From 1a1abaf95368419fe6f051f172c8b0c4aa663720 Mon Sep 17 00:00:00 2001
From: Min-Gu Yoo <mgyoo86@gmail.com>
Date: Wed, 18 Feb 2026 12:28:10 -0800
Subject: [PATCH 1/5] refactor(core): rename _mark_untracked! to
 _record_type_touch! and add named constants
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Tier 1 renames to match evolved architecture after Phase 3/5 optimizations:
- _mark_untracked! → _record_type_touch! (records per-type bitmask, not a boolean)
- _untracked_fixed_masks → _touched_type_masks (struct field)
- _untracked_has_others → _touched_has_others (struct field)

Add named constants replacing magic hex literals:
- _LAZY_MODE_BIT (0x8000), _TYPED_LAZY_BIT (0x4000)
- _MODE_BITS_MASK (0xC000), _TYPE_BITS_MASK (0x00FF)
---
 src/acquire.jl     | 59 +++++++++++++++++++++++-----------------------
 src/convenience.jl | 56 +++++++++++++++++++++----------------------
 src/types.jl       | 25 ++++++++++++++------
 3 files changed, 76 insertions(+), 64 deletions(-)

diff --git a/src/acquire.jl b/src/acquire.jl
index 716517d..b0326f1 100644
--- a/src/acquire.jl
+++ b/src/acquire.jl
@@ -160,53 +160,54 @@ Get an N-dimensional view via `reshape` (zero creation cost).
 end
 
 # ==============================================================================
-# Untracked Acquire Detection
+# Type Touch Recording (for selective rewind)
 # ==============================================================================
 
 """
-    _mark_untracked!(pool::AbstractArrayPool, ::Type{T})
+    _record_type_touch!(pool::AbstractArrayPool, ::Type{T})
 
-Mark that an untracked acquire of type `T` has occurred at the current checkpoint depth.
-Called by `acquire!` wrapper; macro-transformed calls use `_acquire_impl!` directly.
+Record that type `T` was touched (acquired) at the current checkpoint depth.
+Called by `acquire!` and convenience wrappers; macro-transformed calls use
+`_acquire_impl!` directly (bypassing this for zero overhead).
 
-For fixed-slot types, sets the corresponding bit in `_untracked_fixed_masks`.
-For non-fixed-slot types, sets `_untracked_has_others` flag.
+For fixed-slot types, sets the corresponding bit in `_touched_type_masks`.
+For non-fixed-slot types, sets `_touched_has_others` flag.
 """
-@inline function _mark_untracked!(pool::AbstractArrayPool, ::Type{T}) where {T}
+@inline function _record_type_touch!(pool::AbstractArrayPool, ::Type{T}) where {T}
     depth = pool._current_depth
     b = _fixed_slot_bit(T)
     if b == UInt16(0)
-        @inbounds pool._untracked_has_others[depth] = true
+        @inbounds pool._touched_has_others[depth] = true
     else
-        @inbounds pool._untracked_fixed_masks[depth] |= b
+        @inbounds pool._touched_type_masks[depth] |= b
     end
     nothing
 end
 
-# CPU-specific override: adds lazy first-touch checkpoint in dynamic-selective mode
+# CPU-specific override: adds lazy first-touch checkpoint in lazy mode
 # and typed-lazy mode.
-# Bit 15 of _untracked_fixed_masks[depth] == 1  ↔  depth entered via _depth_only_checkpoint!
-# Bit 14 of _untracked_fixed_masks[depth] == 1  ↔  depth entered via _typed_checkpoint_with_lazy!
+# _LAZY_MODE_BIT (bit 15) in _touched_type_masks[depth]  ↔  depth entered via _lazy_checkpoint!
+# _TYPED_LAZY_BIT (bit 14) in _touched_type_masks[depth]  ↔  depth entered via _typed_lazy_checkpoint!
 # On the first acquire of each fixed-slot type T at that depth, we retroactively save
 # n_active BEFORE the acquire (current value is still the parent's count), so that
 # the subsequent rewind can restore the parent's state correctly.
-@inline function _mark_untracked!(pool::AdaptiveArrayPool, ::Type{T}) where {T}
+@inline function _record_type_touch!(pool::AdaptiveArrayPool, ::Type{T}) where {T}
     depth = pool._current_depth
     b = _fixed_slot_bit(T)
     if b == UInt16(0)
-        @inbounds pool._untracked_has_others[depth] = true
+        @inbounds pool._touched_has_others[depth] = true
     else
-        current_mask = @inbounds pool._untracked_fixed_masks[depth]
-        # Lazy checkpoint: dynamic mode (bit 15) OR typed lazy mode (bit 14), AND first touch.
+        current_mask = @inbounds pool._touched_type_masks[depth]
+        # Lazy checkpoint: lazy mode (bit 15) OR typed lazy mode (bit 14), AND first touch.
         # Guard: skip if already checkpointed at this depth (prevents double-push when a
-        # tracked type is also acquired by a helper via acquire! → _mark_untracked!).
-        if (current_mask & 0xC000) != 0 && (current_mask & b) == 0
+        # tracked type is also acquired by a helper via acquire! → _record_type_touch!).
+        if (current_mask & _MODE_BITS_MASK) != 0 && (current_mask & b) == 0
             tp = get_typed_pool!(pool, T)
             if @inbounds(tp._checkpoint_depths[end]) != depth
                 _checkpoint_typed_pool!(tp, depth)
             end
         end
-        @inbounds pool._untracked_fixed_masks[depth] = current_mask | b
+        @inbounds pool._touched_type_masks[depth] = current_mask | b
     end
     nothing
 end
@@ -220,7 +221,7 @@ end
     _acquire_impl!(pool, Type{T}, dims...) -> ReshapedArray{T,N,...}
 
 Internal implementation of acquire!. Called directly by macro-transformed code
-(no untracked marking). User code calls `acquire!` which adds marking.
+(no type touch recording). User code calls `acquire!` which adds recording.
 """
 @inline function _acquire_impl!(pool::AbstractArrayPool, ::Type{T}, n::Int) where {T}
     tp = get_typed_pool!(pool, T)
@@ -263,7 +264,7 @@ end
 @inline _unsafe_acquire_impl!(pool::AbstractArrayPool, x::AbstractArray) = _unsafe_acquire_impl!(pool, eltype(x), size(x))
 
 # ==============================================================================
-# Acquisition API (User-facing with untracked marking)
+# Acquisition API (User-facing with type touch recording)
 # ==============================================================================
 
 """
@@ -299,19 +300,19 @@ end
 See also: [`unsafe_acquire!`](@ref) for native array access.
 """
 @inline function acquire!(pool::AbstractArrayPool, ::Type{T}, n::Int) where {T}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _acquire_impl!(pool, T, n)
 end
 
 # Multi-dimensional support (zero-allocation with N-D cache)
 @inline function acquire!(pool::AbstractArrayPool, ::Type{T}, dims::Vararg{Int, N}) where {T, N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _acquire_impl!(pool, T, dims...)
 end
 
 # Tuple support: allows acquire!(pool, T, size(A)) where size(A) returns NTuple{N,Int}
 @inline function acquire!(pool::AbstractArrayPool, ::Type{T}, dims::NTuple{N, Int}) where {T, N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _acquire_impl!(pool, T, dims...)
 end
 
@@ -331,7 +332,7 @@ end
 ```
 """
 @inline function acquire!(pool::AbstractArrayPool, x::AbstractArray)
-    _mark_untracked!(pool, eltype(x))
+    _record_type_touch!(pool, eltype(x))
     _acquire_impl!(pool, eltype(x), size(x))
 end
 
@@ -386,18 +387,18 @@ end
 See also: [`acquire!`](@ref) for view-based access.
 """
 @inline function unsafe_acquire!(pool::AbstractArrayPool, ::Type{T}, n::Int) where {T}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_acquire_impl!(pool, T, n)
 end
 
 @inline function unsafe_acquire!(pool::AbstractArrayPool, ::Type{T}, dims::Vararg{Int, N}) where {T, N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_acquire_impl!(pool, T, dims...)
 end
 
 # Tuple support
 @inline function unsafe_acquire!(pool::AbstractArrayPool, ::Type{T}, dims::NTuple{N, Int}) where {T, N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_acquire_impl!(pool, T, dims)
 end
 
@@ -417,7 +418,7 @@ end
 ```
 """
 @inline function unsafe_acquire!(pool::AbstractArrayPool, x::AbstractArray)
-    _mark_untracked!(pool, eltype(x))
+    _record_type_touch!(pool, eltype(x))
     _unsafe_acquire_impl!(pool, eltype(x), size(x))
 end
 
diff --git a/src/convenience.jl b/src/convenience.jl
index 62d919f..053f8cb 100644
--- a/src/convenience.jl
+++ b/src/convenience.jl
@@ -43,22 +43,22 @@ end
 See also: [`ones!`](@ref), [`similar!`](@ref), [`acquire!`](@ref)
 """
 @inline function zeros!(pool::AbstractArrayPool, ::Type{T}, dims::Vararg{Int,N}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _zeros_impl!(pool, T, dims...)
 end
 
 @inline function zeros!(pool::AbstractArrayPool, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _zeros_impl!(pool, default_eltype(pool), dims...)
 end
 
 @inline function zeros!(pool::AbstractArrayPool, ::Type{T}, dims::NTuple{N,Int}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _zeros_impl!(pool, T, dims...)
 end
 
 @inline function zeros!(pool::AbstractArrayPool, dims::NTuple{N,Int}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _zeros_impl!(pool, default_eltype(pool), dims...)
 end
 
@@ -116,22 +116,22 @@ end
 See also: [`zeros!`](@ref), [`similar!`](@ref), [`acquire!`](@ref)
 """
 @inline function ones!(pool::AbstractArrayPool, ::Type{T}, dims::Vararg{Int,N}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _ones_impl!(pool, T, dims...)
 end
 
 @inline function ones!(pool::AbstractArrayPool, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _ones_impl!(pool, default_eltype(pool), dims...)
 end
 
 @inline function ones!(pool::AbstractArrayPool, ::Type{T}, dims::NTuple{N,Int}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _ones_impl!(pool, T, dims...)
 end
 
 @inline function ones!(pool::AbstractArrayPool, dims::NTuple{N,Int}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _ones_impl!(pool, default_eltype(pool), dims...)
 end
 
@@ -186,11 +186,11 @@ end
 See also: [`falses!`](@ref), [`ones!`](@ref), [`acquire!`](@ref)
 """
 @inline function trues!(pool::AbstractArrayPool, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, Bit)
+    _record_type_touch!(pool, Bit)
     _trues_impl!(pool, dims...)
 end
 @inline function trues!(pool::AbstractArrayPool, dims::NTuple{N,Int}) where {N}
-    _mark_untracked!(pool, Bit)
+    _record_type_touch!(pool, Bit)
     _trues_impl!(pool, dims...)
 end
 
@@ -226,11 +226,11 @@ end
 See also: [`trues!`](@ref), [`zeros!`](@ref), [`acquire!`](@ref)
 """
 @inline function falses!(pool::AbstractArrayPool, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, Bit)
+    _record_type_touch!(pool, Bit)
     _falses_impl!(pool, dims...)
 end
 @inline function falses!(pool::AbstractArrayPool, dims::NTuple{N,Int}) where {N}
-    _mark_untracked!(pool, Bit)
+    _record_type_touch!(pool, Bit)
     _falses_impl!(pool, dims...)
 end
 
