Files

Patedam f95ba51c13 Added a basic MemoryArena.

Added one scratch, one engine and one game arena.
Converted the game alloc to arena + the display stuff.
WIP

Made using Antigravity+gemini

2026-01-17 21:09:23 -05:00

Memory System Status & Migration Plan

Completed Work

MemoryArena: Implemented linear allocator with alignment, markers, and reset support.
Global Arenas:
- ScratchArena (64MB): Transient per-frame memory.
- EngineArena (256MB): Persistent engine memory (internal).
- GameArena (512MB): Persistent game memory (exported to Game DLL).
Helpers: Added ArenaPushType<T> and ArenaPushArray<T> with automatic zero-initialization.

Display: Win32Window and Win32DisplayDevice now use EngineArena.
Game Entities: Entity.h uses GameArena for entity allocation; manual free calls removed from game.cpp.

The following subsystems still use legacy malloc/calloc/realloc/free and need to be migrated.

Files: Core/HotReload/HotReload.cpp, Core/HotReload/Win32/Win32HotReload.cpp
Allocations: DLLFullPath, LockFullPath, tempDllPath.
Strategy:
- Use EngineArena for persistent paths (DLLFullPath, LockFullPath).
- Use ScratchArena for temporary paths (tempDllPath).

Files: Core/HAL/IO/IOStream.cpp, Core/HAL/IO/Win32/Win32IOStream.cpp
Allocations: IOStream instance, data buffers, Win32IOStreamDataPayload.
Challenge: Realloc is used for growing buffers.
Strategy:
- IOStream struct -> ScratchArena (if transient) or EngineArena.
- Buffers: Evaluate if ArenaPush with large enough capacity is sufficient, or implement a growable buffer on top of arena (or use std::vector with custom allocator if absolutely needed, but prefer simple fixed max size if possible).

Files: Graphics/DebugDisplayRenderer.cpp
Allocations: DepthTestedVertices, OverlayVertices.
Strategy: Use EngineArena or a dedicated RenderArena if these are persistent. If per-frame, move to ScratchArena.

Files: JulietShaderCompiler/ShaderCompiler.cpp
Allocations: Argument arrays, file buffers.
Strategy: Use ScratchArena for all compilation tasks as they are transient.