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pyclass: tidy up frozen implementation

This commit is contained in:
David Hewitt 2022-08-20 10:03:13 +01:00
parent 5def1a0057
commit 24456f3f41
12 changed files with 421 additions and 423 deletions
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2
guide/src/class.md
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@ -1000,7 +1000,7 @@ impl pyo3::impl_::pyclass::PyClassImpl for MyClass {
type Layout = PyCell<MyClass>;
type BaseType = PyAny;
type ThreadChecker = pyo3::impl_::pyclass::ThreadCheckerStub<MyClass>;
type PyClassMutability = pyo3::pycell::MutableClass;
type PyClassMutability = <<pyo3::PyAny as pyo3::impl_::pyclass::PyClassBaseType>::PyClassMutability as pyo3::impl_::pycell::PyClassMutability>::MutableChild;
type Dict = ::pyo3::impl_::pyclass::PyClassDummySlot;
type WeakRef = ::pyo3::impl_::pyclass::PyClassDummySlot;
type BaseNativeType = ::pyo3::PyAny;

2
pyo3-macros-backend/src/proto_method.rs
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@ -125,7 +125,7 @@ fn insert_lifetime(ty: &mut syn::Type) {
match ty {
syn::Type::Reference(ref mut r) => {
r.lifetime.get_or_insert(syn::parse_quote! {'p});
insert_lifetime(&mut *r.elem);
insert_lifetime(&mut r.elem);
}
syn::Type::Path(ref mut path) => insert_lifetime_for_path(path),
_ => {}

10
pyo3-macros-backend/src/pyclass.rs
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@ -767,9 +767,15 @@ impl<'a> PyClassImplsBuilder<'a> {
fn impl_pyclass(&self) -> TokenStream {
let cls = self.cls;
let frozen = if self.attr.options.frozen.is_some() {
quote! { _pyo3::pyclass::boolean_struct::True }
} else {
quote! { _pyo3::pyclass::boolean_struct::False }
};
quote! {
impl _pyo3::PyClass for #cls {
type Frozen = <Self::PyClassMutability as _pyo3::pycell::PyClassMutability>::Frozen;
type Frozen = #frozen;
}
}
}
@ -970,7 +976,7 @@ impl<'a> PyClassImplsBuilder<'a> {
type BaseType = #base;
type ThreadChecker = #thread_checker;
#inventory
type PyClassMutability = <<#base as _pyo3::impl_::pyclass::PyClassBaseType>::PyClassMutability as _pyo3::pycell::PyClassMutability>::#class_mutability;
type PyClassMutability = <<#base as _pyo3::impl_::pyclass::PyClassBaseType>::PyClassMutability as _pyo3::impl_::pycell::PyClassMutability>::#class_mutability;
type Dict = #dict;
type WeakRef = #weakref;
type BaseNativeType = #base_nativetype;

5
src/impl_.rs
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@ -7,15 +7,12 @@
pub mod deprecations;
pub mod extract_argument;
pub mod freelist;
#[doc(hidden)]
pub mod frompyobject;
pub mod ghost;
pub(crate) mod not_send;
pub mod panic;
#[doc(hidden)]
pub mod pycell;
pub mod pyclass;
#[doc(hidden)]
pub mod pyfunction;
#[doc(hidden)]
pub mod pymethods;
pub mod pymodule;

2
src/impl_/pycell.rs Normal file
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@ -0,0 +1,2 @@
//! Externally-accessible implementation of pycell
pub use crate::pycell::impl_::{GetBorrowChecker, PyClassMutability};

3
src/impl_/pyclass.rs
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@ -2,7 +2,8 @@ use crate::{
exceptions::{PyAttributeError, PyNotImplementedError},
ffi,
impl_::freelist::FreeList,
pycell::{GetBorrowChecker, PyCellLayout, PyClassMutability},
impl_::pycell::{GetBorrowChecker, PyClassMutability},
pycell::PyCellLayout,
pyclass_init::PyObjectInit,
type_object::PyLayout,
Py, PyAny, PyCell, PyClass, PyErr, PyMethodDefType, PyNativeType, PyResult, PyTypeInfo, Python,

