raylib-imgui-4.5.0.9: rlImGui/raylib/src/rmem.h
/**********************************************************************************************
*
* rmem v1.3 - raylib memory pool and objects pool
*
* A quick, efficient, and minimal free list and arena-based allocator
*
* PURPOSE:
* - A quicker, efficient memory allocator alternative to 'malloc()' and friends.
* - Reduce the possibilities of memory leaks for beginner developers using raylib.
* - Being able to flexibly range check memory if necessary.
*
* CONFIGURATION:
*
* #define RMEM_IMPLEMENTATION
* Generates the implementation of the library into the included file.
* If not defined, the library is in header only mode and can be included in other headers
* or source files without problems. But only ONE file should hold the implementation.
*
* DOCUMENTATION:
*
* raylib Wiki: https://github.com/raysan5/raylib/wiki/raylib-memory-pool
* Usage example with raylib: https://github.com/raysan5/raylib/issues/1329
*
* CHANGELOG:
*
* v1.0: First version
* v1.1: Bug patches for the mempool and addition of object pool
* v1.2: Addition of bidirectional arena
* v1.3: Several changes:
* Pptimizations of allocators
* Renamed 'Stack' to 'Arena'
* Replaced certain define constants with an anonymous enum
* Refactored MemPool to no longer require active or deferred defragging
*
*
* LICENSE: zlib/libpng
*
* Copyright (c) 2019 Kevin 'Assyrianic' Yonan (@assyrianic) and reviewed by Ramon Santamaria (@raysan5)
*
* This software is provided "as-is", without any express or implied warranty. In no event
* will the authors be held liable for any damages arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose, including commercial
* applications, and to alter it and redistribute it freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not claim that you
* wrote the original software. If you use this software in a product, an acknowledgment
* in the product documentation would be appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be misrepresented
* as being the original software.
*
* 3. This notice may not be removed or altered from any source distribution.
*
**********************************************************************************************/
#ifndef RMEM_H
#define RMEM_H
#include <inttypes.h>
#include <stdbool.h>
//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
#if defined(_WIN32) && defined(BUILD_LIBTYPE_SHARED)
#define RMEMAPI __declspec(dllexport) // We are building library as a Win32 shared library (.dll)
#elif defined(_WIN32) && defined(USE_LIBTYPE_SHARED)
#define RMEMAPI __declspec(dllimport) // We are using library as a Win32 shared library (.dll)
#else
#define RMEMAPI // We are building or using library as a static library (or Linux shared library)
#endif
#define RMEM_VERSION "v1.3" // changelog at bottom of header.
//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
enum {
MEMPOOL_BUCKET_SIZE = 8,
MEMPOOL_BUCKET_BITS = (sizeof(uintptr_t) >> 1) + 1,
MEM_SPLIT_THRESHOLD = sizeof(uintptr_t) * 4
};
// Memory pool node
typedef struct MemNode MemNode;
struct MemNode {
size_t size;
MemNode *next, *prev;
};
// Freelist implementation
typedef struct AllocList {
MemNode *head, *tail;
size_t len;
} AllocList;
// Arena allocator
typedef struct Arena {
uintptr_t mem, offs;
size_t size;
} Arena;
// Memory pool
typedef struct MemPool {
AllocList large, buckets[MEMPOOL_BUCKET_SIZE];
Arena arena;
} MemPool;
// Object pool
typedef struct ObjPool {
uintptr_t mem, offs;
size_t objSize, freeBlocks, memSize;
} ObjPool;
// Double-ended stack (aka Deque)
typedef struct BiStack {
uintptr_t mem, front, back;
size_t size;
} BiStack;
#if defined(__cplusplus)
extern "C" { // Prevents name mangling of functions
#endif
//------------------------------------------------------------------------------------
// Functions Declaration - Memory Pool
//------------------------------------------------------------------------------------
RMEMAPI MemPool CreateMemPool(size_t bytes);
RMEMAPI MemPool CreateMemPoolFromBuffer(void *buf, size_t bytes);
RMEMAPI void DestroyMemPool(MemPool *mempool);
RMEMAPI void *MemPoolAlloc(MemPool *mempool, size_t bytes);
RMEMAPI void *MemPoolRealloc(MemPool *mempool, void *ptr, size_t bytes);
RMEMAPI void MemPoolFree(MemPool *mempool, void *ptr);
RMEMAPI void MemPoolCleanUp(MemPool *mempool, void **ptrref);
RMEMAPI void MemPoolReset(MemPool *mempool);
RMEMAPI size_t GetMemPoolFreeMemory(const MemPool mempool);
