use crate::lockable::{
Lockable, LockableGetMut, LockableIntoInner, OwnedLockable, RawLock, Sharable,
};
use crate::{Keyable, ThreadKey};
use super::{utils, LockGuard, OwnedLockCollection};
unsafe impl<L: Lockable> RawLock for OwnedLockCollection<L> {
#[mutants::skip] // this should never run
#[cfg(not(tarpaulin_include))]
fn poison(&self) {
let locks = utils::get_locks_unsorted(&self.data);
for lock in locks {
lock.poison();
}
}
unsafe fn raw_lock(&self) {
utils::ordered_lock(&utils::get_locks_unsorted(&self.data))
}
unsafe fn raw_try_lock(&self) -> bool {
let locks = utils::get_locks_unsorted(&self.data);
utils::ordered_try_lock(&locks)
}
unsafe fn raw_unlock(&self) {
let locks = utils::get_locks_unsorted(&self.data);
for lock in locks {
lock.raw_unlock();
}
}
unsafe fn raw_read(&self) {
utils::ordered_read(&utils::get_locks_unsorted(&self.data))
}
unsafe fn raw_try_read(&self) -> bool {
let locks = utils::get_locks_unsorted(&self.data);
utils::ordered_try_read(&locks)
}
unsafe fn raw_unlock_read(&self) {
let locks = utils::get_locks_unsorted(&self.data);
for lock in locks {
lock.raw_unlock_read();
}
}
}
unsafe impl<L: Lockable> Lockable for OwnedLockCollection<L> {
type Guard<'g>
= L::Guard<'g>
where
Self: 'g;
type DataMut<'a>
= L::DataMut<'a>
where
Self: 'a;
#[mutants::skip] // It's hard to test lkocks in an OwnedLockCollection, because they're owned
#[cfg(not(tarpaulin_include))]
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 data_mut(&self) -> Self::DataMut<'_> {
self.data.data_mut()
}
}
impl<L: LockableGetMut> LockableGetMut for OwnedLockCollection<L> {
type Inner<'a>
= L::Inner<'a>
where
Self: 'a;
fn get_mut(&mut self) -> Self::Inner<'_> {
self.data.get_mut()
}
}
impl<L: LockableIntoInner> LockableIntoInner for OwnedLockCollection<L> {
type Inner = L::Inner;
fn into_inner(self) -> Self::Inner {
self.data.into_inner()
}
}
unsafe impl<L: Sharable> Sharable for OwnedLockCollection<L> {
type ReadGuard<'g>
= L::ReadGuard<'g>
where
Self: 'g;
type DataRef<'a>
= L::DataRef<'a>
where
Self: 'a;
unsafe fn read_guard(&self) -> Self::ReadGuard<'_> {
self.data.read_guard()
}
unsafe fn data_ref(&self) -> Self::DataRef<'_> {
self.data.data_ref()
}
}
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)
}
}
// AsRef can't be implemented because an impl of AsRef<L> for L could break the
// invariant that there is only one way to lock the collection. AsMut is fine,
// because the collection can't be locked as long as the reference is valid.
impl<T, L: AsMut<T>> AsMut<T> for OwnedLockCollection<L> {
fn as_mut(&mut self) -> &mut T {
self.data.as_mut()
}
}
impl<L: OwnedLockable + Default> Default for OwnedLockCollection<L> {
fn default() -> Self {
Self::new(L::default())
}
}
impl<L: OwnedLockable> 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 }
}
pub fn scoped_lock<R>(&self, key: impl Keyable, f: impl Fn(L::DataMut<'_>) -> R) -> R {
unsafe {
// safety: we have the thread key
self.raw_lock();
// safety: the data was just locked
let r = f(self.data_mut());
// safety: the collection is still locked
self.raw_unlock();
drop(key); // ensure the key stays alive long enough
r
}
}
pub fn scoped_try_lock<Key: Keyable, R>(
&self,
key: Key,
f: impl Fn(L::DataMut<'_>) -> R,
) -> Result<R, Key> {
unsafe {
// safety: we have the thread key
if !self.raw_try_lock() {
return Err(key);
}
// safety: we just locked the collection
let r = f(self.data_mut());
// safety: the collection is still locked
self.raw_unlock();
drop(key); // ensures the key stays valid long enough
Ok(r)
}
}
/// 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(&self, key: ThreadKey) -> LockGuard<L::Guard<'_>> {
let guard = unsafe {
// safety: we have the thread key, and these locks happen in a
// predetermined order
self.raw_lock();
// safety: we've locked all of this already
self.data.guard()
};
LockGuard { guard, key }
}
/// Attempts to lock the without blocking.
