use std::marker::PhantomData;
use crate::lockable::{Lockable, OwnedLockable, RawLock, Sharable};
use crate::Keyable;
use super::{utils, LockGuard, OwnedLockCollection};
fn get_locks<L: Lockable>(data: &L) -> Vec<&dyn RawLock> {
let mut locks = Vec::new();
data.get_ptrs(&mut locks);
locks
}
unsafe impl<L: Lockable> Lockable for OwnedLockCollection<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 OwnedLockCollection<L> {}
unsafe impl<L: OwnedLockable> OwnedLockable for OwnedLockCollection<L> {}
impl<L> IntoIterator for OwnedLockCollection<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<L: OwnedLockable, I: FromIterator<L> + OwnedLockable> FromIterator<L>
for OwnedLockCollection<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 OwnedLockCollection<E> {
fn extend<T: IntoIterator<Item = L>>(&mut self, iter: T) {
self.data.extend(iter)
}
}
impl<L: OwnedLockable> AsMut<L> for OwnedLockCollection<L> {
fn as_mut(&mut self) -> &mut L {
&mut self.data
}
}
impl<L: OwnedLockable + Default> Default for OwnedLockCollection<L> {
fn default() -> Self {
Self::new(L::default())
}
}
impl<L: OwnedLockable + Default> From<L> for OwnedLockCollection<L> {
fn from(value: L) -> Self {
Self::new(value)
}
}
impl<L: OwnedLockable> OwnedLockCollection<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::OwnedLockCollection;
///
/// let data = (Mutex::new(0), Mutex::new(""));
/// let lock = OwnedLockCollection::new(data);
/// ```
#[must_use]
pub const fn new(data: L) -> Self {
Self { data }
}
/// Gets the underlying collection, consuming this collection.
///
/// # Examples
///
/// ```
/// use happylock::{Mutex, ThreadKey};
/// use happylock::collection::OwnedLockCollection;
///
/// let data = (Mutex::new(42), Mutex::new(""));
/// let lock = OwnedLockCollection::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::OwnedLockCollection;
///
/// let key = ThreadKey::get().unwrap();
/// let data = (Mutex::new(0), Mutex::new(""));
/// let lock = OwnedLockCollection::new(data);
///
/// let mut guard = lock.lock(key);
/// *guard.0 += 1;
/// *guard.1 = "1";
/// ```
pub fn lock<'g, 'key, Key: Keyable + 'key>(
&'g self,
key: Key,
) -> LockGuard<'key, L::Guard<'g>, Key> {
let locks = get_locks(&self.data);
for lock in locks {
// safety: we have the thread key, and these locks happen in a
// predetermined order
unsafe { lock.lock() };
}
// safety: we've locked all of this already
let guard = unsafe { 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::OwnedLockCollection;
///
/// let key = ThreadKey::get().unwrap();
/// let data = (Mutex::new(0), Mutex::new(""));
/// let lock = OwnedLockCollection::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 locks = get_locks(&self.data);
let guard = unsafe {
if !utils::ordered_try_lock(&locks) {
return None;
}
// safety: we've acquired the locks
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::OwnedLockCollection;
///
/// let key = ThreadKey::get().unwrap();
/// let data = (Mutex::new(0), Mutex::new(""));
/// let lock = OwnedLockCollection::new(data);
///
/// let mut guard = lock.lock(key);
/// *guard.0 += 1;
/// *guard.1 = "1";
/// let key = OwnedLockCollection::<(Mutex<i32>, Mutex<&str>)>::unlock(guard);
/// ```
#[allow(clippy::missing_const_for_fn)]
pub fn unlock<'g, 'key: 'g, Key: Keyable + 'key>(
guard: LockGuard<'key, L::Guard<'g>, Key>,
) -> Key {
drop(guard.guard);
guard.key
}
}
impl<L: Sharable> OwnedLockCollection<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::OwnedLockCollection;
///
/// let key = ThreadKey::get().unwrap();
/// let data = (RwLock::new(0), RwLock::new(""));
/// let lock = OwnedLockCollection::new(data);
///
/// let mut guard = lock.read(key);
/// assert_eq!(*guard.0, 0);
/// assert_eq!(*guard.1, "");
/// ```
pub fn read<'g, 'key, Key: Keyable + 'key>(
&'g self,
key: Key,
) -> LockGuard<'key, L::ReadGuard<'g>, Key> {
let locks = get_locks(&self.data);
for lock in locks {
// safety: we have the thread key, and these locks happen in a
// predetermined order
unsafe { lock.read() };
}
// safety: we've locked all of this already
let guard = unsafe { 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::OwnedLockCollection;
///
/// let key = ThreadKey::get().unwrap();
/// let data = (RwLock::new(5), RwLock::new("6"));
/// let lock = OwnedLockCollection::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 locks = get_locks(&self.data);
let guard = unsafe {
if !utils::ordered_try_read(&locks) {
return None;
}
// safety: we've acquired the locks
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::OwnedLockCollection;
///
/// let key = ThreadKey::get().unwrap();
/// let data = (RwLock::new(0), RwLock::new(""));
/// let lock = OwnedLockCollection::new(data);
///
/// let mut guard = lock.read(key);
/// let key = OwnedLockCollection::<(RwLock<i32>, RwLock<&str>)>::unlock_read(guard);
/// ```
#[allow(clippy::missing_const_for_fn)]
pub fn unlock_read<'g, 'key: 'g, Key: Keyable + 'key>(
guard: LockGuard<'key, L::ReadGuard<'g>, Key>,
) -> Key {
drop(guard.guard);
guard.key
}
}
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