Simplify Arena allocator

mem/include/allocator/mem_allocator.h

@@ -1,40 +0,0 @@
-#ifndef MEM_ALLOCATOR_H
-#define MEM_ALLOCATOR_H
-
-#include "aliases.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif // __cplusplus
-
-typedef void *(MemAllocFunc)(u64 size, void *alloc_obj);
-typedef void *(MemAllocAlignedFunc)(u64 size, u64 alignment, void *alloc_obj);
-typedef void *(MemReallocFunc)(void *ptr, u64 size, void *alloc_obj);
-typedef void *(MemReallocAlignedFunc)(void *ptr, u64 size, u64 alignment,
-                                      void *alloc_obj);
-typedef void(MemFreeFunc)(void **ptr, void *alloc_obj);
-
-typedef struct allocator Allocator;
-struct allocator {
-  void *obj;
-  MemAllocFunc *alloc;
-  MemAllocAlignedFunc *alloc_aligned;
-  MemReallocFunc *realloc;
-  MemReallocAlignedFunc *realloc_aligned;
-  MemFreeFunc *free;
-};
-
-void *wapp_mem_allocator_alloc(const Allocator *allocator, u64 size);
-void *wapp_mem_allocator_alloc_aligned(const Allocator *allocator, u64 size,
-                                       u64 alignment);
-void *wapp_mem_allocator_realloc(const Allocator *allocator, void *ptr,
-                                 u64 size);
-void *wapp_mem_allocator_realloc_aligned(const Allocator *allocator, void *ptr,
-                                         u64 size, u64 alignment);
-void wapp_mem_allocator_free(const Allocator *allocator, void **ptr);
-
-#ifdef __cplusplus
-}
-#endif // __cplusplus
-
-#endif // !MEM_ALLOCATOR_H

mem/include/arena/mem_arena.h

@@ -2,7 +2,6 @@
 #define MEM_ARENA_H
 
 #include "aliases.h"
-#include "mem_allocator.h"
 #include <stdbool.h>
 
 #ifdef __cplusplus
@@ -11,13 +10,9 @@ extern "C" {
 
 typedef struct growing_arena Arena;
 
-Allocator wapp_mem_arena_allocator(const Arena *arena);
 bool wapp_mem_arena_init(Arena **arena, u64 base_capacity);
 void *wapp_mem_arena_alloc(Arena *arena, u64 size);
 void *wapp_mem_arena_alloc_aligned(Arena *arena, u64 size, u64 alignment);
-void *wapp_mem_arena_realloc(Arena *arena, void *ptr, u64 size);
-void *wapp_mem_arena_realloc_aligned(Arena *arena, void *ptr, u64 size,
-                                     u64 alignment);
 void wapp_mem_arena_clear(Arena *arena);
 void wapp_mem_arena_free(Arena **arena);
 

mem/include/ctx/mem_ctx.h

@@ -1,32 +0,0 @@
-#ifndef MEM_CTX_H
-#define MEM_CTX_H
-
-#include "mem_allocator.h"
-#include "mem_arena.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif // __cplusplus
-
-typedef enum {
-  CTX_DEST_BUFFER_MAIN,
-  CTX_DEST_BUFFER_TEMP,
-
-  COUNT_CTX_DEST_BUFFER,
-} CTXDestBuffer;
-
-Allocator wapp_mem_ctx_allocator(CTXDestBuffer buffer);
-void wapp_mem_ctx_init(u64 main_buf_capacity, u64 temp_buf_capacity);
-void *wapp_mem_ctx_alloc(CTXDestBuffer buffer, u64 size);
-void *wapp_mem_ctx_alloc_aligned(CTXDestBuffer buffer, u64 size, u64 alignment);
-void *wapp_mem_ctx_realloc(CTXDestBuffer buffer, void *ptr, u64 size);
-void *wapp_mem_ctx_realloc_aligned(CTXDestBuffer buffer, void *ptr, u64 size,
-                                   u64 alignment);
-void wapp_mem_ctx_clear(CTXDestBuffer buffer);
-void wapp_mem_ctx_free(void);
-
-#ifdef __cplusplus
-}
-#endif // __cplusplus
-
-#endif // !MEM_CTX_H

