/**********************************************************************************************
							 | 
						|
								*
							 | 
						|
								*   rmem - 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.
							 | 
						|
								*
							 | 
						|
								*
							 | 
						|
								*   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
							 | 
						|
								//----------------------------------------------------------------------------------
							 | 
						|
								
							 | 
						|
								// Memory Pool
							 | 
						|
								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;
							 | 
						|
								
							 | 
						|
								
							 | 
						|
								enum {
							 | 
						|
								    MEMPOOL_BUCKET_SIZE = 8,
							 | 
						|
								    MEMPOOL_BUCKET_BITS = (sizeof(uintptr_t) >> 1) + 1,
							 | 
						|
								    MEM_SPLIT_THRESHOLD = sizeof(uintptr_t) * 4
							 | 
						|
								};
							 | 
						|
								
							 | 
						|
								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 <stdio.h>          // Required for:
							 | 
						|
								#include <stdlib.h>         // Required for:
							 | 
						|
								#include <string.h>         // Required for:
							 | 
						|
								
							 | 
						|
								//----------------------------------------------------------------------------------
							 | 
						|
								// 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;
							 | 
						|
								            }
							 | 
						|
								            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 > 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, iter, node);
							 | 
						|
								                    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
							 | 
						|
								
							 | 
						|
								/*******
							 | 
						|
								 * Changelog
							 | 
						|
								 * v1.0: First Creation.
							 | 
						|
								 * v1.1: bug patches for the mempool and addition of object pool.
							 | 
						|
								 * v1.2: addition of bidirectional arena.
							 | 
						|
								 * v1.3:
							 | 
						|
								    * optimizations of allocators.
							 | 
						|
								    * renamed 'Stack' to 'Arena'.
							 | 
						|
								    * replaced certain define constants with an anonymous enum.
							 | 
						|
								    * refactored MemPool to no longer require active or deferred defragging.
							 | 
						|
								 ********/
							 |