//------------------------------------------------------------------------------------
// Functions Declaration - Object Pool
//------------------------------------------------------------------------------------
RMEMAPI ObjPool CreateObjPool(size_t objsize, size_t len);
RMEMAPI ObjPool CreateObjPoolFromBuffer(void *buf, size_t objsize, size_t len);
RMEMAPI void DestroyObjPool(ObjPool *objpool);
RMEMAPI void *ObjPoolAlloc(ObjPool *objpool);
RMEMAPI void ObjPoolFree(ObjPool *objpool, void *ptr);
RMEMAPI void ObjPoolCleanUp(ObjPool *objpool, void **ptrref);
//------------------------------------------------------------------------------------
// Functions Declaration - Double-Ended Stack
//------------------------------------------------------------------------------------
RMEMAPI BiStack CreateBiStack(size_t len);
RMEMAPI BiStack CreateBiStackFromBuffer(void *buf, size_t len);
RMEMAPI void DestroyBiStack(BiStack *destack);
RMEMAPI void *BiStackAllocFront(BiStack *destack, size_t len);
RMEMAPI void *BiStackAllocBack(BiStack *destack, size_t len);
RMEMAPI void BiStackResetFront(BiStack *destack);
RMEMAPI void BiStackResetBack(BiStack *destack);
RMEMAPI void BiStackResetAll(BiStack *destack);
RMEMAPI intptr_t BiStackMargins(BiStack destack);
#ifdef __cplusplus
}
#endif
#endif // RMEM_H
/***********************************************************************************
*
* RMEM IMPLEMENTATION
*
************************************************************************************/
#if defined(RMEM_IMPLEMENTATION)
#include <stdlib.h> // Required for: malloc(), calloc(), free()
#include <string.h> // Required for: memset(), memcpy(), memmove()
//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
// Make sure restrict type qualifier for pointers is defined
// NOTE: Not supported by C++, it is a C only keyword
#if defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__) || defined(_MSC_VER)
#ifndef restrict
#define restrict __restrict
#endif
#endif
//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
// ...
//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
static inline size_t __AlignSize(const size_t size, const size_t align)
{
return (size + (align - 1)) & -align;
}
static MemNode *__SplitMemNode(MemNode *const node, const size_t bytes)
{
uintptr_t n = ( uintptr_t )node;
MemNode *const r = ( MemNode* )(n + (node->size - bytes));
node->size -= bytes;
r->size = bytes;
return r;
}
static void __InsertMemNodeBefore(AllocList *const list, MemNode *const insert, MemNode *const curr)
{
insert->next = curr;
if (curr->prev==NULL) list->head = insert;
else
{
insert->prev = curr->prev;
curr->prev->next = insert;
}
curr->prev = insert;
}
static void __ReplaceMemNode(MemNode *const old, MemNode *const replace)
{
replace->prev = old->prev;
replace->next = old->next;
if (old->prev != NULL) old->prev->next = replace;
if (old->next != NULL) old->next->prev = replace;
}
static MemNode *__RemoveMemNode(AllocList *const list, MemNode *const node)
{
if (node->prev != NULL) node->prev->next = node->next;
else
{
list->head = node->next;
if (list->head != NULL) list->head->prev = NULL;
else list->tail = NULL;
}
if (node->next != NULL) node->next->prev = node->prev;
else
{
list->tail = node->prev;
if (list->tail != NULL) list->tail->next = NULL;
else list->head = NULL;
}
list->len--;
return node;
}
static MemNode *__FindMemNode(AllocList *const list, const size_t bytes)
{
for (MemNode *node = list->head; node != NULL; node = node->next)
{
if (node->size < bytes) continue;
// Close in size - reduce fragmentation by not splitting
else if (node->size <= bytes + MEM_SPLIT_THRESHOLD) return __RemoveMemNode(list, node);
else return __SplitMemNode(node, bytes);
}
return NULL;
}
static void __InsertMemNode(MemPool *const mempool, AllocList *const list, MemNode *const node, const bool is_bucket)
{
if (list->head == NULL)
{
list->head = node;
list->len++;
}
else
{
for (MemNode *iter = list->head; iter != NULL; iter = iter->next)
{
if ((uintptr_t)iter == mempool->arena.offs)
{
mempool->arena.offs += iter->size;
__RemoveMemNode(list, iter);
iter = list->head;
if (iter == NULL)
{
list->head = node;
return;
}
}
const uintptr_t inode = (uintptr_t)node;
const uintptr_t iiter = (uintptr_t)iter;
const uintptr_t iter_end = iiter + iter->size;
const uintptr_t node_end = inode + node->size;
if (iter == node) return;
else if (iter < node)
{
// node was coalesced prior.