@@ -273,22 +273,22 @@ end
 See also: [`zeros!`](@ref), [`ones!`](@ref), [`acquire!`](@ref)
 """
 @inline function similar!(pool::AbstractArrayPool, x::AbstractArray)
-    _mark_untracked!(pool, eltype(x))
+    _record_type_touch!(pool, eltype(x))
     _similar_impl!(pool, x)
 end
 
 @inline function similar!(pool::AbstractArrayPool, x::AbstractArray, ::Type{T}) where {T}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _similar_impl!(pool, x, T)
 end
 
 @inline function similar!(pool::AbstractArrayPool, x::AbstractArray, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, eltype(x))
+    _record_type_touch!(pool, eltype(x))
     _similar_impl!(pool, x, dims...)
 end
 
 @inline function similar!(pool::AbstractArrayPool, x::AbstractArray, ::Type{T}, dims::Vararg{Int,N}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _similar_impl!(pool, x, T, dims...)
 end
 
@@ -336,22 +336,22 @@ end
 See also: [`unsafe_ones!`](@ref), [`zeros!`](@ref), [`unsafe_acquire!`](@ref)
 """
 @inline function unsafe_zeros!(pool::AbstractArrayPool, ::Type{T}, dims::Vararg{Int,N}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_zeros_impl!(pool, T, dims...)
 end
 
 @inline function unsafe_zeros!(pool::AbstractArrayPool, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _unsafe_zeros_impl!(pool, default_eltype(pool), dims...)
 end
 
 @inline function unsafe_zeros!(pool::AbstractArrayPool, ::Type{T}, dims::NTuple{N,Int}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_zeros_impl!(pool, T, dims...)
 end
 
 @inline function unsafe_zeros!(pool::AbstractArrayPool, dims::NTuple{N,Int}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _unsafe_zeros_impl!(pool, default_eltype(pool), dims...)
 end
 
@@ -403,22 +403,22 @@ end
 See also: [`unsafe_zeros!`](@ref), [`ones!`](@ref), [`unsafe_acquire!`](@ref)
 """
 @inline function unsafe_ones!(pool::AbstractArrayPool, ::Type{T}, dims::Vararg{Int,N}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_ones_impl!(pool, T, dims...)
 end
 
 @inline function unsafe_ones!(pool::AbstractArrayPool, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _unsafe_ones_impl!(pool, default_eltype(pool), dims...)
 end
 
 @inline function unsafe_ones!(pool::AbstractArrayPool, ::Type{T}, dims::NTuple{N,Int}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_ones_impl!(pool, T, dims...)
 end
 
 @inline function unsafe_ones!(pool::AbstractArrayPool, dims::NTuple{N,Int}) where {N}
-    _mark_untracked!(pool, default_eltype(pool))
+    _record_type_touch!(pool, default_eltype(pool))
     _unsafe_ones_impl!(pool, default_eltype(pool), dims...)
 end
 
@@ -473,22 +473,22 @@ end
 See also: [`similar!`](@ref), [`unsafe_acquire!`](@ref)
 """
 @inline function unsafe_similar!(pool::AbstractArrayPool, x::AbstractArray)
-    _mark_untracked!(pool, eltype(x))
+    _record_type_touch!(pool, eltype(x))
     _unsafe_similar_impl!(pool, x)
 end
 
 @inline function unsafe_similar!(pool::AbstractArrayPool, x::AbstractArray, ::Type{T}) where {T}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_similar_impl!(pool, x, T)
 end
 
 @inline function unsafe_similar!(pool::AbstractArrayPool, x::AbstractArray, dims::Vararg{Int,N}) where {N}
-    _mark_untracked!(pool, eltype(x))
+    _record_type_touch!(pool, eltype(x))
     _unsafe_similar_impl!(pool, x, dims...)
 end
 
 @inline function unsafe_similar!(pool::AbstractArrayPool, x::AbstractArray, ::Type{T}, dims::Vararg{Int,N}) where {T,N}
-    _mark_untracked!(pool, T)
+    _record_type_touch!(pool, T)
     _unsafe_similar_impl!(pool, x, T, dims...)
 end
 
diff --git a/src/types.jl b/src/types.jl
index 72b7c1e..847c1d9 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -367,7 +367,18 @@ Tests verify synchronization automatically.
 const FIXED_SLOT_FIELDS = (:float64, :float32, :int64, :int32, :complexf64, :complexf32, :bool, :bits)
 
 # ==============================================================================
-# Fixed-Slot Bit Mapping (for typed untracked tracking)
+# Bitmask Mode Constants
+# ==============================================================================
+# Bits 0-7: fixed-slot type touch tracking (one bit per type)
+# Bits 14-15: mode flags set during checkpoint to control lazy behavior
+
+const _LAZY_MODE_BIT   = UInt16(0x8000)  # bit 15: lazy (dynamic-selective) checkpoint mode
+const _TYPED_LAZY_BIT  = UInt16(0x4000)  # bit 14: typed lazy-fallback mode
+const _MODE_BITS_MASK  = UInt16(0xC000)  # bits 14-15: all mode flags
+const _TYPE_BITS_MASK  = UInt16(0x00FF)  # bits 0-7: fixed-slot type bits
+
+# ==============================================================================
+# Fixed-Slot Bit Mapping (for type touch tracking)
 # ==============================================================================
 # Maps each fixed-slot type to a unique bit in a UInt16 bitmask.
 # Bit ordering matches FIXED_SLOT_FIELDS. Non-fixed types return UInt16(0).
@@ -382,7 +393,7 @@ const FIXED_SLOT_FIELDS = (:float64, :float32, :int64, :int32, :complexf64, :com
 @inline _fixed_slot_bit(::Type{Bit})        = UInt16(1) << 7
 @inline _fixed_slot_bit(::Type)             = UInt16(0)  # non-fixed-slot → triggers has_others
 
-# Check whether a type's bit is set in a bitmask (e.g. _untracked_fixed_masks or combined).
+# Check whether a type's bit is set in a bitmask (e.g. _touched_type_masks or combined).
 @inline _has_bit(mask::UInt16, ::Type{T}) where {T} = (mask & _fixed_slot_bit(T)) != 0
 
 # ==============================================================================
@@ -409,10 +420,10 @@ mutable struct AdaptiveArrayPool <: AbstractArrayPool
     # Fallback: rare types
     others::IdDict{DataType, Any}
 
-    # Untracked acquire detection (1-based sentinel pattern)
+    # Type touch tracking (1-based sentinel pattern)
     _current_depth::Int             # Current scope depth (1 = global scope)
-    _untracked_fixed_masks::Vector{UInt16}  # Per-depth: which fixed slots had untracked acquires
-    _untracked_has_others::Vector{Bool}     # Per-depth: any non-fixed-slot untracked acquire?
+    _touched_type_masks::Vector{UInt16}  # Per-depth: which fixed slots were touched + mode flags
+    _touched_has_others::Vector{Bool}    # Per-depth: any non-fixed-slot type touched?
 end
 
 function AdaptiveArrayPool()
@@ -427,8 +438,8 @@ function AdaptiveArrayPool()
         BitTypedPool(),
         IdDict{DataType, Any}(),
         1,              # _current_depth: 1 = global scope (sentinel)
-        [UInt16(0)],    # _untracked_fixed_masks: sentinel (no bits set)
-        [false]         # _untracked_has_others: sentinel (no others)
+        [UInt16(0)],    # _touched_type_masks: sentinel (no bits set)
+        [false]         # _touched_has_others: sentinel (no others)
     )
 end
 

From 0229de1596dde1ae6d8e319b37a61ebe8a17a841 Mon Sep 17 00:00:00 2001
From: Min-Gu Yoo <mgyoo86@gmail.com>
Date: Wed, 18 Feb 2026 12:28:15 -0800
Subject: [PATCH 2/5] refactor(state): rename mode functions to lazy
 checkpoint/rewind naming
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Tier 2 renames for checkpoint/rewind mode functions:
- _depth_only_checkpoint! → _lazy_checkpoint!
- _dynamic_selective_rewind! → _lazy_rewind!
- _typed_checkpoint_with_lazy! → _typed_lazy_checkpoint!
- _typed_selective_rewind! → _typed_lazy_rewind!
- _generate_dynamic_selective_*_call → _generate_lazy_*_call

Replace magic hex (0x8000, 0x4000, 0xC000, 0x00FF) with named constants.
---
 src/macros.jl |  70 ++++++++++++-------------
 src/state.jl  | 140 +++++++++++++++++++++++++-------------------------
 2 files changed, 105 insertions(+), 105 deletions(-)

diff --git a/src/macros.jl b/src/macros.jl
index 28fba7a..21a7599 100644
--- a/src/macros.jl
+++ b/src/macros.jl
@@ -337,20 +337,20 @@ function _generate_pool_code(pool_name, expr, force_enable; source::Union{LineNu
     # Use typed checkpoint/rewind if all types are static, otherwise fallback to full
     use_typed = !has_dynamic && !isempty(static_types)
 
-    # For typed path: transform acquire! → _acquire_impl! (bypasses untracked marking)
-    # For dynamic path: keep acquire! untransformed so _mark_untracked! is called
+    # For typed path: transform acquire! → _acquire_impl! (bypasses type touch recording)
+    # For dynamic path: keep acquire! untransformed so _record_type_touch! is called
     transformed_expr = use_typed ? _transform_acquire_calls(expr, pool_name) : expr
 
     if use_typed
         checkpoint_call = _generate_typed_checkpoint_call(esc(pool_name), static_types)
     else
-        checkpoint_call = _generate_dynamic_selective_checkpoint_call(esc(pool_name))
+        checkpoint_call = _generate_lazy_checkpoint_call(esc(pool_name))
     end
 
     if use_typed
         rewind_call = _generate_typed_rewind_call(esc(pool_name), static_types)
     else
-        rewind_call = _generate_dynamic_selective_rewind_call(esc(pool_name))
+        rewind_call = _generate_lazy_rewind_call(esc(pool_name))
     end
 
     if force_enable
@@ -429,8 +429,8 @@ function _generate_pool_code_with_backend(backend::Symbol, pool_name, expr, forc
         local_vars = _extract_local_assignments(expr)
         static_types, has_dynamic = _filter_static_types(all_types, local_vars)
         use_typed = !has_dynamic && !isempty(static_types)
-        # For typed path: transform acquire! → _acquire_impl! (bypasses untracked marking)
-        # For dynamic path: keep acquire! untransformed so _mark_untracked! is called
+        # For typed path: transform acquire! → _acquire_impl! (bypasses type touch recording)
+        # For dynamic path: keep acquire! untransformed so _record_type_touch! is called
         transformed_expr = use_typed ? _transform_acquire_calls(expr, pool_name) : expr
         pool_getter = :($_get_pool_for_backend($(Val{backend}())))
 
