mirror of
https://github.com/RGBCube/serenity
synced 2025-05-14 07:44:59 +00:00
f91bcb8895
Problem: - `size_classes` is a C-style array which makes it difficult to use in algorithms. - `all_of` algorithm is re-written for the specific implementation. Solution: - Change `size_classes` to be an `Array`. - Directly use the generic `all_of` algorithm instead of reimplementing.
72 lines
2 KiB
C
72 lines
2 KiB
C
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/AllOf.h>
|
|
#include <AK/Array.h>
|
|
#include <AK/InlineLinkedList.h>
|
|
#include <AK/Types.h>
|
|
|
|
#define MAGIC_PAGE_HEADER 0x42657274 // 'Bert'
|
|
#define MAGIC_BIGALLOC_HEADER 0x42697267 // 'Birg'
|
|
#define MALLOC_SCRUB_BYTE 0xdc
|
|
#define FREE_SCRUB_BYTE 0xed
|
|
|
|
static constexpr Array<unsigned short, 13> size_classes { 8, 16, 32, 64, 128, 256, 504, 1016, 2032, 4088, 8184, 16376, 32752 };
|
|
static constexpr auto malloc_alignment = 8;
|
|
static_assert(all_of(size_classes.begin(), size_classes.end(),
|
|
[](const auto val) { return val % malloc_alignment == 0; }));
|
|
|
|
struct CommonHeader {
|
|
size_t m_magic;
|
|
size_t m_size;
|
|
};
|
|
|
|
struct BigAllocationBlock : public CommonHeader {
|
|
BigAllocationBlock(size_t size)
|
|
{
|
|
m_magic = MAGIC_BIGALLOC_HEADER;
|
|
m_size = size;
|
|
}
|
|
unsigned char* m_slot[0];
|
|
};
|
|
|
|
struct FreelistEntry {
|
|
FreelistEntry* next;
|
|
};
|
|
|
|
struct ChunkedBlock
|
|
: public CommonHeader
|
|
, public InlineLinkedListNode<ChunkedBlock> {
|
|
|
|
static constexpr size_t block_size = 64 * KiB;
|
|
static constexpr size_t block_mask = ~(block_size - 1);
|
|
|
|
ChunkedBlock(size_t bytes_per_chunk)
|
|
{
|
|
m_magic = MAGIC_PAGE_HEADER;
|
|
m_size = bytes_per_chunk;
|
|
m_free_chunks = chunk_capacity();
|
|
}
|
|
|
|
ChunkedBlock* m_prev { nullptr };
|
|
ChunkedBlock* m_next { nullptr };
|
|
size_t m_next_lazy_freelist_index { 0 };
|
|
FreelistEntry* m_freelist { nullptr };
|
|
size_t m_free_chunks { 0 };
|
|
[[gnu::aligned(8)]] unsigned char m_slot[0];
|
|
|
|
void* chunk(size_t index)
|
|
{
|
|
return &m_slot[index * m_size];
|
|
}
|
|
bool is_full() const { return m_free_chunks == 0; }
|
|
size_t bytes_per_chunk() const { return m_size; }
|
|
size_t free_chunks() const { return m_free_chunks; }
|
|
size_t used_chunks() const { return chunk_capacity() - m_free_chunks; }
|
|
size_t chunk_capacity() const { return (block_size - sizeof(ChunkedBlock)) / m_size; }
|
|
};
|