Use our Python allocator on free-threaded builds, but do it correctly with PyMem_Malloc.

Author: jamadden

src/greenlet/greenlet_allocator.hpp

@@ -10,30 +10,6 @@
 
 namespace greenlet
 {
-#if defined(Py_GIL_DISABLED)
-// Python on free threaded builds says this
-// (https://docs.python.org/3/howto/free-threading-extensions.html#memory-allocation-apis):
-//
-//  For thread-safety, the free-threaded build requires that only
-//  Python objects are allocated using the object domain, and that all
-//  Python object are allocated using that domain.
-//
-// This turns out to be important because the GC implementation on
-// free threaded Python uses internal mimalloc APIs to find allocated
-// objects. If we allocate non-PyObject objects using that API, then
-// Bad Things could happen, including crashes and improper results.
-// So in that case, we revert to standard C++ allocation.
-
-    template <class T>
-    struct PythonAllocator : public std::allocator<T> {
-        // This member is deprecated in C++17 and removed in C++20
-        template< class U >
-        struct rebind {
-            typedef PythonAllocator<U> other;
-        };
-    };
-
-#else
     // This allocator is stateless; all instances are identical.
     // It can *ONLY* be used when we're sure we're holding the GIL
     // (Python's allocators require the GIL).
@@ -60,21 +36,32 @@ namespace greenlet
         T* allocate(size_t number_objects, const void* UNUSED(hint)=0)
         {
             void* p;
-            if (number_objects == 1)
+            if (number_objects == 1) {
+#ifdef Py_GIL_DISABLED
+                p = PyMem_Malloc(sizeof(T) * number_objects);
+#else
                 p = PyObject_Malloc(sizeof(T));
-            else
+#endif
+            }
+            else {
                 p = PyMem_Malloc(sizeof(T) * number_objects);
+            }
             return static_cast<T*>(p);
         }
 
         void deallocate(T* t, size_t n)
         {
             void* p = t;
             if (n == 1) {
+#ifdef Py_GIL_DISABLED
+                PyMem_Free(p);
+#else
                 PyObject_Free(p);
+#endif
             }
-            else
+            else {
                 PyMem_Free(p);
+            }
         }
         // This member is deprecated in C++17 and removed in C++20
         template< class U >
@@ -83,7 +70,6 @@ namespace greenlet
         };
 
     };
-#endif // allocator type
 }
 
 #endif