Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 340 insertions, 0 deletions

diff --git a/vendor/spin/src/mutex.rs b/vendor/spin/src/mutex.rs
new file mode 100644
index 0000000..e333d8a
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+++ b/vendor/spin/src/mutex.rs
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+//! Locks that have the same behaviour as a mutex.
+//!
+//! The [`Mutex`] in the root of the crate, can be configured using the `ticket_mutex` feature.
+//! If it's enabled, [`TicketMutex`] and [`TicketMutexGuard`] will be re-exported as [`Mutex`]
+//! and [`MutexGuard`], otherwise the [`SpinMutex`] and guard will be re-exported.
+//!
+//! `ticket_mutex` is disabled by default.
+//!
+//! [`Mutex`]: ../struct.Mutex.html
+//! [`MutexGuard`]: ../struct.MutexGuard.html
+//! [`TicketMutex`]: ./struct.TicketMutex.html
+//! [`TicketMutexGuard`]: ./struct.TicketMutexGuard.html
+//! [`SpinMutex`]: ./struct.SpinMutex.html
+//! [`SpinMutexGuard`]: ./struct.SpinMutexGuard.html
+
+#[cfg(feature = "spin_mutex")]
+#[cfg_attr(docsrs, doc(cfg(feature = "spin_mutex")))]
+pub mod spin;
+#[cfg(feature = "spin_mutex")]
+#[cfg_attr(docsrs, doc(cfg(feature = "spin_mutex")))]
+pub use self::spin::{SpinMutex, SpinMutexGuard};
+
+#[cfg(feature = "ticket_mutex")]
+#[cfg_attr(docsrs, doc(cfg(feature = "ticket_mutex")))]
+pub mod ticket;
+#[cfg(feature = "ticket_mutex")]
+#[cfg_attr(docsrs, doc(cfg(feature = "ticket_mutex")))]
+pub use self::ticket::{TicketMutex, TicketMutexGuard};
+
+#[cfg(feature = "fair_mutex")]
+#[cfg_attr(docsrs, doc(cfg(feature = "fair_mutex")))]
+pub mod fair;
+#[cfg(feature = "fair_mutex")]
+#[cfg_attr(docsrs, doc(cfg(feature = "fair_mutex")))]
+pub use self::fair::{FairMutex, FairMutexGuard, Starvation};
+
+use crate::{RelaxStrategy, Spin};
+use core::{
+    fmt,
+    ops::{Deref, DerefMut},
+};
+
+#[cfg(all(not(feature = "spin_mutex"), not(feature = "use_ticket_mutex")))]
+compile_error!("The `mutex` feature flag was used (perhaps through another feature?) without either `spin_mutex` or `use_ticket_mutex`. One of these is required.");
+
+#[cfg(all(not(feature = "use_ticket_mutex"), feature = "spin_mutex"))]
+type InnerMutex<T, R> = self::spin::SpinMutex<T, R>;
+#[cfg(all(not(feature = "use_ticket_mutex"), feature = "spin_mutex"))]
+type InnerMutexGuard<'a, T> = self::spin::SpinMutexGuard<'a, T>;
+
+#[cfg(feature = "use_ticket_mutex")]
+type InnerMutex<T, R> = self::ticket::TicketMutex<T, R>;
+#[cfg(feature = "use_ticket_mutex")]
+type InnerMutexGuard<'a, T> = self::ticket::TicketMutexGuard<'a, T>;
+
+/// A spin-based lock providing mutually exclusive access to data.
+///
+/// The implementation uses either a ticket mutex or a regular spin mutex depending on whether the `spin_mutex` or
+/// `ticket_mutex` feature flag is enabled.
