Added aligned memory management methods

Author: iiMidknightii

gdextension/gdextension_interface.h

@@ -839,6 +839,45 @@ typedef void *(*GDExtensionInterfaceMemRealloc)(void *p_ptr, size_t p_bytes);
  */
 typedef void (*GDExtensionInterfaceMemFree)(void *p_ptr);
 
+// TODO: Uncomment if the approach is to add to the interface instead of a local implementation
+// /**
+//  * @name mem_aligned_alloc
+//  * @since 4.5
+//  * 
+//  * Allocates memory aligned to user input
+//  * 
+//  * @param p_bytes The amount of memory to allocate in bytes
+//  * @param p_align The alignment of the memory block to allocate to the nearest byte
+//  * 
+//  * @return A pointer to the allocated aligned memory, or NULL if unsucessful
+//  */
+// typedef void *(*GDExtensionInterfaceMemAlignedAlloc)(size_t p_bytes, size_t p_align);
+
+// /**
+//  * @name mem_aligned_realloc
+//  * @since 4.5
+//  *
+//  * Reallocates memory aligned to user input.
+//  *
+//  * @param p_ptr A pointer to the previously allocated aligned memory.
+//  * @param p_bytes The number of bytes to resize the memory block to.
+//  * @param p_prev_bytes The previous size of the memory block in bytes.
+//  * @param p_align The alignment of the memory block to allocate to the nearest byte.
+//  *
+//  * @return A pointer to the allocated aligned memory, or NULL if unsuccessful.
+//  */
+// typedef void *(*GDExtensionInterfaceMemAlignedRealloc)(void *p_ptr, size_t p_bytes, size_t p_prev_bytes, size_t p_align);
+
+// /**
+//  * @name mem_aligned_free
+//  * @since 4.5
+//  *
+//  * Frees memory allocated with `mem_aligned_alloc`.
+//  *
+//  * @param p_ptr A pointer to the previously allocated aligned memory.
+//  */
+// typedef void (*GDExtensionInterfaceMemAlignedFree)(void *p_ptr);
+
 /* INTERFACE: Godot Core */
 
 /**

include/godot_cpp/core/memory.hpp

@@ -79,6 +79,10 @@ class Memory {
 	static void *alloc_static(size_t p_bytes, bool p_pad_align = false);
 	static void *realloc_static(void *p_memory, size_t p_bytes, bool p_pad_align = false);
 	static void free_static(void *p_ptr, bool p_pad_align = false);
+
+	static void *alloc_aligned_static(size_t p_bytes, size_t p_alignment);
+	static void *realloc_aligned_static(void *p_memory, size_t p_bytes, size_t p_prev_bytes, size_t p_alignment);
+	static void free_aligned_static(void *p_ptr);
 };
 
 template <typename T, std::enable_if_t<!std::is_base_of<::godot::Wrapped, T>::value, bool> = true>
@@ -96,6 +100,10 @@ _ALWAYS_INLINE_ T *_post_initialize(T *p_obj) {
 #define memrealloc(m_mem, m_size) ::godot::Memory::realloc_static(m_mem, m_size)
 #define memfree(m_mem) ::godot::Memory::free_static(m_mem)
 
+#define memalloc_aligned(m_size, m_alignment) ::godot::Memory::alloc_aligned_static(m_size, m_alignment)
+#define memrealloc_aligned(m_mem, m_size, m_prev_size, m_alignment) ::godot::Memory::realloc_aligned_static(m_mem, m_size, m_prev_size, m_alignment)
+#define memfree_aligned(m_mem) ::godot::Memory::free_aligned_static(m_mem)
+
 #define memnew(m_class) (::godot::_pre_initialize<std::remove_pointer_t<decltype(new ("", "") m_class)>>(), ::godot::_post_initialize(new ("", "") m_class))
 
 #define memnew_allocator(m_class, m_allocator) (::godot::_pre_initialize<std::remove_pointer_t<decltype(new ("", "") m_class)>>(), ::godot::_post_initialize(new ("", m_allocator::alloc) m_class))

