Merge branch '0.2'

1 files changed, 619 insertions, 0 deletions

diff --git a/src/collection/retry.rs b/src/collection/retry.rs
new file mode 100644
index 0000000..2b9b0a0
--- /dev/null
+++ b/src/collection/retry.rs
@@ -0,0 +1,619 @@
+use crate::lockable::{Lockable, OwnedLockable, RawLock, Sharable};
+use crate::Keyable;
+
+use std::collections::HashSet;
+use std::marker::PhantomData;
+
+use super::{LockGuard, RetryingLockCollection};
+
+/// Checks that a collection contains no duplicate references to a lock.
+fn contains_duplicates<L: Lockable>(data: L) -> bool {
+	let mut locks = Vec::new();
+	data.get_ptrs(&mut locks);
+	let locks = locks.into_iter().map(|l| l as *const dyn RawLock);
+
+	let mut locks_set = HashSet::with_capacity(locks.len());
+	for lock in locks {
+		if !locks_set.insert(lock) {
+			return true;
+		}
+	}
+
+	false
+}
+
+unsafe impl<L: Lockable> Lockable for RetryingLockCollection<L> {
+	type Guard<'g> = L::Guard<'g> where Self: 'g;
+
+	type ReadGuard<'g> = L::ReadGuard<'g> where Self: 'g;
+
+	fn get_ptrs<'a>(&'a self, ptrs: &mut Vec<&'a dyn RawLock>) {
+		self.data.get_ptrs(ptrs)
+	}
+
+	unsafe fn guard(&self) -> Self::Guard<'_> {
+		self.data.guard()
+	}
+
+	unsafe fn read_guard(&self) -> Self::ReadGuard<'_> {
+		self.data.read_guard()
+	}
+}
+
+unsafe impl<L: Sharable> Sharable for RetryingLockCollection<L> {}
+
+unsafe impl<L: OwnedLockable> OwnedLockable for RetryingLockCollection<L> {}
+
+impl<L> IntoIterator for RetryingLockCollection<L>
+where
+	L: IntoIterator,
+{
+	type Item = <L as IntoIterator>::Item;
+	type IntoIter = <L as IntoIterator>::IntoIter;
+
+	fn into_iter(self) -> Self::IntoIter {
+		self.data.into_iter()
+	}
+}
+
+impl<'a, L> IntoIterator for &'a RetryingLockCollection<L>
+where
+	&'a L: IntoIterator,
+{
+	type Item = <&'a L as IntoIterator>::Item;
+	type IntoIter = <&'a L as IntoIterator>::IntoIter;
+
+	fn into_iter(self) -> Self::IntoIter {
+		self.data.into_iter()
+	}
+}
+
+impl<'a, L> IntoIterator for &'a mut RetryingLockCollection<L>
+where
+	&'a mut L: IntoIterator,
+{
+	type Item = <&'a mut L as IntoIterator>::Item;
+	type IntoIter = <&'a mut L as IntoIterator>::IntoIter;
+
+	fn into_iter(self) -> Self::IntoIter {
+		self.data.into_iter()
+	}
+}
+
+impl<L: OwnedLockable, I: FromIterator<L> + OwnedLockable> FromIterator<L>
+	for RetryingLockCollection<I>
+{
+	fn from_iter<T: IntoIterator<Item = L>>(iter: T) -> Self {
+		let iter: I = iter.into_iter().collect();
+		Self::new(iter)
+	}
+}
+
+impl<E: OwnedLockable + Extend<L>, L: OwnedLockable> Extend<L> for RetryingLockCollection<E> {
+	fn extend<T: IntoIterator<Item = L>>(&mut self, iter: T) {
+		self.data.extend(iter)
+	}
+}
+
+impl<L> AsRef<L> for RetryingLockCollection<L> {
+	fn as_ref(&self) -> &L {
+		&self.data
+	}
+}
+
+impl<L> AsMut<L> for RetryingLockCollection<L> {
+	fn as_mut(&mut self) -> &mut L {
+		&mut self.data
+	}
+}
+
+impl<L: OwnedLockable + Default> Default for RetryingLockCollection<L> {
+	fn default() -> Self {
+		Self::new(L::default())
+	}
+}
+
+impl<L: OwnedLockable> From<L> for RetryingLockCollection<L> {
+	fn from(value: L) -> Self {
+		Self::new(value)
+	}
+}
+
+impl<L: OwnedLockable> RetryingLockCollection<L> {
+	/// Creates a new collection of owned locks.
