.gitignore

@@ -1,5 +1,4 @@
 .cache
 .vscode
-test*
 compile_commands.json
 libwapp.so

compile

@@ -1,39 +1,13 @@
 #!/bin/bash
 
-BUILD_TYPE="debug"
-
-while [[ $# > 0 ]];do
-  case $1 in
-    --release)
-      BUILD_TYPE="release"
-      shift
-      ;;
-    *|-*|--*)
-      echo "Unknown option $1"
-      exit 1
-      ;;
-  esac
-done
-
 CC=clang
-CFLAGS="-Wall -Werror -pedantic "
-LIBFLAGS="-fPIC -shared"
 INCLUDE="\
 	$(find src -type d | xargs -I{} echo -n "-I{} ") \
 "
 SRC="\
-	$(find src -type f -name "*.c" | xargs -I{} echo -n "{} ") \
+	$(find src -type f -name *.c | xargs -I{} echo -n "{} ") \
 "
-if [[ $BUILD_TYPE == "release" ]]; then
-  CFLAGS+="-O3"
-else
-  CFLAGS+="-g -fsanitize=address -fsanitize=undefined"
-fi
-
+CFLAGS="-O3 -shared -fPIC -Wall -Werror -pedantic"
 OUT="libwapp.so"
 
-(set -x ; $CC $CFLAGS $LIBFLAGS $INCLUDE $SRC -o $OUT)
-
-if [[ -f ./test.c ]]; then
-	(set -x ; $CC $CFLAGS $INCLUDE $SRC ./test.c -o test)
-fi
+(set -x ; $CC $CFLAGS $INCLUDE $SRC -o $OUT)

src/mem/arena/mem_arena.c

@@ -13,12 +13,27 @@
 
 #define ARENA_MINIMUM_CAPACITY 1024
 
-struct arena {
+typedef struct base_arena BaseArena;
+struct base_arena {
   u8 *buf;
   u8 *offset;
   u64 capacity;
+  BaseArena *prev;
+  BaseArena *next;
 };
 
+struct growing_arena {
+  BaseArena *active_arena;
+  u64 count;
+  u64 initial_capacity;
+};
+
+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_destroy(BaseArena *arena);
+
 // PUBLIC API
 
 bool wapp_mem_arena_init(Arena **arena, u64 base_capacity) {
@@ -32,18 +47,19 @@ bool wapp_mem_arena_init(Arena **arena, u64 base_capacity) {
     return false;
   }
 
-  u64 arena_capacity = base_capacity >= ARENA_MINIMUM_CAPACITY
-                           ? base_capacity
-                           : ARENA_MINIMUM_CAPACITY;
-
-  arena_ptr->buf = (u8 *)calloc(arena_capacity, sizeof(u8));
-  if (!(arena_ptr->buf)) {
+  arena_ptr->active_arena = (BaseArena *)calloc(1, sizeof(BaseArena));
+  if (!(arena_ptr->active_arena)) {
     wapp_mem_arena_destroy(arena);
     return false;
   }
 
-  arena_ptr->capacity = arena_capacity;
-  arena_ptr->offset = arena_ptr->buf;
+  if (!base_arena_init(arena_ptr->active_arena, base_capacity)) {
+    wapp_mem_arena_destroy(arena);
+    return false;
+  }
+
+  arena_ptr->count = 1;
+  arena_ptr->initial_capacity = base_capacity;
 
   return true;
 }
@@ -53,6 +69,130 @@ void *wapp_mem_arena_alloc(Arena *arena, u64 size) {
 }
 
