rdrand: Use once_cell::race::OnceBool

Author: briansmith

Cargo.toml

@@ -13,6 +13,10 @@ exclude = [".*"]
 
 [dependencies]
 cfg-if = "1"
+once_cell = { version = "1.19.0", default-features = false, optional = true }
+
+[target.'cfg(all(target_arch = "x86_64", target_env = "sgx"))'.dependencies]
+once_cell = { version = "1.19.0", default-features = false, features = ["race"] }
 
 # When built as part of libstd
 compiler_builtins = { version = "0.1", optional = true }
@@ -30,6 +34,10 @@ windows-targets = "0.52"
 [target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dependencies]
 wasm-bindgen = { version = "0.2.62", default-features = false, optional = true }
 js-sys = { version = "0.3", optional = true }
+
+[target.'cfg(any(target_arch = "x86", target_arch = "x86_64"))'.dev-dependencies]
+once_cell = { version = "1.19.0", default-features = false, features = ["race"] }
+
 [target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dev-dependencies]
 wasm-bindgen-test = "0.3.18"
 
@@ -40,7 +48,7 @@ std = []
 # Bumps minimum supported Linux kernel version to 3.17 and Android API level to 23 (Marshmallow).
 linux_disable_fallback = []
 # Feature to enable fallback RDRAND-based implementation on x86/x86_64
-rdrand = []
+rdrand = ["once_cell/race"]
 # Feature to enable JavaScript bindings on wasm*-unknown-unknown
 js = ["wasm-bindgen", "js-sys"]
 # Feature to enable custom RNG implementations

src/rdrand.rs

@@ -1,6 +1,7 @@
 //! RDRAND backend for x86(-64) targets
-use crate::{lazy::LazyBool, util::slice_as_uninit, Error};
+use crate::{util::slice_as_uninit, Error};
 use core::mem::{size_of, MaybeUninit};
+use once_cell::race::OnceBool;
 
 cfg_if! {
     if #[cfg(target_arch = "x86_64")] {
@@ -94,8 +95,8 @@ fn is_rdrand_good() -> bool {
 }
 
 pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
-    static RDRAND_GOOD: LazyBool = LazyBool::new();
-    if !RDRAND_GOOD.unsync_init(is_rdrand_good) {
+    static RDRAND_GOOD: OnceBool = OnceBool::new();
+    if !RDRAND_GOOD.get_or_init(is_rdrand_good) {
         return Err(Error::NO_RDRAND);
     }
     // SAFETY: After this point, we know rdrand is supported.

tests/rdrand.rs

@@ -6,8 +6,6 @@
 use getrandom::Error;
 #[macro_use]
 extern crate cfg_if;
-#[path = "../src/lazy.rs"]
-mod lazy;
 #[path = "../src/rdrand.rs"]
 mod rdrand;
 #[path = "../src/util.rs"]