@@ -438,8 +438,8 @@ function _generate_pool_code_with_backend(backend::Symbol, pool_name, expr, forc
             checkpoint_call = _generate_typed_checkpoint_call(esc(pool_name), static_types)
             rewind_call = _generate_typed_rewind_call(esc(pool_name), static_types)
         else
-            checkpoint_call = _generate_dynamic_selective_checkpoint_call(esc(pool_name))
-            rewind_call = _generate_dynamic_selective_rewind_call(esc(pool_name))
+            checkpoint_call = _generate_lazy_checkpoint_call(esc(pool_name))
+            rewind_call = _generate_lazy_rewind_call(esc(pool_name))
         end
 
         return quote
@@ -475,8 +475,8 @@ function _generate_pool_code_with_backend(backend::Symbol, pool_name, expr, forc
     # Use typed checkpoint/rewind if all types are static, otherwise fallback to full
     use_typed = !has_dynamic && !isempty(static_types)
 
-    # For typed path: transform acquire! → _acquire_impl! (bypasses untracked marking)
-    # For dynamic path: keep acquire! untransformed so _mark_untracked! is called
+    # For typed path: transform acquire! → _acquire_impl! (bypasses type touch recording)
+    # For dynamic path: keep acquire! untransformed so _record_type_touch! is called
     transformed_expr = use_typed ? _transform_acquire_calls(expr, pool_name) : expr
 
     # Use Val{backend}() for compile-time dispatch - fully inlinable
@@ -485,13 +485,13 @@ function _generate_pool_code_with_backend(backend::Symbol, pool_name, expr, forc
     if use_typed
         checkpoint_call = _generate_typed_checkpoint_call(esc(pool_name), static_types)
     else
-        checkpoint_call = _generate_dynamic_selective_checkpoint_call(esc(pool_name))
+        checkpoint_call = _generate_lazy_checkpoint_call(esc(pool_name))
     end
 
     if use_typed
         rewind_call = _generate_typed_rewind_call(esc(pool_name), static_types)
     else
-        rewind_call = _generate_dynamic_selective_rewind_call(esc(pool_name))
+        rewind_call = _generate_lazy_rewind_call(esc(pool_name))
     end
 
     return quote
@@ -537,8 +537,8 @@ function _generate_function_pool_code_with_backend(backend::Symbol, pool_name, f
     static_types, has_dynamic = _filter_static_types(all_types, local_vars)
     use_typed = !has_dynamic && !isempty(static_types)
 
-    # For typed path: transform acquire! → _acquire_impl! (bypasses untracked marking)
-    # For dynamic path: keep acquire! untransformed so _mark_untracked! is called
+    # For typed path: transform acquire! → _acquire_impl! (bypasses type touch recording)
+    # For dynamic path: keep acquire! untransformed so _record_type_touch! is called
     transformed_body = use_typed ? _transform_acquire_calls(body, pool_name) : body
 
     # Use Val{backend}() for compile-time dispatch
@@ -547,13 +547,13 @@ function _generate_function_pool_code_with_backend(backend::Symbol, pool_name, f
     if use_typed
         checkpoint_call = _generate_typed_checkpoint_call(esc(pool_name), static_types)
     else
-        checkpoint_call = _generate_dynamic_selective_checkpoint_call(esc(pool_name))
+        checkpoint_call = _generate_lazy_checkpoint_call(esc(pool_name))
     end
 
     if use_typed
         rewind_call = _generate_typed_rewind_call(esc(pool_name), static_types)
     else
-        rewind_call = _generate_dynamic_selective_rewind_call(esc(pool_name))
+        rewind_call = _generate_lazy_rewind_call(esc(pool_name))
     end
 
     new_body = quote
@@ -594,20 +594,20 @@ function _generate_function_pool_code(pool_name, func_def, force_enable, disable
     static_types, has_dynamic = _filter_static_types(all_types, local_vars)
     use_typed = !has_dynamic && !isempty(static_types)
 
-    # For typed path: transform acquire! → _acquire_impl! (bypasses untracked marking)
-    # For dynamic path: keep acquire! untransformed so _mark_untracked! is called
+    # For typed path: transform acquire! → _acquire_impl! (bypasses type touch recording)
+    # For dynamic path: keep acquire! untransformed so _record_type_touch! is called
     transformed_body = use_typed ? _transform_acquire_calls(body, pool_name) : body
 
     if use_typed
         checkpoint_call = _generate_typed_checkpoint_call(esc(pool_name), static_types)
     else
-        checkpoint_call = _generate_dynamic_selective_checkpoint_call(esc(pool_name))
+        checkpoint_call = _generate_lazy_checkpoint_call(esc(pool_name))
     end
 
     if use_typed
         rewind_call = _generate_typed_rewind_call(esc(pool_name), static_types)
     else
-        rewind_call = _generate_dynamic_selective_rewind_call(esc(pool_name))
+        rewind_call = _generate_lazy_rewind_call(esc(pool_name))
     end
 
     if force_enable
@@ -910,8 +910,8 @@ end
 
 Generate bitmask-aware checkpoint call. When types are known at compile time,
 emits a conditional:
-- if untracked types ⊆ tracked types → typed checkpoint (fast path)
-- otherwise → `_typed_checkpoint_with_lazy!` (typed checkpoint + set bit 14 for
+- if touched types ⊆ tracked types → typed checkpoint (fast path)
+- otherwise → `_typed_lazy_checkpoint!` (typed checkpoint + set bit 14 for
   lazy first-touch checkpointing of extra types touched by helpers)
 """
 function _generate_typed_checkpoint_call(pool_expr, types)
@@ -920,7 +920,7 @@ function _generate_typed_checkpoint_call(pool_expr, types)
     else
         escaped_types = [esc(t) for t in types]
         typed_call = :($checkpoint!($pool_expr, $(escaped_types...)))
-        lazy_call  = :($_typed_checkpoint_with_lazy!($pool_expr, $(escaped_types...)))
+        lazy_call  = :($_typed_lazy_checkpoint!($pool_expr, $(escaped_types...)))
         return quote
             if $_can_use_typed_path($pool_expr, $_tracked_mask_for_types($(escaped_types...)))
                 $typed_call
@@ -936,8 +936,8 @@ end
 
 Generate bitmask-aware rewind call. When types are known at compile time,
 emits a conditional:
-- if untracked types ⊆ tracked types → typed rewind (fast path)
-- otherwise → `_typed_selective_rewind!` (rewinds tracked | untracked mask;
+- if touched types ⊆ tracked types → typed rewind (fast path)
+- otherwise → `_typed_lazy_rewind!` (rewinds tracked | touched mask;
   all touched types have Case A checkpoints via bit 14 lazy mode)
 """
 function _generate_typed_rewind_call(pool_expr, types)
@@ -946,7 +946,7 @@ function _generate_typed_rewind_call(pool_expr, types)
     else
         escaped_types = [esc(t) for t in types]
         typed_call     = :($rewind!($pool_expr, $(escaped_types...)))
-        selective_call = :($_typed_selective_rewind!($pool_expr,
+        selective_call = :($_typed_lazy_rewind!($pool_expr,
                               $_tracked_mask_for_types($(escaped_types...))))
         return quote
             if $_can_use_typed_path($pool_expr, $_tracked_mask_for_types($(escaped_types...)))
@@ -959,25 +959,25 @@ function _generate_typed_rewind_call(pool_expr, types)
 end
 
 """
-    _generate_dynamic_selective_checkpoint_call(pool_expr)
+    _generate_lazy_checkpoint_call(pool_expr)
 
 Generate a depth-only checkpoint call for dynamic-selective mode (`use_typed=false`).
 Much lighter than full `checkpoint!`: only increments depth and pushes bitmask sentinels.
 """
-function _generate_dynamic_selective_checkpoint_call(pool_expr)
-    return :($_depth_only_checkpoint!($pool_expr))
+function _generate_lazy_checkpoint_call(pool_expr)
+    return :($_lazy_checkpoint!($pool_expr))
 end
 
 """
-    _generate_dynamic_selective_rewind_call(pool_expr)
+    _generate_lazy_rewind_call(pool_expr)
 
 Generate selective rewind code for dynamic-selective mode (`use_typed=false`).
-Delegates to `_dynamic_selective_rewind!` — a single function call, symmetric
-with `_depth_only_checkpoint!` for checkpoint. This avoids `let`-block overhead
+Delegates to `_lazy_rewind!` — a single function call, symmetric
+with `_lazy_checkpoint!` for checkpoint. This avoids `let`-block overhead
 in `finally` clauses (which can impair Julia's type inference and cause boxing).
 """
-function _generate_dynamic_selective_rewind_call(pool_expr)
-    return :($_dynamic_selective_rewind!($pool_expr))
+function _generate_lazy_rewind_call(pool_expr)
+    return :($_lazy_rewind!($pool_expr))
 end
 
 
@@ -991,7 +991,7 @@ end
 Transform acquire!/unsafe_acquire!/convenience function calls to their _impl! counterparts.
 Only transforms calls where the first argument matches `pool_name`.
 
-This allows macro-transformed code to bypass the untracked marking overhead,
+This allows macro-transformed code to bypass the type touch recording overhead,
 since the macro already knows about these calls at compile time.
 
 Transformation rules:
diff --git a/src/state.jl b/src/state.jl
index 119319c..0eaea1e 100644
--- a/src/state.jl
+++ b/src/state.jl
@@ -13,10 +13,10 @@ After warmup, this function has **zero allocation**.
 See also: [`rewind!`](@ref), [`@with_pool`](@ref)
 """
 function checkpoint!(pool::AdaptiveArrayPool)
-    # Increment depth and initialize untracked bitmask state
+    # Increment depth and initialize type touch tracking state
     pool._current_depth += 1
-    push!(pool._untracked_fixed_masks, UInt16(0))
-    push!(pool._untracked_has_others, false)
+    push!(pool._touched_type_masks, UInt16(0))
+    push!(pool._touched_has_others, false)
     depth = pool._current_depth
 
     # Fixed slots - zero allocation via @generated iteration
@@ -38,14 +38,14 @@ end
 Save state for a specific type only. Used by optimized macros that know
 which types will be used at compile time.
 
-Also updates _current_depth and bitmask state for untracked acquire detection.
+Also updates _current_depth and bitmask state for type touch tracking.
 
 ~77% faster than full checkpoint! when only one type is used.
 """
 @inline function checkpoint!(pool::AdaptiveArrayPool, ::Type{T}) where T
     pool._current_depth += 1
-    push!(pool._untracked_fixed_masks, UInt16(0))
-    push!(pool._untracked_has_others, false)
+    push!(pool._touched_type_masks, UInt16(0))
+    push!(pool._touched_has_others, false)
     _checkpoint_typed_pool!(get_typed_pool!(pool, T), pool._current_depth)
     nothing
 end
@@ -69,8 +69,8 @@ compile-time unrolling. Increments _current_depth once for all types.
     checkpoint_exprs = [:(_checkpoint_typed_pool!(get_typed_pool!(pool, types[$i]), pool._current_depth)) for i in unique_indices]
     quote
         pool._current_depth += 1
-        push!(pool._untracked_fixed_masks, UInt16(0))
-        push!(pool._untracked_has_others, false)
+        push!(pool._touched_type_masks, UInt16(0))
+        push!(pool._touched_has_others, false)
         $(checkpoint_exprs...)
         nothing
     end
@@ -84,14 +84,14 @@ end
 end
 
 """
-    _depth_only_checkpoint!(pool::AdaptiveArrayPool)
+    _lazy_checkpoint!(pool::AdaptiveArrayPool)
 
-Lightweight checkpoint for dynamic-selective mode (`use_typed=false` macro path).
+Lightweight checkpoint for lazy mode (`use_typed=false` macro path).
 