mem/include/libc/mem_libc.h

@@ -1,15 +0,0 @@
-#ifndef MEM_LIBC_H
-#define MEM_LIBC_H
-
-#include "mem_allocator.h"
-#ifdef __cplusplus
-extern "C" {
-#endif // __cplusplus
-
-Allocator wapp_mem_libc_allocator(void);
-
-#ifdef __cplusplus
-}
-#endif // __cplusplus
-
-#endif // !MEM_LIBC_H

mem/src/allocator/mem_allocator.c

@@ -1,45 +0,0 @@
-#include "mem_allocator.h"
-#include <stdlib.h>
-
-void *wapp_mem_allocator_alloc(const Allocator *allocator, u64 size) {
-  if (!allocator || !(allocator->alloc)) {
-    return NULL;
-  }
-
-  return allocator->alloc(size, allocator->obj);
-}
-
-void *wapp_mem_allocator_alloc_aligned(const Allocator *allocator, u64 size,
-                                       u64 alignment) {
-  if (!allocator || !(allocator->alloc_aligned)) {
-    return NULL;
-  }
-
-  return allocator->alloc_aligned(size, alignment, allocator->obj);
-}
-
-void *wapp_mem_allocator_realloc(const Allocator *allocator, void *ptr,
-                                 u64 size) {
-  if (!allocator || !(allocator->realloc)) {
-    return NULL;
-  }
-
-  return allocator->realloc(ptr, size, allocator->obj);
-}
-
-void *wapp_mem_allocator_realloc_aligned(const Allocator *allocator, void *ptr,
-                                         u64 size, u64 alignment) {
-  if (!allocator || !(allocator->realloc_aligned)) {
-    return NULL;
-  }
-
-  return allocator->realloc_aligned(ptr, size, alignment, allocator->obj);
-}
-
-void wapp_mem_allocator_free(const Allocator *allocator, void **ptr) {
-  if (!allocator || !(allocator->free)) {
-    return;
-  }
-
-  allocator->free(ptr, allocator->obj);
-}

mem/src/arena/mem_arena.c

@@ -1,8 +1,6 @@
 #include "mem_arena.h"
 #include "aliases.h"
-#include "mem_allocator.h"
 #include "mem_utils.h"
-#include <math.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
@@ -13,24 +11,12 @@
 #define DEFAULT_ALIGNMENT (2 * sizeof(void *))
 #endif /* ifndef DEFAULT_ALIGNMENT */
 
-#define HDR_MAGIC_BYTE_COUNT 8
-#define HDR_MAGIC                                                              \
-  { 0x57, 0x41, 0x41, 0x52, 0x4e, 0x48, 0x44, 0x52 }
-#define MAX_HDR_SEARCH_LENGTH 256
-
 #define ARENA_MINIMUM_CAPACITY 1024
 
-typedef struct arena_alloc_hdr ArenaAllocHDR;
-struct arena_alloc_hdr {
-  u8 magic[HDR_MAGIC_BYTE_COUNT];
-  u64 alloc_size;
-  u64 alignment;
-  u8 *alloc_start;
-};
-
 typedef struct base_arena BaseArena;
 struct base_arena {
   u8 *buf;
+  u8 *last;
   u8 *offset;
   u64 capacity;
   BaseArena *prev;
@@ -43,35 +29,14 @@ struct growing_arena {
   u64 initial_capacity;
 };
 