189
src/pycell.rs
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@ -200,11 +200,7 @@ use crate::exceptions::PyRuntimeError;
use crate::impl_::pyclass::{
PyClassBaseType, PyClassDict, PyClassImpl, PyClassThreadChecker, PyClassWeakRef,
};
use crate::pyclass::PyClass;
use crate::pyclass::{
boolean_struct::{False, True},
Frozen,
};
use crate::pyclass::{boolean_struct::False, PyClass};
use crate::pyclass_init::PyClassInitializer;
use crate::type_object::{PyLayout, PySizedLayout};
use crate::types::PyAny;
@ -215,175 +211,13 @@ use crate::{
PyTypeInfo,
};
use crate::{ffi, IntoPy, PyErr, PyNativeType, PyObject, PyResult, Python};
use std::cell::{Cell, UnsafeCell};
use std::cell::UnsafeCell;
use std::fmt;
use std::marker::PhantomData;
use std::mem::ManuallyDrop;
use std::ops::{Deref, DerefMut};
pub struct EmptySlot(());
pub struct BorrowChecker(Cell<BorrowFlag>);
pub trait PyClassBorrowChecker {
/// Initial value for self
fn new() -> Self;
/// Increments immutable borrow count, if possible
fn try_borrow(&self) -> Result<(), PyBorrowError>;
fn try_borrow_unguarded(&self) -> Result<(), PyBorrowError>;
/// Decrements immutable borrow count
fn release_borrow(&self);
/// Increments mutable borrow count, if possible
fn try_borrow_mut(&self) -> Result<(), PyBorrowMutError>;
/// Decremements mutable borrow count
fn release_borrow_mut(&self);
}
impl PyClassBorrowChecker for EmptySlot {
#[inline]
fn new() -> Self {
EmptySlot(())
}
#[inline]
fn try_borrow(&self) -> Result<(), PyBorrowError> {
Ok(())
}
#[inline]
fn try_borrow_unguarded(&self) -> Result<(), PyBorrowError> {
Ok(())
}
#[inline]
fn release_borrow(&self) {}
#[inline]
fn try_borrow_mut(&self) -> Result<(), PyBorrowMutError> {
unreachable!()
}
#[inline]
fn release_borrow_mut(&self) {
unreachable!()
}
}
impl PyClassBorrowChecker for BorrowChecker {
#[inline]
fn new() -> Self {
Self(Cell::new(BorrowFlag::UNUSED))
}
fn try_borrow(&self) -> Result<(), PyBorrowError> {
let flag = self.0.get();
if flag != BorrowFlag::HAS_MUTABLE_BORROW {
self.0.set(flag.increment());
Ok(())
} else {
Err(PyBorrowError { _private: () })
}
}
fn try_borrow_unguarded(&self) -> Result<(), PyBorrowError> {
let flag = self.0.get();
if flag != BorrowFlag::HAS_MUTABLE_BORROW {
Ok(())
} else {
Err(PyBorrowError { _private: () })
}
}
fn release_borrow(&self) {
let flag = self.0.get();
self.0.set(flag.decrement())
}
fn try_borrow_mut(&self) -> Result<(), PyBorrowMutError> {
let flag = self.0.get();
if flag == BorrowFlag::UNUSED {
self.0.set(BorrowFlag::HAS_MUTABLE_BORROW);
Ok(())
} else {
Err(PyBorrowMutError { _private: () })
}
}
fn release_borrow_mut(&self) {
self.0.set(BorrowFlag::UNUSED)
}
}
pub trait PyClassMutability {
// The storage for this inheritance layer. Only the first mutable class in
// an inheritance hierarchy needs to store the borrow flag.
type Storage: PyClassBorrowChecker;
// The borrow flag needed to implement this class' mutability. Empty until
// the first mutable class, at which point it is BorrowChecker and will be
// for all subclasses.
type Checker: PyClassBorrowChecker;
type ImmutableChild: PyClassMutability;
type MutableChild: PyClassMutability;
type Frozen: Frozen;
}
pub trait GetBorrowChecker<T: PyClassImpl> {
fn borrow_checker(cell: &PyCell<T>) -> &<T::PyClassMutability as PyClassMutability>::Checker;
}
impl<T: PyClassImpl<PyClassMutability = Self>> GetBorrowChecker<T> for MutableClass {
fn borrow_checker(cell: &PyCell<T>) -> &BorrowChecker {
&cell.contents.borrow_checker
}
}
impl<T: PyClassImpl<PyClassMutability = Self>> GetBorrowChecker<T> for ImmutableClass {
fn borrow_checker(cell: &PyCell<T>) -> &EmptySlot {
&cell.contents.borrow_checker
}
}
impl<T: PyClassImpl<PyClassMutability = Self>, M: PyClassMutability> GetBorrowChecker<T>
for ExtendsMutableAncestor<M>
where
T::BaseType: PyClassImpl<Layout = PyCell<T::BaseType>>
+ PyClassBaseType<LayoutAsBase = PyCell<T::BaseType>>,
<T::BaseType as PyClassImpl>::PyClassMutability: PyClassMutability<Checker = BorrowChecker>,
{
fn borrow_checker(cell: &PyCell<T>) -> &BorrowChecker {
<<T::BaseType as PyClassImpl>::PyClassMutability as GetBorrowChecker<T::BaseType>>::borrow_checker(&cell.ob_base)
}
}
pub struct ImmutableClass(());
pub struct MutableClass(());
pub struct ExtendsMutableAncestor<M: PyClassMutability>(PhantomData<M>);
impl PyClassMutability for ImmutableClass {
type Storage = EmptySlot;
type Checker = EmptySlot;
type ImmutableChild = ImmutableClass;
type MutableChild = MutableClass;
type Frozen = True;
}
impl PyClassMutability for MutableClass {
type Storage = BorrowChecker;
type Checker = BorrowChecker;
type ImmutableChild = ExtendsMutableAncestor<ImmutableClass>;
type MutableChild = ExtendsMutableAncestor<MutableClass>;
type Frozen = False;
}
impl<M: PyClassMutability> PyClassMutability for ExtendsMutableAncestor<M> {
type Storage = EmptySlot;
type Checker = BorrowChecker;
type ImmutableChild = ExtendsMutableAncestor<ImmutableClass>;
type MutableChild = ExtendsMutableAncestor<MutableClass>;
type Frozen = M::Frozen;
}
pub(crate) mod impl_;
use impl_::{GetBorrowChecker, PyClassBorrowChecker, PyClassMutability};
/// Base layout of PyCell.
#[doc(hidden)]
@ -968,21 +802,6 @@ impl<T: PyClass<Frozen = False> + fmt::Debug> fmt::Debug for PyRefMut<'_, T> {
}
}
#[doc(hidden)]
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct BorrowFlag(usize);
impl BorrowFlag {
pub(crate) const UNUSED: BorrowFlag = BorrowFlag(0);
const HAS_MUTABLE_BORROW: BorrowFlag = BorrowFlag(usize::max_value());
const fn increment(self) -> Self {
Self(self.0 + 1)
}
const fn decrement(self) -> Self {
Self(self.0 - 1)
}
}
/// An error type returned by [`PyCell::try_borrow`].
///
/// If this error is allowed to bubble up into Python code it will raise a `RuntimeError`.