 Increments `_current_depth` and pushes bitmask sentinels — but does **not** save
-`n_active` for any fixed-slot typed pool. The mode flag (bit 15) in
-`_untracked_fixed_masks` marks this depth as dynamic-selective so that
-`_mark_untracked!` can trigger lazy first-touch checkpoints.
+`n_active` for any fixed-slot typed pool. The `_LAZY_MODE_BIT` (bit 15) in
+`_touched_type_masks` marks this depth as lazy mode so that
+`_record_type_touch!` can trigger lazy first-touch checkpoints.
 
 Existing `others` entries are eagerly checkpointed since there is no per-type
 tracking for non-fixed-slot pools; Case B in `_rewind_typed_pool!` handles any
@@ -99,17 +99,17 @@ new `others` entries created during the scope (n_active starts at 0 = sentinel).
 
 Performance: ~2ns vs ~540ns for full `checkpoint!`.
 """
-@inline function _depth_only_checkpoint!(pool::AdaptiveArrayPool)
+@inline function _lazy_checkpoint!(pool::AdaptiveArrayPool)
     pool._current_depth += 1
-    # Bit 15 = dynamic-selective mode flag (bits 0–7 are fixed-slot bits)
-    push!(pool._untracked_fixed_masks, UInt16(0x8000))
-    push!(pool._untracked_has_others, false)
+    # _LAZY_MODE_BIT = lazy mode flag (bits 0–7 are fixed-slot type bits)
+    push!(pool._touched_type_masks, _LAZY_MODE_BIT)
+    push!(pool._touched_has_others, false)
     depth = pool._current_depth
     # Eagerly checkpoint any pre-existing others entries.
     # New others types created during the scope start at n_active=0 (sentinel covers them).
     for p in values(pool.others)
         _checkpoint_typed_pool!(p, depth)
-        @inbounds pool._untracked_has_others[depth] = true
+        @inbounds pool._touched_has_others[depth] = true
     end
     nothing
 end
@@ -125,7 +125,7 @@ Restore the pool state (n_active counters) from internal stacks.
 Uses _checkpoint_depths to accurately determine which entries to pop vs restore.
 
 Only the counters are restored; allocated memory remains for reuse.
-Handles untracked acquires by checking _checkpoint_depths for accurate restoration.
+Handles touched types by checking _checkpoint_depths for accurate restoration.
 
 **Safety**: If called at global scope (depth=1, no pending checkpoints),
 automatically delegates to `reset!` to safely clear all n_active counters.
@@ -152,8 +152,8 @@ function rewind!(pool::AdaptiveArrayPool)
         _rewind_typed_pool!(tp, cur_depth)
     end
 
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
 
     return nothing
@@ -172,8 +172,8 @@ Also updates _current_depth and bitmask state.
         return nothing
     end
     _rewind_typed_pool!(get_typed_pool!(pool, T), pool._current_depth)
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
     nothing
 end
@@ -203,8 +203,8 @@ Decrements _current_depth once after all types are rewound.
             return nothing
         end
         $(rewind_exprs...)
-        pop!(pool._untracked_fixed_masks)
-        pop!(pool._untracked_has_others)
+        pop!(pool._touched_type_masks)
+        pop!(pool._touched_has_others)
         pool._current_depth -= 1
         nothing
     end
@@ -239,89 +239,89 @@ end
 end
 
 """
-    _dynamic_selective_rewind!(pool::AdaptiveArrayPool)
+    _lazy_rewind!(pool::AdaptiveArrayPool)
 
-Complete rewind for dynamic-selective mode (`use_typed=false` macro path).
+Complete rewind for lazy mode (`use_typed=false` macro path).
 
 Reads the combined mask at the current depth, rewinds only the fixed-slot pools
 whose bits are set, handles any `others` entries, then pops the depth metadata.
 
 Called directly from the macro-generated `finally` clause as a single function call
-(matching the structure of `_depth_only_checkpoint!` for symmetry and performance).
+(matching the structure of `_lazy_checkpoint!` for symmetry and performance).
 """
-@inline function _dynamic_selective_rewind!(pool::AdaptiveArrayPool)
+@inline function _lazy_rewind!(pool::AdaptiveArrayPool)
     d    = pool._current_depth
-    bits = @inbounds(pool._untracked_fixed_masks[d]) & UInt16(0x00FF)
+    bits = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
     _selective_rewind_fixed_slots!(pool, bits)
-    if @inbounds(pool._untracked_has_others[d])
+    if @inbounds(pool._touched_has_others[d])
         for tp in values(pool.others)
             _rewind_typed_pool!(tp, d)
         end
     end
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
     nothing
 end
 
 """
-    _typed_checkpoint_with_lazy!(pool::AdaptiveArrayPool, types::Type...)
+    _typed_lazy_checkpoint!(pool::AdaptiveArrayPool, types::Type...)
 
 Typed checkpoint that enables lazy first-touch checkpointing for extra types touched
 by helpers (`use_typed=true`, `_can_use_typed_path=false` path).
 
 Calls `checkpoint!(pool, types...)` (checkpoints only the statically-known types),
-then sets bit 14 (`0x4000`) in `_untracked_fixed_masks[depth]` to signal typed lazy mode.
+then sets `_TYPED_LAZY_BIT` (bit 14) in `_touched_type_masks[depth]` to signal typed lazy mode.
 
-`_mark_untracked!` checks `(mask & 0xC000) != 0` (bit 14 OR bit 15) to trigger a
+`_record_type_touch!` checks `(mask & _MODE_BITS_MASK) != 0` (bit 14 OR bit 15) to trigger a
 lazy first-touch checkpoint for each extra type on first acquire, ensuring Case A
 (not Case B) applies at rewind and parent `n_active` is preserved correctly.
 """
-@inline function _typed_checkpoint_with_lazy!(pool::AdaptiveArrayPool, types::Type...)
+@inline function _typed_lazy_checkpoint!(pool::AdaptiveArrayPool, types::Type...)
     checkpoint!(pool, types...)
     d = pool._current_depth
-    @inbounds pool._untracked_fixed_masks[d] |= UInt16(0x4000)   # set bit 14
-    # Eagerly snapshot pre-existing others entries — mirrors _depth_only_checkpoint!.
-    # _mark_untracked! cannot lazy-checkpoint others types (b==0 branch, no per-type bit).
+    @inbounds pool._touched_type_masks[d] |= _TYPED_LAZY_BIT
+    # Eagerly snapshot pre-existing others entries — mirrors _lazy_checkpoint!.
+    # _record_type_touch! cannot lazy-checkpoint others types (b==0 branch, no per-type bit).
     # Without this, a helper that re-acquires an already-active others type triggers Case B
     # at rewind and restores the wrong parent n_active value.
     #
-    # Also set has_others=true when pool.others is non-empty, so _typed_selective_rewind!
+    # Also set has_others=true when pool.others is non-empty, so _typed_lazy_rewind!
     # enters the others loop even for tracked non-fixed-slot types (e.g. CPU Float16) that
-    # used _acquire_impl! (bypassing _mark_untracked!, leaving has_others=false otherwise).
+    # used _acquire_impl! (bypassing _record_type_touch!, leaving has_others=false otherwise).
     # Skip re-snapshot for entries already checkpointed at d by checkpoint!(pool, types...)
     # (e.g. Float16 in types... was just checkpointed above — avoid double-push).
     for p in values(pool.others)
         if @inbounds(p._checkpoint_depths[end]) != d
             _checkpoint_typed_pool!(p, d)
         end
-        @inbounds pool._untracked_has_others[d] = true
+        @inbounds pool._touched_has_others[d] = true
     end
     nothing
 end
 
 """
-    _typed_selective_rewind!(pool::AdaptiveArrayPool, tracked_mask::UInt16)
+    _typed_lazy_rewind!(pool::AdaptiveArrayPool, tracked_mask::UInt16)
 
 Selective rewind for typed mode (`use_typed=true`) fallback path.
 
 Called when `_can_use_typed_path` returns false (helpers touched types beyond the
 statically-tracked set). Rewinds only pools whose bits are set in
-`tracked_mask | untracked_mask`. All touched types have Case A checkpoints,
-guaranteed by the bit 14 lazy mode set in `_typed_checkpoint_with_lazy!`.
+`tracked_mask | touched_mask`. All touched types have Case A checkpoints,
+guaranteed by the `_TYPED_LAZY_BIT` mode set in `_typed_lazy_checkpoint!`.
 """
-@inline function _typed_selective_rewind!(pool::AdaptiveArrayPool, tracked_mask::UInt16)
+@inline function _typed_lazy_rewind!(pool::AdaptiveArrayPool, tracked_mask::UInt16)
     d = pool._current_depth
-    untracked = @inbounds(pool._untracked_fixed_masks[d]) & UInt16(0x00FF)
+    untracked = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
     combined = tracked_mask | untracked
     _selective_rewind_fixed_slots!(pool, combined)
-    if @inbounds(pool._untracked_has_others[d])
+    if @inbounds(pool._touched_has_others[d])
         for tp in values(pool.others)
             _rewind_typed_pool!(tp, d)
         end
     end
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
     nothing
 end
@@ -333,7 +333,7 @@ Rewind only the fixed-slot typed pools whose bits are set in `mask`.
 
 Each of the 8 fixed-slot pools maps to bits 0–7 (same encoding as `_fixed_slot_bit`).
 Bits 8–15 (mode flags) are **not** checked here — callers must strip them
-before passing the mask (e.g. `mask & UInt16(0x00FF)`).
+before passing the mask (e.g. `mask & _TYPE_BITS_MASK`).
 
 Unset bits are skipped entirely: for pools that were acquired without a matching
 checkpoint, `_rewind_typed_pool!` Case B safely restores from the parent checkpoint.
@@ -432,12 +432,12 @@ function Base.empty!(pool::AdaptiveArrayPool)
     end
     empty!(pool.others)
 
-    # Reset untracked detection state (1-based sentinel pattern)
+    # Reset type touch tracking state (1-based sentinel pattern)
     pool._current_depth = 1                   # 1 = global scope (sentinel)
-    empty!(pool._untracked_fixed_masks)
-    push!(pool._untracked_fixed_masks, UInt16(0))   # Sentinel: no bits set
-    empty!(pool._untracked_has_others)
-    push!(pool._untracked_has_others, false)         # Sentinel: no others
+    empty!(pool._touched_type_masks)
+    push!(pool._touched_type_masks, UInt16(0))   # Sentinel: no bits set
+    empty!(pool._touched_has_others)
+    push!(pool._touched_has_others, false)         # Sentinel: no others
 
     return pool
 end
@@ -470,7 +470,7 @@ Reset pool state without clearing allocated storage.
 This function:
 - Resets all `n_active` counters to 0
 - Restores all checkpoint stacks to sentinel state
-- Resets `_current_depth` and untracked bitmask state
+- Resets `_current_depth` and type touch tracking state
 
 Unlike `empty!`, this **preserves** all allocated vectors, views, and N-D arrays
 for reuse, avoiding reallocation costs.
@@ -513,12 +513,12 @@ function reset!(pool::AdaptiveArrayPool)
         reset!(tp)
     end
 
-    # Reset untracked detection state (1-based sentinel pattern)
+    # Reset type touch tracking state (1-based sentinel pattern)
     pool._current_depth = 1                   # 1 = global scope (sentinel)
-    empty!(pool._untracked_fixed_masks)
-    push!(pool._untracked_fixed_masks, UInt16(0))   # Sentinel: no bits set
-    empty!(pool._untracked_has_others)
-    push!(pool._untracked_has_others, false)         # Sentinel: no others
+    empty!(pool._touched_type_masks)
+    push!(pool._touched_type_masks, UInt16(0))   # Sentinel: no bits set
+    empty!(pool._touched_has_others)
+    push!(pool._touched_has_others, false)         # Sentinel: no others
 
     return pool
 end
@@ -579,17 +579,17 @@ end
 
 Check if the typed (fast) checkpoint/rewind path is safe to use.
 
