[meta] switch to once_cell impls in std (#7580)

`once_cell` is now part of std, so switch over to it almost everywhere,
and add lints for it.

This is purely mechanical -- there are no semantic changes compared to
`once_cell`.

There's one place that still needs `once_cell`'s `try_`, so keep that
around. See rust-lang/rust#109737.

clippy.toml

@@ -16,4 +16,15 @@ disallowed-methods = [
     # Instead, the "transaction_retry_wrapper" should be preferred, as it
     # automatically retries transactions experiencing contention.
     { path = "async_bb8_diesel::AsyncConnection::transaction_async", reason = "Prefer to use transaction_retry_wrapper, if possible. For tests and nested transactions, use transaction_non_retry_wrapper to at least get dtrace probes" },
+
+    # We use disallowed-methods for these rather than disallowed-types, because
+    # there's still one legitimate use for `once_cell`'s types:
+    # `get_or_try_init`, which isn't stablet yet.
+    # https://github.com/rust-lang/rust/issues/109737
+    { path = "once_cell::unsync::OnceCell::get_or_init", reason = "use `std::cell::OnceCell` instead, unless you need get_or_try_init in which case #[expect] this lint" },
+    { path = "once_cell::sync::OnceCell::get_or_init", reason = "use `std::sync::OnceLock` instead, unless you need get_or_try_init in which case #[expect] this lint" },
+]
+disallowed-types = [
+    { path = "once_cell::unsync::Lazy", reason = "use `std::cell::LazyCell` instead" },
+    { path = "once_cell::unsync::LazyCell", reason = "use `std::cell::LazyCell` instead" },
 ]

cockroach-admin/Cargo.toml

@@ -20,7 +20,6 @@ http.workspace = true
 illumos-utils.workspace = true
 omicron-common.workspace = true
 omicron-uuid-kinds.workspace = true
-once_cell.workspace = true
 # See omicron-rpaths for more about the "pq-sys" dependency.
 pq-sys = "*"
 schemars.workspace = true

common/Cargo.toml

@@ -49,7 +49,6 @@ uuid.workspace = true
 parse-display.workspace = true
 progenitor-client.workspace = true
 omicron-workspace-hack.workspace = true
-once_cell.workspace = true
 regress.workspace = true
 
 [dev-dependencies]

common/src/address.rs

@@ -10,11 +10,13 @@
 use crate::api::external::{self, Error};
 use crate::policy::INTERNAL_DNS_REDUNDANCY;
 use ipnetwork::Ipv6Network;
-use once_cell::sync::Lazy;
 use oxnet::{Ipv4Net, Ipv6Net};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
-use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddrV6};
+use std::{
+    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddrV6},
+    sync::LazyLock,
+};
 
 pub const AZ_PREFIX: u8 = 48;
 pub const RACK_PREFIX: u8 = 56;
@@ -101,7 +103,7 @@ pub const NUM_SOURCE_NAT_PORTS: u16 = 1 << 14;
 // prefix range (`fd00::/48`). See `random_vpc_ipv6_prefix`.
 // Furthermore, all the below *_OPTE_IPV6_SUBNET constants are
 // /64's within this prefix.
-pub static SERVICE_VPC_IPV6_PREFIX: Lazy<Ipv6Net> = Lazy::new(|| {
+pub static SERVICE_VPC_IPV6_PREFIX: LazyLock<Ipv6Net> = LazyLock::new(|| {
     Ipv6Net::new(
         Ipv6Addr::new(0xfd77, 0xe9d2, 0x9cd9, 0, 0, 0, 0, 0),
         VPC_IPV6_PREFIX_LENGTH,
@@ -110,11 +112,11 @@ pub static SERVICE_VPC_IPV6_PREFIX: Lazy<Ipv6Net> = Lazy::new(|| {
 });
 
