Musa-Cpp-Lib-V2/lib/Base/Expandable_Arena.h

27 lines
1.4 KiB
C

// Just an idea I had so that we can start with a small arena and increase on an as-needed basis,
// this way allocations are always extremely fast.
// Note that this downcasts to Arena, so can be initialized in the same way.
// DO NOT USE push_arena WITH THIS! IT WILL CALL THE WRONG PROC!
struct ExpandableArena {
u8* current_point = nullptr;
u8* memory_base = nullptr;
u8* first_uncommitted_page = nullptr;
u16 alignment = CPU_REGISTER_WIDTH_BYTES;
Arena_Reserve reserve_size = Arena_Reserve::Size_64K;
Arena_Flags flags = Arena_Flags::None;
u32 initial_commit_page_count = ARENA_DEFAULT_COMMIT_PAGE_COUNT;
// 32 bytes up to here
Arena* current;
Array<Arena*> next_arenas; // 40 B
};
ExpandableArena* expandable_arena_new (Arena_Reserve starting_reserve=Arena_Reserve::Size_64K, s32 commit_page_count=8);
void* expandable_arena_allocator_proc (Allocator_Mode mode, s64 requested_size, s64 old_size, void* old_memory, void* allocator_data);
bool is_valid (ExpandableArena* arena);
void* expandable_arena_alloc (ExpandableArena* arena_ex, s64 byte_count);
u8* expandable_arena_start (ExpandableArena* arena_ex);
Allocator get_allocator (ExpandableArena* arena_ex);
void arena_reset (ExpandableArena* arena_ex, bool free_extra_pages=true);
force_inline void arena_delete (ExpandableArena* arena_ex);