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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:03:36 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:03:36 +0000 |
commit | 17d40c6057c88f4c432b0d7bac88e1b84cb7e67f (patch) | |
tree | 3f66c4a5918660bb8a758ab6cda5ff8ee4f6cdcd /library/std/src/sys_common/remutex.rs | |
parent | Adding upstream version 1.64.0+dfsg1. (diff) | |
download | rustc-17d40c6057c88f4c432b0d7bac88e1b84cb7e67f.tar.xz rustc-17d40c6057c88f4c432b0d7bac88e1b84cb7e67f.zip |
Adding upstream version 1.65.0+dfsg1.upstream/1.65.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | library/std/src/sys_common/remutex.rs | 46 |
1 files changed, 12 insertions, 34 deletions
diff --git a/library/std/src/sys_common/remutex.rs b/library/std/src/sys_common/remutex.rs index 8921af311..b448ae3a9 100644 --- a/library/std/src/sys_common/remutex.rs +++ b/library/std/src/sys_common/remutex.rs @@ -1,13 +1,11 @@ #[cfg(all(test, not(target_os = "emscripten")))] mod tests; +use super::mutex as sys; use crate::cell::UnsafeCell; -use crate::marker::PhantomPinned; use crate::ops::Deref; use crate::panic::{RefUnwindSafe, UnwindSafe}; -use crate::pin::Pin; use crate::sync::atomic::{AtomicUsize, Ordering::Relaxed}; -use crate::sys::locks as sys; /// A re-entrant mutual exclusion /// @@ -41,11 +39,10 @@ use crate::sys::locks as sys; /// synchronization is left to the mutex, making relaxed memory ordering for /// the `owner` field fine in all cases. pub struct ReentrantMutex<T> { - mutex: sys::Mutex, + mutex: sys::MovableMutex, owner: AtomicUsize, lock_count: UnsafeCell<u32>, data: T, - _pinned: PhantomPinned, } unsafe impl<T: Send> Send for ReentrantMutex<T> {} @@ -68,39 +65,22 @@ impl<T> RefUnwindSafe for ReentrantMutex<T> {} /// guarded data. #[must_use = "if unused the ReentrantMutex will immediately unlock"] pub struct ReentrantMutexGuard<'a, T: 'a> { - lock: Pin<&'a ReentrantMutex<T>>, + lock: &'a ReentrantMutex<T>, } impl<T> !Send for ReentrantMutexGuard<'_, T> {} impl<T> ReentrantMutex<T> { /// Creates a new reentrant mutex in an unlocked state. - /// - /// # Unsafety - /// - /// This function is unsafe because it is required that `init` is called - /// once this mutex is in its final resting place, and only then are the - /// lock/unlock methods safe. - pub const unsafe fn new(t: T) -> ReentrantMutex<T> { + pub const fn new(t: T) -> ReentrantMutex<T> { ReentrantMutex { - mutex: sys::Mutex::new(), + mutex: sys::MovableMutex::new(), owner: AtomicUsize::new(0), lock_count: UnsafeCell::new(0), data: t, - _pinned: PhantomPinned, } } - /// Initializes this mutex so it's ready for use. - /// - /// # Unsafety - /// - /// Unsafe to call more than once, and must be called after this will no - /// longer move in memory. - pub unsafe fn init(self: Pin<&mut Self>) { - self.get_unchecked_mut().mutex.init() - } - /// Acquires a mutex, blocking the current thread until it is able to do so. /// /// This function will block the caller until it is available to acquire the mutex. @@ -113,15 +93,14 @@ impl<T> ReentrantMutex<T> { /// If another user of this mutex panicked while holding the mutex, then /// this call will return failure if the mutex would otherwise be /// acquired. - pub fn lock(self: Pin<&Self>) -> ReentrantMutexGuard<'_, T> { + pub fn lock(&self) -> ReentrantMutexGuard<'_, T> { let this_thread = current_thread_unique_ptr(); - // Safety: We only touch lock_count when we own the lock, - // and since self is pinned we can safely call the lock() on the mutex. + // Safety: We only touch lock_count when we own the lock. unsafe { if self.owner.load(Relaxed) == this_thread { self.increment_lock_count(); } else { - self.mutex.lock(); + self.mutex.raw_lock(); self.owner.store(this_thread, Relaxed); debug_assert_eq!(*self.lock_count.get(), 0); *self.lock_count.get() = 1; @@ -142,10 +121,9 @@ impl<T> ReentrantMutex<T> { /// If another user of this mutex panicked while holding the mutex, then /// this call will return failure if the mutex would otherwise be /// acquired. - pub fn try_lock(self: Pin<&Self>) -> Option<ReentrantMutexGuard<'_, T>> { + pub fn try_lock(&self) -> Option<ReentrantMutexGuard<'_, T>> { let this_thread = current_thread_unique_ptr(); - // Safety: We only touch lock_count when we own the lock, - // and since self is pinned we can safely call the try_lock on the mutex. + // Safety: We only touch lock_count when we own the lock. unsafe { if self.owner.load(Relaxed) == this_thread { self.increment_lock_count(); @@ -179,12 +157,12 @@ impl<T> Deref for ReentrantMutexGuard<'_, T> { impl<T> Drop for ReentrantMutexGuard<'_, T> { #[inline] fn drop(&mut self) { - // Safety: We own the lock, and the lock is pinned. + // Safety: We own the lock. unsafe { *self.lock.lock_count.get() -= 1; if *self.lock.lock_count.get() == 0 { self.lock.owner.store(0, Relaxed); - self.lock.mutex.unlock(); + self.lock.mutex.raw_unlock(); } } } |