_id = self.counter.fetch_add(1);
let next_id = crate::id::Id::from_u32(next_id);
let value = self.value_map.entry(next_id).or_insert(Alloc::new(Value {
id: next_id,
fields: internal_data,
}));
let value_raw = value.as_raw();
drop(value);
entry.insert(next_id);
// SAFETY: Items are only removed from the `value_map` with an `&mut self` reference.
unsafe { C::struct_from_raw(value_raw) }
}
})
}
}
pub fn interned_value(&self, id: Id) -> C::Struct<'_> {

4
src/key.rs
View file

@ -1,4 +1,4 @@
use crate::{cycle::CycleRecoveryStrategy, local_state, storage::IngredientIndex, Database, Id};
use crate::{cycle::CycleRecoveryStrategy, storage::IngredientIndex, Database, Id};
/// An integer that uniquely identifies a particular query instance within the
/// database. Used to track dependencies between queries. Fully ordered and
@ -60,7 +60,7 @@ impl DependencyIndex {
impl std::fmt::Debug for DependencyIndex {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
local_state::with_attached_database(|db| {
crate::attach::with_attached_database(|db| {
let ingredient = db.zalsa().lookup_ingredient(self.ingredient_index);
ingredient.fmt_index(self.key_index, f)
})

6
src/lib.rs
View file

@ -2,6 +2,7 @@ mod accumulator;
mod active_query;
mod alloc;
mod array;
mod attach;
mod cancelled;
mod cycle;
mod database;
@ -41,7 +42,7 @@ pub use self::key::DatabaseKeyIndex;
pub use self::revision::Revision;
pub use self::runtime::Runtime;
pub use self::update::Update;
pub use crate::local_state::with_attached_database;
pub use crate::attach::with_attached_database;
pub use salsa_macros::accumulator;
pub use salsa_macros::db;
pub use salsa_macros::input;
@ -63,6 +64,8 @@ pub mod prelude {
pub mod plumbing {
pub use crate::accumulator::Accumulator;
pub use crate::array::Array;
pub use crate::attach::attach;
pub use crate::attach::with_attached_database;
pub use crate::cycle::Cycle;
pub use crate::cycle::CycleRecoveryStrategy;
pub use crate::database::current_revision;
@ -76,7 +79,6 @@ pub mod plumbing {
pub use crate::ingredient::Ingredient;
pub use crate::ingredient::Jar;
pub use crate::key::DatabaseKeyIndex;
pub use crate::local_state::with_attached_database;
pub use crate::revision::Revision;
pub use crate::runtime::stamp;
pub use crate::runtime::Runtime;

81
src/local_state.rs
View file

@ -13,49 +13,16 @@ use crate::Database;
use crate::Event;
use crate::EventKind;
use crate::Revision;
use std::cell::Cell;
use std::cell::RefCell;
use std::ptr::NonNull;
use std::sync::Arc;
thread_local! {
/// The thread-local state salsa requires for a given thread
static LOCAL_STATE: LocalState = const { LocalState::new() }
}
/// Attach the database to the current thread and execute `op`.
/// Panics if a different database has already been attached.
pub(crate) fn attach<R, DB>(db: &DB, op: impl FnOnce(&LocalState) -> R) -> R
where
DB: ?Sized + Database,
{
LOCAL_STATE.with(|state| state.attach(db.as_dyn_database(), || op(state)))
}
/// Access the "attached" database. Returns `None` if no database is attached.
/// Databases are attached with `attach_database`.
pub fn with_attached_database<R>(op: impl FnOnce(&dyn Database) -> R) -> Option<R> {
LOCAL_STATE.with(|state| {
if let Some(db) = state.database.get() {
// SAFETY: We always attach the database in for the entire duration of a function,
// so it cannot become "unattached" while this function is running.
Some(op(unsafe { db.as_ref() }))
} else {
None
}
})
}
/// State that is specific to a single execution thread.
///
/// Internally, this type uses ref-cells.
///
/// **Note also that all mutations to the database handle (and hence
/// to the local-state) must be undone during unwinding.**
pub(crate) struct LocalState {
/// Pointer to the currently attached database.
database: Cell<Option<NonNull<dyn Database>>>,
pub struct LocalState {
/// Vector of active queries.
///
/// This is normally `Some`, but it is set to `None`
@ -67,56 +34,12 @@ pub(crate) struct LocalState {
}
impl LocalState {
const fn new() -> Self {
pub(crate) fn new() -> Self {
LocalState {
database: Cell::new(None),
query_stack: RefCell::new(Some(vec![])),
}
}
fn attach<R>(&self, db: &dyn Database, op: impl FnOnce() -> R) -> R {
struct DbGuard<'s> {
state: Option<&'s LocalState>,
}
impl<'s> DbGuard<'s> {
fn new(state: &'s LocalState, db: &dyn Database) -> Self {
if let Some(current_db) = state.database.get() {
let new_db = NonNull::from(db);
// Already attached? Assert that the database has not changed.
// NOTE: It's important to use `addr_eq` here because `NonNull::eq` not only compares the address but also the type's metadata.
if !std::ptr::addr_eq(current_db.as_ptr(), new_db.as_ptr()) {
panic!(
"Cannot change database mid-query. current: {current_db:?}, new: {new_db:?}",
);
}
Self { state: None }
} else {
// Otherwise, set the database.
state.database.set(Some(NonNull::from(db)));
Self { state: Some(state) }
}
}
}
impl Drop for DbGuard<'_> {
fn drop(&mut self) {
// Reset database to null if we did anything in `DbGuard::new`.
if let Some(state) = self.state {
state.database.set(None);
// All stack frames should have been popped from the local stack.
assert!(state.query_stack.borrow().as_ref().unwrap().is_empty());
}
}
}
let _guard = DbGuard::new(self, db);
op()
}
#[inline]
pub(crate) fn push_query(&self, database_key_index: DatabaseKeyIndex) -> ActiveQueryGuard<'_> {
let mut query_stack = self.query_stack.borrow_mut();