-Returns `true` when all untracked acquires at the current depth are a subset
-of the tracked types (bitmask subset check) AND no non-fixed-slot types were used.
+Returns `true` when all touched types at the current depth are a subset
+of the tracked types (bitmask subset check) AND no non-fixed-slot types were touched.
 
-The subset check: `(untracked_mask & ~tracked_mask) == 0` means every bit set
-in `untracked_mask` is also set in `tracked_mask`.
+The subset check: `(touched_mask & ~tracked_mask) == 0` means every bit set
+in `touched_mask` is also set in `tracked_mask`.
 """
 @inline function _can_use_typed_path(pool::AbstractArrayPool, tracked_mask::UInt16)
     depth = pool._current_depth
-    untracked_mask = @inbounds pool._untracked_fixed_masks[depth]
-    has_others = @inbounds pool._untracked_has_others[depth]
-    return (untracked_mask & ~tracked_mask) == UInt16(0) && !has_others
+    touched_mask = @inbounds pool._touched_type_masks[depth]
+    has_others = @inbounds pool._touched_has_others[depth]
+    return (touched_mask & ~tracked_mask) == UInt16(0) && !has_others
 end
 
 # ==============================================================================

From 4cfedbdf46e7f464659a00b95e324de752d9f6a3 Mon Sep 17 00:00:00 2001
From: Min-Gu Yoo <mgyoo86@gmail.com>
Date: Wed, 18 Feb 2026 12:28:20 -0800
Subject: [PATCH 3/5] refactor(cuda): mirror all naming changes in CUDA
 extension

Apply Tier 1 + Tier 2 renames to CUDA extension:
- Struct fields, function overrides, imports, and magic numbers
- Float16 special handling preserved (bit 7 reassignment)
---
 ext/AdaptiveArrayPoolsCUDAExt/acquire.jl |  21 ++---
 ext/AdaptiveArrayPoolsCUDAExt/state.jl   | 101 ++++++++++++-----------
 ext/AdaptiveArrayPoolsCUDAExt/types.jl   |   8 +-
 3 files changed, 66 insertions(+), 64 deletions(-)

diff --git a/ext/AdaptiveArrayPoolsCUDAExt/acquire.jl b/ext/AdaptiveArrayPoolsCUDAExt/acquire.jl
index 23cbb36..437d516 100644
--- a/ext/AdaptiveArrayPoolsCUDAExt/acquire.jl
+++ b/ext/AdaptiveArrayPoolsCUDAExt/acquire.jl
@@ -28,7 +28,8 @@
 # ==============================================================================
 
 using AdaptiveArrayPools: get_view!, get_nd_view!, get_nd_array!, allocate_vector, safe_prod,
-                          _mark_untracked!, _fixed_slot_bit, _checkpoint_typed_pool!
+                          _record_type_touch!, _fixed_slot_bit, _checkpoint_typed_pool!,
+                          _MODE_BITS_MASK
 
 """
     get_view!(tp::CuTypedPool{T}, n::Int) -> CuVector{T}
@@ -165,44 +166,44 @@ Used by `unsafe_acquire!` - same zero-allocation behavior as `acquire!`.
 end
 
 # ==============================================================================
-# CUDA _mark_untracked! override (Issue #2 / #2a fix)
+# CUDA _record_type_touch! override (Issue #2 / #2a fix)
 # ==============================================================================
 # Float16 on CUDA: direct struct field with _fixed_slot_bit(Float16)=0.
 # We track Float16 via bit 7 (CUDA reassignment; CPU uses bit 7 for Bit type, absent on GPU).
 # This gives Float16 lazy first-touch checkpointing in bit-14 (typed lazy) and bit-15 (dynamic)
 # modes, ensuring Case A (not Case B) fires at rewind and parent n_active is preserved.
 
-@inline function AdaptiveArrayPools._mark_untracked!(pool::CuAdaptiveArrayPool, ::Type{T}) where {T}
+@inline function AdaptiveArrayPools._record_type_touch!(pool::CuAdaptiveArrayPool, ::Type{T}) where {T}
     depth = pool._current_depth
     b = _fixed_slot_bit(T)
     if b == UInt16(0)
         if T === Float16
             # Float16: CUDA direct field tracked via bit 7 (not in pool.others dict).
             b16 = UInt16(1) << 7
-            current_mask = @inbounds pool._untracked_fixed_masks[depth]
+            current_mask = @inbounds pool._touched_type_masks[depth]
             # Lazy first-touch checkpoint: bit 14 (typed lazy) OR bit 15 (dynamic), first touch only.
             # Guard: skip if already checkpointed at this depth (prevents double-push).
-            if (current_mask & 0xC000) != 0 && (current_mask & b16) == 0
+            if (current_mask & _MODE_BITS_MASK) != 0 && (current_mask & b16) == 0
                 if @inbounds(pool.float16._checkpoint_depths[end]) != depth
                     _checkpoint_typed_pool!(pool.float16, depth)
                 end
             end
-            @inbounds pool._untracked_fixed_masks[depth] = current_mask | b16
+            @inbounds pool._touched_type_masks[depth] = current_mask | b16
         else
             # Genuine others type (UInt8, Int8, etc.) — eagerly snapshotted at scope entry.
-            @inbounds pool._untracked_has_others[depth] = true
+            @inbounds pool._touched_has_others[depth] = true
         end
     else
-        current_mask = @inbounds pool._untracked_fixed_masks[depth]
+        current_mask = @inbounds pool._touched_type_masks[depth]
         # Lazy first-touch checkpoint for fixed-slot types in bit 14/15 modes.
         # Guard: skip if already checkpointed at this depth (prevents double-push).
-        if (current_mask & 0xC000) != 0 && (current_mask & b) == 0
+        if (current_mask & _MODE_BITS_MASK) != 0 && (current_mask & b) == 0
             tp = AdaptiveArrayPools.get_typed_pool!(pool, T)
             if @inbounds(tp._checkpoint_depths[end]) != depth
                 _checkpoint_typed_pool!(tp, depth)
             end
         end
-        @inbounds pool._untracked_fixed_masks[depth] = current_mask | b
+        @inbounds pool._touched_type_masks[depth] = current_mask | b
     end
     nothing
 end
diff --git a/ext/AdaptiveArrayPoolsCUDAExt/state.jl b/ext/AdaptiveArrayPoolsCUDAExt/state.jl
index 23d4ba6..e800c9f 100644
--- a/ext/AdaptiveArrayPoolsCUDAExt/state.jl
+++ b/ext/AdaptiveArrayPoolsCUDAExt/state.jl
@@ -6,7 +6,8 @@
 # AbstractTypedPool, so they work for CuTypedPool automatically.
 
 using AdaptiveArrayPools: checkpoint!, rewind!, reset!,
-                          _checkpoint_typed_pool!, _rewind_typed_pool!, _has_bit
+                          _checkpoint_typed_pool!, _rewind_typed_pool!, _has_bit,
+                          _LAZY_MODE_BIT, _TYPED_LAZY_BIT, _TYPE_BITS_MASK
 
 # ==============================================================================
 # GPU Fixed Slot Iteration
@@ -33,8 +34,8 @@ end
 function AdaptiveArrayPools.checkpoint!(pool::CuAdaptiveArrayPool)
     # Increment depth and initialize untracked bitmask state
     pool._current_depth += 1
-    push!(pool._untracked_fixed_masks, UInt16(0))
-    push!(pool._untracked_has_others, false)
+    push!(pool._touched_type_masks, UInt16(0))
+    push!(pool._touched_has_others, false)
     depth = pool._current_depth
 
     # Fixed slots - zero allocation via @generated iteration
@@ -53,8 +54,8 @@ end
 # Type-specific checkpoint (single type)
 @inline function AdaptiveArrayPools.checkpoint!(pool::CuAdaptiveArrayPool, ::Type{T}) where {T}
     pool._current_depth += 1
-    push!(pool._untracked_fixed_masks, UInt16(0))
-    push!(pool._untracked_has_others, false)
+    push!(pool._touched_type_masks, UInt16(0))
+    push!(pool._touched_has_others, false)
     _checkpoint_typed_pool!(AdaptiveArrayPools.get_typed_pool!(pool, T), pool._current_depth)
     nothing
 end
@@ -72,8 +73,8 @@ end
     checkpoint_exprs = [:(_checkpoint_typed_pool!(AdaptiveArrayPools.get_typed_pool!(pool, types[$i]), pool._current_depth)) for i in unique_indices]
     quote
         pool._current_depth += 1
-        push!(pool._untracked_fixed_masks, UInt16(0))
-        push!(pool._untracked_has_others, false)
+        push!(pool._touched_type_masks, UInt16(0))
+        push!(pool._touched_has_others, false)
         $(checkpoint_exprs...)
         nothing
     end
@@ -102,8 +103,8 @@ function AdaptiveArrayPools.rewind!(pool::CuAdaptiveArrayPool)
         _rewind_typed_pool!(tp, cur_depth)
     end
 
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
 
     return nothing
@@ -116,8 +117,8 @@ end
         return nothing
     end
     _rewind_typed_pool!(AdaptiveArrayPools.get_typed_pool!(pool, T), pool._current_depth)
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
     nothing
 end
@@ -140,17 +141,17 @@ end
             return nothing
         end
         $(rewind_exprs...)
-        pop!(pool._untracked_fixed_masks)
-        pop!(pool._untracked_has_others)
+        pop!(pool._touched_type_masks)
+        pop!(pool._touched_has_others)
         pool._current_depth -= 1
         nothing
     end
 end
 
 # ==============================================================================
-# Dynamic-Selective Mode for CuAdaptiveArrayPool (use_typed=false path)
+# Lazy Mode for CuAdaptiveArrayPool (use_typed=false path)
 # ==============================================================================
-# Mirrors CPU _depth_only_checkpoint! / _dynamic_selective_rewind! in src/state.jl.
+# Mirrors CPU _lazy_checkpoint! / _lazy_rewind! in src/state.jl.
 #
 # Float16 on CUDA: direct struct field (not in pool.others dict), but _fixed_slot_bit(Float16)=0.
 # We reassign Float16 to bit 7 (unused on CUDA; CPU uses bit 7 for Bit type which has no GPU equivalent).
@@ -160,25 +161,25 @@ end
 # Bit 7 on CUDA is reserved for Float16 (CPU uses it for Bit; Bit type does not exist on GPU).
 @inline _cuda_float16_bit() = UInt16(1) << 7
 