+///
+/// # Example
+///
+/// ```
+/// use spin;
+///
+/// let lock = spin::Mutex::new(0);
+///
+/// // Modify the data
+/// *lock.lock() = 2;
+///
+/// // Read the data
+/// let answer = *lock.lock();
+/// assert_eq!(answer, 2);
+/// ```
+///
+/// # Thread safety example
+///
+/// ```
+/// use spin;
+/// use std::sync::{Arc, Barrier};
+///
+/// let thread_count = 1000;
+/// let spin_mutex = Arc::new(spin::Mutex::new(0));
+///
+/// // We use a barrier to ensure the readout happens after all writing
+/// let barrier = Arc::new(Barrier::new(thread_count + 1));
+///
+/// # let mut ts = Vec::new();
+/// for _ in (0..thread_count) {
+///     let my_barrier = barrier.clone();
+///     let my_lock = spin_mutex.clone();
+/// # let t =
+///     std::thread::spawn(move || {
+///         let mut guard = my_lock.lock();
+///         *guard += 1;
+///
+///         // Release the lock to prevent a deadlock
+///         drop(guard);
+///         my_barrier.wait();
+///     });
+/// # ts.push(t);
+/// }
+///
+/// barrier.wait();
+///
+/// let answer = { *spin_mutex.lock() };
+/// assert_eq!(answer, thread_count);
+///
+/// # for t in ts {
+/// #     t.join().unwrap();
+/// # }
+/// ```
+pub struct Mutex<T: ?Sized, R = Spin> {
+    inner: InnerMutex<T, R>,
+}
+
+unsafe impl<T: ?Sized + Send, R> Sync for Mutex<T, R> {}
+unsafe impl<T: ?Sized + Send, R> Send for Mutex<T, R> {}
+
+/// A generic guard that will protect some data access and
+/// uses either a ticket lock or a normal spin mutex.
+///
+/// For more info see [`TicketMutexGuard`] or [`SpinMutexGuard`].
+///
+/// [`TicketMutexGuard`]: ./struct.TicketMutexGuard.html
+/// [`SpinMutexGuard`]: ./struct.SpinMutexGuard.html
+pub struct MutexGuard<'a, T: 'a + ?Sized> {
+    inner: InnerMutexGuard<'a, T>,
+}
+
+impl<T, R> Mutex<T, R> {
+    /// Creates a new [`Mutex`] wrapping the supplied data.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use spin::Mutex;
+    ///
+    /// static MUTEX: Mutex<()> = Mutex::new(());
+    ///
+    /// fn demo() {
+    ///     let lock = MUTEX.lock();
+    ///     // do something with lock
+    ///     drop(lock);
+    /// }
+    /// ```
+    #[inline(always)]
+    pub const fn new(value: T) -> Self {
+        Self {
+            inner: InnerMutex::new(value),
+        }
+    }
+
+    /// Consumes this [`Mutex`] and unwraps the underlying data.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// let lock = spin::Mutex::new(42);
+    /// assert_eq!(42, lock.into_inner());
+    /// ```
+    #[inline(always)]
+    pub fn into_inner(self) -> T {
+        self.inner.into_inner()
+    }
+}
+
+impl<T: ?Sized, R: RelaxStrategy> Mutex<T, R> {
+    /// Locks the [`Mutex`] and returns a guard that permits access to the inner data.
+    ///
+    /// The returned value may be dereferenced for data access
+    /// and the lock will be dropped when the guard falls out of scope.
+    ///
+    /// ```
+    /// let lock = spin::Mutex::new(0);
+    /// {
+    ///     let mut data = lock.lock();
+    ///     // The lock is now locked and the data can be accessed
+    ///     *data += 1;
+    ///     // The lock is implicitly dropped at the end of the scope
+    /// }
+    /// ```
+    #[inline(always)]
+    pub fn lock(&self) -> MutexGuard<T> {
+        MutexGuard {
+            inner: self.inner.lock(),
+        }
+    }
+}
+
+impl<T: ?Sized, R> Mutex<T, R> {
+    /// Returns `true` if the lock is currently held.
+    ///
+    /// # Safety
+    ///
+    /// This function provides no synchronization guarantees and so its result should be considered 'out of date'
+    /// the instant it is called. Do not use it for synchronization purposes. However, it may be useful as a heuristic.
+    #[inline(always)]
+    pub fn is_locked(&self) -> bool {
+        self.inner.is_locked()
+    }
+
+    /// Force unlock this [`Mutex`].