387
src/pycell/impl_.rs Normal file
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@ -0,0 +1,387 @@
//! Crate-private implementation of pycell
use std::cell::Cell;
use std::marker::PhantomData;
use crate::impl_::pyclass::{PyClassBaseType, PyClassImpl};
use crate::PyCell;
use super::{PyBorrowError, PyBorrowMutError};
pub trait PyClassMutability {
// The storage for this inheritance layer. Only the first mutable class in
// an inheritance hierarchy needs to store the borrow flag.
type Storage: PyClassBorrowChecker;
// The borrow flag needed to implement this class' mutability. Empty until
// the first mutable class, at which point it is BorrowChecker and will be
// for all subclasses.
type Checker: PyClassBorrowChecker;
type ImmutableChild: PyClassMutability;
type MutableChild: PyClassMutability;
}
pub struct ImmutableClass(());
pub struct MutableClass(());
pub struct ExtendsMutableAncestor<M: PyClassMutability>(PhantomData<M>);
impl PyClassMutability for ImmutableClass {
type Storage = EmptySlot;
type Checker = EmptySlot;
type ImmutableChild = ImmutableClass;
type MutableChild = MutableClass;
}
impl PyClassMutability for MutableClass {
type Storage = BorrowChecker;
type Checker = BorrowChecker;
type ImmutableChild = ExtendsMutableAncestor<ImmutableClass>;
type MutableChild = ExtendsMutableAncestor<MutableClass>;
}
impl<M: PyClassMutability> PyClassMutability for ExtendsMutableAncestor<M> {
type Storage = EmptySlot;
type Checker = BorrowChecker;
type ImmutableChild = ExtendsMutableAncestor<ImmutableClass>;
type MutableChild = ExtendsMutableAncestor<MutableClass>;
}
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
struct BorrowFlag(usize);
impl BorrowFlag {
pub(crate) const UNUSED: BorrowFlag = BorrowFlag(0);
const HAS_MUTABLE_BORROW: BorrowFlag = BorrowFlag(usize::max_value());
const fn increment(self) -> Self {
Self(self.0 + 1)
}
const fn decrement(self) -> Self {
Self(self.0 - 1)
}
}
pub struct EmptySlot(());
pub struct BorrowChecker(Cell<BorrowFlag>);
pub trait PyClassBorrowChecker {
/// Initial value for self
fn new() -> Self;
/// Increments immutable borrow count, if possible
fn try_borrow(&self) -> Result<(), PyBorrowError>;
fn try_borrow_unguarded(&self) -> Result<(), PyBorrowError>;
/// Decrements immutable borrow count
fn release_borrow(&self);
/// Increments mutable borrow count, if possible
fn try_borrow_mut(&self) -> Result<(), PyBorrowMutError>;
/// Decremements mutable borrow count
fn release_borrow_mut(&self);
}
impl PyClassBorrowChecker for EmptySlot {
#[inline]
fn new() -> Self {
EmptySlot(())
}
#[inline]
fn try_borrow(&self) -> Result<(), PyBorrowError> {
Ok(())
}
#[inline]
fn try_borrow_unguarded(&self) -> Result<(), PyBorrowError> {
Ok(())
}
#[inline]
fn release_borrow(&self) {}
#[inline]
fn try_borrow_mut(&self) -> Result<(), PyBorrowMutError> {
unreachable!()
}
#[inline]
fn release_borrow_mut(&self) {
unreachable!()
}
}
impl PyClassBorrowChecker for BorrowChecker {
#[inline]
fn new() -> Self {
Self(Cell::new(BorrowFlag::UNUSED))
}
fn try_borrow(&self) -> Result<(), PyBorrowError> {
let flag = self.0.get();
if flag != BorrowFlag::HAS_MUTABLE_BORROW {
self.0.set(flag.increment());
Ok(())
} else {
Err(PyBorrowError { _private: () })
}
}
fn try_borrow_unguarded(&self) -> Result<(), PyBorrowError> {
let flag = self.0.get();
if flag != BorrowFlag::HAS_MUTABLE_BORROW {
Ok(())
} else {
Err(PyBorrowError { _private: () })
}
}
fn release_borrow(&self) {
let flag = self.0.get();
self.0.set(flag.decrement())
}