-@inline function AdaptiveArrayPools._depth_only_checkpoint!(pool::CuAdaptiveArrayPool)
+@inline function AdaptiveArrayPools._lazy_checkpoint!(pool::CuAdaptiveArrayPool)
     pool._current_depth += 1
-    push!(pool._untracked_fixed_masks, UInt16(0x8000))  # bit 15: dynamic-selective mode
-    push!(pool._untracked_has_others, false)
+    push!(pool._touched_type_masks, _LAZY_MODE_BIT)  # lazy mode flag
+    push!(pool._touched_has_others, false)
     depth = pool._current_depth
-    # Eagerly checkpoint pre-existing others entries — same as CPU _depth_only_checkpoint!.
+    # Eagerly checkpoint pre-existing others entries — same as CPU _lazy_checkpoint!.
     # New types created during the scope start at n_active=0 (sentinel covers them, Case B safe).
     # Pre-existing types need their count saved now so Case A fires correctly at rewind.
     for p in values(pool.others)
         _checkpoint_typed_pool!(p, depth)
-        @inbounds pool._untracked_has_others[depth] = true
+        @inbounds pool._touched_has_others[depth] = true
     end
-    # Float16 uses lazy first-touch via bit 7 in _mark_untracked! — no eager checkpoint needed.
+    # Float16 uses lazy first-touch via bit 7 in _record_type_touch! — no eager checkpoint needed.
     nothing
 end
 
-@inline function AdaptiveArrayPools._dynamic_selective_rewind!(pool::CuAdaptiveArrayPool)
+@inline function AdaptiveArrayPools._lazy_rewind!(pool::CuAdaptiveArrayPool)
     d = pool._current_depth
-    mask = @inbounds(pool._untracked_fixed_masks[d]) & UInt16(0x00FF)
+    mask = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
     _has_bit(mask, Float64)    && _rewind_typed_pool!(pool.float64,    d)
     _has_bit(mask, Float32)    && _rewind_typed_pool!(pool.float32,    d)
     _has_bit(mask, Int64)      && _rewind_typed_pool!(pool.int64,      d)
@@ -188,13 +189,13 @@ end
     _has_bit(mask, Bool)       && _rewind_typed_pool!(pool.bool,       d)
     # Bit 7: Float16 (CUDA reassignment — _fixed_slot_bit(Float16)==0, must use explicit bit check)
     mask & _cuda_float16_bit() != 0 && _rewind_typed_pool!(pool.float16, d)
-    if @inbounds(pool._untracked_has_others[d])
+    if @inbounds(pool._touched_has_others[d])
         for tp in values(pool.others)
             _rewind_typed_pool!(tp, d)
         end
     end
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
     nothing
 end
@@ -203,32 +204,32 @@ end
 # Typed-Fallback Helpers for CuAdaptiveArrayPool (Phase 5 parity)
 # ==============================================================================
 
-# _typed_checkpoint_with_lazy!: typed checkpoint + set bit 14 for lazy extra-type tracking.
+# _typed_lazy_checkpoint!: typed checkpoint + set bit 14 for lazy extra-type tracking.
 # Also eagerly snapshots pre-existing others entries (mirrors CPU fix for Issue #3).
-@inline function AdaptiveArrayPools._typed_checkpoint_with_lazy!(pool::CuAdaptiveArrayPool, types::Type...)
+@inline function AdaptiveArrayPools._typed_lazy_checkpoint!(pool::CuAdaptiveArrayPool, types::Type...)
     checkpoint!(pool, types...)
     d = pool._current_depth
-    @inbounds pool._untracked_fixed_masks[d] |= UInt16(0x4000)   # set bit 14
-    # Eagerly snapshot pre-existing others entries — same reasoning as _depth_only_checkpoint!.
+    @inbounds pool._touched_type_masks[d] |= _TYPED_LAZY_BIT
+    # Eagerly snapshot pre-existing others entries — same reasoning as _lazy_checkpoint!.
     # Skip re-snapshot for entries already checkpointed at d by checkpoint!(pool, types...)
     # (e.g. Float16 in types... was just checkpointed above — avoid double-push).
     for p in values(pool.others)
         if @inbounds(p._checkpoint_depths[end]) != d
             _checkpoint_typed_pool!(p, d)
         end
-        @inbounds pool._untracked_has_others[d] = true
+        @inbounds pool._touched_has_others[d] = true
     end
-    # Float16 uses lazy first-touch via bit 7 in _mark_untracked! — no eager checkpoint needed.
+    # Float16 uses lazy first-touch via bit 7 in _record_type_touch! — no eager checkpoint needed.
     nothing
 end
 
-# _typed_selective_rewind!: selective rewind of (tracked | untracked) mask.
+# _typed_lazy_rewind!: selective rewind of (tracked | untracked) mask.
 # Uses direct field access with bit checks — foreach_fixed_slot is single-argument (no bit yield).
-# Bit 7: Float16 (CUDA-specific; lazy-checkpointed on first touch by _mark_untracked!).
+# Bit 7: Float16 (CUDA-specific; lazy-checkpointed on first touch by _record_type_touch!).
 # has_others: genuine others types (UInt8, Int8, etc.) — eagerly checkpointed at scope entry.
-@inline function AdaptiveArrayPools._typed_selective_rewind!(pool::CuAdaptiveArrayPool, tracked_mask::UInt16)
+@inline function AdaptiveArrayPools._typed_lazy_rewind!(pool::CuAdaptiveArrayPool, tracked_mask::UInt16)
     d = pool._current_depth
-    untracked = @inbounds(pool._untracked_fixed_masks[d]) & UInt16(0x00FF)
+    untracked = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
     combined = tracked_mask | untracked
     _has_bit(combined, Float64)    && _rewind_typed_pool!(pool.float64,    d)
     _has_bit(combined, Float32)    && _rewind_typed_pool!(pool.float32,    d)
@@ -237,23 +238,23 @@ end
     _has_bit(combined, ComplexF64) && _rewind_typed_pool!(pool.complexf64, d)
     _has_bit(combined, ComplexF32) && _rewind_typed_pool!(pool.complexf32, d)
     _has_bit(combined, Bool)       && _rewind_typed_pool!(pool.bool,       d)
-    # Float16: bit 7 is set by _mark_untracked! on first untracked touch (lazy first-touch).
-    # Also rewind when Float16 was a *tracked* type in the macro: _typed_checkpoint_with_lazy!
+    # Float16: bit 7 is set by _record_type_touch! on first untracked touch (lazy first-touch).
+    # Also rewind when Float16 was a *tracked* type in the macro: _typed_lazy_checkpoint!
     # calls checkpoint!(pool, Float16) which pushes a checkpoint at depth d, but _acquire_impl!
-    # (macro transform) bypasses _mark_untracked!, leaving bit 7 = 0.
+    # (macro transform) bypasses _record_type_touch!, leaving bit 7 = 0.
     # _tracked_mask_for_types(Float16) == 0 (since _fixed_slot_bit(Float16) == 0), so
     # tracked_mask carries no bit for Float16 either.
     # Solution: check _checkpoint_depths to detect "Float16 was checkpointed at this depth".
     if combined & _cuda_float16_bit() != 0 || @inbounds(pool.float16._checkpoint_depths[end]) == d
         _rewind_typed_pool!(pool.float16, d)
     end
-    if @inbounds(pool._untracked_has_others[d])
+    if @inbounds(pool._touched_has_others[d])
         for tp in values(pool.others)
             _rewind_typed_pool!(tp, d)
         end
     end
-    pop!(pool._untracked_fixed_masks)
-    pop!(pool._untracked_has_others)
+    pop!(pool._touched_type_masks)
+    pop!(pool._touched_has_others)
     pool._current_depth -= 1
     nothing
 end
@@ -275,10 +276,10 @@ function AdaptiveArrayPools.reset!(pool::CuAdaptiveArrayPool)
 
     # Reset depth and bitmask sentinel state
     pool._current_depth = 1
-    empty!(pool._untracked_fixed_masks)
-    push!(pool._untracked_fixed_masks, UInt16(0))   # Sentinel: no bits set
-    empty!(pool._untracked_has_others)
-    push!(pool._untracked_has_others, false)         # Sentinel: no others
+    empty!(pool._touched_type_masks)
+    push!(pool._touched_type_masks, UInt16(0))   # Sentinel: no bits set
+    empty!(pool._touched_has_others)
+    push!(pool._touched_has_others, false)         # Sentinel: no others
 
     return pool
 end
@@ -334,10 +335,10 @@ function Base.empty!(pool::CuAdaptiveArrayPool)
 
     # Reset depth and bitmask sentinel state
     pool._current_depth = 1
-    empty!(pool._untracked_fixed_masks)
-    push!(pool._untracked_fixed_masks, UInt16(0))   # Sentinel: no bits set
-    empty!(pool._untracked_has_others)
-    push!(pool._untracked_has_others, false)         # Sentinel: no others
+    empty!(pool._touched_type_masks)
+    push!(pool._touched_type_masks, UInt16(0))   # Sentinel: no bits set
+    empty!(pool._touched_has_others)
+    push!(pool._touched_has_others, false)         # Sentinel: no others
 
     return pool
 end
diff --git a/ext/AdaptiveArrayPoolsCUDAExt/types.jl b/ext/AdaptiveArrayPoolsCUDAExt/types.jl
index 056bd18..a3673f2 100644
--- a/ext/AdaptiveArrayPoolsCUDAExt/types.jl
+++ b/ext/AdaptiveArrayPoolsCUDAExt/types.jl
@@ -112,8 +112,8 @@ mutable struct CuAdaptiveArrayPool <: AbstractArrayPool
 
     # State management (same as CPU)
     _current_depth::Int
-    _untracked_fixed_masks::Vector{UInt16}  # Per-depth: which fixed slots had untracked acquires
-    _untracked_has_others::Vector{Bool}     # Per-depth: any non-fixed-slot untracked acquire?
+    _touched_type_masks::Vector{UInt16}  # Per-depth: which fixed slots were touched + mode flags
+    _touched_has_others::Vector{Bool}    # Per-depth: any non-fixed-slot type touched?
 
