once_cell -> std::sync in fbcode/buck2

Summary: Most of `once_cell` is now in `std`: `OnceCell`/`OnceLock` (Rust 1.70) and `LazyCell`/`LazyLock` (Rust 1.80). The `race` module and fallible `get_or_try_init` have no stable std equivalent yet.

Reviewed By: diliop

Differential Revision: D109642549

fbshipit-source-id: 7554e52c246d9f3e59708270bd333945efb7eb90

Author: David Tolnay

Cargo.toml

@@ -371,7 +371,6 @@ notify = "8.2.0"
 num-bigint = { version = "0.4.6", features = ["rand", "serde"] }
 num_enum = "0.7.6"
 object = { version = "0.36.7", features = ["read", "write"] }
-once_cell = "1.21.4"
 os_str_bytes = { version = "6.6.1", features = ["conversions"] }
 pagable = { path = "pagable", features = ["tokio"] }
 pagable_storage = { path = "pagable_storage", features = ["tokio"] }

app/buck2_action_impl/BUCK

@@ -27,7 +27,6 @@ rust_library(
         "fbsource//third-party/rust:hex",
         "fbsource//third-party/rust:http",
         "fbsource//third-party/rust:itertools",
-        "fbsource//third-party/rust:once_cell",
         "fbsource//third-party/rust:parking_lot",
         "fbsource//third-party/rust:serde_json",
         "fbsource//third-party/rust:sha1",

app/buck2_action_impl/Cargo.toml

@@ -41,7 +41,6 @@ hex.workspace = true
 host_sharing.workspace = true
 http.workspace = true
 itertools.workspace = true
-once_cell.workspace = true
 pagable.workspace = true
 parking_lot.workspace = true
 remote_execution.workspace = true

app/buck2_action_impl/src/actions/impls/run/dep_files.rs

@@ -10,6 +10,7 @@
 
 use std::borrow::Cow;
 use std::sync::Arc;
+use std::sync::LazyLock;
 
 use allocative::Allocative;
 use async_trait::async_trait;
@@ -82,7 +83,6 @@ use buck2_hash::StdBuckHashSet;
 use derive_more::Display;
 use dupe::Dupe;
 use futures::StreamExt;
-use once_cell::sync::Lazy;
 use pagable::Pagable;
 use parking_lot::MappedMutexGuard;
 use parking_lot::Mutex;
@@ -93,7 +93,8 @@ use tracing::instrument;
 use crate::actions::impls::run::RunActionKey;
 
 #[allocative::root]
-static DEP_FILES: Lazy<BuckDashMap<RunActionKey, Arc<DepFileState>>> = Lazy::new(BuckDashMap::new);
+static DEP_FILES: LazyLock<BuckDashMap<RunActionKey, Arc<DepFileState>>> =
+    LazyLock::new(BuckDashMap::new);
 
 /// When this is set, we retain directories after fingerprinting, so that we can output them later
 /// for debugging via `buck2 audit dep-files`.

app/buck2_build_api/BUCK

@@ -36,7 +36,6 @@ rust_library(
         "fbsource//third-party/rust:itertools",
         "fbsource//third-party/rust:linkme",
         "fbsource//third-party/rust:multimap",
-        "fbsource//third-party/rust:once_cell",
         "fbsource//third-party/rust:ref-cast",
         "fbsource//third-party/rust:regex",
         "fbsource//third-party/rust:serde",

app/buck2_build_api/Cargo.toml

@@ -53,7 +53,6 @@ inventory.workspace = true
 itertools.workspace = true
 linkme.workspace = true
 multimap.workspace = true
-once_cell.workspace = true
 pagable.workspace = true
 ref-cast.workspace = true
 regex.workspace = true

app/buck2_build_api/src/interpreter/rule_defs/cmd_args/command_line_arg_like_type.rs

@@ -8,7 +8,8 @@
  * above-listed licenses.
  */
 
-use once_cell::sync::Lazy;
+use std::sync::LazyLock;
+
 use starlark::typing::Ty;
 
 pub struct CommandLineArgLikeImpl {
@@ -41,7 +42,7 @@ pub use command_line_arg_like_impl;
 pub static COMMAND_LINE_ARG_LIKE_IMPLS: [CommandLineArgLikeImpl] = [..];
 
 pub(crate) fn command_line_arg_like_ty() -> &'static Ty {
-    static TY: Lazy<Ty> = Lazy::new(|| {
+    static TY: LazyLock<Ty> = LazyLock::new(|| {
         assert!(!COMMAND_LINE_ARG_LIKE_IMPLS.is_empty());
         let ty = Ty::unions(
             COMMAND_LINE_ARG_LIKE_IMPLS

app/buck2_bxl/BUCK

@@ -21,7 +21,6 @@ rust_library(
         "fbsource//third-party/rust:futures",
         "fbsource//third-party/rust:itertools",
         "fbsource//third-party/rust:num-bigint",
-        "fbsource//third-party/rust:once_cell",
         "fbsource//third-party/rust:serde",
         "fbsource//third-party/rust:serde_json",
         "fbsource//third-party/rust:tokio",

app/buck2_bxl/Cargo.toml

@@ -46,7 +46,6 @@ futures.workspace = true
 gazebo.workspace = true
 itertools.workspace = true
 num-bigint.workspace = true
-once_cell.workspace = true
 pagable.workspace = true
 serde.workspace = true
 serde_json.workspace = true

app/buck2_bxl/src/bxl/eval.rs

@@ -10,6 +10,7 @@
 
 use std::future::Future;
 use std::sync::Arc;
+use std::sync::LazyLock;
 
 use allocative::Allocative;
 use buck2_build_api::bxl::result::BxlResult;
@@ -47,7 +48,6 @@ use dice::DiceTransaction;
 use dice_futures::cancellation::CancellationObserver;
 use dupe::Dupe;
 use itertools::Itertools;
-use once_cell::sync::Lazy;
 use starlark::eval::Evaluator;
 use starlark::values::OwnedFrozenValueTyped;
 use starlark::values::UnpackValue;
@@ -69,7 +69,7 @@ use crate::bxl::starlark_defs::context::starlark_async::BxlDiceComputations;
 use crate::bxl::starlark_defs::eval_extra::BxlEvalExtra;
 use crate::bxl::starlark_defs::functions::BxlErrorWithoutStacktrace;
 
-pub(crate) static LIMITED_EXECUTOR: Lazy<Arc<LimitedExecutor>> = Lazy::new(|| {
+pub(crate) static LIMITED_EXECUTOR: LazyLock<Arc<LimitedExecutor>> = LazyLock::new(|| {
     Arc::new(LimitedExecutor::new(500)) // Default working thread of tokio is 512 threads. We set it to 500 for here to leave some room for other things.
 });