10
src/storage.rs
View file

@ -5,12 +5,12 @@ use parking_lot::Mutex;
use rustc_hash::FxHashMap;
use crate::cycle::CycleRecoveryStrategy;
use crate::database::{DatabaseImpl, UserData};
use crate::database::UserData;
use crate::ingredient::{Ingredient, Jar};
use crate::nonce::{Nonce, NonceGenerator};
use crate::runtime::Runtime;
use crate::views::{Views, ViewsOf};
use crate::{Database, Durability, Revision};
use crate::views::Views;
use crate::{Database, DatabaseImpl, Durability, Revision};
pub fn views<Db: ?Sized + Database>(db: &Db) -> &Views {
db.zalsa().views()
@ -191,7 +191,7 @@ impl IngredientIndex {
pub(crate) struct ZalsaImpl<U: UserData> {
user_data: U,
views_of: ViewsOf<DatabaseImpl<U>>,
views_of: Views,
nonce: Nonce<StorageNonce>,
@ -227,7 +227,7 @@ impl<U: UserData + Default> Default for ZalsaImpl<U> {
impl<U: UserData> ZalsaImpl<U> {
pub(crate) fn with(user_data: U) -> Self {
Self {
views_of: Default::default(),
views_of: Views::new::<DatabaseImpl<U>>(),
nonce: NONCE.nonce(),
jar_map: Default::default(),
ingredients_vec: Default::default(),

