Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix memory leak with recursive definitions creating reference cycles #1125

Merged
merged 1 commit into from
Dec 20, 2023
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
94 changes: 47 additions & 47 deletions src/definitions.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@ use std::{
fmt::Debug,
sync::{
atomic::{AtomicBool, Ordering},
Arc, OnceLock,
Arc, OnceLock, Weak,
},
};

Expand All @@ -28,47 +28,50 @@ use crate::{build_tools::py_schema_err, py_gc::PyGcTraverse};
/// They get indexed by a ReferenceId, which are integer identifiers
/// that are handed out and managed by DefinitionsBuilder when the Schema{Validator,Serializer}
/// gets build.
#[derive(Clone)]
pub struct Definitions<T>(AHashMap<Arc<String>, Definition<T>>);

/// Internal type which contains a definition to be filled
pub struct Definition<T>(Arc<DefinitionInner<T>>);

struct DefinitionInner<T> {
value: OnceLock<T>,
name: LazyName,
struct Definition<T> {
value: Arc<OnceLock<T>>,
name: Arc<LazyName>,
}

/// Reference to a definition.
pub struct DefinitionRef<T> {
name: Arc<String>,
value: Definition<T>,
reference: Arc<String>,
// We use a weak reference to the definition to avoid a reference cycle
// when recursive definitions are used.
value: Weak<OnceLock<T>>,
name: Arc<LazyName>,
}

// DefinitionRef can always be cloned (#[derive(Clone)] would require T: Clone)
impl<T> Clone for DefinitionRef<T> {
fn clone(&self) -> Self {
Self {
name: self.name.clone(),
reference: self.reference.clone(),
value: self.value.clone(),
name: self.name.clone(),
}
}
}

impl<T> DefinitionRef<T> {
pub fn id(&self) -> usize {
Arc::as_ptr(&self.value.0) as usize
Weak::as_ptr(&self.value) as usize
}

pub fn get_or_init_name(&self, init: impl FnOnce(&T) -> String) -> &str {
match self.value.0.value.get() {
Some(value) => self.value.0.name.get_or_init(|| init(value)),
let Some(definition) = self.value.upgrade() else {
return "...";
};
match definition.get() {
Some(value) => self.name.get_or_init(|| init(value)),
None => "...",
}
}

pub fn get(&self) -> Option<&T> {
self.value.0.value.get()
pub fn read<R>(&self, f: impl FnOnce(Option<&T>) -> R) -> R {
f(self.value.upgrade().as_ref().and_then(|value| value.get()))
}
}

Expand Down Expand Up @@ -96,15 +99,9 @@ impl<T: Debug> Debug for Definitions<T> {
}
}

impl<T> Clone for Definition<T> {
fn clone(&self) -> Self {
Self(self.0.clone())
}
}

impl<T: Debug> Debug for Definition<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self.0.value.get() {
match self.value.get() {
Some(value) => value.fmt(f),
None => "...".fmt(f),
}
Expand All @@ -113,7 +110,7 @@ impl<T: Debug> Debug for Definition<T> {

impl<T: PyGcTraverse> PyGcTraverse for DefinitionRef<T> {
fn py_gc_traverse(&self, visit: &PyVisit<'_>) -> Result<(), PyTraverseError> {
if let Some(value) = self.value.0.value.get() {
if let Some(value) = self.value.upgrade().as_ref().and_then(|v| v.get()) {
value.py_gc_traverse(visit)?;
}
Ok(())
Expand All @@ -123,15 +120,15 @@ impl<T: PyGcTraverse> PyGcTraverse for DefinitionRef<T> {
impl<T: PyGcTraverse> PyGcTraverse for Definitions<T> {
fn py_gc_traverse(&self, visit: &PyVisit<'_>) -> Result<(), PyTraverseError> {
for value in self.0.values() {
if let Some(value) = value.0.value.get() {
if let Some(value) = value.value.get() {
value.py_gc_traverse(visit)?;
}
}
Ok(())
}
}

