replaces once_cell::sync::OnceCell with std::sync::OnceLock (#33140)

std::sync::OnceLock has become stable since rust 1.70.0 and there is no
longer a need for an external crate dependency.

Cargo.toml

@@ -243,7 +243,6 @@ num_cpus = "1.16.0"
 num_enum = "0.6.1"
 num-derive = "0.3"
 num-traits = "0.2"
-once_cell = "1.18.0"
 openssl = "0.10"
 ouroboros = "0.15.6"
 parking_lot = "0.12"

accounts-db/Cargo.toml

@@ -36,7 +36,6 @@ num-derive = { workspace = true }
 num-traits = { workspace = true }
 num_cpus = { workspace = true }
 num_enum = { workspace = true }
-once_cell = { workspace = true }
 ouroboros = { workspace = true }
 percentage = { workspace = true }
 qualifier_attr = { workspace = true }

accounts-db/src/accounts_index.rs

@@ -13,7 +13,6 @@ use {
         secondary_index::*,
     },
     log::*,
-    once_cell::sync::OnceCell,
     ouroboros::self_referencing,
     rand::{thread_rng, Rng},
     rayon::{
@@ -37,7 +36,7 @@ use {
         path::PathBuf,
         sync::{
             atomic::{AtomicBool, AtomicU64, AtomicU8, AtomicUsize, Ordering},
-            Arc, Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard,
+            Arc, Mutex, OnceLock, RwLock, RwLockReadGuard, RwLockWriteGuard,
         },
     },
     thiserror::Error,
@@ -703,7 +702,7 @@ pub struct AccountsIndex<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> {
     pub max_distance_to_min_scan_slot: AtomicU64,
 
     /// populated at generate_index time - accounts that could possibly be rent paying
-    pub rent_paying_accounts_by_partition: OnceCell<RentPayingAccountsByPartition>,
+    pub rent_paying_accounts_by_partition: OnceLock<RentPayingAccountsByPartition>,
 }
 
 impl<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> AccountsIndex<T, U> {
@@ -737,7 +736,7 @@ impl<T: IndexValue, U: DiskIndexValue + From<T> + Into<T>> AccountsIndex<T, U> {
             roots_removed: AtomicUsize::default(),
             active_scans: AtomicUsize::default(),
             max_distance_to_min_scan_slot: AtomicU64::default(),
-            rent_paying_accounts_by_partition: OnceCell::default(),
+            rent_paying_accounts_by_partition: OnceLock::default(),
         }
     }
 

accounts-db/src/tiered_storage.rs

@@ -19,13 +19,13 @@ use {
     error::TieredStorageError,
     footer::{AccountBlockFormat, AccountMetaFormat, OwnersBlockFormat},
     index::AccountIndexFormat,
-    once_cell::sync::OnceCell,
     readable::TieredStorageReader,
     solana_sdk::{account::ReadableAccount, hash::Hash},
     std::{
         borrow::Borrow,
         fs::OpenOptions,
         path::{Path, PathBuf},
+        sync::OnceLock,
     },
     writer::TieredStorageWriter,
 };
@@ -45,7 +45,7 @@ pub struct TieredStorageFormat {
 
 #[derive(Debug)]
 pub struct TieredStorage {
-    reader: OnceCell<TieredStorageReader>,
+    reader: OnceLock<TieredStorageReader>,
     format: Option<TieredStorageFormat>,
     path: PathBuf,
 }
@@ -66,7 +66,7 @@ impl TieredStorage {
     /// is called.
     pub fn new_writable(path: impl Into<PathBuf>, format: TieredStorageFormat) -> Self {
         Self {
-            reader: OnceCell::<TieredStorageReader>::new(),
+            reader: OnceLock::<TieredStorageReader>::new(),
             format: Some(format),
             path: path.into(),
         }
@@ -77,7 +77,7 @@ impl TieredStorage {
     pub fn new_readonly(path: impl Into<PathBuf>) -> TieredStorageResult<Self> {
         let path = path.into();
         Ok(Self {
-            reader: OnceCell::with_value(TieredStorageReader::new_from_path(&path)?),
+            reader: TieredStorageReader::new_from_path(&path).map(OnceLock::from)?,
             format: None,
             path,
         })

frozen-abi/Cargo.toml

@@ -14,7 +14,6 @@ bs58 = { workspace = true }
 bv = { workspace = true, features = ["serde"] }
 lazy_static = { workspace = true }
 log = { workspace = true, features = ["std"] }
-once_cell = { workspace = true }
 serde = { workspace = true, features = ["derive", "rc"] }
 serde_bytes = { workspace = true }
 serde_derive = { workspace = true }
@@ -32,7 +31,6 @@ either = { workspace = true, features = ["use_std"] }
 generic-array = { workspace = true, features = ["serde", "more_lengths"] }
 im = { workspace = true, features = ["rayon", "serde"] }
 memmap2 = { workspace = true }
-once_cell = { workspace = true, features = ["alloc", "race"] }
 subtle = { workspace = true }
 
