Files
text_editor/src/basic/basic_alloc.cpp
2025-12-14 17:05:55 +01:00

387 lines
11 KiB
C++

#if defined(USE_ADDRESS_SANITIZER)
#include <sanitizer/asan_interface.h>
#endif
#if !defined(ASAN_POISON_MEMORY_REGION)
#define MA_ASAN_POISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
#define MA_ASAN_UNPOISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
#else
#define MA_ASAN_POISON_MEMORY_REGION(addr, size) ASAN_POISON_MEMORY_REGION(addr, size)
#define MA_ASAN_UNPOISON_MEMORY_REGION(addr, size) ASAN_UNPOISON_MEMORY_REGION(addr, size)
#endif
#include <stdlib.h>
#if OS_WINDOWS
#ifndef NOMINMAX
#define NOMINMAX
#endif
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
API void *VReserve(size_t size) {
void *result = (uint8_t *)VirtualAlloc(0, size, MEM_RESERVE, PAGE_READWRITE);
return result;
}
API bool VCommit(void *p, size_t size) {
void *result = VirtualAlloc(p, size, MEM_COMMIT, PAGE_READWRITE);
return result ? true : false;
}
API bool VRelease(void *p, size_t size) {
BOOL result = VirtualFree(p, 0, MEM_RELEASE);
return result ? true : false;
}
API bool VDecommit(void *p, size_t size) {
BOOL result = VirtualFree(p, size, MEM_DECOMMIT);
return result ? true : false;
}
#elif OS_LINUX || OS_MAC
#include <sys/mman.h>
API void *VReserve(size_t size) {
void *result = mmap(0, size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, (off_t)0);
return result == (void *)-1 ? 0 : result;
}
API bool VCommit(void *p, size_t size) {
int result = mprotect(p, size, PROT_READ | PROT_WRITE);
return result == 0;
}
API bool VRelease(void *p, size_t size) {
int result = munmap(p, size);
return result == 0;
}
API bool VDecommit(void *p, size_t size) {
mprotect(p, size, PROT_NONE);
madvise(p, size, MADV_DONTNEED);
return true;
}
#else
API void *VReserve(size_t size) {
InvalidCodepath();
return NULL;
}
API bool VCommit(void *p, size_t size) {
InvalidCodepath();
return false;
}
API bool VRelease(void *p, size_t size) {
InvalidCodepath();
return false;
}
API bool VDecommit(void *p, size_t size) {
InvalidCodepath();
return false;
}
#endif
API void *SystemAllocatorProc(void *object, int kind, void *p, size_t size) {
void *result = NULL;
if (kind == AllocatorKind_Allocate) {
result = malloc(size);
Assert(result);
} else if (kind == AllocatorKind_Deallocate) {
free(p);
} else {
InvalidCodepath();
}
return result;
}
API Allocator GetSystemAllocator() {
Allocator result = {SystemAllocatorProc};
return result;
}
API void *_AllocSize_(Allocator alo, size_t size) {
void *result = alo.proc(alo.object, AllocatorKind_Allocate, NULL, size);
memset(result, 0, size);
return result;
}
struct MemoryRecord {
size_t size;
void *addr;
char *file;
int line;
};
thread_local Array<MemoryRecord> MemoryTrackingRecord;
API void *TrackingAllocatorProc(void *object, int kind, void *p, size_t size) {
void *result = NULL;
if (kind == AllocatorKind_Allocate) {
result = malloc(size);
Add(&MemoryTrackingRecord, {size, result, LocationTraceO.file, LocationTraceO.line});
Assert(result);
} else if (kind == AllocatorKind_Deallocate) {
free(p);
bool found = false;
For(IterateInReverse(&MemoryTrackingRecord)) {