+	///
+	/// Because the locks are owned, there's no need to do any checks for
+	/// duplicate values. The locks also don't need to be sorted by memory
+	/// address because they aren't used anywhere else.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::Mutex;
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let data = (Mutex::new(0), Mutex::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	/// ```
+	#[must_use]
+	pub const fn new(data: L) -> Self {
+		Self { data }
+	}
+}
+
+impl<'a, L: OwnedLockable> RetryingLockCollection<&'a L> {
+	/// Creates a new collection of owned locks.
+	///
+	/// Because the locks are owned, there's no need to do any checks for
+	/// duplicate values.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::Mutex;
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let data = (Mutex::new(0), Mutex::new(""));
+	/// let lock = RetryingLockCollection::new_ref(&data);
+	/// ```
+	#[must_use]
+	pub const fn new_ref(data: &'a L) -> Self {
+		Self { data }
+	}
+}
+
+impl<L: Lockable> RetryingLockCollection<L> {
+	/// Creates a new collections of locks.
+	///
+	/// # Safety
+	///
+	/// This results in undefined behavior if any locks are presented twice
+	/// within this collection.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::Mutex;
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let data1 = Mutex::new(0);
+	/// let data2 = Mutex::new("");
+	///
+	/// // safety: data1 and data2 refer to distinct mutexes
+	/// let data = (&data1, &data2);
+	/// let lock = unsafe { RetryingLockCollection::new_unchecked(&data) };
+	/// ```
+	#[must_use]
+	pub const unsafe fn new_unchecked(data: L) -> Self {
+		Self { data }
+	}
+
+	/// Creates a new collection of locks.
+	///
+	/// This returns `None` if any locks are found twice in the given
+	/// collection.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::Mutex;
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let data1 = Mutex::new(0);
+	/// let data2 = Mutex::new("");
+	///
+	/// // data1 and data2 refer to distinct mutexes, so this won't panic
+	/// let data = (&data1, &data2);
+	/// let lock = RetryingLockCollection::try_new(&data).unwrap();
+	/// ```
+	#[must_use]
+	pub fn try_new(data: L) -> Option<Self> {
+		(!contains_duplicates(&data)).then_some(Self { data })
+	}
+
+	/// Gets the underlying collection, consuming this collection.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{Mutex, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let data = (Mutex::new(42), Mutex::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let inner = lock.into_inner();
+	/// let guard = inner.0.lock(key);
+	/// assert_eq!(*guard, 42);
+	/// ```
+	#[must_use]
+	pub fn into_inner(self) -> L {
+		self.data
+	}
+
+	/// Locks the collection
+	///
+	/// This function returns a guard that can be used to access the underlying
+	/// data. When the guard is dropped, the locks in the collection are also
+	/// dropped.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{Mutex, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = (Mutex::new(0), Mutex::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// let mut guard = lock.lock(key);
+	/// *guard.0 += 1;
+	/// *guard.1 = "1";
+	/// ```
+	pub fn lock<'g, 'key: 'g, Key: Keyable + 'key>(
+		&'g self,
+		key: Key,
+	) -> LockGuard<'key, L::Guard<'g>, Key> {
+		let mut first_index = 0;
+		let mut locks = Vec::new();
+		self.data.get_ptrs(&mut locks);
+
+		if locks.is_empty() {
+			return LockGuard {
+				// safety: there's no data being returned
+				guard: unsafe { self.data.guard() },
+				key,
+				_phantom: PhantomData,
+			};
+		}
+
+		let guard = unsafe {
+			'outer: loop {
+				// safety: we have the thread key
+				locks[first_index].lock();
+				for (i, lock) in locks.iter().enumerate() {
+					if i == first_index {
+						continue;
+					}
+
+					// safety: we have the thread key
+					if !lock.try_lock() {
+						for lock in locks.iter().take(i) {
+							// safety: we already locked all of these
+							lock.unlock();
+						}
+
+						if first_index >= i {
+							// safety: this is already locked and can't be unlocked
+							//         by the previous loop
+							locks[first_index].unlock();
+						}
+
+						first_index = i;
+						continue 'outer;
+					}
+				}
+
+				// safety: we locked all the data
+				break self.data.guard();
+			}
+		};
+
+		LockGuard {
+			guard,
+			key,
+			_phantom: PhantomData,
+		}
+	}
+
+	/// Attempts to lock the without blocking.