fn try_borrow_mut(&self) -> Result<(), PyBorrowMutError> {
let flag = self.0.get();
if flag == BorrowFlag::UNUSED {
self.0.set(BorrowFlag::HAS_MUTABLE_BORROW);
Ok(())
} else {
Err(PyBorrowMutError { _private: () })
}
}
fn release_borrow_mut(&self) {
self.0.set(BorrowFlag::UNUSED)
}
}
pub trait GetBorrowChecker<T: PyClassImpl> {
fn borrow_checker(cell: &PyCell<T>) -> &<T::PyClassMutability as PyClassMutability>::Checker;
}
impl<T: PyClassImpl<PyClassMutability = Self>> GetBorrowChecker<T> for MutableClass {
fn borrow_checker(cell: &PyCell<T>) -> &BorrowChecker {
&cell.contents.borrow_checker
}
}
impl<T: PyClassImpl<PyClassMutability = Self>> GetBorrowChecker<T> for ImmutableClass {
fn borrow_checker(cell: &PyCell<T>) -> &EmptySlot {
&cell.contents.borrow_checker
}
}
impl<T: PyClassImpl<PyClassMutability = Self>, M: PyClassMutability> GetBorrowChecker<T>
for ExtendsMutableAncestor<M>
where
T::BaseType: PyClassImpl<Layout = PyCell<T::BaseType>>
+ PyClassBaseType<LayoutAsBase = PyCell<T::BaseType>>,
<T::BaseType as PyClassImpl>::PyClassMutability: PyClassMutability<Checker = BorrowChecker>,
{
fn borrow_checker(cell: &PyCell<T>) -> &BorrowChecker {
<<T::BaseType as PyClassImpl>::PyClassMutability as GetBorrowChecker<T::BaseType>>::borrow_checker(&cell.ob_base)
}
}
#[cfg(test)]
#[cfg(feature = "macros")]
mod tests {
use super::*;
use crate::impl_::pyclass::{PyClassBaseType, PyClassImpl};
use crate::prelude::*;
use crate::pyclass::boolean_struct::{False, True};
use crate::PyClass;
#[pyclass(crate = "crate", subclass)]
struct MutableBase;
#[pyclass(crate = "crate", extends = MutableBase, subclass)]
struct MutableChildOfMutableBase;
#[pyclass(crate = "crate", extends = MutableBase, frozen, subclass)]
struct ImmutableChildOfMutableBase;
#[pyclass(crate = "crate", extends = MutableChildOfMutableBase)]
struct MutableChildOfMutableChildOfMutableBase;
#[pyclass(crate = "crate", extends = ImmutableChildOfMutableBase)]
struct MutableChildOfImmutableChildOfMutableBase;
#[pyclass(crate = "crate", extends = MutableChildOfMutableBase, frozen)]
struct ImmutableChildOfMutableChildOfMutableBase;
#[pyclass(crate = "crate", extends = ImmutableChildOfMutableBase, frozen)]
struct ImmutableChildOfImmutableChildOfMutableBase;
#[pyclass(crate = "crate", frozen, subclass)]
struct ImmutableBase;
#[pyclass(crate = "crate", extends = ImmutableBase, subclass)]
struct MutableChildOfImmutableBase;
#[pyclass(crate = "crate", extends = ImmutableBase, frozen, subclass)]
struct ImmutableChildOfImmutableBase;
#[pyclass(crate = "crate", extends = MutableChildOfImmutableBase)]
struct MutableChildOfMutableChildOfImmutableBase;
#[pyclass(crate = "crate", extends = ImmutableChildOfImmutableBase)]
struct MutableChildOfImmutableChildOfImmutableBase;
#[pyclass(crate = "crate", extends = MutableChildOfImmutableBase, frozen)]
struct ImmutableChildOfMutableChildOfImmutableBase;
#[pyclass(crate = "crate", extends = ImmutableChildOfImmutableBase, frozen)]
struct ImmutableChildOfImmutableChildOfImmutableBase;
fn assert_mutable<T: PyClass<Frozen = False, PyClassMutability = MutableClass>>() {}
fn assert_immutable<T: PyClass<Frozen = True, PyClassMutability = ImmutableClass>>() {}
fn assert_mutable_with_mutable_ancestor<
T: PyClass<Frozen = False, PyClassMutability = ExtendsMutableAncestor<MutableClass>>,
>()
// These horrible bounds are necessary for Rust 1.48 but not newer versions
where
<T as PyClassImpl>::BaseType: PyClassImpl<Layout = PyCell<T::BaseType>>,