if (it.addr == p) {
found = true;
UnorderedRemove(&MemoryTrackingRecord, it);
break;
}
}
Assert(found);
} else {
InvalidCodepath();
}
return result;
}
API void TrackingAllocatorCheck() {
// For (MemoryTrackingRecord) {
// ReportConsolef("%s(%d): error: memory leak");
// }
Assert(MemoryTrackingRecord.len == 0);
}
API Allocator GetTrackingAllocator() {
Allocator result = {TrackingAllocatorProc};
return result;
}
///////////////////////////////
// Virtual Arena
API void InitArena(VirtualArena *arena, size_t reserve) {
reserve = AlignUp(reserve, PAGE_SIZE);
arena->align = DEFAULT_ALIGNMENT;
arena->data = (uint8_t *)VReserve(reserve);
if (arena->data) {
arena->reserve = reserve;
}
}
API VirtualArena *AllocArena(Allocator allocator, size_t size) {
VirtualArena *result = AllocType(allocator, VirtualArena);
result->data = (uint8_t *)AllocSize(allocator, size);
result->reserve = size;
result->commit = size;
result->align = DEFAULT_ALIGNMENT;
return result;
}
API VirtualArena *AllocArena(size_t reserve) {
VirtualArena *result = NULL;
void *data = VReserve(reserve);
if (!data) return result;
bool success = VCommit(data, PAGE_SIZE);
if (!success) {
VRelease(data, reserve);
return result;
}
result = (VirtualArena *)data;
result->data = (uint8_t *)data;
result->reserve = reserve;
result->commit = PAGE_SIZE;
result->len = result->base_len = sizeof(VirtualArena);
result->align = DEFAULT_ALIGNMENT;
return result;
}
API void *PushSize(VirtualArena *arena, size_t size) {
// base_len is used for bootstraping arenas, it denotes the
// space occupied by the arena. If len is smaller then base_len then
// we start to overwrite the arena itself - pure barbarism.
Assert(arena->len >= arena->base_len);
size_t align_offset = 0;
if (arena->align) {
align_offset = GetAlignOffset((uintptr_t)arena->data + arena->len, arena->align);
}
size_t size_with_alignment = size + align_offset;
size_t new_len = arena->len + size_with_alignment;
if (new_len > arena->commit) {
size_t new_len_aligned_to_page_size = AlignUp(new_len, PAGE_SIZE);
size_t to_commit = new_len_aligned_to_page_size - arena->commit;
size_t to_commit_clamped = ClampTop(to_commit, arena->reserve);
if (to_commit_clamped > 0) {
bool success = VCommit(arena->data + arena->commit, to_commit_clamped);
if (success) {
MA_ASAN_POISON_MEMORY_REGION(arena->data + arena->commit, to_commit_clamped);
arena->commit += to_commit_clamped;
}
}
if (new_len > arena->commit) {
return NULL;
}
}
uint8_t *result = arena->data + arena->len + align_offset;
arena->len = new_len;
MA_ASAN_UNPOISON_MEMORY_REGION(result, size);
return (void *)result;
}
API void Release(VirtualArena *arena) {
if (arena == NULL || arena->data == NULL) return;
bool zero_memory = (uint8_t *)arena != arena->data;
VRelease(arena->data, arena->reserve);
if (zero_memory) MemoryZero(arena, sizeof(VirtualArena));
}
API void PopToPos(VirtualArena *arena, size_t pos) {
// base_len is used for bootstraping arenas, it denotes the
// space occupied by the arena. If len is smaller then base_len then
// we start to overwrite the arena itself - pure barbarism.