+	///
+	/// If successful, this method returns a guard that can be used to access
+	/// the data, and unlocks the data when it is dropped. Otherwise, `None` is
+	/// returned.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{Mutex, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = (Mutex::new(0), Mutex::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// match lock.try_lock(key) {
+	///     Some(mut guard) => {
+	///         *guard.0 += 1;
+	///         *guard.1 = "1";
+	///     },
+	///     None => unreachable!(),
+	/// };
+	///
+	/// ```
+	pub fn try_lock<'g, 'key: 'g, Key: Keyable + 'key>(
+		&'g self,
+		key: Key,
+	) -> Option<LockGuard<'key, L::Guard<'g>, Key>> {
+		let mut locks = Vec::new();
+		self.data.get_ptrs(&mut locks);
+
+		if locks.is_empty() {
+			return Some(LockGuard {
+				// safety: there's no data being returned
+				guard: unsafe { self.data.guard() },
+				key,
+				_phantom: PhantomData,
+			});
+		}
+
+		let guard = unsafe {
+			for (i, lock) in locks.iter().enumerate() {
+				// safety: we have the thread key
+				if !lock.try_lock() {
+					for lock in locks.iter().take(i) {
+						// safety: we already locked all of these
+						lock.unlock();
+					}
+					return None;
+				}
+			}
+
+			// safety: we locked all the data
+			self.data.guard()
+		};
+
+		Some(LockGuard {
+			guard,
+			key,
+			_phantom: PhantomData,
+		})
+	}
+
+	/// Unlocks the underlying lockable data type, returning the key that's
+	/// associated with it.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{Mutex, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = (Mutex::new(0), Mutex::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// let mut guard = lock.lock(key);
+	/// *guard.0 += 1;
+	/// *guard.1 = "1";
+	/// let key = RetryingLockCollection::<(Mutex<i32>, Mutex<&str>)>::unlock(guard);
+	/// ```
+	pub fn unlock<'key, Key: Keyable + 'key>(guard: LockGuard<'key, L::Guard<'_>, Key>) -> Key {
+		drop(guard.guard);
+		guard.key
+	}
+}
+
+impl<L: Sharable> RetryingLockCollection<L> {
+	/// Locks the collection, so that other threads can still read from it
+	///
+	/// This function returns a guard that can be used to access the underlying
+	/// data immutably. When the guard is dropped, the locks in the collection
+	/// are also dropped.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{RwLock, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = (RwLock::new(0), RwLock::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// let mut guard = lock.read(key);
+	/// assert_eq!(*guard.0, 0);
+	/// assert_eq!(*guard.1, "");
+	/// ```
+	pub fn read<'g, 'key: 'g, Key: Keyable + 'key>(
+		&'g self,
+		key: Key,
+	) -> LockGuard<'key, L::ReadGuard<'g>, Key> {
+		let mut first_index = 0;
+		let mut locks = Vec::new();
+		self.data.get_ptrs(&mut locks);
+
+		if locks.is_empty() {
+			return LockGuard {
+				// safety: there's no data being returned
+				guard: unsafe { self.data.read_guard() },
+				key,
+				_phantom: PhantomData,
+			};
+		}
+
+		let guard = unsafe {
+			'outer: loop {
+				// safety: we have the thread key
+				locks[first_index].read();
+				for (i, lock) in locks.iter().enumerate() {
+					if i == first_index {
+						continue;
+					}
+
+					// safety: we have the thread key
+					if !lock.try_read() {
+						for lock in locks.iter().take(i) {
+							// safety: we already locked all of these
+							lock.unlock_read();
+						}
+
+						if first_index >= i {
+							// safety: this is already locked and can't be unlocked
+							//         by the previous loop
+							locks[first_index].unlock_read();
+						}
+
+						first_index = i;
+						continue 'outer;
+					}
+				}
+
+				// safety: we locked all the data
+				break self.data.read_guard();
+			}
+		};
+
+		LockGuard {
+			guard,
+			key,
+			_phantom: PhantomData,
+		}
+	}
+
+	/// Attempts to lock the without blocking, in such a way that other threads
+	/// can still read from the collection.