<<T as PyClassImpl>::BaseType as PyClassImpl>::PyClassMutability:
PyClassMutability<Checker = BorrowChecker>,
<T as PyClassImpl>::BaseType: PyClassBaseType<LayoutAsBase = PyCell<T::BaseType>>,
{
}
fn assert_immutable_with_mutable_ancestor<
T: PyClass<Frozen = True, PyClassMutability = ExtendsMutableAncestor<ImmutableClass>>,
>()
// These horrible bounds are necessary for Rust 1.48 but not newer versions
where
<T as PyClassImpl>::BaseType: PyClassImpl<Layout = PyCell<T::BaseType>>,
<<T as PyClassImpl>::BaseType as PyClassImpl>::PyClassMutability:
PyClassMutability<Checker = BorrowChecker>,
<T as PyClassImpl>::BaseType: PyClassBaseType<LayoutAsBase = PyCell<T::BaseType>>,
{
}
#[test]
fn test_inherited_mutability() {
// mutable base
assert_mutable::<MutableBase>();
// children of mutable base have a mutable ancestor
assert_mutable_with_mutable_ancestor::<MutableChildOfMutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfMutableBase>();
// grandchildren of mutable base have a mutable ancestor
assert_mutable_with_mutable_ancestor::<MutableChildOfMutableChildOfMutableBase>();
assert_mutable_with_mutable_ancestor::<MutableChildOfImmutableChildOfMutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfMutableChildOfMutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfImmutableChildOfMutableBase>();
// immutable base and children
assert_immutable::<ImmutableBase>();
assert_immutable::<ImmutableChildOfImmutableBase>();
assert_immutable::<ImmutableChildOfImmutableChildOfImmutableBase>();
// mutable children of immutable at any level are simply mutable
assert_mutable::<MutableChildOfImmutableBase>();
assert_mutable::<MutableChildOfImmutableChildOfImmutableBase>();
// children of the mutable child display this property
assert_mutable_with_mutable_ancestor::<MutableChildOfMutableChildOfImmutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfMutableChildOfImmutableBase>();
}
#[test]
fn test_mutable_borrow_prevents_further_borrows() {
Python::with_gil(|py| {
let mmm = Py::new(
py,
PyClassInitializer::from(MutableBase)
.add_subclass(MutableChildOfMutableBase)
.add_subclass(MutableChildOfMutableChildOfMutableBase),
)
.unwrap();
let mmm_cell: &PyCell<MutableChildOfMutableChildOfMutableBase> = mmm.as_ref(py);
let mmm_refmut = mmm_cell.borrow_mut();
// Cannot take any other mutable or immutable borrows whilst the object is borrowed mutably
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell.extract::<PyRef<'_, MutableBase>>().is_err());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_err());
// With the borrow dropped, all other borrow attempts will succeed
drop(mmm_refmut);
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRef<'_, MutableBase>>().is_ok());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_ok());
})
}
#[test]
fn test_immutable_borrows_prevent_mutable_borrows() {
Python::with_gil(|py| {
let mmm = Py::new(
py,
PyClassInitializer::from(MutableBase)
.add_subclass(MutableChildOfMutableBase)
.add_subclass(MutableChildOfMutableChildOfMutableBase),
)
.unwrap();
let mmm_cell: &PyCell<MutableChildOfMutableChildOfMutableBase> = mmm.as_ref(py);
let mmm_refmut = mmm_cell.borrow();
// Further immutable borrows are ok
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRef<'_, MutableBase>>().is_ok());
// Further mutable borrows are not ok
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_err());
// With the borrow dropped, all mutable borrow attempts will succeed
drop(mmm_refmut);
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_ok());
})
}
}