-internal BaseArena *find_arena_from_pointer(const Arena *arena, void *ptr);
-
 internal bool base_arena_init(BaseArena *arena, u64 capacity);
 internal void *base_arena_alloc_aligned(BaseArena *arena, u64 size,
                                         u64 alignment);
 internal void base_arena_clear(BaseArena *arena);
 internal void base_arena_free(BaseArena *arena);
-internal ArenaAllocHDR *find_alloc_header(BaseArena *arena, void *alloc_ptr);
-
-internal void *mem_arena_alloc(u64 size, void *alloc_obj);
-internal void *mem_arena_alloc_aligned(u64 size, u64 alignment,
-                                       void *alloc_obj);
-internal void *mem_arena_realloc(void *ptr, u64 size, void *alloc_obj);
-internal void *mem_arena_realloc_aligned(void *ptr, u64 size, u64 alignment,
-                                         void *alloc_obj);
 
 // PUBLIC API
 
-Allocator wapp_mem_arena_allocator(const Arena *arena) {
-  return (Allocator){
-      .obj = (void *)arena,
-      .alloc = mem_arena_alloc,
-      .alloc_aligned = mem_arena_alloc_aligned,
-      .realloc = mem_arena_realloc,
-      .realloc_aligned = mem_arena_realloc_aligned,
-      .free = NULL,
-  };
-}
-
 bool wapp_mem_arena_init(Arena **arena, u64 base_capacity) {
   if (!arena || *arena || base_capacity == 0) {
     return false;
@@ -142,54 +107,6 @@ void *wapp_mem_arena_alloc_aligned(Arena *arena, u64 size, u64 alignment) {
   return output;
 }
 
-void *wapp_mem_arena_realloc(Arena *arena, void *ptr, u64 size) {
-  return wapp_mem_arena_realloc_aligned(arena, ptr, size, DEFAULT_ALIGNMENT);
-}
-
-void *wapp_mem_arena_realloc_aligned(Arena *arena, void *ptr, u64 size,
-                                     u64 alignment) {
-  if (!arena) {
-    return NULL;
-  }
-
-  BaseArena *base_arena = find_arena_from_pointer(arena, ptr);
-  if (!base_arena) {
-    return NULL;
-  }
-
-  ArenaAllocHDR *header = find_alloc_header(base_arena, ptr);
-  if (!header) {
-    return NULL;
-  }
-
-  if (header->alloc_start + header->alloc_size == base_arena->offset) {
-    // Avoid allocating new pointer and copying memory if pointer is at the end
-    // of the arena
-    i64 diff = size - header->alloc_size;
-
-    u8 *new_offset = base_arena->offset + diff;
-
-    u8 *clear_start = diff < 0 ? new_offset : base_arena->offset;
-    memset(clear_start, 0, llabs(diff));
-
-    header->alloc_size = size;
-    base_arena->offset = new_offset;
-
-    return header->alloc_start;
-  }
-
-  void *new_alloc = wapp_mem_arena_alloc_aligned(arena, size, alignment);
-  if (!new_alloc) {
-    return NULL;
-  }
-
-  u64 to_copy = size < header->alloc_size ? size : header->alloc_size;
-
-  memcpy(new_alloc, ptr, to_copy);
-
-  return new_alloc;
-}
-
 void wapp_mem_arena_clear(Arena *arena) {
   if (!arena) {
     return;
@@ -255,30 +172,6 @@ void wapp_mem_arena_free(Arena **arena) {
 
 // INTERNAL FUNCTIONS
 
-internal BaseArena *find_arena_from_pointer(const Arena *arena, void *ptr) {
-  if (!arena || !ptr) {
-    return NULL;
-  }
-
-  // Ensure pointer is not out of bounds
-  u8 *alloc = (u8 *)ptr;
-  BaseArena *active = arena->active_arena;
-
-  if (alloc > active->buf + arena->initial_capacity) {
-    return NULL;
-  }
-
-  for (u64 i = 0; i < arena->count; ++i) {
-    if (alloc >= active->buf && alloc < active->buf + arena->initial_capacity) {
-      return (BaseArena *)active;
-    }
-
-    active = active->prev;
-  }
-
-  return NULL;
-}
-
 internal bool base_arena_init(BaseArena *arena, u64 capacity) {
   if (!arena || arena->buf || capacity == 0) {
     return false;
@@ -305,23 +198,15 @@ internal void *base_arena_alloc_aligned(BaseArena *arena, u64 size,
     return NULL;
   }
 