     # Device tracking (safety)
     device_id::Int
@@ -132,8 +132,8 @@ function CuAdaptiveArrayPool()
         CuTypedPool{Bool}(),
         IdDict{DataType, Any}(),
         1,              # _current_depth (1 = global scope)
-        [UInt16(0)],    # _untracked_fixed_masks: sentinel (no bits set)
-        [false],        # _untracked_has_others: sentinel (no others)
+        [UInt16(0)],    # _touched_type_masks: sentinel (no bits set)
+        [false],        # _touched_has_others: sentinel (no others)
         CUDA.deviceid(dev)  # Use public API
     )
 end

From 6ac4b23381352a4b0fd37fcccc177833be268c36 Mon Sep 17 00:00:00 2001
From: Min-Gu Yoo <mgyoo86@gmail.com>
Date: Wed, 18 Feb 2026 12:28:25 -0800
Subject: [PATCH 4/5] refactor(tests,docs): update all tests and docs for
 naming changes

- Update imports, function calls, field refs, and string assertions in tests
- Update architecture docs with new function names and diagrams
- Add naming_refactor_proposal.md as design record
---
 docs/design/naming_refactor_proposal.md  | 429 +++++++++++++++++++++++
 docs/src/architecture/macro-internals.md |  30 +-
 test/test_backend_macro_expansion.jl     |   4 +-
 test/test_macro_expansion.jl             |  42 +--
 test/test_macro_internals.jl             |  56 +--
 test/test_state.jl                       | 384 ++++++++++----------
 6 files changed, 687 insertions(+), 258 deletions(-)
 create mode 100644 docs/design/naming_refactor_proposal.md