5
src/pyclass_init.rs
View File

@ -4,7 +4,10 @@ use crate::impl_::pyclass::{PyClassBaseType, PyClassDict, PyClassThreadChecker,
use crate::{ffi, PyCell, PyClass, PyErr, PyResult, Python};
use crate::{
ffi::PyTypeObject,
pycell::{PyCellContents, PyClassBorrowChecker, PyClassMutability},
pycell::{
impl_::{PyClassBorrowChecker, PyClassMutability},
PyCellContents,
},
type_object::{get_tp_alloc, PyTypeInfo},
};
use std::{

2
src/types/mod.rs
View File

@ -242,7 +242,7 @@ macro_rules! pyobject_native_type_sized {
type BaseNativeType = $name;
type ThreadChecker = $crate::impl_::pyclass::ThreadCheckerStub<$crate::PyObject>;
type Initializer = $crate::pyclass_init::PyNativeTypeInitializer<Self>;
type PyClassMutability = $crate::pycell::ImmutableClass;
type PyClassMutability = $crate::pycell::impl_::ImmutableClass;
}
}
}

202
tests/test_mutable_pyclass.rs
View File

@ -1,202 +0,0 @@
#![cfg(feature = "macros")]
use pyo3::impl_::pyclass::{PyClassBaseType, PyClassImpl};
use pyo3::prelude::*;
use pyo3::pycell::{
BorrowChecker, ExtendsMutableAncestor, ImmutableClass, MutableClass, PyClassMutability,
};
use pyo3::pyclass::boolean_struct::{False, True};
use pyo3::PyClass;
#[pyclass(subclass)]
struct MutableBase;
#[pyclass(extends = MutableBase, subclass)]
struct MutableChildOfMutableBase;
#[pyclass(extends = MutableBase, frozen, subclass)]
struct ImmutableChildOfMutableBase;
#[pyclass(extends = MutableChildOfMutableBase)]
struct MutableChildOfMutableChildOfMutableBase;
#[pyclass(extends = ImmutableChildOfMutableBase)]
struct MutableChildOfImmutableChildOfMutableBase;
#[pyclass(extends = MutableChildOfMutableBase, frozen)]
struct ImmutableChildOfMutableChildOfMutableBase;
#[pyclass(extends = ImmutableChildOfMutableBase, frozen)]
struct ImmutableChildOfImmutableChildOfMutableBase;
#[pyclass(frozen, subclass)]
struct ImmutableBase;
#[pyclass(extends = ImmutableBase, subclass)]
struct MutableChildOfImmutableBase;
#[pyclass(extends = ImmutableBase, frozen, subclass)]
struct ImmutableChildOfImmutableBase;
#[pyclass(extends = MutableChildOfImmutableBase)]
struct MutableChildOfMutableChildOfImmutableBase;
#[pyclass(extends = ImmutableChildOfImmutableBase)]
struct MutableChildOfImmutableChildOfImmutableBase;
#[pyclass(extends = MutableChildOfImmutableBase, frozen)]
struct ImmutableChildOfMutableChildOfImmutableBase;
#[pyclass(extends = ImmutableChildOfImmutableBase, frozen)]
struct ImmutableChildOfImmutableChildOfImmutableBase;
fn assert_mutable<T: PyClass<Frozen = False, PyClassMutability = MutableClass>>() {}
fn assert_immutable<T: PyClass<Frozen = True, PyClassMutability = ImmutableClass>>() {}
fn assert_mutable_with_mutable_ancestor<
T: PyClass<Frozen = False, PyClassMutability = ExtendsMutableAncestor<MutableClass>>,
>()
// These horrible bounds are necessary for Rust 1.48 but not newer versions
where
<T as PyClassImpl>::BaseType: PyClassImpl<Layout = PyCell<T::BaseType>>,
<<T as PyClassImpl>::BaseType as PyClassImpl>::PyClassMutability:
PyClassMutability<Checker = BorrowChecker>,
<T as PyClassImpl>::BaseType: PyClassBaseType<LayoutAsBase = PyCell<T::BaseType>>,
{
}
fn assert_immutable_with_mutable_ancestor<
T: PyClass<Frozen = True, PyClassMutability = ExtendsMutableAncestor<ImmutableClass>>,
>()
// These horrible bounds are necessary for Rust 1.48 but not newer versions
where