#[derive(Clone, Debug)]
#[derive(Debug)]
pub struct DefinitionsBuilder<T> {
definitions: Definitions<T>,
}
Expand All @@ -148,45 +145,48 @@ impl<T: std::fmt::Debug> DefinitionsBuilder<T> {
// We either need a String copy or two hashmap lookups
// Neither is better than the other
// We opted for the easier outward facing API
let name = Arc::new(reference.to_string());
let value = match self.definitions.0.entry(name.clone()) {
let reference = Arc::new(reference.to_string());
let value = match self.definitions.0.entry(reference.clone()) {
Entry::Occupied(entry) => entry.into_mut(),
Entry::Vacant(entry) => entry.insert(Definition(Arc::new(DefinitionInner {
value: OnceLock::new(),
name: LazyName::new(),
}))),
Entry::Vacant(entry) => entry.insert(Definition {
value: Arc::new(OnceLock::new()),
name: Arc::new(LazyName::new()),
}),
};
DefinitionRef {
name,
value: value.clone(),
reference,
value: Arc::downgrade(&value.value),
name: value.name.clone(),
}
}

/// Add a definition, returning the ReferenceId that maps to it
pub fn add_definition(&mut self, reference: String, value: T) -> PyResult<DefinitionRef<T>> {
let name = Arc::new(reference);
let value = match self.definitions.0.entry(name.clone()) {
let reference = Arc::new(reference);
let value = match self.definitions.0.entry(reference.clone()) {
Entry::Occupied(entry) => {
let definition = entry.into_mut();
match definition.0.value.set(value) {
Ok(()) => definition.clone(),
Err(_) => return py_schema_err!("Duplicate ref: `{}`", name),
match definition.value.set(value) {
Ok(()) => definition,
Err(_) => return py_schema_err!("Duplicate ref: `{}`", reference),
}
}
Entry::Vacant(entry) => entry
.insert(Definition(Arc::new(DefinitionInner {
value: OnceLock::from(value),
name: LazyName::new(),
})))
.clone(),
Entry::Vacant(entry) => entry.insert(Definition {
value: Arc::new(OnceLock::from(value)),
name: Arc::new(LazyName::new()),
}),
};
Ok(DefinitionRef { name, value })
Ok(DefinitionRef {
reference,
value: Arc::downgrade(&value.value),
name: value.name.clone(),
})
}

/// Consume this Definitions into a vector of items, indexed by each items ReferenceId
pub fn finish(self) -> PyResult<Definitions<T>> {
for (reference, def) in &self.definitions.0 {
if def.0.value.get().is_none() {
if def.value.get().is_none() {
return py_schema_err!("Definitions error: definition `{}` was never filled", reference);
}
}
Expand Down
34 changes: 19 additions & 15 deletions src/serializers/type_serializers/definitions.rs
Original file line number Diff line number Diff line change
Expand Up @@ -68,15 +68,17 @@ impl TypeSerializer for DefinitionRefSerializer {
exclude: Option<&PyAny>,
extra: &Extra,
) -> PyResult<PyObject> {
let comb_serializer = self.definition.get().unwrap();
let value_id = extra.rec_guard.add(value, self.definition.id())?;
let r = comb_serializer.to_python(value, include, exclude, extra);
extra.rec_guard.pop(value_id, self.definition.id());
r
self.definition.read(|comb_serializer| {
let comb_serializer = comb_serializer.unwrap();
let value_id = extra.rec_guard.add(value, self.definition.id())?;
let r = comb_serializer.to_python(value, include, exclude, extra);
extra.rec_guard.pop(value_id, self.definition.id());
r
})
}

fn json_key<'py>(&self, key: &'py PyAny, extra: &Extra) -> PyResult<Cow<'py, str>> {
self.definition.get().unwrap().json_key(key, extra)
self.definition.read(|s| s.unwrap().json_key(key, extra))
}