Assert(arena->len >= arena->base_len);
pos = Clamp(pos, arena->base_len, arena->len);
size_t size = arena->len - pos;
arena->len = pos;
MA_ASAN_POISON_MEMORY_REGION(arena->data + arena->len, size);
}
API void *ArenaAllocatorProc(void *object, int kind, void *p, size_t size) {
if (kind == AllocatorKind_Allocate) {
return PushSize((VirtualArena *)object, size);
} else if (AllocatorKind_Deallocate) {
} else {
Assert(!"invalid codepath");
}
return NULL;
}
///////////////////////////////
// Block Arena
API void *PushSize(BlockArena *arena, size_t size) {
if (size > (size_t)(arena->end - arena->start)) {
size_t block_size = MiB(1);
if (size > block_size) {
block_size = size;
}
if (arena->allocator.proc == NULL) {
arena->allocator = GetSystemAllocator();
}
BlockArenaNode *new_block = (BlockArenaNode *)AllocSize(arena->allocator, block_size + sizeof(BlockArenaNode));
Assert(GetAlignOffset((size_t)new_block->start, DEFAULT_ALIGNMENT) == 0);
arena->start = new_block->start;
new_block->end = arena->end = new_block->start + block_size;
SLL_STACK_ADD(arena->blocks, new_block);
}
U8 *result = arena->start;
Assert(GetAlignOffset((size_t)result, DEFAULT_ALIGNMENT) == 0);
arena->start = (U8 *)AlignUp((size_t)(arena->start + size), DEFAULT_ALIGNMENT);
return result;
}
API void Release(BlockArena *arena) {
for (BlockArenaNode *it = arena->blocks, *next = NULL; it; it = next) {
next = it->next;
Dealloc(arena->allocator, it);
}
MemoryZero(arena, sizeof(BlockArena));
}
API void Unwind(BlockArena *arena, U8 *pos) {
bool contains = false;
for (BlockArenaNode *it = arena->blocks, *next = NULL; it; it = next) {
next = it->next;
if ((pos >= it->start) && (pos < it->end)) {
contains = true;
break;
} else {
arena->blocks = arena->blocks->next;
Dealloc(arena->allocator, it);
}
}
Assert(contains || pos == NULL);
arena->start = pos;
}
API void *BlockArenaAllocatorProc(void *object, int kind, void *p, size_t size) {
BlockArena *arena = (BlockArena *)object;
if (kind == AllocatorKind_Allocate) {
return PushSize(arena, size);
} else if (AllocatorKind_Deallocate) {
} else {
Assert(!"invalid codepath");
}
return NULL;
}
void RunArenaTest() {
Allocator memory_tracking_allocator = GetTrackingAllocator();
{
BlockArena arena = {};
arena.allocator = memory_tracking_allocator;
for (int i = 0; i < 10000; i += 1) {
int *vals = (int *)PushSize(&arena, sizeof(int)*i);
for (int j = 0; j < i; j += 1) {
vals[j] = j;
}
}
Release(&arena);
TrackingAllocatorCheck();
}
{
BlockArena arena = {};
U8 *start = arena.start;
arena.allocator = memory_tracking_allocator;
int *vals = (int *)PushSize(&arena, sizeof(int) * 32);
for (int i = 0; i < 32; i += 1) vals[i] = i;
Unwind(&arena, (U8 *)vals);
Assert(arena.blocks);
Assert(arena.blocks->next == NULL);
Assert(arena.start == (U8 *)vals);
Assert(arena.blocks[0].start == (U8 *)vals);
Unwind(&arena, NULL);
Dealloc(arena.allocator, arena.blocks);
TrackingAllocatorCheck();
}
{
BlockArena arena = {};
arena.allocator = memory_tracking_allocator;
int *vals = (int *)PushSize(&arena, sizeof(int) * 32);
for (int i = 0; i < 32; i += 1) vals[i] = i;
U8 *p = arena.start;
U8 *a = (U8 *)PushSize(&arena, KiB(32));
U8 *b = (U8 *)PushSize(&arena, KiB(1000));
Assert(arena.blocks);
Assert(arena.blocks->next);
Assert(arena.blocks->next->next == NULL);
Unwind(&arena, a);
Assert(arena.blocks);
Assert(arena.blocks->next == NULL);
Assert(arena.start == p);
Release(&arena);
TrackingAllocatorCheck();
}
{
BlockArena arena = {};
arena.allocator = memory_tracking_allocator;
U8 *a = (U8 *)PushSize(&arena, KiB(2000));
Assert((size_t)(arena.blocks[0].end - arena.blocks[0].start) == KiB(2000));
Release(&arena);
TrackingAllocatorCheck();
}
}