if (iter_end > inode) return;
else if ((iter_end == inode) && !is_bucket)
{
// if we can coalesce, do so.
iter->size += node->size;
return;
}
else if (iter->next == NULL)
{
// we reached the end of the free list -> append the node
iter->next = node;
node->prev = iter;
list->len++;
return;
}
}
else if (iter > node)
{
// Address sort, lowest to highest aka ascending order.
if (iiter < node_end) return;
else if ((iter == list->head) && !is_bucket)
{
if (iter_end == inode) iter->size += node->size;
else if (node_end == iiter)
{
node->size += list->head->size;
node->next = list->head->next;
node->prev = NULL;
list->head = node;
}
else
{
node->next = iter;
node->prev = NULL;
iter->prev = node;
list->head = node;
list->len++;
}
return;
}
else if ((iter_end == inode) && !is_bucket)
{
// if we can coalesce, do so.
iter->size += node->size;
return;
}
else
{
__InsertMemNodeBefore(list, node, iter);
list->len++;
return;
}
}
}
}
}
//----------------------------------------------------------------------------------
// Module Functions Definition - Memory Pool
//----------------------------------------------------------------------------------
MemPool CreateMemPool(const size_t size)
{
MemPool mempool = { 0 };
if (size == 0) return mempool;
else
{
// Align the mempool size to at least the size of an alloc node.
uint8_t *const restrict buf = malloc(size*sizeof *buf);
if (buf==NULL) return mempool;
else
{
mempool.arena.size = size;
mempool.arena.mem = (uintptr_t)buf;
mempool.arena.offs = mempool.arena.mem + mempool.arena.size;
return mempool;
}
}
}
MemPool CreateMemPoolFromBuffer(void *const restrict buf, const size_t size)
{
MemPool mempool = { 0 };
if ((size == 0) || (buf == NULL) || (size <= sizeof(MemNode))) return mempool;
else
{
mempool.arena.size = size;
mempool.arena.mem = (uintptr_t)buf;
mempool.arena.offs = mempool.arena.mem + mempool.arena.size;
return mempool;
}
}
void DestroyMemPool(MemPool *const restrict mempool)
{
if (mempool->arena.mem == 0) return;
else
{
void *const restrict ptr = (void *)mempool->arena.mem;
free(ptr);
*mempool = (MemPool){ 0 };
}
}
void *MemPoolAlloc(MemPool *const mempool, const size_t size)
{
if ((size == 0) || (size > mempool->arena.size)) return NULL;
else
{
MemNode *new_mem = NULL;
const size_t ALLOC_SIZE = __AlignSize(size + sizeof *new_mem, sizeof(intptr_t));
const size_t BUCKET_SLOT = (ALLOC_SIZE >> MEMPOOL_BUCKET_BITS) - 1;
// If the size is small enough, let's check if our buckets has a fitting memory block.
if (BUCKET_SLOT < MEMPOOL_BUCKET_SIZE)
{
new_mem = __FindMemNode(&mempool->buckets[BUCKET_SLOT], ALLOC_SIZE);
}
else if (mempool->large.head != NULL)
{
new_mem = __FindMemNode(&mempool->large, ALLOC_SIZE);
}
if (new_mem == NULL)
{
// not enough memory to support the size!
if ((mempool->arena.offs - ALLOC_SIZE) < mempool->arena.mem) return NULL;
else
{
// Couldn't allocate from a freelist, allocate from available mempool.
// Subtract allocation size from the mempool.
mempool->arena.offs -= ALLOC_SIZE;
// Use the available mempool space as the new node.
new_mem = ( MemNode* )mempool->arena.offs;
new_mem->size = ALLOC_SIZE;
}
}
// Visual of the allocation block.