///
/// If the access could not be granted at this time, then `Err` is
/// returned. Otherwise, an RAII guard is returned which will release the
/// locks when it is dropped.
///
/// # Errors
///
/// If any of the locks in this collection are already locked, this returns
/// an error containing the given key.
///
/// # 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) {
/// Ok(mut guard) => {
/// *guard.0 += 1;
/// *guard.1 = "1";
/// },
/// Err(_) => unreachable!(),
/// };
///
/// ```
pub fn try_lock(&self, key: ThreadKey) -> Result<LockGuard<L::Guard<'_>>, ThreadKey> {
let guard = unsafe {
if !self.raw_try_lock() {
return Err(key);
}
// safety: we've acquired the locks
self.data.guard()
};
Ok(LockGuard { guard, key })
}
/// 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(guard: LockGuard<L::Guard<'_>>) -> ThreadKey {
drop(guard.guard);
guard.key
}
}
impl<L: Sharable> OwnedLockCollection<L> {
pub fn scoped_read<R>(&self, key: impl Keyable, f: impl Fn(L::DataRef<'_>) -> R) -> R {
unsafe {
// safety: we have the thread key
self.raw_read();
// safety: the data was just locked
let r = f(self.data_ref());
// safety: the collection is still locked
self.raw_unlock_read();
drop(key); // ensure the key stays alive long enough
r
}
}
pub fn scoped_try_read<Key: Keyable, R>(
&self,
key: Key,
f: impl Fn(L::DataRef<'_>) -> R,
) -> Result<R, Key> {
unsafe {
// safety: we have the thread key
if !self.raw_try_read() {
return Err(key);
}
// safety: we just locked the collection
let r = f(self.data_ref());
// safety: the collection is still locked
self.raw_unlock_read();
drop(key); // ensures the key stays valid long enough
Ok(r)
}
}
/// 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(&self, key: ThreadKey) -> LockGuard<L::ReadGuard<'_>> {
unsafe {
// safety: we have the thread key
self.raw_read();
LockGuard {
// safety: we've already acquired the lock
guard: self.data.read_guard(),
key,
}
}
}
/// Attempts to lock the without blocking, in such a way that other threads
/// can still read from the collection.
///
/// If the access could not be granted at this time, then `Err` is
/// returned. Otherwise, an RAII guard is returned which will release the
/// shared access when it is dropped.
///
/// # Errors
///
/// If any of the locks in this collection can't be acquired, then an error
/// is returned containing the given key.
///
/// # 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) {
/// Ok(mut guard) => {
/// assert_eq!(*guard.0, 5);
/// assert_eq!(*guard.1, "6");
/// },
/// Err(_) => unreachable!(),
/// };
///
/// ```
pub fn try_read(&self, key: ThreadKey) -> Result<LockGuard<L::ReadGuard<'_>>, ThreadKey> {
let guard = unsafe {
// safety: we have the thread key
if !self.raw_try_read() {
return Err(key);
}
// safety: we've acquired the locks
self.data.read_guard()
};
Ok(LockGuard { guard, key })
}
/// 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(guard: LockGuard<L::ReadGuard<'_>>) -> ThreadKey {
drop(guard.guard);
guard.key
}
}
impl<L> OwnedLockCollection<L> {
/// 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_child();
/// let guard = inner.0.lock(key);
/// assert_eq!(*guard, 42);
/// ```
#[must_use]
pub fn into_child(self) -> L {
self.data
}
/// Gets a mutable reference to the underlying collection.
///
/// # Examples
///
/// ```
/// use happylock::{Mutex, ThreadKey};
/// use happylock::collection::OwnedLockCollection;
///
/// let data = (Mutex::new(42), Mutex::new(""));
/// let mut lock = OwnedLockCollection::new(data);
///
/// let key = ThreadKey::get().unwrap();
/// let mut inner = lock.child_mut();
/// let guard = inner.0.get_mut();
/// assert_eq!(*guard, 42);
/// ```
#[must_use]
pub fn child_mut(&mut self) -> &mut L {
&mut self.data
}
}
impl<L: LockableGetMut> OwnedLockCollection<L> {
/// Gets a mutable reference to the data behind this `OwnedLockCollection`.