<T as PyClassImpl>::BaseType: PyClassImpl<Layout = PyCell<T::BaseType>>,
<<T as PyClassImpl>::BaseType as PyClassImpl>::PyClassMutability:
PyClassMutability<Checker = BorrowChecker>,
<T as PyClassImpl>::BaseType: PyClassBaseType<LayoutAsBase = PyCell<T::BaseType>>,
{
}
#[test]
fn test_inherited_mutability() {
// mutable base
assert_mutable::<MutableBase>();
// children of mutable base have a mutable ancestor
assert_mutable_with_mutable_ancestor::<MutableChildOfMutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfMutableBase>();
// grandchildren of mutable base have a mutable ancestor
assert_mutable_with_mutable_ancestor::<MutableChildOfMutableChildOfMutableBase>();
assert_mutable_with_mutable_ancestor::<MutableChildOfImmutableChildOfMutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfMutableChildOfMutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfImmutableChildOfMutableBase>();
// immutable base and children
assert_immutable::<ImmutableBase>();
assert_immutable::<ImmutableChildOfImmutableBase>();
assert_immutable::<ImmutableChildOfImmutableChildOfImmutableBase>();
// mutable children of immutable at any level are simply mutable
assert_mutable::<MutableChildOfImmutableBase>();
assert_mutable::<MutableChildOfImmutableChildOfImmutableBase>();
// children of the mutable child display this property
assert_mutable_with_mutable_ancestor::<MutableChildOfMutableChildOfImmutableBase>();
assert_immutable_with_mutable_ancestor::<ImmutableChildOfMutableChildOfImmutableBase>();
}
#[test]
fn test_mutable_borrow_prevents_further_borrows() {
Python::with_gil(|py| {
let mmm = Py::new(
py,
PyClassInitializer::from(MutableBase)
.add_subclass(MutableChildOfMutableBase)
.add_subclass(MutableChildOfMutableChildOfMutableBase),
)
.unwrap();
let mmm_cell: &PyCell<MutableChildOfMutableChildOfMutableBase> = mmm.as_ref(py);
let mmm_refmut = mmm_cell.borrow_mut();
// Cannot take any other mutable or immutable borrows whilst the object is borrowed mutably
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell.extract::<PyRef<'_, MutableBase>>().is_err());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_err());
// With the borrow dropped, all other borrow attempts will succeed
drop(mmm_refmut);
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRef<'_, MutableBase>>().is_ok());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_ok());
})
}
#[test]
fn test_immutable_borrows_prevent_mutable_borrows() {
Python::with_gil(|py| {
let mmm = Py::new(
py,
PyClassInitializer::from(MutableBase)
.add_subclass(MutableChildOfMutableBase)
.add_subclass(MutableChildOfMutableChildOfMutableBase),
)
.unwrap();
let mmm_cell: &PyCell<MutableChildOfMutableChildOfMutableBase> = mmm.as_ref(py);
let mmm_refmut = mmm_cell.borrow();
// Further immutable borrows are ok
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRef<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRef<'_, MutableBase>>().is_ok());
// Further mutable borrows are not ok
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_err());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_err());
// With the borrow dropped, all mutable borrow attempts will succeed
drop(mmm_refmut);
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell
.extract::<PyRefMut<'_, MutableChildOfMutableBase>>()
.is_ok());
assert!(mmm_cell.extract::<PyRefMut<'_, MutableBase>>().is_ok());
})
}

