Add safe read-write lock

stratum-apps/src/custom_rw_lock.rs

@@ -0,0 +1,63 @@
+//! A custom read write lock safe implementation
+
+use std::sync::{PoisonError, RwLock as InnerRwLock, RwLockReadGuard, RwLockWriteGuard};
+
+/// A thin wrapper around [`std::sync::RwLock`] with an explicit locking policy.
+///
+/// This type exists to provide clearer, more ergonomic locking APIs while
+/// preserving the semantics of `std::sync::RwLock`.
+///
+/// Higher-level methods on this type distinguish between:
+/// - Scoped, closure-based access, which prevents lock guards from escaping
+/// - Explicit guard-based access, for advanced use cases that require flexible control flow
+#[derive(Debug)]
+pub struct RwLock<T: ?Sized>(InnerRwLock<T>);
+
+impl<T> RwLock<T> {
+    /// Creates a new `RwLock` protecting `value`.
+    pub fn new(value: T) -> Self {
+        Self(InnerRwLock::new(value))
+    }
+}
+
+impl<T: ?Sized> RwLock<T> {
+    /// Executes `f` while holding a read lock.
+    ///
+    /// The lock guard cannot escape this method.
+    /// Prefer this over [`read`] for small, self-contained operations.
+    pub fn safe_read<F, R>(&self, f: F) -> Result<R, PoisonError<RwLockReadGuard<'_, T>>>
+    where
+        F: FnOnce(&T) -> R,
+    {
+        let guard = self.0.read()?;
+        Ok(f(&*guard))
+    }
+
+    /// Executes `f` while holding a write lock.
+    ///
+    /// The lock guard cannot escape this method.
+    /// Poisoning is propagated to the caller.
+    pub fn safe_write<F, R>(&self, f: F) -> Result<R, PoisonError<RwLockWriteGuard<'_, T>>>
+    where
+        F: FnOnce(&mut T) -> R,
+    {
+        let mut guard = self.0.write()?;
+        Ok(f(&mut *guard))
+    }
+
+    /// Acquires a read lock and returns the guard directly.
+    ///
+    /// This is an API intended for complex control flow where
+    /// closure-based locking would harm readability.
+    pub fn read(&self) -> Result<RwLockReadGuard<'_, T>, PoisonError<RwLockReadGuard<'_, T>>> {
+        self.0.read()
+    }
+
+    /// Acquires a write lock and returns the guard directly.
+    ///
+    /// Callers are responsible for keeping the
+    /// guard scope small and avoiding `.await` while holding it.
+    pub fn write(&self) -> Result<RwLockWriteGuard<'_, T>, PoisonError<RwLockWriteGuard<'_, T>>> {
+        self.0.write()
+    }
+}

stratum-apps/src/lib.rs

@@ -46,6 +46,7 @@ pub mod config_helpers;
 ///
 /// A wrapper around std::sync::Mutex
 pub mod custom_mutex;
+pub mod custom_rw_lock;
 /// RPC utilities for Job Declaration Server
 ///
 /// HTTP-based RPC server implementation for JD Server functionality.