Integrate mimalloc allocator

SConstruct

@@ -1074,6 +1074,9 @@ SConscript("main/SCsub")
 
 SConscript("platform/" + env["platform"] + "/SCsub")  # Build selected platform.
 
+if "mimalloc" in env.get("supported", []):
+    SConscript("mimalloc/SCsub")
+
 # Microsoft Visual Studio Project Generation
 if env["vsproj"]:
     methods.generate_cpp_hint_file("cpp.hint")

mimalloc/SCsub

@@ -0,0 +1,100 @@
+#!/usr/bin/env python
+from misc.utility.scons_hints import *
+
+Import("env")
+
+# For platforms not supported out-of-the-box by mimalloc, the following options
+# can be used to add support for them:
+# mimalloc_custom_prims (bool): If true, the prim.c file is not included. Important because otherwise it falls back to UNIX.
+# mimalloc_custom_tls_slot (bool): If true, mimalloc is built assuming primitives for TLS operations will be provided separately.
+# mimalloc_custom_get_thread_id (string): If non-empty, mimalloc will use the function named here to get the current thread id.
+
+
+mimalloc_sources = []
+
+if env["platform"] == "windows":
+    override_type = "windows"
+elif env.get("mimalloc_custom_prims"):
+    override_type = "none"
+else:
+    override_type = "static"
+
+use_mingw_custom_tls_slot = override_type == "windows" and not env.msvc
+
+# Thirdparty source files
+
+env_thirdparty = env.Clone()
+env_thirdparty.disable_warnings()
+
+thirdparty_obj = []
+
+thirdparty_dir = "#thirdparty/mimalloc/"
+if override_type == "static":
+    thirdparty_sources = ["src/static.c"]
+    env_thirdparty.Append(CPPDEFINES=["MI_MALLOC_OVERRIDE"])
+else:
+    thirdparty_sources = [
+        "src/alloc.c",
+        "src/alloc-aligned.c",
+        "src/alloc-posix.c",
+        "src/arena.c",
+        "src/bitmap.c",
+        "src/heap.c",
+        "src/init.c",
+        "src/libc.c",
+        "src/options.c",
+        "src/os.c",
+        "src/page.c",
+        "src/random.c",
+        "src/segment-map.c",
+        "src/segment.c",
+        "src/stats.c",
+    ]
+    if not env.get("mimalloc_custom_prims"):
+        thirdparty_sources += ["src/prim/prim.c"]
+
+thirdparty_sources = [thirdparty_dir + file for file in thirdparty_sources]
+
+if use_mingw_custom_tls_slot:
+    thirdparty_sources += ["#mimalloc/mingw_custom_tls_slot.cpp"]
+
+env_thirdparty.add_source_files(thirdparty_obj, thirdparty_sources)
+
+env_thirdparty.Append(CPPDEFINES=[("MI_TRACK_ASAN", 1 if env.get("use_asan") else 0)])
+
+if env.get("mimalloc_custom_tls_slot") or use_mingw_custom_tls_slot:
+    env_thirdparty.Append(CPPFLAGS=["-includemimalloc/custom_tls_slot.h"])
+
+if env.get("mimalloc_custom_get_thread_id"):
+    env_thirdparty.Append(CPPDEFINES=[("MI_PRIM_THREAD_ID", env.get("mimalloc_custom_get_thread_id"))])
+
+env_thirdparty.Append(CPPPATH=[f"{thirdparty_dir}include/"])
+
+mimalloc_sources += thirdparty_obj
+
+
+# Godot source files
+
+if override_type == "windows":
+    godot_obj = []
+
+    env_mimalloc = env_thirdparty.Clone()
+    env_mimalloc.Append(CPPPATH=[thirdparty_dir])
+
+    env_mimalloc.add_source_files(godot_obj, "windows_override.cpp")
+
+    mimalloc_sources += godot_obj
+
+    if env.msvc:
+        if env["arch"] == "x86_32":
+            env.Append(LINKFLAGS=["/INCLUDE:_mimalloc_godot_force_override"])
+        else:
+            env.Append(LINKFLAGS=["/INCLUDE:mimalloc_godot_force_override"])
+
+lib = env.add_library("mimalloc", mimalloc_sources)
+
+# For override to work on non-Windows platforms, it must be linked first.
+# This way is somewhat hacky, but reliable.
+env.Prepend(LINKFLAGS=[f"mimalloc/{lib[0].get_path()}"])
+# We still add it the regular way to ensure the program depends on it.
+env.Prepend(LIBS=[lib])

mimalloc/custom_tls_slot.h

@@ -0,0 +1,55 @@
+/**************************************************************************/
+/*  custom_tls_slot.h                                                     */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef CUSTOM_TLS_SLOT_H
+#define CUSTOM_TLS_SLOT_H
+
+#include <stddef.h>
+
+// This is included both in the third-party and the engine code
+// to ensure both mimalloc and Godot see the same, non-default,
+// signatures. Otherwise, for instance, in mimalloc mi_prim_tls_slot()
+// could be assumed to return 'int', which would truncate pointers.
+
+#define MI_HAS_TLS_SLOT
+#define MI_TLS_SLOT 0
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void *mi_prim_tls_slot(size_t slot);
+void mi_prim_tls_slot_set(size_t slot, void *value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // CUSTOM_TLS_SLOT_H

mimalloc/mingw_custom_tls_slot.cpp

@@ -0,0 +1,58 @@
+/**************************************************************************/
+/*  mingw_custom_tls_slot.cpp                                             */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "core/error/error_macros.h"
+#include "core/typedefs.h"
+#include "mimalloc/custom_tls_slot.h"
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+static DWORD tls_slot = -1;
+
+extern "C" {
+void *mi_prim_tls_slot(size_t slot) {
+	DEV_ASSERT(slot == MI_TLS_SLOT);
+	if (unlikely(tls_slot == -1)) {
+		return nullptr;
+	} else {
+		return TlsGetValue(tls_slot);
+	}
+}
+
+void mi_prim_tls_slot_set(size_t slot, void *value) {
+	DEV_ASSERT(slot == MI_TLS_SLOT);
+	if (unlikely(tls_slot == -1)) {
+		tls_slot = TlsAlloc();
+		CRASH_COND(tls_slot == TLS_OUT_OF_INDEXES);
+	}
+	TlsSetValue(tls_slot, value);
+}
+}