 /// The IPv4 subnet for External DNS OPTE ports.
-pub static DNS_OPTE_IPV4_SUBNET: Lazy<Ipv4Net> =
-    Lazy::new(|| Ipv4Net::new(Ipv4Addr::new(172, 30, 1, 0), 24).unwrap());
+pub static DNS_OPTE_IPV4_SUBNET: LazyLock<Ipv4Net> =
+    LazyLock::new(|| Ipv4Net::new(Ipv4Addr::new(172, 30, 1, 0), 24).unwrap());
 
 /// The IPv6 subnet for External DNS OPTE ports.
-pub static DNS_OPTE_IPV6_SUBNET: Lazy<Ipv6Net> = Lazy::new(|| {
+pub static DNS_OPTE_IPV6_SUBNET: LazyLock<Ipv6Net> = LazyLock::new(|| {
     Ipv6Net::new(
         Ipv6Addr::new(0xfd77, 0xe9d2, 0x9cd9, 1, 0, 0, 0, 0),
         VPC_SUBNET_IPV6_PREFIX_LENGTH,
@@ -123,11 +125,11 @@ pub static DNS_OPTE_IPV6_SUBNET: Lazy<Ipv6Net> = Lazy::new(|| {
 });
 
 /// The IPv4 subnet for Nexus OPTE ports.
-pub static NEXUS_OPTE_IPV4_SUBNET: Lazy<Ipv4Net> =
-    Lazy::new(|| Ipv4Net::new(Ipv4Addr::new(172, 30, 2, 0), 24).unwrap());
+pub static NEXUS_OPTE_IPV4_SUBNET: LazyLock<Ipv4Net> =
+    LazyLock::new(|| Ipv4Net::new(Ipv4Addr::new(172, 30, 2, 0), 24).unwrap());
 
 /// The IPv6 subnet for Nexus OPTE ports.
-pub static NEXUS_OPTE_IPV6_SUBNET: Lazy<Ipv6Net> = Lazy::new(|| {
+pub static NEXUS_OPTE_IPV6_SUBNET: LazyLock<Ipv6Net> = LazyLock::new(|| {
     Ipv6Net::new(
         Ipv6Addr::new(0xfd77, 0xe9d2, 0x9cd9, 2, 0, 0, 0, 0),
         VPC_SUBNET_IPV6_PREFIX_LENGTH,
@@ -136,11 +138,11 @@ pub static NEXUS_OPTE_IPV6_SUBNET: Lazy<Ipv6Net> = Lazy::new(|| {
 });
 
 /// The IPv4 subnet for Boundary NTP OPTE ports.
-pub static NTP_OPTE_IPV4_SUBNET: Lazy<Ipv4Net> =
-    Lazy::new(|| Ipv4Net::new(Ipv4Addr::new(172, 30, 3, 0), 24).unwrap());
+pub static NTP_OPTE_IPV4_SUBNET: LazyLock<Ipv4Net> =
+    LazyLock::new(|| Ipv4Net::new(Ipv4Addr::new(172, 30, 3, 0), 24).unwrap());
 
 /// The IPv6 subnet for Boundary NTP OPTE ports.
-pub static NTP_OPTE_IPV6_SUBNET: Lazy<Ipv6Net> = Lazy::new(|| {
+pub static NTP_OPTE_IPV6_SUBNET: LazyLock<Ipv6Net> = LazyLock::new(|| {
     Ipv6Net::new(
         Ipv6Addr::new(0xfd77, 0xe9d2, 0x9cd9, 3, 0, 0, 0, 0),
         VPC_SUBNET_IPV6_PREFIX_LENGTH,

dev-tools/releng/Cargo.toml

@@ -18,7 +18,6 @@ omicron-common.workspace = true
 omicron-pins.workspace = true
 omicron-workspace-hack.workspace = true
 omicron-zone-package.workspace = true
-once_cell.workspace = true
 reqwest.workspace = true
 semver.workspace = true
 serde.workspace = true

dev-tools/releng/src/main.rs

@@ -8,6 +8,7 @@ mod job;
 mod tuf;
 
 use std::sync::Arc;
+use std::sync::LazyLock;
 use std::time::Duration;
 use std::time::Instant;
 