 [target.'cfg(any(unix, windows))'.dependencies]

frozen-abi/src/abi_example.rs

@@ -555,9 +555,3 @@ impl<O: AbiEnumVisitor, E: AbiEnumVisitor> AbiEnumVisitor for Result<O, E> {
         digester.create_child()
     }
 }
-
-impl<T: AbiExample> AbiExample for once_cell::sync::OnceCell<T> {
-    fn example() -> Self {
-        Self::with_value(T::example())
-    }
-}

runtime/Cargo.toml

@@ -37,7 +37,6 @@ num-derive = { workspace = true }
 num-traits = { workspace = true }
 num_cpus = { workspace = true }
 num_enum = { workspace = true }
-once_cell = { workspace = true }
 ouroboros = { workspace = true }
 percentage = { workspace = true }
 rand = { workspace = true }

runtime/src/vote_account.rs

@@ -1,6 +1,7 @@
+#[cfg(RUSTC_WITH_SPECIALIZATION)]
+use solana_frozen_abi::abi_example::AbiExample;
 use {
     itertools::Itertools,
-    once_cell::sync::OnceCell,
     serde::ser::{Serialize, Serializer},
     solana_sdk::{
         account::{AccountSharedData, ReadableAccount},
@@ -12,7 +13,7 @@ use {
         cmp::Ordering,
         collections::{hash_map::Entry, HashMap},
         iter::FromIterator,
-        sync::Arc,
+        sync::{Arc, OnceLock},
     },
     thiserror::Error,
 };
@@ -29,20 +30,20 @@ pub enum Error {
     InvalidOwner(/*owner:*/ Pubkey),
 }
 
-#[derive(Debug, AbiExample)]
+#[derive(Debug)]
 struct VoteAccountInner {
     account: AccountSharedData,
-    vote_state: OnceCell<Result<VoteState, Error>>,
+    vote_state: OnceLock<Result<VoteState, Error>>,
 }
 
 pub type VoteAccountsHashMap = HashMap<Pubkey, (/*stake:*/ u64, VoteAccount)>;
 
-#[derive(Clone, Debug, AbiExample, Deserialize)]
+#[derive(Clone, Debug, Deserialize)]
 #[serde(from = "Arc<VoteAccountsHashMap>")]
 pub struct VoteAccounts {
     vote_accounts: Arc<VoteAccountsHashMap>,
     // Inner Arc is meant to implement copy-on-write semantics.
-    staked_nodes: OnceCell<
+    staked_nodes: OnceLock<
         Arc<
             HashMap<
                 Pubkey, // VoteAccount.vote_state.node_pubkey.
@@ -243,7 +244,7 @@ impl TryFrom<AccountSharedData> for VoteAccountInner {
         }
         Ok(Self {
             account,
-            vote_state: OnceCell::new(),
+            vote_state: OnceLock::new(),
         })
     }
 }
@@ -262,7 +263,7 @@ impl Default for VoteAccounts {
     fn default() -> Self {
         Self {
             vote_accounts: Arc::default(),
-            staked_nodes: OnceCell::new(),
+            staked_nodes: OnceLock::new(),
         }
     }
 }
@@ -281,7 +282,7 @@ impl From<Arc<VoteAccountsHashMap>> for VoteAccounts {
     fn from(vote_accounts: Arc<VoteAccountsHashMap>) -> Self {
         Self {
             vote_accounts,
-            staked_nodes: OnceCell::new(),
+            staked_nodes: OnceLock::new(),
         }
     }
 }
@@ -316,6 +317,26 @@ impl Serialize for VoteAccounts {
     }
 }
 
+#[cfg(RUSTC_WITH_SPECIALIZATION)]
+impl AbiExample for VoteAccountInner {
+    fn example() -> Self {
+        Self {
+            account: AccountSharedData::example(),
+            vote_state: OnceLock::from(Result::<VoteState, Error>::example()),
+        }
+    }
+}
+
+#[cfg(RUSTC_WITH_SPECIALIZATION)]
+impl AbiExample for VoteAccounts {
+    fn example() -> Self {
+        Self {
+            vote_accounts: Arc::<VoteAccountsHashMap>::example(),
+            staked_nodes: OnceLock::from(Arc::<HashMap<Pubkey, u64>>::example()),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use {