162
src/tracked_struct.rs
View file

@ -11,7 +11,7 @@ use crate::{
ingredient::{fmt_index, Ingredient, Jar},
ingredient_list::IngredientList,
key::{DatabaseKeyIndex, DependencyIndex},
local_state::{self, QueryOrigin},
local_state::QueryOrigin,
salsa_struct::SalsaStructInDb,
storage::IngredientIndex,
Database, Durability, Event, Id, Revision,
@ -290,86 +290,85 @@ where
db: &'db dyn Database,
fields: C::Fields<'db>,
) -> C::Struct<'db> {
local_state::attach(db, |local_state| {
let zalsa = db.zalsa();
let zalsa = db.zalsa();
let zalsa_local = db.zalsa_local();
let data_hash = crate::hash::hash(&C::id_fields(&fields));
let data_hash = crate::hash::hash(&C::id_fields(&fields));
let (query_key, current_deps, disambiguator) =
local_state.disambiguate(self.ingredient_index, Revision::start(), data_hash);
let (query_key, current_deps, disambiguator) =
zalsa_local.disambiguate(self.ingredient_index, Revision::start(), data_hash);
let entity_key = KeyStruct {
query_key,
disambiguator,
data_hash,
};
let entity_key = KeyStruct {
query_key,
disambiguator,
data_hash,
};
let (id, new_id) = self.intern(entity_key);
local_state.add_output(self.database_key_index(id).into());
let (id, new_id) = self.intern(entity_key);
zalsa_local.add_output(self.database_key_index(id).into());
let current_revision = zalsa.current_revision();
if new_id {
// This is a new tracked struct, so create an entry in the struct map.
let current_revision = zalsa.current_revision();
if new_id {
// This is a new tracked struct, so create an entry in the struct map.
self.struct_map.insert(
current_revision,
Value {
id,
key: entity_key,
struct_ingredient_index: self.ingredient_index,
created_at: current_revision,
durability: current_deps.durability,
fields: unsafe { self.to_static(fields) },
revisions: C::new_revisions(current_deps.changed_at),
},
)
} else {
// The struct already exists in the intern map.
// Note that we assume there is at most one executing copy of
// the current query at a time, which implies that the
// struct must exist in `self.struct_map` already
// (if the same query could execute twice in parallel,
// then it would potentially create the same struct twice in parallel,
// which means the interned key could exist but `struct_map` not yet have
// been updated).
self.struct_map.insert(
current_revision,
Value {
id,
key: entity_key,
struct_ingredient_index: self.ingredient_index,
created_at: current_revision,
durability: current_deps.durability,
fields: unsafe { self.to_static(fields) },
revisions: C::new_revisions(current_deps.changed_at),
},
)
} else {
// The struct already exists in the intern map.
// Note that we assume there is at most one executing copy of
// the current query at a time, which implies that the
// struct must exist in `self.struct_map` already
// (if the same query could execute twice in parallel,
// then it would potentially create the same struct twice in parallel,
// which means the interned key could exist but `struct_map` not yet have
// been updated).
match self.struct_map.update(current_revision, id) {
Update::Current(r) => {
// All inputs up to this point were previously
// observed to be green and this struct was already
// verified. Therefore, the durability ought not to have
// changed (nor the field values, but the user could've
// done something stupid, so we can't *assert* this is true).
assert!(C::deref_struct(r).durability == current_deps.durability);
match self.struct_map.update(current_revision, id) {
Update::Current(r) => {
// All inputs up to this point were previously
// observed to be green and this struct was already
// verified. Therefore, the durability ought not to have
// changed (nor the field values, but the user could've
// done something stupid, so we can't *assert* this is true).
assert!(C::deref_struct(r).durability == current_deps.durability);
r
r
}
Update::Outdated(mut data_ref) => {
let data = &mut *data_ref;
// SAFETY: We assert that the pointer to `data.revisions`
// is a pointer into the database referencing a value
// from a previous revision. As such, it continues to meet
// its validity invariant and any owned content also continues
// to meet its safety invariant.
unsafe {
C::update_fields(
current_revision,
&mut data.revisions,
self.to_self_ptr(std::ptr::addr_of_mut!(data.fields)),
fields,
);
}
Update::Outdated(mut data_ref) => {
let data = &mut *data_ref;
// SAFETY: We assert that the pointer to `data.revisions`
// is a pointer into the database referencing a value
// from a previous revision. As such, it continues to meet
// its validity invariant and any owned content also continues
// to meet its safety invariant.
unsafe {
C::update_fields(
current_revision,
&mut data.revisions,
self.to_self_ptr(std::ptr::addr_of_mut!(data.fields)),
fields,
);
}
if current_deps.durability < data.durability {
data.revisions = C::new_revisions(current_revision);
}
data.durability = current_deps.durability;
data.created_at = current_revision;
data_ref.freeze()
if current_deps.durability < data.durability {
data.revisions = C::new_revisions(current_revision);
}
data.durability = current_deps.durability;
data.created_at = current_revision;
data_ref.freeze()
}
}
})
}
}
/// Given the id of a tracked struct created in this revision,
@ -520,21 +519,20 @@ where
db: &dyn crate::Database,
field_index: usize,
) -> &'db C::Fields<'db> {
local_state::attach(db, |local_state| {
let field_ingredient_index = self.struct_ingredient_index.successor(field_index);
let changed_at = self.revisions[field_index];
let zalsa_local = db.zalsa_local();
let field_ingredient_index = self.struct_ingredient_index.successor(field_index);
let changed_at = self.revisions[field_index];
local_state.report_tracked_read(
DependencyIndex {
ingredient_index: field_ingredient_index,
key_index: Some(self.id.as_id()),
},
self.durability,
changed_at,
);
zalsa_local.report_tracked_read(
DependencyIndex {
ingredient_index: field_ingredient_index,
key_index: Some(self.id.as_id()),
},
self.durability,
changed_at,
);
unsafe { self.to_self_ref(&self.fields) }
})
unsafe { self.to_self_ref(&self.fields) }
}
unsafe fn to_self_ref<'db>(&'db self, fields: &'db C::Fields<'static>) -> &'db C::Fields<'db> {