fn serde_serialize<S: serde::ser::Serializer>(
Expand All @@ -87,21 +89,23 @@ impl TypeSerializer for DefinitionRefSerializer {
exclude: Option<&PyAny>,
extra: &Extra,
) -> Result<S::Ok, S::Error> {
let comb_serializer = self.definition.get().unwrap();
let value_id = extra
.rec_guard
.add(value, self.definition.id())
.map_err(py_err_se_err)?;
let r = comb_serializer.serde_serialize(value, serializer, include, exclude, extra);
extra.rec_guard.pop(value_id, self.definition.id());
r
self.definition.read(|comb_serializer| {
let comb_serializer = comb_serializer.unwrap();
let value_id = extra
.rec_guard
.add(value, self.definition.id())
.map_err(py_err_se_err)?;
let r = comb_serializer.serde_serialize(value, serializer, include, exclude, extra);
extra.rec_guard.pop(value_id, self.definition.id());
r
})
}

fn get_name(&self) -> &str {
Self::EXPECTED_TYPE
}

fn retry_with_lax_check(&self) -> bool {
self.definition.get().unwrap().retry_with_lax_check()
self.definition.read(|s| s.unwrap().retry_with_lax_check())
}
}
64 changes: 34 additions & 30 deletions src/validators/definitions.rs
Original file line number Diff line number Diff line change
Expand Up @@ -73,23 +73,25 @@ impl Validator for DefinitionRefValidator {
input: &'data impl Input<'data>,
state: &mut ValidationState,
) -> ValResult<PyObject> {
let validator = self.definition.get().unwrap();
if let Some(id) = input.identity() {
if state.recursion_guard.contains_or_insert(id, self.definition.id()) {
// we don't remove id here, we leave that to the validator which originally added id to `recursion_guard`
Err(ValError::new(ErrorTypeDefaults::RecursionLoop, input))
} else {
if state.recursion_guard.incr_depth() {
return Err(ValError::new(ErrorTypeDefaults::RecursionLoop, input));
self.definition.read(|validator| {
let validator = validator.unwrap();
if let Some(id) = input.identity() {
if state.recursion_guard.contains_or_insert(id, self.definition.id()) {
// we don't remove id here, we leave that to the validator which originally added id to `recursion_guard`
Err(ValError::new(ErrorTypeDefaults::RecursionLoop, input))
} else {
if state.recursion_guard.incr_depth() {
return Err(ValError::new(ErrorTypeDefaults::RecursionLoop, input));
}
let output = validator.validate(py, input, state);
state.recursion_guard.remove(id, self.definition.id());
state.recursion_guard.decr_depth();
output
}
let output = validator.validate(py, input, state);
state.recursion_guard.remove(id, self.definition.id());
state.recursion_guard.decr_depth();
output
} else {
validator.validate(py, input, state)
}
} else {
validator.validate(py, input, state)
}
})
}

fn validate_assignment<'data>(
Expand All @@ -100,23 +102,25 @@ impl Validator for DefinitionRefValidator {
field_value: &'data PyAny,
state: &mut ValidationState,
) -> ValResult<PyObject> {
let validator = self.definition.get().unwrap();
if let Some(id) = obj.identity() {
if state.recursion_guard.contains_or_insert(id, self.definition.id()) {
// we don't remove id here, we leave that to the validator which originally added id to `recursion_guard`
Err(ValError::new(ErrorTypeDefaults::RecursionLoop, obj))
} else {
if state.recursion_guard.incr_depth() {
return Err(ValError::new(ErrorTypeDefaults::RecursionLoop, obj));
self.definition.read(|validator| {
let validator = validator.unwrap();
if let Some(id) = obj.identity() {
if state.recursion_guard.contains_or_insert(id, self.definition.id()) {
// we don't remove id here, we leave that to the validator which originally added id to `recursion_guard`
Err(ValError::new(ErrorTypeDefaults::RecursionLoop, obj))
} else {
if state.recursion_guard.incr_depth() {
return Err(ValError::new(ErrorTypeDefaults::RecursionLoop, obj));
}
let output = validator.validate_assignment(py, obj, field_name, field_value, state);
state.recursion_guard.remove(id, self.definition.id());
state.recursion_guard.decr_depth();
output
}
let output = validator.validate_assignment(py, obj, field_name, field_value, state);
state.recursion_guard.remove(id, self.definition.id());
state.recursion_guard.decr_depth();
output
} else {
validator.validate_assignment(py, obj, field_name, field_value, state)
}
} else {
validator.validate_assignment(py, obj, field_name, field_value, state)
}
})
}

fn get_name(&self) -> &str {
Expand Down