Remove register_gil

CHANGELOG.md

@@ -12,10 +12,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Changed
 - Update `parking_lot` dependency to `0.11`. [#1010](https://github.com/PyO3/pyo3/pull/1010)
-- `PyString::to_string` is now renamed to `to_str` and returns `&str` instead of `Cow<str>`. [#1023](https://github.com/PyO3/pyo3/pull/1023)
+- `PyString::to_string` is now renamed `to_str` and returns `&str` instead of `Cow<str>`. [#1023](https://github.com/PyO3/pyo3/pull/1023)
 
 ### Removed
-- Remove `PyString::as_bytes` is removed. [#1023](https://github.com/PyO3/pyo3/pull/1023)
+- Remove `PyString::as_bytes`. [#1023](https://github.com/PyO3/pyo3/pull/1023)
+- Remove `Python::register_gil`. [#1023](https://github.com/PyO3/pyo3/pull/1023)
 
 ## [0.11.0] - 2020-06-28
 ### Added

src/gil.rs

@@ -5,30 +5,10 @@
 use crate::{ffi, internal_tricks::Unsendable, Python};
 use parking_lot::{const_mutex, Mutex};
 use std::cell::{Cell, RefCell};
-use std::{any, mem::ManuallyDrop, ptr::NonNull, sync};
+use std::{mem::ManuallyDrop, ptr::NonNull, sync};
 
 static START: sync::Once = sync::Once::new();
 
-/// Holds temporally owned objects.
-struct ObjectHolder {
-    /// Objects owned by the current thread
-    obj: Vec<NonNull<ffi::PyObject>>,
-    /// Non-python objects(e.g., String) owned by the current thread
-    any: Vec<Box<dyn any::Any>>,
-}
-
-impl ObjectHolder {
-    fn new() -> Self {
-        Self {
-            obj: Vec::with_capacity(256),
-            any: Vec::with_capacity(4),
-        }
-    }
-    fn len(&self) -> (usize, usize) {
-        (self.obj.len(), self.any.len())
-    }
-}
-
 thread_local! {
     /// This is a internal counter in pyo3 monitoring whether this thread has the GIL.
     ///
@@ -41,7 +21,7 @@ thread_local! {
     pub(crate) static GIL_COUNT: Cell<u32> = Cell::new(0);
 
     /// Temporally hold objects that will be released when the GILPool drops.
-    static OWNED_OBJECTS: RefCell<ObjectHolder> = RefCell::new(ObjectHolder::new());
+    static OWNED_OBJECTS: RefCell<Vec<NonNull<ffi::PyObject>>> = RefCell::new(Vec::with_capacity(256));
 }
 
 /// Check whether the GIL is acquired.
@@ -51,7 +31,7 @@ thread_local! {
 ///  2) PyGILState_Check always returns 1 if the sub-interpreter APIs have ever been called,
 ///     which could lead to incorrect conclusions that the GIL is held.
 fn gil_is_acquired() -> bool {
-    GIL_COUNT.with(|c| c.get() > 0)
+    GIL_COUNT.try_with(|c| c.get() > 0).unwrap_or(false)
 }
 
 /// Prepares the use of Python in a free-threaded context.
@@ -159,21 +139,19 @@ impl GILGuard {
     pub fn acquire() -> GILGuard {
         prepare_freethreaded_python();
 
-        unsafe {
-            let gstate = ffi::PyGILState_Ensure(); // acquire GIL
+        let gstate = unsafe { ffi::PyGILState_Ensure() }; // acquire GIL
 
-            // If there's already a GILPool, we should not create another or this could lead to
-            // incorrect dangling references in safe code (see #864).
-            let pool = if !gil_is_acquired() {
-                Some(GILPool::new())
-            } else {
-                None
-            };
+        // If there's already a GILPool, we should not create another or this could lead to
+        // incorrect dangling references in safe code (see #864).
+        let pool = if !gil_is_acquired() {
+            Some(unsafe { GILPool::new() })
+        } else {
+            None
+        };
 
-            GILGuard {
-                gstate,
-                pool: ManuallyDrop::new(pool),
-            }
+        GILGuard {
+            gstate,
+            pool: ManuallyDrop::new(pool),
         }
     }
 
@@ -252,7 +230,7 @@ static POOL: ReferencePool = ReferencePool::new();
 pub struct GILPool {
     /// Initial length of owned objects and anys.
     /// `Option` is used since TSL can be broken when `new` is called from `atexit`.
-    start: Option<(usize, usize)>,
+    start: Option<usize>,
     no_send: Unsendable,
 }
 