-  u8 *start_offset = arena->offset;
-  u8 *alloc_start = arena->offset + sizeof(ArenaAllocHDR);
+  u8 *alloc_start = arena->offset;
 
   u8 *output = wapp_mem_util_align_forward((void *)alloc_start, alignment);
   if (output + size >= arena->buf + arena->capacity) {
     return NULL;
   }
 
-  ArenaAllocHDR *header = (ArenaAllocHDR *)start_offset;
-  *header = (ArenaAllocHDR){
-      .magic = HDR_MAGIC,
-      .alloc_size = size,
-      .alignment = alignment,
-      .alloc_start = output,
-  };
-
   arena->offset = output + size;
+  arena->last = output;
 
   return (void *)output;
 }
@@ -348,59 +233,3 @@ internal void base_arena_free(BaseArena *arena) {
   arena->capacity = 0;
   arena->prev = arena->next = NULL;
 }
-
-internal ArenaAllocHDR *find_alloc_header(BaseArena *arena, void *alloc_ptr) {
-  persistent const u8 magic[HDR_MAGIC_BYTE_COUNT] = HDR_MAGIC;
-
-  u8 *current = (u8 *)alloc_ptr;
-
-  u8 *max_search_end = current - MAX_HDR_SEARCH_LENGTH;
-  u8 *arena_buf_start = arena->buf;
-
-  u8 *search_end =
-      max_search_end > arena_buf_start ? max_search_end : arena_buf_start;
-
-  bool match;
-  for (; current >= search_end; --current) {
-    match = true;
-
-    for (u64 i = 0; i < HDR_MAGIC_BYTE_COUNT; ++i) {
-      if (current[i] != magic[i]) {
-        match = false;
-        break;
-      }
-    }
-
-    if (match) {
-      return (ArenaAllocHDR *)current;
-    }
-  }
-
-  return NULL;
-}
-
-internal void *mem_arena_alloc(u64 size, void *alloc_obj) {
-  Arena *arena = (Arena *)alloc_obj;
-
-  return wapp_mem_arena_alloc(arena, size);
-}
-
-internal void *mem_arena_alloc_aligned(u64 size, u64 alignment,
-                                       void *alloc_obj) {
-  Arena *arena = (Arena *)alloc_obj;
-
-  return wapp_mem_arena_alloc_aligned(arena, size, alignment);
-}
-
-internal void *mem_arena_realloc(void *ptr, u64 size, void *alloc_obj) {
-  Arena *arena = (Arena *)alloc_obj;
-
-  return wapp_mem_arena_realloc(arena, ptr, size);
-}
-
-internal void *mem_arena_realloc_aligned(void *ptr, u64 size, u64 alignment,
-                                         void *alloc_obj) {
-  Arena *arena = (Arena *)alloc_obj;
-
-  return wapp_mem_arena_realloc_aligned(arena, ptr, size, alignment);
-}