+	///
+	/// If successful, this method returns a guard that can be used to access
+	/// the data immutably, and unlocks the data when it is dropped. Otherwise,
+	/// `None` is returned.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{RwLock, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = (RwLock::new(5), RwLock::new("6"));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// match lock.try_read(key) {
+	///     Some(mut guard) => {
+	///         assert_eq!(*guard.0, 5);
+	///         assert_eq!(*guard.1, "6");
+	///     },
+	///     None => unreachable!(),
+	/// };
+	///
+	/// ```
+	pub fn try_read<'g, 'key: 'g, Key: Keyable + 'key>(
+		&'g self,
+		key: Key,
+	) -> Option<LockGuard<'key, L::ReadGuard<'g>, Key>> {
+		let mut locks = Vec::new();
+		self.data.get_ptrs(&mut locks);
+
+		if locks.is_empty() {
+			return Some(LockGuard {
+				// safety: there's no data being returned
+				guard: unsafe { self.data.read_guard() },
+				key,
+				_phantom: PhantomData,
+			});
+		}
+
+		let guard = unsafe {
+			for (i, lock) in locks.iter().enumerate() {
+				// safety: we have the thread key
+				if !lock.try_read() {
+					for lock in locks.iter().take(i) {
+						// safety: we already locked all of these
+						lock.unlock_read();
+					}
+					return None;
+				}
+			}
+
+			// safety: we locked all the data
+			self.data.read_guard()
+		};
+
+		Some(LockGuard {
+			guard,
+			key,
+			_phantom: PhantomData,
+		})
+	}
+
+	/// Unlocks the underlying lockable data type, returning the key that's
+	/// associated with it.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{RwLock, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = (RwLock::new(0), RwLock::new(""));
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// let mut guard = lock.read(key);
+	/// let key = RetryingLockCollection::<(RwLock<i32>, RwLock<&str>)>::unlock_read(guard);
+	/// ```
+	pub fn unlock_read<'key, Key: Keyable + 'key>(
+		guard: LockGuard<'key, L::ReadGuard<'_>, Key>,
+	) -> Key {
+		drop(guard.guard);
+		guard.key
+	}
+}
+
+impl<'a, L: 'a> RetryingLockCollection<L>
+where
+	&'a L: IntoIterator,
+{
+	/// Returns an iterator over references to each value in the collection.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{Mutex, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = [Mutex::new(26), Mutex::new(1)];
+	/// let lock = RetryingLockCollection::new(data);
+	///
+	/// let mut iter = lock.iter();
+	/// let mutex = iter.next().unwrap();
+	/// let guard = mutex.lock(key);
+	///
+	/// assert_eq!(*guard, 26);
+	/// ```
+	#[must_use]
+	pub fn iter(&'a self) -> <&'a L as IntoIterator>::IntoIter {
+		self.into_iter()
+	}
+}
+
+impl<'a, L: 'a> RetryingLockCollection<L>
+where
+	&'a mut L: IntoIterator,
+{
+	/// Returns an iterator over mutable references to each value in the
+	/// collection.
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use happylock::{Mutex, ThreadKey};
+	/// use happylock::collection::RetryingLockCollection;
+	///
+	/// let key = ThreadKey::get().unwrap();
+	/// let data = [Mutex::new(26), Mutex::new(1)];
+	/// let mut lock = RetryingLockCollection::new(data);
+	///
+	/// let mut iter = lock.iter_mut();
+	/// let mutex = iter.next().unwrap();
+	///
+	/// assert_eq!(*mutex.as_mut(), 26);
+	/// ```
+	#[must_use]
+	pub fn iter_mut(&'a mut self) -> <&'a mut L as IntoIterator>::IntoIter {
+		self.into_iter()
+	}
+}