32
src/tracked_struct/tracked_field.rs
View file

@ -1,6 +1,5 @@
use crate::{
id::AsId, ingredient::Ingredient, key::DependencyIndex, local_state, storage::IngredientIndex,
Database, Id,
id::AsId, ingredient::Ingredient, key::DependencyIndex, storage::IngredientIndex, Database, Id,
};
use super::{struct_map::StructMapView, Configuration};
@ -47,23 +46,22 @@ where
/// Note that this function returns the entire tuple of value fields.
/// The caller is responible for selecting the appropriate element.
pub fn field<'db>(&'db self, db: &'db dyn Database, id: Id) -> &'db C::Fields<'db> {
local_state::attach(db, |local_state| {
let current_revision = db.zalsa().current_revision();
let data = self.struct_map.get(current_revision, id);
let data = C::deref_struct(data);
let changed_at = data.revisions[self.field_index];
let zalsa_local = db.zalsa_local();
let current_revision = db.zalsa().current_revision();
let data = self.struct_map.get(current_revision, id);
let data = C::deref_struct(data);
let changed_at = data.revisions[self.field_index];
local_state.report_tracked_read(
DependencyIndex {
ingredient_index: self.ingredient_index,
key_index: Some(id.as_id()),
},
data.durability,
changed_at,
);
zalsa_local.report_tracked_read(
DependencyIndex {
ingredient_index: self.ingredient_index,
key_index: Some(id.as_id()),
},
data.durability,
changed_at,
);
unsafe { self.to_self_ref(&data.fields) }
})
unsafe { self.to_self_ref(&data.fields) }
}
}

35
src/views.rs
View file

@ -1,7 +1,5 @@
use std::{
any::{Any, TypeId},
marker::PhantomData,
ops::Deref,
sync::Arc,
};
@ -9,11 +7,6 @@ use orx_concurrent_vec::ConcurrentVec;
use crate::Database;
pub struct ViewsOf<Db: Database> {
upcasts: Views,
phantom: PhantomData<Db>,
}
#[derive(Clone)]
pub struct Views {
source_type_id: TypeId,
@ -29,25 +22,8 @@ struct ViewCaster {
#[allow(dead_code)]
enum Dummy {}
impl<Db: Database> Default for ViewsOf<Db> {
fn default() -> Self {
Self {
upcasts: Views::new::<Db>(),
phantom: Default::default(),
}
}
}
impl<Db: Database> Deref for ViewsOf<Db> {
type Target = Views;
fn deref(&self) -> &Self::Target {
&self.upcasts
}
}
impl Views {
fn new<Db: Database>() -> Self {
pub(crate) fn new<Db: Database>() -> Self {
let source_type_id = TypeId::of::<Db>();
Self {
source_type_id,
@ -127,12 +103,3 @@ fn data_ptr<T: ?Sized>(t: &T) -> &() {
let u: *const () = t as *const ();
unsafe { &*u }
}
impl<Db: Database> Clone for ViewsOf<Db> {
fn clone(&self) -> Self {
Self {
upcasts: self.upcasts.clone(),
phantom: self.phantom,
}
}
}

2
tests/accumulate.rs
View file

@ -55,7 +55,7 @@ fn push_b_logs(db: &dyn LogDatabase, input: MyInput) {
#[test]
fn accumulate_once() {
let mut db = salsa::DatabaseImpl::with(Logger::default());
let db = salsa::DatabaseImpl::with(Logger::default());
// Just call accumulate on a base input to see what happens.
let input = MyInput::new(&db, 2, 3);

4
tests/common/mod.rs
View file

@ -25,7 +25,7 @@ pub trait LogDatabase: HasLogger + salsa::Database {
/// Asserts what the (formatted) logs should look like,
/// clearing the logged events. This takes `&mut self` because
/// it is meant to be run from outside any tracked functions.
fn assert_logs(&mut self, expected: expect_test::Expect) {
fn assert_logs(&self, expected: expect_test::Expect) {
let logs = std::mem::take(&mut *self.logger().logs.lock().unwrap());
expected.assert_eq(&format!("{:#?}", logs));
}
@ -33,7 +33,7 @@ pub trait LogDatabase: HasLogger + salsa::Database {
/// Asserts the length of the logs,
/// clearing the logged events. This takes `&mut self` because
/// it is meant to be run from outside any tracked functions.
fn assert_logs_len(&mut self, expected: usize) {
fn assert_logs_len(&self, expected: usize) {
let logs = std::mem::take(&mut *self.logger().logs.lock().unwrap());
assert_eq!(logs.len(), expected);
}