+    ///
+    /// # Safety
+    ///
+    /// This is *extremely* unsafe if the lock is not held by the current
+    /// thread. However, this can be useful in some instances for exposing the
+    /// lock to FFI that doesn't know how to deal with RAII.
+    #[inline(always)]
+    pub unsafe fn force_unlock(&self) {
+        self.inner.force_unlock()
+    }
+
+    /// Try to lock this [`Mutex`], returning a lock guard if successful.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// let lock = spin::Mutex::new(42);
+    ///
+    /// let maybe_guard = lock.try_lock();
+    /// assert!(maybe_guard.is_some());
+    ///
+    /// // `maybe_guard` is still held, so the second call fails
+    /// let maybe_guard2 = lock.try_lock();
+    /// assert!(maybe_guard2.is_none());
+    /// ```
+    #[inline(always)]
+    pub fn try_lock(&self) -> Option<MutexGuard<T>> {
+        self.inner
+            .try_lock()
+            .map(|guard| MutexGuard { inner: guard })
+    }
+
+    /// Returns a mutable reference to the underlying data.
+    ///
+    /// Since this call borrows the [`Mutex`] mutably, and a mutable reference is guaranteed to be exclusive in Rust,
+    /// no actual locking needs to take place -- the mutable borrow statically guarantees no locks exist. As such,
+    /// this is a 'zero-cost' operation.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// let mut lock = spin::Mutex::new(0);
+    /// *lock.get_mut() = 10;
+    /// assert_eq!(*lock.lock(), 10);
+    /// ```
+    #[inline(always)]
+    pub fn get_mut(&mut self) -> &mut T {
+        self.inner.get_mut()
+    }
+}
+
+impl<T: ?Sized + fmt::Debug, R> fmt::Debug for Mutex<T, R> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(&self.inner, f)
+    }
+}
+
+impl<T: ?Sized + Default, R> Default for Mutex<T, R> {
+    fn default() -> Self {
+        Self::new(Default::default())
+    }
+}
+
+impl<T, R> From<T> for Mutex<T, R> {
+    fn from(data: T) -> Self {
+        Self::new(data)
+    }
+}
+
+impl<'a, T: ?Sized> MutexGuard<'a, T> {
+    /// Leak the lock guard, yielding a mutable reference to the underlying data.
+    ///
+    /// Note that this function will permanently lock the original [`Mutex`].
+    ///
+    /// ```
+    /// let mylock = spin::Mutex::new(0);
+    ///
+    /// let data: &mut i32 = spin::MutexGuard::leak(mylock.lock());
+    ///
+    /// *data = 1;
+    /// assert_eq!(*data, 1);
+    /// ```
+    #[inline(always)]
+    pub fn leak(this: Self) -> &'a mut T {
+        InnerMutexGuard::leak(this.inner)
+    }
+}
+
+impl<'a, T: ?Sized + fmt::Debug> fmt::Debug for MutexGuard<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(&**self, f)
+    }
+}
+
+impl<'a, T: ?Sized + fmt::Display> fmt::Display for MutexGuard<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Display::fmt(&**self, f)
+    }
+}
+
+impl<'a, T: ?Sized> Deref for MutexGuard<'a, T> {
+    type Target = T;
+    fn deref(&self) -> &T {
+        &*self.inner
+    }
+}
+
+impl<'a, T: ?Sized> DerefMut for MutexGuard<'a, T> {
+    fn deref_mut(&mut self) -> &mut T {
+        &mut *self.inner
+    }
+}
+
+#[cfg(feature = "lock_api")]
+unsafe impl<R: RelaxStrategy> lock_api_crate::RawMutex for Mutex<(), R> {
+    type GuardMarker = lock_api_crate::GuardSend;
+
+    const INIT: Self = Self::new(());
+
+    fn lock(&self) {
+        // Prevent guard destructor running
+        core::mem::forget(Self::lock(self));
+    }
+
+    fn try_lock(&self) -> bool {
+        // Prevent guard destructor running
+        Self::try_lock(self).map(core::mem::forget).is_some()
+    }
+
+    unsafe fn unlock(&self) {
+        self.force_unlock();
+    }
+
+    fn is_locked(&self) -> bool {
+        self.inner.is_locked()
+    }
+}