Add mmap allocator

src/arena.c

@@ -1,17 +1,6 @@
 #include "arena.h"
 #include "base_core.h"
-#include <stdlib.h>
-//
-//note(nos) Move to platrofm layer
-static void *memory_allocate(size_t sz)
-{
-    return malloc(sz);
-}
-
-static void memory_release(void *mem)
-{
-    free(mem);
-}
+#include "platform.h"
 
 static INLINE U32 arena_absolute_pos(const Arena *arena)
 {
@@ -19,23 +8,28 @@ static INLINE U32 arena_absolute_pos(const Arena *arena)
     return current->base_pos + current->pos;
 }
 
-Arena *arena_alloc_(const ArenaParams *params)
+Arena *arena_alloc(const ArenaParams *params)
 {
     Assert(params->size > ARENA_HEADER_SZ);
     Assert(params->size < (U32_Max -  ARENA_HEADER_SZ - 1));
 
     // Note: only backend now is malloc
-    void *base = memory_allocate(params->size);
-    //((U8*)base)[1023+ARENA_HEADER_SZ] = 1;
-
+    void *base;
+    if (params->flags & ArenaFlag_UseMalloc){
+        base = platform_malloc(params->size);
+    }  else {
+        base = memory_allocate(params->size);
+    }
     Assert(base != NULL);
+    ASAN_UNPOISON_MEMORY_REGION(base, ARENA_HEADER_SZ);
 
     Arena *arena = (Arena *)base;
-    arena->base     = base;
+    arena->base     = (U8 *)base;
     arena->current  = arena;
     arena->size     = params->size;
     arena->pos      = ARENA_HEADER_SZ;
     arena->base_pos = 0;
+    arena->flags    = params->flags;
     arena->prev     = NULL;
     arena->checkpoint_level = 0;
 
@@ -49,7 +43,11 @@ void arena_free(Arena *arena)
 
     while (it != NULL) {
         Arena *prev = it->prev;
-        memory_release(it);
+        if (it->flags & ArenaFlag_UseMalloc){
+            platform_free(it->base);
+        }  else {
+            memory_free(it->base, it->size);
+        }
         it = prev;
     }
 }
@@ -58,6 +56,7 @@ void *arena_push(Arena *arena, U32 size, U32 align)
 {
     Assert(size < (U32_Max - align - ARENA_HEADER_SZ - 1));
     Assert(IsPow2(align));
+
     Arena *current = arena->current;
     U32 start_pos = AlignUpPow2(current->pos, align);
     U32 available = arena_available(current);
@@ -72,7 +71,7 @@ void *arena_push(Arena *arena, U32 size, U32 align)
         new_params.flags        = current->flags;
         new_params.size         = new_size;
 
-        Arena *new_arena    = arena_alloc_(&new_params);
+        Arena *new_arena    = arena_alloc(&new_params);
         new_arena->base_pos = current->base_pos + current->size;
         new_arena->prev     = current;
         arena->current      = new_arena;
@@ -98,8 +97,13 @@ void arena_pop_to(Arena *arena, U32 abs_pos)
         Arena *prev = current->prev;
 
         if (current->base_pos >= abs_pos) {
-            ASAN_UNPOISON_MEMORY_REGION(current->base, current->size);
-            memory_release(current->base);
+            ASAN_UNPOISON_MEMORY_REGION(current->base, current->size); // needed as we use malloc
+            if (current->flags & ArenaFlag_UseMalloc){
+                platform_free(current->base);
+            }  else {
+                memory_free(current->base, current->size);
+            }
+
             arena->current = prev;
         } else {
             U32 new_pos = abs_pos - current->base_pos;
@@ -121,14 +125,15 @@ ArenaCheckPoint arena_temp_begin(Arena *arena)
     checkpoint.arena = arena;
     checkpoint.absolute_pos = arena_absolute_pos(arena);
     arena->checkpoint_level++;
+
     return checkpoint;
 }
 
 void arena_temp_end(ArenaCheckPoint *checkpoint)
 {
     Arena *arena = checkpoint->arena;
-    arena_pop_to(arena, checkpoint->absolute_pos);
     Assert(arena->checkpoint_level > 0);
+    arena_pop_to(arena, checkpoint->absolute_pos);
     arena->checkpoint_level--;
 }