[K/N] Refactor allocator modules ^KT-60928

- Move std_alloc, opt_alloc and custom_alloc into alloc/std,
  alloc/mimalloc and alloc/custom to mirror convention of gc,
  gcScheduler modules.
- Add alloc/common with common allocator API
- Add alloc/legacy with common implementation details of alloc/std and
  alloc/mimalloc. alloc/custom does not depend on alloc/legacy.
- Removes experimental_memory_manager_custom as it's now unused
- Additionally, renames experimental_memory_manager module into mm

kotlin-native/runtime/src/main/cpp/Memory.h

@@ -612,6 +612,9 @@ bool FinalizersThreadIsRunning() noexcept;
 
 void OnMemoryAllocation(size_t totalAllocatedBytes) noexcept;
 
+void initObjectPool() noexcept;
+void compactObjectPoolInCurrentThread() noexcept;
+
 } // namespace kotlin
 
 RUNTIME_NOTHROW ALWAYS_INLINE extern "C" void Kotlin_processObjectInMark(void* state, ObjHeader* object);

kotlin-native/runtime/src/main/cpp/ObjectAlloc.hpp

@@ -1,54 +0,0 @@
-/*
- * Copyright 2010-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
- * that can be found in the LICENSE file.
- */
-
-#pragma once
-
-#include <cstddef>
-#include <type_traits>
-
-namespace kotlin {
-
-void initObjectPool() noexcept;
-void* allocateInObjectPool(size_t size) noexcept;
-void freeInObjectPool(void* ptr, size_t size) noexcept;
-// Instruct the allocator to free unused resources.
-void compactObjectPoolInCurrentThread() noexcept;
-// Platform dependent. Schedule `compactObjectPoolInCurrentThread` on the main thread.
-// May do nothing if the main thread is not an event loop.
-void compactObjectPoolInMainThread() noexcept;
-
-size_t allocatedBytes() noexcept;
-
-template <typename T>
-struct ObjectPoolAllocator {
-    using value_type = T;
-    using size_type = std::size_t;
-    using difference_type = std::ptrdiff_t;
-    using propagate_on_container_move_assignment = std::true_type;
-    using is_always_equal = std::true_type;
-
-    constexpr ObjectPoolAllocator() noexcept = default;
-
-    constexpr ObjectPoolAllocator(const ObjectPoolAllocator&) noexcept = default;
-
-    template <typename U>
-    constexpr ObjectPoolAllocator(const ObjectPoolAllocator<U>&) noexcept {}
-
-    T* allocate(std::size_t n) noexcept { return static_cast<T*>(allocateInObjectPool(n * sizeof(T))); }
-
-    void deallocate(T* p, std::size_t n) noexcept { freeInObjectPool(p, n * sizeof(T)); }
-};
-
-template <typename T, typename U>
-constexpr bool operator==(const ObjectPoolAllocator<T>&, const ObjectPoolAllocator<U>&) noexcept {
-    return true;
-}
-
-template <typename T, typename U>
-constexpr bool operator!=(const ObjectPoolAllocator<T>&, const ObjectPoolAllocator<U>&) noexcept {
-    return false;
-}
-
-}

kotlin-native/runtime/src/main/cpp/Runtime.cpp

@@ -11,7 +11,6 @@
 #include "MainQueueProcessor.hpp"
 #include "Memory.h"
 #include "ObjCExportInit.h"
-#include "ObjectAlloc.hpp"
 #include "Porting.h"
 #include "Runtime.h"
 #include "RuntimePrivate.hpp"

kotlin-native/runtime/src/main/cpp/Worker.cpp

@@ -32,7 +32,6 @@
 #include "Memory.h"
 #include "Natives.h"
 #include "ObjCMMAPI.h"
-#include "ObjectAlloc.hpp"
 #include "Runtime.h"
 #include "Types.h"
 #include "Worker.h"