 void *wapp_mem_arena_alloc_aligned(Arena *arena, u64 size, u64 alignment) {
+  if (!arena || !(arena->active_arena)) {
+    return NULL;
+  }
+
+  void *output = base_arena_alloc_aligned(arena->active_arena, size, alignment);
+  if (!output) {
+    if (arena->active_arena->next) {
+      arena->active_arena = arena->active_arena->next;
+    } else {
+      arena->active_arena->next = (BaseArena *)calloc(1, sizeof(BaseArena));
+      if (!(arena->active_arena->next)) {
+        return NULL;
+      }
+
+      if (!base_arena_init(arena->active_arena->next,
+                           arena->initial_capacity)) {
+        free(arena->active_arena->next);
+        return NULL;
+      }
+
+      arena->active_arena->next->prev = arena->active_arena;
+      arena->active_arena = arena->active_arena->next;
+
+      ++(arena->count);
+    }
+
+    output = base_arena_alloc_aligned(arena->active_arena, size, alignment);
+    if (!output) {
+      return NULL;
+    }
+  }
+
+  memset(output, 0, size);
+
+  return output;
+}
+
+void wapp_mem_arena_clear(Arena *arena) {
+  if (!arena) {
+    return;
+  }
+
+  BaseArena *last_active = NULL;
+  while (arena->active_arena) {
+    base_arena_clear(arena->active_arena);
+
+    last_active = arena->active_arena;
+
+    arena->active_arena = arena->active_arena->prev;
+  }
+
+  arena->active_arena = last_active;
+}
+
+void wapp_mem_arena_destroy(Arena **arena) {
+  if (!arena) {
+    return;
+  }
+
+  Arena *arena_ptr = *arena;
+  if (!arena_ptr) {
+    return;
+  }
+
+  BaseArena *current;
+  BaseArena *next;
+  BaseArena *prev;
+
+  current = arena_ptr->active_arena->next;
+  while (current) {
+    next = current->next;
+
+    base_arena_destroy(current);
+    free(current);
+
+    current = next;
+  }
+
+  current = arena_ptr->active_arena->prev;
+  while (current) {
+    prev = current->prev;
+
+    base_arena_destroy(current);
+    free(current);
+
+    current = prev;
+  }
+
+  base_arena_destroy(arena_ptr->active_arena);
+
+  free(arena_ptr->active_arena);
+  arena_ptr->active_arena = NULL;
+
+  arena_ptr->count = 0;
+  arena_ptr->initial_capacity = 0;
+
+  free(*arena);
+  *arena = NULL;
+}
+
+// INTERNAL FUNCTIONS
+
+internal bool base_arena_init(BaseArena *arena, u64 capacity) {
+  if (!arena || arena->buf || capacity == 0) {
+    return false;
+  }
+
+  u64 arena_capacity =
+      capacity >= ARENA_MINIMUM_CAPACITY ? capacity : ARENA_MINIMUM_CAPACITY;
+
+  arena->buf = (u8 *)calloc(arena_capacity, sizeof(u8));
+  if (!(arena->buf)) {
+    return false;
+  }
+
+  arena->capacity = arena_capacity;
+  arena->offset = arena->buf;
+  arena->prev = arena->next = NULL;
+
+  return true;
+}
+
+internal void *base_arena_alloc_aligned(BaseArena *arena, u64 size,
+                                        u64 alignment) {
   if (!arena) {
     return NULL;
   }
@@ -66,12 +206,10 @@ void *wapp_mem_arena_alloc_aligned(Arena *arena, u64 size, u64 alignment) {
 
   arena->offset = output + size;
 
-  memset(output, 0, size);
-
   return (void *)output;
 }
 
-void wapp_mem_arena_clear(Arena *arena) {
+internal void base_arena_clear(BaseArena *arena) {
   if (!arena) {
     return;
   }
@@ -80,19 +218,16 @@ void wapp_mem_arena_clear(Arena *arena) {
   arena->offset = arena->buf;
 }
 
-void wapp_mem_arena_destroy(Arena **arena) {
+internal void base_arena_destroy(BaseArena *arena) {
   if (!arena) {
     return;
   }
 
-  Arena *arena_ptr = *arena;
-  if (arena_ptr->buf) {
-    free(arena_ptr->buf);
+  if (arena->buf) {
+    free(arena->buf);
   }
 
-  arena_ptr->buf = arena_ptr->offset = NULL;
-  arena_ptr->capacity = 0;
-
-  free(*arena);
-  *arena = NULL;
+  arena->buf = arena->offset = NULL;
+  arena->capacity = 0;
+  arena->prev = arena->next = NULL;
 }

src/mem/arena/mem_arena.h

@@ -8,7 +8,7 @@
 extern "C" {
 #endif // __cplusplus
 
-typedef struct arena Arena;
+typedef struct growing_arena Arena;
 
 bool wapp_mem_arena_init(Arena **arena, u64 base_capacity);
 void *wapp_mem_arena_alloc(Arena *arena, u64 size);