@@ -20,7 +21,6 @@ use clap::Parser;
 use fs_err::tokio as fs;
 use omicron_zone_package::config::Config;
 use omicron_zone_package::config::PackageName;
-use once_cell::sync::Lazy;
 use semver::Version;
 use slog::debug;
 use slog::error;
@@ -88,7 +88,7 @@ const TUF_PACKAGES: [&PackageName; 11] = [
 
 const HELIOS_REPO: &str = "https://pkg.oxide.computer/helios/2/dev/";
 
-static WORKSPACE_DIR: Lazy<Utf8PathBuf> = Lazy::new(|| {
+static WORKSPACE_DIR: LazyLock<Utf8PathBuf> = LazyLock::new(|| {
     // $CARGO_MANIFEST_DIR is at `.../omicron/dev-tools/releng`
     let mut dir =
         Utf8PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").expect(

gateway/Cargo.toml

@@ -25,7 +25,6 @@ hyper.workspace = true
 illumos-utils.workspace = true
 ipcc.workspace = true
 omicron-common.workspace = true
-once_cell.workspace = true
 schemars.workspace = true
 serde.workspace = true
 signal-hook.workspace = true

gateway/src/management_switch.rs

@@ -29,7 +29,6 @@ use gateway_sp_comms::HostPhase2Provider;
 use gateway_sp_comms::SharedSocket;
 use gateway_sp_comms::SingleSp;
 use gateway_sp_comms::SpRetryConfig;
-use once_cell::sync::OnceCell;
 use serde::Deserialize;
 use serde::Serialize;
 use slog::o;
@@ -39,6 +38,7 @@ use std::collections::HashMap;
 use std::net::Ipv6Addr;
 use std::net::SocketAddrV6;
 use std::sync::Arc;
+use std::sync::OnceLock;
 use std::time::Duration;
 use tokio::net::UdpSocket;
 use tokio::task::JoinHandle;
@@ -162,7 +162,7 @@ pub struct ManagementSwitch {
     // When it's dropped, it cancels the background tokio task that loops on
     // that socket receiving incoming packets.
     _shared_socket: Option<SharedSocket>,
-    location_map: Arc<OnceCell<Result<LocationMap, String>>>,
+    location_map: Arc<OnceLock<Result<LocationMap, String>>>,
     discovery_task: JoinHandle<()>,
     log: Logger,
 }
@@ -290,7 +290,7 @@ impl ManagementSwitch {
         // completes (because we won't be able to map "the SP of sled 7" to a
         // correct switch port).
         let port_to_handle = Arc::new(port_to_handle);
-        let location_map = Arc::new(OnceCell::new());
+        let location_map = Arc::new(OnceLock::new());
         let discovery_task = {
             let log = log.clone();
             let port_to_handle = Arc::clone(&port_to_handle);

nexus/Cargo.toml

@@ -59,7 +59,6 @@ nexus-networking.workspace = true
 nexus-saga-recovery.workspace = true
 nexus-test-interface.workspace = true
 num-integer.workspace = true
-once_cell.workspace = true
 openssl.workspace = true
 oximeter-client.workspace = true
 oximeter-db = { workspace = true, default-features = false, features = [ "oxql" ] }

nexus/auth/Cargo.toml

@@ -24,7 +24,6 @@ hyper.workspace = true
 newtype_derive.workspace = true
 # See omicron-rpaths for more about the "pq-sys" dependency.
 pq-sys = "*"
-once_cell.workspace = true
 openssl.workspace = true
 oso.workspace = true
 samael.workspace = true

nexus/auth/src/authn/external/spoof.rs

@@ -4,6 +4,8 @@
 
 //! Custom, test-only authn scheme that trusts whatever the client says
 
+use std::sync::LazyLock;
+
 use super::super::Details;
 use super::HttpAuthnScheme;
 use super::Reason;
@@ -16,7 +18,6 @@ use anyhow::Context;
 use async_trait::async_trait;
 use headers::authorization::{Authorization, Bearer};
 use headers::HeaderMapExt;
-use once_cell::sync::Lazy;
 use slog::debug;
 use uuid::Uuid;
 
