Decouple JobOwner from cache.

This commit is contained in:
Camille GILLOT 2021-05-11 20:12:52 +02:00
parent d2304008c1
commit 307aacaf05
2 changed files with 66 additions and 73 deletions

View File

@ -143,6 +143,8 @@ impl<D> QueryJobId<D>
where
D: Copy + Clone + Eq + Hash,
{
#[cold]
#[inline(never)]
pub(super) fn find_cycle_in_stack(
&self,
query_map: QueryMap<D>,

View File

@ -12,12 +12,12 @@ use crate::query::{QueryContext, QueryMap, QuerySideEffects, QueryStackFrame};
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::{FxHashMap, FxHasher};
#[cfg(parallel_compiler)]
use rustc_data_structures::profiling::TimingGuard;
use rustc_data_structures::sharded::{get_shard_index_by_hash, Sharded};
use rustc_data_structures::sync::{Lock, LockGuard};
use rustc_data_structures::thin_vec::ThinVec;
#[cfg(not(parallel_compiler))]
use rustc_errors::DiagnosticBuilder;
use rustc_errors::{Diagnostic, FatalError};
use rustc_errors::{Diagnostic, DiagnosticBuilder, FatalError};
use rustc_span::{Span, DUMMY_SP};
use std::cell::Cell;
use std::collections::hash_map::Entry;
@ -147,24 +147,21 @@ impl<D, K> Default for QueryState<D, K> {
/// A type representing the responsibility to execute the job in the `job` field.
/// This will poison the relevant query if dropped.
struct JobOwner<'tcx, D, C>
struct JobOwner<'tcx, D, K>
where
D: Copy + Clone + Eq + Hash,
C: QueryCache,
K: Eq + Hash + Clone,
{
state: &'tcx QueryState<D, C::Key>,
cache: &'tcx QueryCacheStore<C>,
key: C::Key,
state: &'tcx QueryState<D, K>,
key: K,
id: QueryJobId<D>,
}
#[cold]
#[inline(never)]
#[cfg(not(parallel_compiler))]
fn mk_cycle<CTX, V, R>(
tcx: CTX,
root: QueryJobId<CTX::DepKind>,
span: Span,
error: CycleError,
handle_cycle_error: fn(CTX, DiagnosticBuilder<'_>) -> V,
cache: &dyn crate::query::QueryStorage<Value = V, Stored = R>,
) -> R
@ -173,20 +170,15 @@ where
V: std::fmt::Debug,
R: Clone,
{
let error: CycleError = root.find_cycle_in_stack(
tcx.try_collect_active_jobs().unwrap(),
&tcx.current_query_job(),
span,
);
let error = report_cycle(tcx.dep_context().sess(), error);
let value = handle_cycle_error(tcx, error);
cache.store_nocache(value)
}
impl<'tcx, D, C> JobOwner<'tcx, D, C>
impl<'tcx, D, K> JobOwner<'tcx, D, K>
where
D: Copy + Clone + Eq + Hash,
C: QueryCache,
K: Eq + Hash + Clone,
{
/// Either gets a `JobOwner` corresponding the query, allowing us to
/// start executing the query, or returns with the result of the query.
@ -198,14 +190,13 @@ where
/// for some compile-time benchmarks.
#[inline(always)]
fn try_start<'b, CTX>(
tcx: CTX,
state: &'b QueryState<CTX::DepKind, C::Key>,
cache: &'b QueryCacheStore<C>,
tcx: &'b CTX,
state: &'b QueryState<CTX::DepKind, K>,
span: Span,
key: C::Key,
key: K,
lookup: QueryLookup,
query: &QueryVtable<CTX, C::Key, C::Value>,
) -> TryGetJob<'b, CTX::DepKind, C>
dep_kind: CTX::DepKind,
) -> TryGetJob<'b, CTX::DepKind, K>
where
CTX: QueryContext,
{
@ -226,26 +217,24 @@ where
let key = entry.key().clone();
entry.insert(QueryResult::Started(job));
let global_id = QueryJobId::new(id, shard, query.dep_kind);
let owner = JobOwner { state, cache, id: global_id, key };
let global_id = QueryJobId::new(id, shard, dep_kind);
let owner = JobOwner { state, id: global_id, key };
return TryGetJob::NotYetStarted(owner);
}
Entry::Occupied(mut entry) => {
match entry.get_mut() {
#[cfg(not(parallel_compiler))]
QueryResult::Started(job) => {
let id = QueryJobId::new(job.id, shard, query.dep_kind);
let id = QueryJobId::new(job.id, shard, dep_kind);
drop(state_lock);
// If we are single-threaded we know that we have cycle error,
// so we just return the error.
return TryGetJob::Cycle(mk_cycle(
tcx,
id,
return TryGetJob::Cycle(id.find_cycle_in_stack(
tcx.try_collect_active_jobs().unwrap(),
&tcx.current_query_job(),
span,
query.handle_cycle_error,
&cache.cache,
));
}
#[cfg(parallel_compiler)]
@ -257,7 +246,6 @@ where
// Get the latch out
let latch = job.latch();
let key = entry.key().clone();
drop(state_lock);
@ -265,30 +253,10 @@ where
// thread.
let result = latch.wait_on(tcx.current_query_job(), span);
if let Err(cycle) = result {
let cycle = report_cycle(tcx.dep_context().sess(), cycle);