// --------------
// | mem size | lowest addr of block
// | next node | 12 byte (32-bit) header
// | prev node | 24 byte (64-bit) header
// |------------|
// | alloc'd |
// | memory |
// | space | highest addr of block
// --------------
new_mem->next = new_mem->prev = NULL;
uint8_t *const restrict final_mem = (uint8_t *)new_mem + sizeof *new_mem;
return memset(final_mem, 0, new_mem->size - sizeof *new_mem);
}
}
void *MemPoolRealloc(MemPool *const restrict mempool, void *const ptr, const size_t size)
{
if (size > mempool->arena.size) return NULL;
// NULL ptr should make this work like regular Allocation
else if (ptr == NULL) return MemPoolAlloc(mempool, size);
else if ((uintptr_t)ptr - sizeof(MemNode) < mempool->arena.mem) return NULL;
else
{
MemNode *const node = (MemNode *)((uint8_t *)ptr - sizeof *node);
const size_t NODE_SIZE = sizeof *node;
uint8_t *const resized_block = MemPoolAlloc(mempool, size);
if (resized_block == NULL) return NULL;
else
{
MemNode *const resized = (MemNode *)(resized_block - sizeof *resized);
memmove(resized_block, ptr, (node->size > resized->size)? (resized->size - NODE_SIZE) : (node->size - NODE_SIZE));
MemPoolFree(mempool, ptr);
return resized_block;
}
}
}
void MemPoolFree(MemPool *const restrict mempool, void *const ptr)
{
const uintptr_t p = (uintptr_t)ptr;
if ((ptr == NULL) || (p - sizeof(MemNode) < mempool->arena.mem)) return;
else
{
// Behind the actual pointer data is the allocation info.
const uintptr_t block = p - sizeof(MemNode);
MemNode *const mem_node = ( MemNode* )block;
const size_t BUCKET_SLOT = (mem_node->size >> MEMPOOL_BUCKET_BITS) - 1;
// Make sure the pointer data is valid.
if ((block < mempool->arena.offs) ||
((block - mempool->arena.mem) > mempool->arena.size) ||
(mem_node->size == 0) ||
(mem_node->size > mempool->arena.size)) return;
// If the mem_node is right at the arena offs, then merge it back to the arena.
else if (block == mempool->arena.offs)
{
mempool->arena.offs += mem_node->size;
}
else
{
// try to place it into bucket or large freelist.
struct AllocList *const l = (BUCKET_SLOT < MEMPOOL_BUCKET_SIZE) ? &mempool->buckets[BUCKET_SLOT] : &mempool->large;
__InsertMemNode(mempool, l, mem_node, (BUCKET_SLOT < MEMPOOL_BUCKET_SIZE));
}
}
}
void MemPoolCleanUp(MemPool *const restrict mempool, void **const ptrref)
{
if ((ptrref == NULL) || (*ptrref == NULL)) return;
else
{
MemPoolFree(mempool, *ptrref);
*ptrref = NULL;
}
}
size_t GetMemPoolFreeMemory(const MemPool mempool)
{
size_t total_remaining = mempool.arena.offs - mempool.arena.mem;
for (MemNode *n = mempool.large.head; n != NULL; n = n->next) total_remaining += n->size;
for (size_t i = 0; i < MEMPOOL_BUCKET_SIZE; i++) for (MemNode *n = mempool.buckets[i].head; n != NULL; n = n->next) total_remaining += n->size;
return total_remaining;
}
void MemPoolReset(MemPool *const mempool)
{
mempool->large.head = mempool->large.tail = NULL;
mempool->large.len = 0;
for (size_t i = 0; i < MEMPOOL_BUCKET_SIZE; i++)
{
mempool->buckets[i].head = mempool->buckets[i].tail = NULL;
mempool->buckets[i].len = 0;
}
mempool->arena.offs = mempool->arena.mem + mempool->arena.size;
}
//----------------------------------------------------------------------------------
// Module Functions Definition - Object Pool
//----------------------------------------------------------------------------------
ObjPool CreateObjPool(const size_t objsize, const size_t len)
{
ObjPool objpool = { 0 };
if ((len == 0) || (objsize == 0)) return objpool;
else
{
const size_t aligned_size = __AlignSize(objsize, sizeof(size_t));
uint8_t *const restrict buf = calloc(len, aligned_size);
if (buf == NULL) return objpool;
objpool.objSize = aligned_size;
objpool.memSize = objpool.freeBlocks = len;
objpool.mem = (uintptr_t)buf;
for (size_t i=0; i<objpool.freeBlocks; i++)
{
size_t *const restrict index = (size_t *)(objpool.mem + (i*aligned_size));
*index = i + 1;
}
objpool.offs = objpool.mem;
return objpool;
}
}
ObjPool CreateObjPoolFromBuffer(void *const restrict buf, const size_t objsize, const size_t len)
{
ObjPool objpool = { 0 };
// If the object size isn't large enough to align to a size_t, then we can't use it
const size_t aligned_size = __AlignSize(objsize, sizeof(size_t));
if ((buf == NULL) || (len == 0) || (objsize < sizeof(size_t)) || (objsize*len != aligned_size*len)) return objpool;
else
{
objpool.objSize = aligned_size;
objpool.memSize = objpool.freeBlocks = len;
objpool.mem = (uintptr_t)buf;
for (size_t i=0; i<objpool.freeBlocks; i++)
{
size_t *const restrict index = (size_t *)(objpool.mem + (i*aligned_size));
*index = i + 1;
}
objpool.offs = objpool.mem;
return objpool;
}
}
void DestroyObjPool(ObjPool *const restrict objpool)
{
if (objpool->mem == 0) return;
else
{
void *const restrict ptr = (void *)objpool->mem;
free(ptr);
*objpool = (ObjPool){ 0 };
}
}
void *ObjPoolAlloc(ObjPool *const objpool)
{
if (objpool->freeBlocks > 0)
{
// For first allocation, head points to the very first index.