mem/src/ctx/mem_ctx.c

@@ -1,106 +0,0 @@
-#include "mem_ctx.h"
-#include "aliases.h"
-#include "mem_arena.h"
-#include <assert.h>
-#include <stdlib.h>
-
-typedef struct mem_ctx MemCTX;
-struct mem_ctx {
-  Arena *main;
-  Arena *temp;
-  bool main_initialised;
-  bool temp_initialised;
-};
-
-internal MemCTX g_context = {0};
-
-internal Arena *get_arena(CTXDestBuffer buffer);
-
-Allocator wapp_mem_ctx_allocator(CTXDestBuffer buffer) {
-  Arena *arena = get_arena(buffer);
-  return wapp_mem_arena_allocator(arena);
-}
-
-void wapp_mem_ctx_init(u64 main_buf_capacity, u64 temp_buf_capacity) {
-  g_context.main_initialised =
-      wapp_mem_arena_init(&g_context.main, main_buf_capacity);
-  g_context.temp_initialised =
-      wapp_mem_arena_init(&g_context.temp, temp_buf_capacity);
-}
-
-void *wapp_mem_ctx_alloc(CTXDestBuffer buffer, u64 size) {
-  Arena *arena = get_arena(buffer);
-  if (!arena) {
-    return NULL;
-  }
-
-  return wapp_mem_arena_alloc(arena, size);
-}
-
-void *wapp_mem_ctx_alloc_aligned(CTXDestBuffer buffer, u64 size,
-                                 u64 alignment) {
-  Arena *arena = get_arena(buffer);
-  if (!arena) {
-    return NULL;
-  }
-
-  return wapp_mem_arena_alloc_aligned(arena, size, alignment);
-}
-
-void *wapp_mem_ctx_realloc(CTXDestBuffer buffer, void *ptr, u64 size) {
-  Arena *arena = get_arena(buffer);
-  if (!arena) {
-    return NULL;
-  }
-
-  return wapp_mem_arena_realloc(arena, ptr, size);
-}
-
-void *wapp_mem_ctx_realloc_aligned(CTXDestBuffer buffer, void *ptr, u64 size,
-                                   u64 alignment) {
-  Arena *arena = get_arena(buffer);
-  if (!arena) {
-    return NULL;
-  }
-
-  return wapp_mem_arena_realloc_aligned(arena, ptr, size, alignment);
-}
-
-void wapp_mem_ctx_clear(CTXDestBuffer buffer) {
-  Arena *arena = get_arena(buffer);
-  if (!arena) {
-    return;
-  }
-
-  wapp_mem_arena_clear(arena);
-}
-
-void wapp_mem_ctx_free(void) {
-  wapp_mem_arena_free(&(g_context.main));
-  g_context.main_initialised = false;
-
-  wapp_mem_arena_free(&(g_context.temp));
-  g_context.temp_initialised = false;
-}
-
-internal Arena *get_arena(CTXDestBuffer buffer) {
-  Arena *output = NULL;
-
-  switch (buffer) {
-  case CTX_DEST_BUFFER_MAIN:
-    if (g_context.main_initialised) {
-      output = g_context.main;
-    }
-    break;
-  case CTX_DEST_BUFFER_TEMP:
-    if (g_context.temp_initialised) {
-      output = g_context.temp;
-    }
-    break;
-  default:
-    assert(false && "Not all context destination buffers are handled");
-    break;
-  }
-
-  return output;
-}

mem/src/libc/mem_libc.c

@@ -1,48 +0,0 @@
-#include "mem_libc.h"
-#include "aliases.h"
-#include "mem_allocator.h"
-#include <stdlib.h>
-#include <string.h>
-
-internal void *mem_libc_alloc(u64 size, void *alloc_obj);
-internal void *mem_libc_alloc_aligned(u64 size, u64 alignment, void *alloc_obj);
-internal void *mem_libc_realloc(void *ptr, u64 size, void *alloc_obj);
-internal void mem_libc_free(void **ptr, void *alloc_obj);
-
-Allocator wapp_mem_libc_allocator(void) {
-  return (Allocator){
-      .obj = NULL,
-      .alloc = mem_libc_alloc,
-      .alloc_aligned = mem_libc_alloc_aligned,
-      .realloc = mem_libc_realloc,
-      .realloc_aligned = NULL,
-      .free = mem_libc_free,
-  };
-}
-
-internal void *mem_libc_alloc(u64 size, void *alloc_obj) {
-  return calloc(1, size);
-}
-
-internal void *mem_libc_alloc_aligned(u64 size, u64 alignment,
-                                      void *alloc_obj) {
-  void *output = aligned_alloc(alignment, size);
-  if (output) {
-    memset(output, 0, size);
-  }
-
-  return output;
-}
-
-internal void *mem_libc_realloc(void *ptr, u64 size, void *alloc_obj) {
-  return realloc(ptr, size);
-}
-
-internal void mem_libc_free(void **ptr, void *alloc_obj) {
-  if (!ptr || !(*ptr)) {
-    return;
-  }
-
-  free(*ptr);
-  *ptr = NULL;
-}