let value = (query.handle_cycle_error)(tcx, cycle);
let value = cache.cache.store_nocache(value);
return TryGetJob::Cycle(value);
match result {
Ok(()) => TryGetJob::JobCompleted(query_blocked_prof_timer),
Err(cycle) => TryGetJob::Cycle(cycle),
}
let cached = cache
.cache
.lookup(cache, &key, |value, index| {
if unlikely!(tcx.dep_context().profiler().enabled()) {
tcx.dep_context().profiler().query_cache_hit(index.into());
}
#[cfg(debug_assertions)]
{
cache.cache_hits.fetch_add(1, Ordering::Relaxed);
}
(value.clone(), index)
})
.unwrap_or_else(|_| panic!("value must be in cache after waiting"));
query_blocked_prof_timer.finish_with_query_invocation_id(cached.1.into());
return TryGetJob::JobCompleted(cached);
}
QueryResult::Poisoned => FatalError.raise(),
}
@ -298,11 +266,18 @@ where
/// Completes the query by updating the query cache with the `result`,
/// signals the waiter and forgets the JobOwner, so it won't poison the query
fn complete(self, result: C::Value, dep_node_index: DepNodeIndex) -> C::Stored {
fn complete<C>(
self,
cache: &QueryCacheStore<C>,
result: C::Value,
dep_node_index: DepNodeIndex,
) -> C::Stored
where
C: QueryCache<Key = K>,
{
// We can move out of `self` here because we `mem::forget` it below
let key = unsafe { ptr::read(&self.key) };
let state = self.state;
let cache = self.cache;
// Forget ourself so our destructor won't poison the query
mem::forget(self);
@ -338,10 +313,10 @@ where
(result, diagnostics.into_inner())
}
impl<'tcx, D, C> Drop for JobOwner<'tcx, D, C>
impl<'tcx, D, K> Drop for JobOwner<'tcx, D, K>
where
D: Copy + Clone + Eq + Hash,
C: QueryCache,
K: Eq + Hash + Clone,
{
#[inline(never)]
#[cold]
@ -372,22 +347,22 @@ pub(crate) struct CycleError {
}
/// The result of `try_start`.
enum TryGetJob<'tcx, D, C>
enum TryGetJob<'tcx, D, K>
where
D: Copy + Clone + Eq + Hash,
C: QueryCache,
K: Eq + Hash + Clone,
{
/// The query is not yet started. Contains a guard to the cache eventually used to start it.
NotYetStarted(JobOwner<'tcx, D, C>),
NotYetStarted(JobOwner<'tcx, D, K>),
/// The query was already completed.
/// Returns the result of the query and its dep-node index
/// if it succeeded or a cycle error if it failed.
#[cfg(parallel_compiler)]
JobCompleted((C::Stored, DepNodeIndex)),
JobCompleted(TimingGuard<'tcx>),
/// Trying to execute the query resulted in a cycle.
Cycle(C::Stored),
Cycle(CycleError),
}
/// Checks if the query is already computed and in the cache.
@ -436,19 +411,35 @@ where
C::Key: Clone + DepNodeParams<CTX::DepContext>,
CTX: QueryContext,
{
let job = match JobOwner::<'_, CTX::DepKind, C>::try_start(
tcx,
let job = match JobOwner::<'_, CTX::DepKind, C::Key>::try_start(
&tcx,
state,
cache,
span,
key.clone(),
lookup,
query,
query.dep_kind,
) {
TryGetJob::NotYetStarted(job) => job,
TryGetJob::Cycle(result) => return (result, None),
TryGetJob::Cycle(error) => {
let result = mk_cycle(tcx, error, query.handle_cycle_error, &cache.cache);
return (result, None);
}
#[cfg(parallel_compiler)]
TryGetJob::JobCompleted((v, index)) => {
TryGetJob::JobCompleted(query_blocked_prof_timer) => {
let (v, index) = cache
.cache
.lookup(cache, &key, |value, index| (value.clone(), index))
.unwrap_or_else(|_| panic!("value must be in cache after waiting"));
if unlikely!(tcx.dep_context().profiler().enabled()) {
tcx.dep_context().profiler().query_cache_hit(index.into());
}
#[cfg(debug_assertions)]
{
cache.cache_hits.fetch_add(1, Ordering::Relaxed);
}
query_blocked_prof_timer.finish_with_query_invocation_id(index.into());
return (v, Some(index));
}
};
@ -461,7 +452,7 @@ where
let result = tcx.start_query(job.id, None, || compute(*tcx.dep_context(), key));
let dep_node_index = dep_graph.next_virtual_depnode_index();
prof_timer.finish_with_query_invocation_id(dep_node_index.into());
let result = job.complete(result, dep_node_index);
let result = job.complete(cache, result, dep_node_index);
return (result, None);
}
@ -504,7 +495,7 @@ where
force_query_with_job(tcx, key, job.id, dep_node, query, compute)
}
};
let result = job.complete(result, dep_node_index);
let result = job.complete(cache, result, dep_node_index);
(result, Some(dep_node_index))
}