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use std::{mem::size_of, sync::Arc};
use crate::{
id::Id,
identity::IdentityManager,
lock::{rank, RwLock, RwLockReadGuard, RwLockWriteGuard},
storage::{Element, Storage, StorageItem},
};
#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
pub struct RegistryReport {
pub num_allocated: usize,
pub num_kept_from_user: usize,
pub num_released_from_user: usize,
pub element_size: usize,
}
impl RegistryReport {
pub fn is_empty(&self) -> bool {
self.num_allocated + self.num_kept_from_user == 0
}
}
/// Registry is the primary holder of each resource type
/// Every resource is now arcanized so the last arc released
/// will in the end free the memory and release the inner raw resource
///
/// Registry act as the main entry point to keep resource alive
/// when created and released from user land code
///
/// A resource may still be alive when released from user land code
/// if it's used in active submission or anyway kept alive from
/// any other dependent resource
///
#[derive(Debug)]
pub(crate) struct Registry<T: StorageItem> {
// Must only contain an id which has either never been used or has been released from `storage`
identity: Arc<IdentityManager<T::Marker>>,
storage: RwLock<Storage<T>>,
}
impl<T: StorageItem> Registry<T> {
pub(crate) fn new() -> Self {
Self {
identity: Arc::new(IdentityManager::new()),
storage: RwLock::new(rank::REGISTRY_STORAGE, Storage::new()),
}
}
}
#[must_use]
pub(crate) struct FutureId<'a, T: StorageItem> {
id: Id<T::Marker>,
data: &'a RwLock<Storage<T>>,
}
impl<T: StorageItem> FutureId<'_, T> {
pub fn id(&self) -> Id<T::Marker> {
self.id
}
/// Assign a new resource to this ID.
///
/// Registers it with the registry.
pub fn assign(self, value: T) -> Id<T::Marker> {
let mut data = self.data.write();
data.insert(self.id, value);
self.id
}
}
impl<T: StorageItem> Registry<T> {
pub(crate) fn prepare(&self, id_in: Option<Id<T::Marker>>) -> FutureId<T> {
FutureId {
id: match id_in {
Some(id_in) => {
self.identity.mark_as_used(id_in);
id_in
}
None => self.identity.process(),
},
data: &self.storage,
}
}
#[track_caller]
pub(crate) fn read<'a>(&'a self) -> RwLockReadGuard<'a, Storage<T>> {
self.storage.read()
}
#[track_caller]
pub(crate) fn write<'a>(&'a self) -> RwLockWriteGuard<'a, Storage<T>> {
self.storage.write()
}
pub(crate) fn remove(&self, id: Id<T::Marker>) -> T {
let value = self.storage.write().remove(id);
// This needs to happen *after* removing it from the storage, to maintain the
// invariant that `self.identity` only contains ids which are actually available
self.identity.free(id);
//Returning None is legal if it's an error ID
value
}
pub(crate) fn generate_report(&self) -> RegistryReport {
let storage = self.storage.read();
let mut report = RegistryReport {
element_size: size_of::<T>(),
..Default::default()
};
report.num_allocated = self.identity.values.lock().count();
for element in storage.map.iter() {
match *element {
Element::Occupied(..) => report.num_kept_from_user += 1,
Element::Vacant => report.num_released_from_user += 1,
}
}
report
}
}
impl<T: StorageItem + Clone> Registry<T> {
pub(crate) fn get(&self, id: Id<T::Marker>) -> T {
self.read().get(id)
}
}
#[cfg(test)]
mod tests {
use std::sync::Arc;
use crate::{id::Marker, resource::ResourceType, storage::StorageItem};
use super::Registry;
struct TestData;
struct TestDataId;
impl Marker for TestDataId {}
impl ResourceType for TestData {
const TYPE: &'static str = "TestData";
}
impl StorageItem for TestData {
type Marker = TestDataId;
}
#[test]
fn simultaneous_registration() {
let registry = Registry::new();
std::thread::scope(|s| {
for _ in 0..5 {
s.spawn(|| {
for _ in 0..1000 {
let value = Arc::new(TestData);
let new_id = registry.prepare(None);
let id = new_id.assign(value);
registry.remove(id);
}
});
}
})
}
}