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//! Plain, uninstrumented wrappers around [`parking_lot`] lock types.
//!
//! These definitions are used when no particular lock instrumentation
//! Cargo feature is selected.
use core::{fmt, ops};
use crate::lock::rank::LockRank;
pub struct RankData;
/// A plain wrapper around [`parking_lot::Mutex`].
///
/// This is just like [`parking_lot::Mutex`], except that our [`new`]
/// method takes a rank, indicating where the new mutex should sit in
/// `wgpu-core`'s lock ordering. The rank is ignored.
///
/// See the [`lock`] module documentation for other wrappers.
///
/// [`new`]: Mutex::new
/// [`lock`]: crate::lock
pub struct Mutex<T>(parking_lot::Mutex<T>);
/// A guard produced by locking [`Mutex`].
///
/// This is just a wrapper around a [`parking_lot::MutexGuard`].
pub struct MutexGuard<'a, T>(parking_lot::MutexGuard<'a, T>);
impl<T> Mutex<T> {
pub fn new(_rank: LockRank, value: T) -> Mutex<T> {
Mutex(parking_lot::Mutex::new(value))
}
pub fn lock(&self) -> MutexGuard<'_, T> {
MutexGuard(self.0.lock())
}
pub fn into_inner(self) -> T {
self.0.into_inner()
}
}
impl<'a, T> ops::Deref for MutexGuard<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.0.deref()
}
}
impl<'a, T> ops::DerefMut for MutexGuard<'a, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.0.deref_mut()
}
}
impl<T: fmt::Debug> fmt::Debug for Mutex<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
/// A plain wrapper around [`parking_lot::RwLock`].
///
/// This is just like [`parking_lot::RwLock`], except that our [`new`]
/// method takes a rank, indicating where the new mutex should sit in
/// `wgpu-core`'s lock ordering. The rank is ignored.
///
/// See the [`lock`] module documentation for other wrappers.
///
/// [`new`]: RwLock::new
/// [`lock`]: crate::lock
pub struct RwLock<T>(parking_lot::RwLock<T>);
/// A read guard produced by locking [`RwLock`] as a reader.
///
/// This is just a wrapper around a [`parking_lot::RwLockReadGuard`].
pub struct RwLockReadGuard<'a, T>(parking_lot::RwLockReadGuard<'a, T>);
/// A write guard produced by locking [`RwLock`] as a writer.
///
/// This is just a wrapper around a [`parking_lot::RwLockWriteGuard`].
pub struct RwLockWriteGuard<'a, T>(parking_lot::RwLockWriteGuard<'a, T>);
impl<T> RwLock<T> {
pub fn new(_rank: LockRank, value: T) -> RwLock<T> {
RwLock(parking_lot::RwLock::new(value))
}
pub fn read(&self) -> RwLockReadGuard<'_, T> {
RwLockReadGuard(self.0.read())
}
pub fn write(&self) -> RwLockWriteGuard<'_, T> {
RwLockWriteGuard(self.0.write())
}
/// Force an read-unlock operation on this lock.
///
/// Safety:
/// - A read lock must be held which is not held by a guard.
pub unsafe fn force_unlock_read(&self, _data: RankData) {
unsafe { self.0.force_unlock_read() };
}
}
impl<'a, T> RwLockReadGuard<'a, T> {
// Forget the read guard, leaving the lock in a locked state with no guard.
//
// Equivalent to std::mem::forget, but preserves the information about the lock
// rank.
pub fn forget(this: Self) -> RankData {
core::mem::forget(this.0);
RankData
}
}
impl<'a, T> RwLockWriteGuard<'a, T> {
pub fn downgrade(this: Self) -> RwLockReadGuard<'a, T> {
RwLockReadGuard(parking_lot::RwLockWriteGuard::downgrade(this.0))
}
}
impl<T: fmt::Debug> fmt::Debug for RwLock<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl<'a, T> ops::Deref for RwLockReadGuard<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.0.deref()
}
}
impl<'a, T> ops::Deref for RwLockWriteGuard<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.0.deref()
}
}
impl<'a, T> ops::DerefMut for RwLockWriteGuard<'a, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.0.deref_mut()
}
}