Add no_std once primitive for stdlib deserialization

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 - [BREAKING] Wrapped `MastForest`s in `Program` and `Library` structs in `Arc` (#1465).
 - `MastForestBuilder`: use `MastNodeId` instead of MAST root to uniquely identify procedures (#1473)
+- Added `miden_core::utils::sync::racy_lock` module (#1463).
+- Updated `miden_core::utils` to re-export `std::sync::LazyLock` and `racy_lock::RacyLock as LazyLock` for std and no_std environments, respectively (#1463).
 
 #### Fixes
 

core/README.md

@@ -11,3 +11,7 @@ This crate contains core components used by Miden VM. These components include:
 
 ## License
 This project is [MIT licensed](../LICENSE).
+
+## Acknowledgements
+
+The `racy_lock` module found under `core/src/utils/sync` is based on the [once_cell](https://crates.io/crates/once_cell) crate's implementation of `race::OnceBox`.

core/src/utils/sync/mod.rs

@@ -0,0 +1,12 @@
+pub mod racy_lock;
+pub mod rw_lock;
+
+#[cfg(feature = "std")]
+pub use std::sync::LazyLock;
+
+#[cfg(feature = "std")]
+pub use parking_lot::{RwLock, RwLockReadGuard, RwLockWriteGuard};
+#[cfg(not(feature = "std"))]
+pub use racy_lock::RacyLock as LazyLock;
+#[cfg(not(feature = "std"))]
+pub use rw_lock::{RwLock, RwLockReadGuard, RwLockWriteGuard};