@@ -283,20 +261,19 @@ impl GILPool {
 
 impl Drop for GILPool {
     fn drop(&mut self) {
-        unsafe {
-            if let Some((obj_len_start, any_len_start)) = self.start {
-                let dropping_obj = OWNED_OBJECTS.with(|holder| {
-                    // `holder` must be dropped before calling Py_DECREF, or Py_DECREF may call
-                    // `GILPool::drop` recursively, resulting in invalid borrowing.
-                    let mut holder = holder.borrow_mut();
-                    holder.any.truncate(any_len_start);
-                    if obj_len_start < holder.obj.len() {
-                        holder.obj.split_off(obj_len_start)
-                    } else {
-                        Vec::new()
-                    }
-                });
-                for obj in dropping_obj {
+        if let Some(obj_len_start) = self.start {
+            let dropping_obj = OWNED_OBJECTS.with(|holder| {
+                // `holder` must be dropped before calling Py_DECREF, or Py_DECREF may call
+                // `GILPool::drop` recursively, resulting in invalid borrowing.
+                let mut holder = holder.borrow_mut();
+                if obj_len_start < holder.len() {
+                    holder.split_off(obj_len_start)
+                } else {
+                    Vec::new()
+                }
+            });
+            for obj in dropping_obj {
+                unsafe {
                     ffi::Py_DECREF(obj.as_ptr());
                 }
             }
@@ -343,36 +320,21 @@ pub unsafe fn register_decref(obj: NonNull<ffi::PyObject>) {
 /// The object must be an owned Python reference.
 pub unsafe fn register_owned(_py: Python, obj: NonNull<ffi::PyObject>) {
     debug_assert!(gil_is_acquired());
-    // Ignoring the error means we do nothing if the TLS is broken.
-    let _ = OWNED_OBJECTS.try_with(|holder| holder.borrow_mut().obj.push(obj));
-}
-
-/// Register any value inside the GILPool.
-///
-/// # Safety
-/// It is the caller's responsibility to ensure that the inferred lifetime 'p is not inferred by
-/// the Rust compiler to outlast the current GILPool.
-pub unsafe fn register_any<'p, T: 'static>(obj: T) -> &'p T {
-    debug_assert!(gil_is_acquired());
-    OWNED_OBJECTS.with(|holder| {
-        let boxed = Box::new(obj);
-        let value_ref: *const T = &*boxed;
-        holder.borrow_mut().any.push(boxed);
-        &*value_ref
-    })
+    // Ignores the error in case this function called from `atexit`.
+    let _ = OWNED_OBJECTS.try_with(|holder| holder.borrow_mut().push(obj));
 }
 
 /// Increment pyo3's internal GIL count - to be called whenever GILPool or GILGuard is created.
-// Ignores the error in case this function called from `atexit`.
 #[inline(always)]
 fn increment_gil_count() {
+    // Ignores the error in case this function called from `atexit`.
     let _ = GIL_COUNT.with(|c| c.set(c.get() + 1));
 }
 
 /// Decrement pyo3's internal GIL count - to be called whenever GILPool or GILGuard is dropped.
-// Ignores the error in case this function called from `atexit`.
 #[inline(always)]
 fn decrement_gil_count() {
+    // Ignores the error in case this function called from `atexit`.
     let _ = GIL_COUNT.try_with(|c| {
         let current = c.get();
         debug_assert!(
@@ -431,7 +393,7 @@ mod test {
     }
 
     fn owned_object_count() -> usize {
-        OWNED_OBJECTS.with(|holder| holder.borrow().obj.len())
+        OWNED_OBJECTS.with(|holder| holder.borrow().len())
     }
 
     #[test]

src/python.rs

@@ -435,13 +435,6 @@ impl<'p> Python<'p> {
         FromPyPointer::from_borrowed_ptr_or_opt(self, ptr)
     }
 
-    #[doc(hidden)]
-    /// Passes value ownership to `Python` object and get reference back.
-    /// Value get cleaned up on the GIL release.
-    pub fn register_any<T: 'static>(self, ob: T) -> &'p T {
-        unsafe { gil::register_any(ob) }
-    }
-
     /// Releases a PyObject reference.
     #[inline]
     pub fn release<T>(self, ob: T)