Implement dummy Mutex, Condvar and RwLock

[rust-lightning] / lightning / src / sync.rs

diff --git a/lightning/src/sync.rs b/lightning/src/sync.rs
new file mode 100644 (file)
index 0000000..bde5470
--- /dev/null
+++ b/lightning/src/sync.rs
@@ -0,0 +1,115 @@
+pub use ::alloc::sync::Arc;
+use core::ops::{Deref, DerefMut};
+use core::time::Duration;
+use core::cell::{RefCell, Ref, RefMut};
+
+pub type LockResult<Guard> = Result<Guard, ()>;
+
+pub struct Condvar {}
+
+impl Condvar {
+       pub fn new() -> Condvar {
+               Condvar { }
+       }
+
+       pub fn wait<'a, T>(&'a self, guard: MutexGuard<'a, T>) -> LockResult<MutexGuard<'a, T>> {
+               Ok(guard)
+       }
+
+       #[allow(unused)]
+       pub fn wait_timeout<'a, T>(&'a self, guard: MutexGuard<'a, T>, _dur: Duration) -> LockResult<(MutexGuard<'a, T>, ())> {
+               Ok((guard, ()))
+       }
+
+       pub fn notify_all(&self) {}
+}
+
+pub struct Mutex<T: ?Sized> {
+       inner: RefCell<T>
+}
+
+#[must_use = "if unused the Mutex will immediately unlock"]
+pub struct MutexGuard<'a, T: ?Sized + 'a> {
+       lock: RefMut<'a, T>,
+}
+
+impl<T: ?Sized> Deref for MutexGuard<'_, T> {
+       type Target = T;
+
+       fn deref(&self) -> &T {
+               &self.lock.deref()
+       }
+}
+
+impl<T: ?Sized> DerefMut for MutexGuard<'_, T> {
+       fn deref_mut(&mut self) -> &mut T {
+               self.lock.deref_mut()
+       }
+}
+
+impl<T> Mutex<T> {
+       pub fn new(inner: T) -> Mutex<T> {
+               Mutex { inner: RefCell::new(inner) }
+       }
+
+       pub fn lock<'a>(&'a self) -> LockResult<MutexGuard<'a, T>> {
+               Ok(MutexGuard { lock: self.inner.borrow_mut() })
+       }
+
+       pub fn try_lock<'a>(&'a self) -> LockResult<MutexGuard<'a, T>> {
+               Ok(MutexGuard { lock: self.inner.borrow_mut() })
+       }
+}
+
+pub struct RwLock<T: ?Sized> {
+       inner: RefCell<T>
+}
+
+pub struct RwLockReadGuard<'a, T: ?Sized + 'a> {
+       lock: Ref<'a, T>,
+}
+
+pub struct RwLockWriteGuard<'a, T: ?Sized + 'a> {
+       lock: RefMut<'a, T>,
+}
+
+impl<T: ?Sized> Deref for RwLockReadGuard<'_, T> {
+       type Target = T;
+
+       fn deref(&self) -> &T {
+               &self.lock.deref()
+       }
+}
+
+impl<T: ?Sized> Deref for RwLockWriteGuard<'_, T> {
+       type Target = T;
+
+       fn deref(&self) -> &T {
+               &self.lock.deref()
+       }
+}
+
+impl<T: ?Sized> DerefMut for RwLockWriteGuard<'_, T> {
+       fn deref_mut(&mut self) -> &mut T {
+               self.lock.deref_mut()
+       }
+}
+
+impl<T> RwLock<T> {
+       pub fn new(inner: T) -> RwLock<T> {
+               RwLock { inner: RefCell::new(inner) }
+       }
+
+       pub fn read<'a>(&'a self) -> LockResult<RwLockReadGuard<'a, T>> {
+               Ok(RwLockReadGuard { lock: self.inner.borrow() })
+       }
+
+       pub fn write<'a>(&'a self) -> LockResult<RwLockWriteGuard<'a, T>> {
+               Ok(RwLockWriteGuard { lock: self.inner.borrow_mut() })
+       }
+
+       pub fn try_write<'a>(&'a self) -> LockResult<RwLockWriteGuard<'a, T>> {
+               // There is no try, grasshopper - only used for tests and expected to fail
+               Err(())
+       }
+}