// Head = &pool[0];
// ret = Head == ret = &pool[0];
size_t *const restrict block = (size_t *)objpool->offs;
objpool->freeBlocks--;
// After allocating, we set head to the address of the index that *Head holds.
// Head = &pool[*Head * pool.objsize];
objpool->offs = (objpool->freeBlocks != 0)? objpool->mem + (*block*objpool->objSize) : 0;
return memset(block, 0, objpool->objSize);
}
else return NULL;
}
void ObjPoolFree(ObjPool *const restrict objpool, void *const ptr)
{
uintptr_t block = (uintptr_t)ptr;
if ((ptr == NULL) || (block < objpool->mem) || (block > objpool->mem + objpool->memSize*objpool->objSize)) return;
else
{
// When we free our pointer, we recycle the pointer space to store the previous index and then we push it as our new head.
// *p = index of Head in relation to the buffer;
// Head = p;
size_t *const restrict index = (size_t *)block;
*index = (objpool->offs != 0)? (objpool->offs - objpool->mem)/objpool->objSize : objpool->memSize;
objpool->offs = block;
objpool->freeBlocks++;
}
}
void ObjPoolCleanUp(ObjPool *const restrict objpool, void **const restrict ptrref)
{
if (ptrref == NULL) return;
else
{
ObjPoolFree(objpool, *ptrref);
*ptrref = NULL;
}
}
//----------------------------------------------------------------------------------
// Module Functions Definition - Double-Ended Stack
//----------------------------------------------------------------------------------
BiStack CreateBiStack(const size_t len)
{
BiStack destack = { 0 };
if (len == 0) return destack;
uint8_t *const buf = malloc(len*sizeof *buf);
if (buf == NULL) return destack;
destack.size = len;
destack.mem = (uintptr_t)buf;
destack.front = destack.mem;
destack.back = destack.mem + len;
return destack;
}
BiStack CreateBiStackFromBuffer(void *const buf, const size_t len)
{
BiStack destack = { 0 };
if ((len == 0) || (buf == NULL)) return destack;
else
{
destack.size = len;
destack.mem = destack.front = (uintptr_t)buf;
destack.back = destack.mem + len;
return destack;
}
}
void DestroyBiStack(BiStack *const restrict destack)
{
if (destack->mem == 0) return;
else
{
uint8_t *const restrict buf = (uint8_t *)destack->mem;
free(buf);
*destack = (BiStack){ 0 };
}
}
void *BiStackAllocFront(BiStack *const restrict destack, const size_t len)
{
if (destack->mem == 0) return NULL;
else
{
const size_t ALIGNED_LEN = __AlignSize(len, sizeof(uintptr_t));
// front end arena is too high!
if (destack->front + ALIGNED_LEN >= destack->back) return NULL;
else
{
uint8_t *const restrict ptr = (uint8_t *)destack->front;
destack->front += ALIGNED_LEN;
return ptr;
}
}
}
void *BiStackAllocBack(BiStack *const restrict destack, const size_t len)
{
if (destack->mem == 0) return NULL;
else
{
const size_t ALIGNED_LEN = __AlignSize(len, sizeof(uintptr_t));
// back end arena is too low
if (destack->back - ALIGNED_LEN <= destack->front) return NULL;
else
{
destack->back -= ALIGNED_LEN;
uint8_t *const restrict ptr = (uint8_t *)destack->back;
return ptr;
}
}
}
void BiStackResetFront(BiStack *const destack)
{
if (destack->mem == 0) return;
else destack->front = destack->mem;
}
void BiStackResetBack(BiStack *const destack)
{
if (destack->mem == 0) return;
else destack->back = destack->mem + destack->size;
}
void BiStackResetAll(BiStack *const destack)
{
BiStackResetBack(destack);
BiStackResetFront(destack);
}
inline intptr_t BiStackMargins(const BiStack destack)
{
return destack.back - destack.front;
}
#endif // RMEM_IMPLEMENTATION