35
tests/ui/abi3_nativetype_inheritance.stderr
View File

@ -1,28 +1,3 @@
error[E0277]: the trait bound `PyDict: PyClass` is not satisfied
--> tests/ui/abi3_nativetype_inheritance.rs:5:1
|
5 | #[pyclass(extends=PyDict)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `PyClass` is not implemented for `PyDict`
|
= help: the trait `PyClass` is implemented for `TestClass`
= note: required because of the requirements on the impl of `PyClassBaseType` for `PyDict`
= note: this error originates in the attribute macro `pyclass` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0277]: the trait bound `PyDict: PyClass` is not satisfied
--> tests/ui/abi3_nativetype_inheritance.rs:5:1
|
5 | #[pyclass(extends=PyDict)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `PyClass` is not implemented for `PyDict`
|
= help: the trait `PyClass` is implemented for `TestClass`
= note: required because of the requirements on the impl of `PyClassBaseType` for `PyDict`
note: required by a bound in `PyRefMut`
--> src/pycell.rs
|
| pub struct PyRefMut<'p, T: PyClass<Frozen = False>> {
| ^^^^^^^^^^^^^^ required by this bound in `PyRefMut`
= note: this error originates in the attribute macro `pyclass` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0277]: the trait bound `PyDict: PyClass` is not satisfied
--> tests/ui/abi3_nativetype_inheritance.rs:5:1
|
@ -37,3 +12,13 @@ note: required by a bound in `ThreadCheckerInherited`
| pub struct ThreadCheckerInherited<T: PyClass + Send, U: PyClassBaseType>(
| ^^^^^^^^^^^^^^^ required by this bound in `ThreadCheckerInherited`
= note: this error originates in the attribute macro `pyclass` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0277]: the trait bound `PyDict: PyClass` is not satisfied
--> tests/ui/abi3_nativetype_inheritance.rs:5:1
|
5 | #[pyclass(extends=PyDict)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `PyClass` is not implemented for `PyDict`
|
= help: the trait `PyClass` is implemented for `TestClass`
= note: required because of the requirements on the impl of `PyClassBaseType` for `PyDict`
= note: this error originates in the attribute macro `pyclass` (in Nightly builds, run with -Z macro-backtrace for more info)