///
/// Since this call borrows the `OwnedLockCollection` mutably, no actual
/// locking needs to take place - the mutable borrow statically guarantees
/// no locks exist.
///
/// # Examples
///
/// ```
/// use happylock::{Mutex, LockCollection};
/// use happylock::collection::OwnedLockCollection;
///
/// let mut mutex = OwnedLockCollection::new([Mutex::new(0), Mutex::new(0)]);
/// assert_eq!(mutex.get_mut(), [&mut 0, &mut 0]);
/// ```
pub fn get_mut(&mut self) -> L::Inner<'_> {
LockableGetMut::get_mut(self)
}
}
impl<L: LockableIntoInner> OwnedLockCollection<L> {
/// Consumes this `OwnedLockCollection`, returning the underlying data.
///
/// # Examples
///
/// ```
/// use happylock::{Mutex, LockCollection};
/// use happylock::collection::OwnedLockCollection;
///
/// let mutex = OwnedLockCollection::new([Mutex::new(0), Mutex::new(0)]);
/// assert_eq!(mutex.into_inner(), [0, 0]);
/// ```
#[must_use]
pub fn into_inner(self) -> L::Inner {
LockableIntoInner::into_inner(self)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{Mutex, ThreadKey};
#[test]
fn get_mut_applies_changes() {
let key = ThreadKey::get().unwrap();
let mut collection = OwnedLockCollection::new([Mutex::new("foo"), Mutex::new("bar")]);
assert_eq!(*collection.get_mut()[0], "foo");
assert_eq!(*collection.get_mut()[1], "bar");
*collection.get_mut()[0] = "baz";
let guard = collection.lock(key);
assert_eq!(*guard[0], "baz");
assert_eq!(*guard[1], "bar");
}
#[test]
fn into_inner_works() {
let key = ThreadKey::get().unwrap();
let collection = OwnedLockCollection::from([Mutex::new("foo")]);
let mut guard = collection.lock(key);
*guard[0] = "bar";
drop(guard);
let array = collection.into_inner();
assert_eq!(array.len(), 1);
assert_eq!(array[0], "bar");
}
#[test]
fn from_into_iter_is_correct() {
let array = [Mutex::new(0), Mutex::new(1), Mutex::new(2), Mutex::new(3)];
let mut collection: OwnedLockCollection<Vec<Mutex<usize>>> = array.into_iter().collect();
assert_eq!(collection.get_mut().len(), 4);
for (i, lock) in collection.into_iter().enumerate() {
assert_eq!(lock.into_inner(), i);
}
}
#[test]
fn from_iter_is_correct() {
let array = [Mutex::new(0), Mutex::new(1), Mutex::new(2), Mutex::new(3)];
let mut collection: OwnedLockCollection<Vec<Mutex<usize>>> = array.into_iter().collect();
let collection: &mut Vec<_> = collection.as_mut();
assert_eq!(collection.len(), 4);
for (i, lock) in collection.iter_mut().enumerate() {
assert_eq!(*lock.get_mut(), i);
}
}
#[test]
fn try_lock_works_on_unlocked() {
let key = ThreadKey::get().unwrap();
let collection = OwnedLockCollection::new((Mutex::new(0), Mutex::new(1)));
let guard = collection.try_lock(key).unwrap();
assert_eq!(*guard.0, 0);
assert_eq!(*guard.1, 1);
}
#[test]
fn try_lock_fails_on_locked() {
let key = ThreadKey::get().unwrap();
let collection = OwnedLockCollection::new((Mutex::new(0), Mutex::new(1)));
std::thread::scope(|s| {
s.spawn(|| {
let key = ThreadKey::get().unwrap();
#[allow(unused)]
let guard = collection.lock(key);
std::mem::forget(guard);
});
});
assert!(collection.try_lock(key).is_err());
}
#[test]
fn default_works() {
type MyCollection = OwnedLockCollection<(Mutex<i32>, Mutex<Option<i32>>, Mutex<String>)>;
let collection = MyCollection::default();
let inner = collection.into_inner();
assert_eq!(inner.0, 0);
assert_eq!(inner.1, None);
assert_eq!(inner.2, String::new());
}
#[test]
fn can_be_extended() {
let mutex1 = Mutex::new(0);
let mutex2 = Mutex::new(1);
let mut collection = OwnedLockCollection::new(vec![mutex1, mutex2]);
collection.extend([Mutex::new(2)]);
assert_eq!(collection.data.len(), 3);
}
}
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