rust-cpython: require GIL to borrow immutable reference from PySharedRefCell

Since the inner value may be leaked, we probably need GIL to guarantee that
there's no data race.

inner(py).borrow() is replaced with inner_shared(py).borrow(), which basically
means any PySharedRefCell data should be accessed through PySharedRef wrapper.

rust/hg-cpython/src/dirstate/dirs_multiset.rs

@@ -100,7 +100,7 b' py_class!(pub class Dirs |py| {'
     }
 
     def __contains__(&self, item: PyObject) -> PyResult<bool> {
-        Ok(self.inner(py).borrow().contains(HgPath::new(
+        Ok(self.inner_shared(py).borrow().contains(HgPath::new(
             item.extract::<PyBytes>(py)?.data(py).as_ref(),
         )))
     }

rust/hg-cpython/src/dirstate/dirstate_map.rs

@@ -63,7 +63,7 b' py_class!(pub class DirstateMap |py| {'
         default: Option<PyObject> = None
     ) -> PyResult<Option<PyObject>> {
         let key = key.extract::<PyBytes>(py)?;
-        match self.inner(py).borrow().get(HgPath::new(key.data(py))) {
+        match self.inner_shared(py).borrow().get(HgPath::new(key.data(py))) {
             Some(entry) => {
                 Ok(Some(make_dirstate_tuple(py, entry)?))
             },
@@ -170,7 +170,7 b' py_class!(pub class DirstateMap |py| {'
     // TODO share the reference
     def nonnormalentries(&self) -> PyResult<PyObject> {
         let (non_normal, other_parent) =
-            self.inner(py).borrow().non_normal_other_parent_entries();
+            self.inner_shared(py).borrow().non_normal_other_parent_entries();
 
         let locals = PyDict::new(py);
         locals.set_item(
@@ -281,18 +281,18 b' py_class!(pub class DirstateMap |py| {'
     }
 
     def __len__(&self) -> PyResult<usize> {
-        Ok(self.inner(py).borrow().len())
+        Ok(self.inner_shared(py).borrow().len())
     }
 
     def __contains__(&self, key: PyObject) -> PyResult<bool> {
         let key = key.extract::<PyBytes>(py)?;
-        Ok(self.inner(py).borrow().contains_key(HgPath::new(key.data(py))))
+        Ok(self.inner_shared(py).borrow().contains_key(HgPath::new(key.data(py))))
     }
 
     def __getitem__(&self, key: PyObject) -> PyResult<PyObject> {
         let key = key.extract::<PyBytes>(py)?;
         let key = HgPath::new(key.data(py));
-        match self.inner(py).borrow().get(key) {
+        match self.inner_shared(py).borrow().get(key) {
             Some(entry) => {
                 Ok(make_dirstate_tuple(py, entry)?)
             },
@@ -333,7 +333,7 b' py_class!(pub class DirstateMap |py| {'
         Dirs::from_inner(
             py,
             DirsMultiset::from_dirstate(
-                &self.inner(py).borrow(),
+                &self.inner_shared(py).borrow(),
                 Some(EntryState::Removed),
             ),
         )
@@ -344,7 +344,7 b' py_class!(pub class DirstateMap |py| {'
         Dirs::from_inner(
             py,
             DirsMultiset::from_dirstate(
-                &self.inner(py).borrow(),
+                &self.inner_shared(py).borrow(),
                 None,
             ),
         )
@@ -353,7 +353,7 b' py_class!(pub class DirstateMap |py| {'
     // TODO all copymap* methods, see docstring above
     def copymapcopy(&self) -> PyResult<PyDict> {
         let dict = PyDict::new(py);
-        for (key, value) in self.inner(py).borrow().copy_map.iter() {
+        for (key, value) in self.inner_shared(py).borrow().copy_map.iter() {
             dict.set_item(
                 py,
                 PyBytes::new(py, key.as_ref()),
@@ -365,7 +365,7 b' py_class!(pub class DirstateMap |py| {'
 
     def copymapgetitem(&self, key: PyObject) -> PyResult<PyBytes> {
         let key = key.extract::<PyBytes>(py)?;
-        match self.inner(py).borrow().copy_map.get(HgPath::new(key.data(py))) {
+        match self.inner_shared(py).borrow().copy_map.get(HgPath::new(key.data(py))) {
             Some(copy) => Ok(PyBytes::new(py, copy.as_ref())),
             None => Err(PyErr::new::<exc::KeyError, _>(
                 py,
@@ -378,12 +378,12 b' py_class!(pub class DirstateMap |py| {'
     }
 
     def copymaplen(&self) -> PyResult<usize> {
-        Ok(self.inner(py).borrow().copy_map.len())
+        Ok(self.inner_shared(py).borrow().copy_map.len())
     }
     def copymapcontains(&self, key: PyObject) -> PyResult<bool> {
         let key = key.extract::<PyBytes>(py)?;
         Ok(self
-            .inner(py)
+            .inner_shared(py)
             .borrow()
             .copy_map
             .contains_key(HgPath::new(key.data(py))))
@@ -395,7 +395,7 b' py_class!(pub class DirstateMap |py| {'
     ) -> PyResult<Option<PyObject>> {
         let key = key.extract::<PyBytes>(py)?;
         match self
-            .inner(py)
+            .inner_shared(py)
             .borrow()
             .copy_map
             .get(HgPath::new(key.data(py)))

rust/hg-cpython/src/ref_sharing.rs

@@ -136,7 +136,7 b' impl<T> PySharedRefCell<T> {'
         }
     }
 
-    pub fn borrow(&self) -> Ref<T> {
+    pub fn borrow<'a>(&'a self, _py: Python<'a>) -> Ref<'a, T> {
         // py_shared_state isn't involved since
         // - inner.borrow() would fail if self is mutably borrowed,
         // - and inner.borrow_mut() would fail while self is borrowed.
@@ -180,7 +180,7 b" impl<'a, T> PySharedRef<'a, T> {"
     }
 
     pub fn borrow(&self) -> Ref<'a, T> {
-        self.data.borrow()
+        self.data.borrow(self.py)
     }
 
     pub fn borrow_mut(&self) -> PyResult<PyRefMut<'a, T>> {