@@ -56,20 +57,20 @@ const SPOOF_RESERVED_BAD_CREDS: &str = "this-fake-ID-it-is-truly-excellent";
 const SPOOF_PREFIX: &str = "oxide-spoof-";
 
 /// Actor (id) used for the special "bad credentials" error
-static SPOOF_RESERVED_BAD_CREDS_ACTOR: Lazy<Actor> =
-    Lazy::new(|| Actor::UserBuiltin {
+static SPOOF_RESERVED_BAD_CREDS_ACTOR: LazyLock<Actor> =
+    LazyLock::new(|| Actor::UserBuiltin {
         user_builtin_id: "22222222-2222-2222-2222-222222222222"
             .parse()
             .unwrap(),
     });
 
 /// Complete HTTP header value to trigger the "bad actor" error
-pub static SPOOF_HEADER_BAD_ACTOR: Lazy<Authorization<Bearer>> =
-    Lazy::new(|| make_header_value_str(SPOOF_RESERVED_BAD_ACTOR).unwrap());
+pub static SPOOF_HEADER_BAD_ACTOR: LazyLock<Authorization<Bearer>> =
+    LazyLock::new(|| make_header_value_str(SPOOF_RESERVED_BAD_ACTOR).unwrap());
 
 /// Complete HTTP header value to trigger the "bad creds" error
-pub static SPOOF_HEADER_BAD_CREDS: Lazy<Authorization<Bearer>> =
-    Lazy::new(|| make_header_value_str(SPOOF_RESERVED_BAD_CREDS).unwrap());
+pub static SPOOF_HEADER_BAD_CREDS: LazyLock<Authorization<Bearer>> =
+    LazyLock::new(|| make_header_value_str(SPOOF_RESERVED_BAD_CREDS).unwrap());
 
 /// Implements a (test-only) authentication scheme where the client simply
 /// provides the actor information in a custom bearer token and we always trust

nexus/auth/src/authz/api_resources.rs

@@ -26,6 +26,8 @@
 //!
 //! Most `authz` types are generated by the `authz_resource!` macro.
 
+use std::sync::LazyLock;
+
 use super::actor::AnyActor;
 use super::context::AuthorizedResource;
 use super::oso_generic::Init;
@@ -40,7 +42,6 @@ use futures::FutureExt;
 use nexus_db_fixed_data::FLEET_ID;
 use nexus_types::external_api::shared::{FleetRole, ProjectRole, SiloRole};
 use omicron_common::api::external::{Error, LookupType, ResourceType};
-use once_cell::sync::Lazy;
 use oso::PolarClass;
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
@@ -159,8 +160,8 @@ pub struct Fleet;
 /// Singleton representing the [`Fleet`] itself for authz purposes
 pub const FLEET: Fleet = Fleet;
 
-pub static FLEET_LOOKUP: Lazy<LookupType> =
-    Lazy::new(|| LookupType::ById(*FLEET_ID));
+pub static FLEET_LOOKUP: LazyLock<LookupType> =
+    LazyLock::new(|| LookupType::ById(*FLEET_ID));
 
 impl Eq for Fleet {}
 impl PartialEq for Fleet {

nexus/db-fixed-data/Cargo.toml

@@ -12,7 +12,6 @@ workspace = true
 omicron-rpaths.workspace = true
 
 [dependencies]
-once_cell.workspace = true
 # See omicron-rpaths for more about the "pq-sys" dependency.
 pq-sys = "*"
 strum.workspace = true
@@ -22,4 +21,3 @@ nexus-db-model.workspace = true
 nexus-types.workspace = true
 omicron-common.workspace = true
 omicron-workspace-hack.workspace = true
-