Added arena checkpointing

src/main.c

@@ -9,16 +9,16 @@ void arena_dump(const Arena *arena)
     puts("@@@@@@@@@@");
     while (arena) {
         puts("-----Arena-----");
-        printf("base: %p\n", arena->base);
-        printf("size: %u\n", arena->size);
-        printf("pos:  %u\n", arena->pos);
+        printf("base:        %p\n", arena->base);
+        printf("size:        %u\n", arena->size);
+        printf("pos:         %u\n", arena->pos);
+        printf("base_pos:    %u\n", arena->base_pos);
         printf("prev: %p\n", arena->prev);
         puts("-----Arena  end-");
         arena = arena->prev;
     }
 }
-
-int main(int argc, char *argv[])
+static void arena_test_1(void)
 {
     ArenaParams arena_params = {};
     arena_params.size = 1024+ARENA_HEADER_SZ;
@@ -39,3 +39,37 @@ int main(int argc, char *argv[])
     arena_dump(arena);
     arena_free(arena);
 }
+static void arena_test_2(void)
+{
+    ArenaParams arena_params = {};
+    arena_params.size = 1024+ARENA_HEADER_SZ;
+    Arena *arena = arena_alloc_(&arena_params);
+
+    void *ptr;
+    ptr = arena_push(arena, 1024, 8);
+    printf("Allocated ptr %p\n", ptr);
+
+    arena_dump(arena);
+    ArenaCheckPoint checkpoint = arena_temp_begin(arena);
+    ptr = arena_push(arena, 4096, 8);
+    ptr = arena_push(arena, 4096, 8);
+
+    ArenaCheckPoint checkpoint2 = arena_temp_begin(arena);
+    ptr = arena_push(arena, 64, 8);
+    arena_temp_end(&checkpoint2);
+
+    arena_temp_end(&checkpoint);
+    arena_pop_to(arena, 1088);
+    arena_dump(arena);
+    ptr = arena_push(arena, 1, 1);
+    ptr = arena_push(arena, 1, 1);
+    arena_pop_to(arena, 1089);
+    arena_dump(arena);
+
+    arena_free(arena);
+}
+
+int main(int argc, char *argv[])
+{
+    arena_test_2();
+}