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authorValentin Popov <valentin@popov.link>2024-07-19 15:37:58 +0300
committerValentin Popov <valentin@popov.link>2024-07-19 15:37:58 +0300
commita990de90fe41456a23e58bd087d2f107d321f3a1 (patch)
tree15afc392522a9e85dc3332235e311b7d39352ea9 /vendor/crossbeam-utils/src/sync/once_lock.rs
parent3d48cd3f81164bbfc1a755dc1d4a9a02f98c8ddd (diff)
downloadfparkan-a990de90fe41456a23e58bd087d2f107d321f3a1.tar.xz
fparkan-a990de90fe41456a23e58bd087d2f107d321f3a1.zip
Deleted vendor folder
Diffstat (limited to 'vendor/crossbeam-utils/src/sync/once_lock.rs')
-rw-r--r--vendor/crossbeam-utils/src/sync/once_lock.rs88
1 files changed, 0 insertions, 88 deletions
diff --git a/vendor/crossbeam-utils/src/sync/once_lock.rs b/vendor/crossbeam-utils/src/sync/once_lock.rs
deleted file mode 100644
index e057aca..0000000
--- a/vendor/crossbeam-utils/src/sync/once_lock.rs
+++ /dev/null
@@ -1,88 +0,0 @@
-// Based on unstable std::sync::OnceLock.
-//
-// Source: https://github.com/rust-lang/rust/blob/8e9c93df464b7ada3fc7a1c8ccddd9dcb24ee0a0/library/std/src/sync/once_lock.rs
-
-use core::cell::UnsafeCell;
-use core::mem::MaybeUninit;
-use std::sync::Once;
-
-pub(crate) struct OnceLock<T> {
- once: Once,
- value: UnsafeCell<MaybeUninit<T>>,
- // Unlike std::sync::OnceLock, we don't need PhantomData here because
- // we don't use #[may_dangle].
-}
-
-unsafe impl<T: Sync + Send> Sync for OnceLock<T> {}
-unsafe impl<T: Send> Send for OnceLock<T> {}
-
-impl<T> OnceLock<T> {
- /// Creates a new empty cell.
- #[must_use]
- pub(crate) const fn new() -> Self {
- Self {
- once: Once::new(),
- value: UnsafeCell::new(MaybeUninit::uninit()),
- }
- }
-
- /// Gets the contents of the cell, initializing it with `f` if the cell
- /// was empty.
- ///
- /// Many threads may call `get_or_init` concurrently with different
- /// initializing functions, but it is guaranteed that only one function
- /// will be executed.
- ///
- /// # Panics
- ///
- /// If `f` panics, the panic is propagated to the caller, and the cell
- /// remains uninitialized.
- ///
- /// It is an error to reentrantly initialize the cell from `f`. The
- /// exact outcome is unspecified. Current implementation deadlocks, but
- /// this may be changed to a panic in the future.
- pub(crate) fn get_or_init<F>(&self, f: F) -> &T
- where
- F: FnOnce() -> T,
- {
- // Fast path check
- if self.once.is_completed() {
- // SAFETY: The inner value has been initialized
- return unsafe { self.get_unchecked() };
- }
- self.initialize(f);
-
- // SAFETY: The inner value has been initialized
- unsafe { self.get_unchecked() }
- }
-
- #[cold]
- fn initialize<F>(&self, f: F)
- where
- F: FnOnce() -> T,
- {
- let slot = self.value.get();
-
- self.once.call_once(|| {
- let value = f();
- unsafe { slot.write(MaybeUninit::new(value)) }
- });
- }
-
- /// # Safety
- ///
- /// The value must be initialized
- unsafe fn get_unchecked(&self) -> &T {
- debug_assert!(self.once.is_completed());
- &*self.value.get().cast::<T>()
- }
-}
-
-impl<T> Drop for OnceLock<T> {
- fn drop(&mut self) {
- if self.once.is_completed() {
- // SAFETY: The inner value has been initialized
- unsafe { (*self.value.get()).assume_init_drop() };
- }
- }
-}