include/godot_cpp/godot.hpp

@@ -47,6 +47,10 @@ extern "C" GDExtensionInterfaceGetGodotVersion gdextension_interface_get_godot_v
 extern "C" GDExtensionInterfaceMemAlloc gdextension_interface_mem_alloc;
 extern "C" GDExtensionInterfaceMemRealloc gdextension_interface_mem_realloc;
 extern "C" GDExtensionInterfaceMemFree gdextension_interface_mem_free;
+// TODO: Uncomment if the engine is updated to use this extended interface
+// extern "C" GDExtensionInterfaceMemAlignedAlloc gdextension_interface_mem_aligned_alloc;
+// extern "C" GDExtensionInterfaceMemAlignedRealloc gdextension_interface_mem_aligned_realloc;
+// extern "C" GDExtensionInterfaceMemAlignedFree gdextension_interface_mem_aligned_free;
 extern "C" GDExtensionInterfacePrintError gdextension_interface_print_error;
 extern "C" GDExtensionInterfacePrintErrorWithMessage gdextension_interface_print_error_with_message;
 extern "C" GDExtensionInterfacePrintWarning gdextension_interface_print_warning;

src/core/memory.cpp

@@ -93,6 +93,60 @@ void Memory::free_static(void *p_ptr, bool p_pad_align) {
 	internal::gdextension_interface_mem_free(mem);
 }
 
+void *Memory::alloc_aligned_static(size_t p_bytes, size_t p_alignment) {
+	DEV_ASSERT(is_power_of_2(p_alignment));
+
+	void *p1, *p2;
+	if ((p1 = (void *)alloc_static(p_bytes + p_alignment - 1 + sizeof(uint32_t))) == nullptr) {
+		return nullptr;
+	}
+
+	p2 = (void *)(((uintptr_t)p1 + sizeof(uint32_t) + p_alignment - 1) & ~((p_alignment)-1));
+	*((uint32_t *)p2 - 1) = (uint32_t)((uintptr_t)p2 - (uintptr_t)p1);
+	return p2;
+
+	// TODO: Alternate implementation if engine accepts this interface
+	// void *mem = internal::gdextension_interface_mem_aligned_alloc(p_bytes, p_alignment);
+	// ERR_FAIL_NULL_V(mem, nullptr);
+	// return mem;
+}
+
+void *Memory::realloc_aligned_static(void *p_memory, size_t p_bytes, size_t p_prev_bytes, size_t p_alignment) {
+	DEV_ASSERT(is_power_of_2(p_alignment));
+
+	if (p_memory == nullptr) {
+		return alloc_aligned_static(p_bytes, p_alignment);
+	}
+
+	void *ret = alloc_aligned_static(p_bytes, p_alignment);
+	if (ret) {
+		memcpy(ret, p_memory, p_prev_bytes);
+	}
+	free_aligned_static(p_memory);
+	return ret;
+
+	// TODO: Alternate implementation if engine accepts this interface
+	// if (p_memory == nullptr) {
+	// 	return alloc_aligned_static(p_bytes, p_alignment);
+	// } else if (p_bytes == 0) {
+	// 	free_aligned_static(p_memory);
+	// 	return nullptr;
+	// }
+
+	// void *mem = internal::gdextension_interface_mem_aligned_realloc(p_memory, p_bytes, p_prev_bytes, p_alignment);
+	// ERR_FAIL_NULL_V(mem, nullptr);
+	// return mem;
+}
+
+void Memory::free_aligned_static(void *p_ptr) {
+	uint32_t offset = *((uint32_t *)p_ptr - 1);
+	void *p = (void *)((uint8_t *)p_ptr - offset);
+	free_static(p);
+
+	// TODO: Alternate implementation if engine accepts this interface
+	// internal::gdextension_interface_mem_aligned_free(p_ptr);
+}
+
 _GlobalNil::_GlobalNil() {
 	left = this;
 	right = this;

src/godot.cpp

@@ -54,6 +54,10 @@ GDExtensionInterfaceGetGodotVersion gdextension_interface_get_godot_version = nu
 GDExtensionInterfaceMemAlloc gdextension_interface_mem_alloc = nullptr;
 GDExtensionInterfaceMemRealloc gdextension_interface_mem_realloc = nullptr;
 GDExtensionInterfaceMemFree gdextension_interface_mem_free = nullptr;
+// TODO: Uncomment if the engine is updated to use this extended interface
+// GDExtensionInterfaceMemAlignedAlloc gdextension_interface_mem_aligned_alloc = nullptr;
+// GDExtensionInterfaceMemAlignedRealloc gdextension_interface_mem_aligned_realloc = nullptr;
+// GDExtensionInterfaceMemAlignedFree gdextension_interface_mem_aligned_free = nullptr;
 GDExtensionInterfacePrintError gdextension_interface_print_error = nullptr;
 GDExtensionInterfacePrintErrorWithMessage gdextension_interface_print_error_with_message = nullptr;
 GDExtensionInterfacePrintWarning gdextension_interface_print_warning = nullptr;