diff --git a/docs/design/naming_refactor_proposal.md b/docs/design/naming_refactor_proposal.md
new file mode 100644
index 0000000..28085c6
--- /dev/null
+++ b/docs/design/naming_refactor_proposal.md
@@ -0,0 +1,429 @@
+# Naming & Refactoring Proposal: Post-Optimization Cleanup
+
+> **Status**: Brainstorm / RFC
+> **Context**: After Phase 3 (dynamic-selective) and Phase 5 (typed-fallback) optimizations,
+> many internal function names still reflect the original "untracked acquire detection" mental
+> model. This document proposes renaming to match the evolved architecture.
+
+---
+
+## 1. Current Architecture: Three Execution Modes
+
+The `@with_pool` macro generates one of three checkpoint/rewind strategies:
+
+| Mode | Checkpoint | Acquire | Rewind | When |
+|------|-----------|---------|--------|------|
+| **Typed** | `checkpoint!(pool, T...)` | `_acquire_impl!(pool, T, ...)` | `rewind!(pool, T...)` | All types statically known |
+| **Dynamic-Selective** | `_depth_only_checkpoint!(pool)` | `acquire!(pool, T, ...)` *(unchanged)* | `_dynamic_selective_rewind!(pool)` | Types only known at runtime |
+| **Full** (manual) | `checkpoint!(pool)` | `acquire!(pool, T, ...)` | `rewind!(pool)` | User calls manually |
+
+Additionally, the **Typed** mode has a runtime fallback:
+- If `_can_use_typed_path()` is false → `_typed_checkpoint_with_lazy!` + `_typed_selective_rewind!`
+
+---
+
+## 2. Naming Tensions
+
+### 2.1 `_mark_untracked!` — The Core Irony
+
+**Current name**: `_mark_untracked!`
+**What it does**: Records type usage in bitmask. Triggers lazy checkpoint on first touch.
+
+The word "untracked" is **doubly misleading**:
+1. The function **tracks** type usage (sets bitmask bits)
+2. The data it records is used to **selectively rewind** (the opposite of "untracked")
+
+The original semantics: "mark that this acquire happened in a path the macro doesn't track."
+The actual semantics now: "record that type T was touched at this depth, and lazily checkpoint if needed."
+
+#### Candidates
+
+| Candidate | Pros | Cons |
+|-----------|------|------|
+| `_record_type_touch!` | "touch" captures first-touch/lazy-checkpoint semantics; action-oriented | Doesn't convey the bitmask mechanism |
+| `_track_type_usage!` | Most literal description of what happens | "track" is overloaded (macro "tracks" types too) |
+| `_notify_acquire!` | Observer-pattern feel; captures side-effect (lazy checkpoint) | Too generic; doesn't convey type-specificity |
+| `_register_type!` | Clean, idiomatic ("register X in a registry") | Doesn't convey the "at this depth" scoping |
+| `_touch_type!` | Shortest; "touch" is a Unix/DB idiom for "first access triggers action" | Might be too terse for complex semantics |
+| `_mark_type_used!` | Simple and accurate | Still has "mark" which is vague |
+
+### 2.2 `_acquire_impl!` — The "Fast Path" Naming
+
+**Current name**: `_acquire_impl!`
+**What it does**: Core acquire logic without type tracking. Called by macro-transformed code.
+
+The `_impl!` suffix is conventional but **non-descriptive**. It doesn't convey *why* this variant
+exists (to skip tracking overhead when the macro already knows the types).
+
+#### Candidates
+
+| Candidate | Pros | Cons |
+|-----------|------|------|
+| `_acquire_direct!` | "direct" = no intermediary tracking step | Might imply "direct memory access" |
+| `_acquire_bare!` | "bare" = stripped of wrapper logic | Non-standard terminology |
+| `_acquire_core!` | "core" = the essential operation | Generic; doesn't explain *why* it's separate |
+| `_acquire_scoped!` | "scoped" = macro already manages this scope | Misleading — the function itself isn't scoped |
+| Keep `_acquire_impl!` | Well-understood `_impl` convention in Julia | Doesn't explain the tracking bypass |
+
+### 2.3 `_untracked_fixed_masks` / `_untracked_has_others` — Field Names
+
+**Current names**: Pool fields storing per-depth bitmask data.
+**What they store**: Which types were acquired at each depth (for selective rewind).
+
+These fields are the **runtime type tracking** data structure, yet named "untracked."
+
+#### Candidates
+
+| Candidate | Pros | Cons |
+|-----------|------|------|
+| `_touched_fixed_masks` / `_touched_has_others` | "touched" matches first-touch semantics | Might confuse with "dirty" bit patterns |
+| `_used_fixed_masks` / `_used_has_others` | Simplest, most literal | Too generic |
+| `_acquired_fixed_masks` / `_acquired_has_others` | Directly describes the event (acquire happened) | Slightly long |
+| `_runtime_fixed_masks` / `_runtime_has_others` | Contrasts with "compile-time" tracked types | Doesn't describe *what* is tracked |
+| Keep current names | Consistency with existing code, comments, tests | Perpetuates the "untracked" confusion |
+
+### 2.4 Mode-Specific Functions — Consistency
+
+The three modes don't follow a consistent naming pattern:
+
+```
+Typed:             checkpoint!(pool, T...)     / rewind!(pool, T...)
+  + fallback:      _typed_checkpoint_with_lazy!(pool, T...) / _typed_selective_rewind!(pool, mask)
+Dynamic-Selective: _depth_only_checkpoint!(pool) / _dynamic_selective_rewind!(pool)
+Full:              checkpoint!(pool)           / rewind!(pool)
+```
+
+**Observation**: The "typed" fallback functions have long compound names that mix the *mode*
+(`typed`) with the *mechanism* (`with_lazy`, `selective`).
+
+#### Possible Consistent Scheme
+
+Option A — Mode prefix:
+```
+_typed_checkpoint!          → checkpoint!(pool, T...)    (already clean)
+_typed_lazy_checkpoint!     → _typed_checkpoint_with_lazy!(pool, T...)
+_typed_selective_rewind!    → _typed_selective_rewind!(pool, mask)  (already clean)
+_dynamic_checkpoint!        → _depth_only_checkpoint!(pool)
+_dynamic_rewind!            → _dynamic_selective_rewind!(pool)
+```
+
+Option B — Mechanism suffix:
+```
+_checkpoint_typed!          (checkpoint the typed pools)
+_checkpoint_lazy!           (checkpoint with lazy first-touch)
+_checkpoint_depth_only!     (only increment depth)
+_rewind_typed!              (rewind typed pools)
+_rewind_selective!          (rewind based on bitmask)
+_rewind_dynamic!            (dynamic bitmask rewind)
+```
+
+---
+
+## 3. Holistic Renaming Proposals
+
+### Proposal A: "Touch" Metaphor (First-Touch Semantics)
+
+The architecture's key insight is **first-touch tracking**: when a type is first used at a depth,
+it gets recorded (and lazily checkpointed). The "touch" metaphor captures this cleanly.
+
+```
+# Type tracking
+_mark_untracked!(pool, T)        → _touch_type!(pool, T)
+
+# Pool fields
+_untracked_fixed_masks           → _touched_fixed_masks
+_untracked_has_others            → _touched_has_others
+
+# Acquire internals (keep _impl convention)
+_acquire_impl!(pool, T, n)      → (keep as is, or _acquire_core!)
+_unsafe_acquire_impl!(...)      → (keep as is, or _unsafe_acquire_core!)
+
+# Dynamic mode (rename for symmetry)
+_depth_only_checkpoint!(pool)    → _lazy_checkpoint!(pool)       # "lazy" = defers to first touch
+_dynamic_selective_rewind!(pool) → _lazy_rewind!(pool)           # symmetric with checkpoint
+
+# Typed fallback (simplify)
+_typed_checkpoint_with_lazy!     → _typed_lazy_checkpoint!       # adjective before noun
+_typed_selective_rewind!         → _typed_lazy_rewind!           # symmetric pair
+
+# Macro generators (follow function names)
+_generate_dynamic_selective_checkpoint_call → _generate_lazy_checkpoint_call
+_generate_dynamic_selective_rewind_call    → _generate_lazy_rewind_call
+
+# Guards
+_can_use_typed_path              → (keep as is — already clear)
+_tracked_mask_for_types          → (keep as is — already clear)
+```
+
+**Pros**: Concise, consistent metaphor, captures the core mechanism.
+**Cons**: "lazy" is overloaded in CS (lazy evaluation, lazy initialization).
+
+### Proposal B: "Record/Direct" Pair (Action-Based)
+
+Focus on what each function *does* as an action:
+
+```
+# Type tracking
+_mark_untracked!(pool, T)        → _record_type_touch!(pool, T)
+
+# Pool fields
+_untracked_fixed_masks           → _acquired_type_masks
+_untracked_has_others            → _acquired_has_others
+
+# Acquire internals
+_acquire_impl!(pool, T, n)      → _acquire_direct!(pool, T, n)     # "direct" = no recording
+_unsafe_acquire_impl!(...)      → _unsafe_acquire_direct!(...)
+
+# All convenience _impl! follow:
+_zeros_impl!                     → _zeros_direct!
+_ones_impl!                      → _ones_direct!
+_similar_impl!                   → _similar_direct!
+
+# Dynamic mode
+_depth_only_checkpoint!(pool)    → _deferred_checkpoint!(pool)       # "deferred" = save later
+_dynamic_selective_rewind!(pool) → _deferred_selective_rewind!(pool) # rewind what was deferred
+
+# Typed fallback
+_typed_checkpoint_with_lazy!     → _typed_deferred_checkpoint!       # typed + deferred for extras
+_typed_selective_rewind!         → (keep — already descriptive)
+
+# Macro generators
+_generate_dynamic_selective_*    → _generate_deferred_*
+```
+
+**Pros**: Very descriptive, each name tells you exactly what happens.
+**Cons**: Longer names, "deferred" is less intuitive than "lazy."
+
+### Proposal C: "Scope" Metaphor (Inside/Outside Macro Scope)
+
+Frame the naming around the key architectural distinction: code inside `@with_pool` scope
+(macro-managed) vs outside (self-tracking):
+
+```
+# Type tracking — called from "outside scope" or "dynamic scope"
+_mark_untracked!(pool, T)        → _track_type!(pool, T)
+
+# Pool fields
+_untracked_fixed_masks           → _scope_type_masks      # per-scope tracking
+_untracked_has_others            → _scope_has_others
+
+# Acquire internals — used by "in-scope" (macro-managed) code
+_acquire_impl!(pool, T, n)      → _scoped_acquire!(pool, T, n)   # "scoped" = macro handles tracking
+_unsafe_acquire_impl!(...)      → _scoped_unsafe_acquire!(...)
+
+# Dynamic mode
+_depth_only_checkpoint!(pool)    → _open_scope!(pool)              # "open" a new tracking scope
+_dynamic_selective_rewind!(pool) → _close_scope!(pool)             # "close" and rewind the scope
+
+# Typed fallback
+_typed_checkpoint_with_lazy!     → _open_typed_scope_with_fallback!
+_typed_selective_rewind!         → _close_typed_scope_with_fallback!
+
+# Guards
+_can_use_typed_path              → _scope_is_typed_only
+```
+
+**Pros**: Captures the architectural mental model cleanly.
+**Cons**: "scope" semantics might clash with Julia's lexical scoping concepts.
+
+### Proposal D: Minimal Rename (Conservative)
+
+Only rename the most confusing items, keep everything else:
+
+```
+# The one truly misleading name:
+_mark_untracked!(pool, T)        → _record_type_touch!(pool, T)
+
+# The confusing fields:
+_untracked_fixed_masks           → _touched_type_masks
+_untracked_has_others            → _touched_has_others
+
+# Everything else stays as-is
+_acquire_impl!                   → (keep)
+_depth_only_checkpoint!          → (keep)
+_dynamic_selective_rewind!       → (keep)
+_typed_checkpoint_with_lazy!     → (keep)
+_typed_selective_rewind!         → (keep)
+```
+
+**Pros**: Minimal churn, only fixes the genuinely confusing names.
+**Cons**: Misses the opportunity for holistic consistency.
+
+---
+
+## 4. Cross-Cutting Concerns
+
+### 4.1 Public API — Should NOT Change
+
+These are stable public APIs and should **never** be renamed:
+- `acquire!`, `unsafe_acquire!`, `acquire_view!`, `acquire_array!`
+- `checkpoint!`, `rewind!`, `reset!`, `empty!`
+- `zeros!`, `ones!`, `trues!`, `falses!`, `similar!`
+- `@with_pool`, `@maybe_with_pool`
+- `get_task_local_pool`
+
+### 4.2 CUDA Extension Parity
+
+Any rename must be mirrored in:
+- `ext/AdaptiveArrayPoolsCUDAExt/types.jl`
+- `ext/AdaptiveArrayPoolsCUDAExt/state.jl`
+- `ext/AdaptiveArrayPoolsCUDAExt/acquire.jl`
+
+### 4.3 Test Impact
+
+Renaming internal functions affects:
+- `test/test_macro_internals.jl` (directly calls `_depth_only_checkpoint!`, `_dynamic_selective_rewind!`, etc.)
+- `test/test_state.jl` (checkpoint/rewind tests)
+- `test/test_macroexpand.jl` (checks expanded code contains specific function names)
+- Any benchmarks referencing internal functions
+
+### 4.4 `Bit` 15 / Bit 14 Constants
+
+Currently the mode flags are raw hex literals (`0x8000`, `0x4000`). A related cleanup:
+```julia
+const _DYNAMIC_MODE_BIT   = UInt16(0x8000)  # bit 15
+const _LAZY_MODE_BIT      = UInt16(0x4000)  # bit 14
+const _MODE_BITS_MASK     = UInt16(0xC000)  # bits 14-15
+const _TYPE_BITS_MASK     = UInt16(0x00FF)  # bits 0-7
+```
+
+These constants would replace scattered magic numbers throughout `state.jl` and `acquire.jl`.
+
+### 4.5 The `_impl!` Convention — Keep or Replace?
+
+The `_impl!` suffix is a **widely understood Julia convention** (e.g., `Base._similar_impl`).
+Replacing it with `_direct!`, `_core!`, or `_scoped!` trades familiarity for specificity.
+
+Arguments for keeping `_impl!`:
+- Julia developers immediately understand it as "internal implementation"
+- No ambiguity about the function's role as a building block
+- Grep-friendly: `_*_impl!` finds all implementation functions
+
+Arguments for replacing:
+- `_impl!` doesn't explain *why* the split exists (tracking bypass)
+- New developers might not realize the critical difference between `acquire!` and `_acquire_impl!`
+
+---
+
+## 5. Recommended Changes (for Discussion)
+
+### Tier 1: High Impact, Low Risk (Do First)
+
+| Current | Proposed | Rationale |
+|---------|----------|-----------|
+| `_mark_untracked!` | `_record_type_touch!` | Most misleading name; "touch" captures first-touch + lazy checkpoint |
+| `_untracked_fixed_masks` | `_touched_type_masks` | Field stores which types were *touched*, not which are "untracked" |
+| `_untracked_has_others` | `_touched_has_others` | Consistent with above |
+
+### Tier 2: Medium Impact, Medium Risk
+
+| Current | Proposed | Rationale |
+|---------|----------|-----------|
+| `_depth_only_checkpoint!` | `_lazy_checkpoint!` | "lazy" captures the deferred-to-first-touch semantics |
+| `_dynamic_selective_rewind!` | `_lazy_rewind!` | Symmetric with `_lazy_checkpoint!` |
+| `_typed_checkpoint_with_lazy!` | `_typed_lazy_checkpoint!` | Cleaner word order |
+| Magic numbers `0x8000`, `0x4000`, `0xC000`, `0x00FF` | Named constants (see 4.4) | Self-documenting code |
+
+### Tier 3: Low Impact, Higher Risk (Optional)
+
+| Current | Proposed | Rationale |
+|---------|----------|-----------|
+| `_acquire_impl!` | Keep as `_acquire_impl!` | Julia convention, well-understood |
+| `_generate_dynamic_selective_*` | `_generate_lazy_*` | Follows Tier 2 rename |
+| `_typed_selective_rewind!` | `_typed_lazy_rewind!` | Consistent with pair |
+
+---
+
+## 6. Alternative: Do Nothing
+
+**Case for not renaming**: The current names work. They're documented. Tests pass.
+"Untracked" has a clear historical meaning in the codebase, and commit history explains
+the evolution. Renaming has a nonzero risk of introducing bugs (missed references,
+CUDA extension drift) and makes git blame harder to follow.
+
+**Counter-argument**: The package is pre-1.0 and has few external users. Now is the
+cheapest time to fix naming before the API surface solidifies.
+
+---
+
+## 7. Open Questions
+
+1. **Should `_impl!` functions be renamed?** They work fine as a convention, but
+   `_acquire_direct!` or `_acquire_core!` would be more self-documenting.
+
+2. **Is "lazy" the right word?** In Julia, `lazy` is associated with `Lazy.jl` and
+   lazy evaluation. "Deferred" is more precise but longer.
+
+3. **Should mode names be formalized?** Currently modes are described in comments
+   as "typed", "dynamic-selective", "full". Should there be an enum or named constants?
+
+4. **How deep should the rename go?** Renaming `_mark_untracked!` alone fixes 80%
+   of the confusion. Is a holistic rename worth the churn?
+
+5. **Should the bitmask `_touched_type_masks` also track mode bits?** Currently
+   bits 0-7 = types, bits 14-15 = mode flags, all in the same field. Should mode
+   flags be a separate field for clarity?
+
+---
+
+## Appendix: Complete Current → Proposed Mapping (Proposal A: "Touch/Lazy")
+
+```
+# === Type Tracking ===
+_mark_untracked!(pool, T)                    → _record_type_touch!(pool, T)
+
+# === Pool Fields ===
+_untracked_fixed_masks                       → _touched_type_masks
+_untracked_has_others                        → _touched_has_others
+
+# === Acquire (keep _impl convention) ===
+_acquire_impl!(pool, T, n)                   → (no change)
+_unsafe_acquire_impl!(pool, T, n)            → (no change)
+_zeros_impl!(pool, T, dims...)               → (no change)
+_ones_impl!(pool, T, dims...)                → (no change)
+_similar_impl!(pool, T, dims...)             → (no change)
+
+# === Dynamic-Selective Mode ===
+_depth_only_checkpoint!(pool)                → _lazy_checkpoint!(pool)
+_dynamic_selective_rewind!(pool)             → _lazy_rewind!(pool)
+
+# === Typed Fallback ===
+_typed_checkpoint_with_lazy!(pool, T...)     → _typed_lazy_checkpoint!(pool, T...)
+_typed_selective_rewind!(pool, mask)         → _typed_lazy_rewind!(pool, mask)
+
+# === Selective Rewind Helper ===
+_selective_rewind_fixed_slots!(pool, mask)   → (no change — already descriptive)
+
+# === Guards ===
+_can_use_typed_path(pool, mask)              → (no change)
+_tracked_mask_for_types(T...)                → (no change)
+
+# === Macro Generators ===
+_generate_dynamic_selective_checkpoint_call  → _generate_lazy_checkpoint_call
+_generate_dynamic_selective_rewind_call      → _generate_lazy_rewind_call
+_generate_typed_checkpoint_call              → (no change)
+_generate_typed_rewind_call                  → (no change)
+
+# === Constants (new) ===
+(raw 0x8000)                                 → _LAZY_MODE_BIT (or _DYNAMIC_MODE_BIT)
+(raw 0x4000)                                 → _TYPED_LAZY_BIT
+(raw 0xC000)                                 → _MODE_BITS_MASK
+(raw 0x00FF)                                 → _TYPE_BITS_MASK
+```
+
+### Files Affected
+
+| File | Changes |
+|------|---------|
+| `src/types.jl` | Field renames: `_untracked_*` → `_touched_*` |
+| `src/acquire.jl` | `_mark_untracked!` → `_record_type_touch!` |
+| `src/state.jl` | Mode functions, field references, constants |
+| `src/macros.jl` | Generator function renames, field references |
+| `src/convenience.jl` | `_mark_untracked!` calls |
+| `src/task_local_pool.jl` | (unlikely changes) |
+| `src/utils.jl` | (unlikely changes) |
+| `ext/AdaptiveArrayPoolsCUDAExt/*.jl` | Mirror all renames |
+| `test/test_macro_internals.jl` | Direct calls to renamed functions |
+| `test/test_state.jl` | Field references |
+| `test/test_macroexpand.jl` | String matching on expanded names |
+| `test/test_allocation.jl` | (unlikely changes) |
diff --git a/docs/src/architecture/macro-internals.md b/docs/src/architecture/macro-internals.md
index 4c2c920..d983237 100644
--- a/docs/src/architecture/macro-internals.md
+++ b/docs/src/architecture/macro-internals.md
@@ -115,24 +115,24 @@ end
 # If only checkpoint!(pool, Int64), Float64 arrays won't be rewound!
 ```
 
-### The Solution: Bitmask-Based Untracked Tracking
+### The Solution: Bitmask-Based Type Touch Tracking
 
-Every `acquire!` call (and convenience functions) marks itself as "untracked" with type-specific bitmask information:
+Every `acquire!` call (and convenience functions) records the type touch with type-specific bitmask information:
 
 ```julia
 # Public API (called from user code outside macro)
 @inline function acquire!(pool, ::Type{T}, n::Int) where {T}
-    _mark_untracked!(pool, T)           # ← Sets type-specific bitmask!
+    _record_type_touch!(pool, T)         # ← Records type-specific bitmask!
     _acquire_impl!(pool, T, n)
 end
 
-# Macro-transformed calls skip the marking
+# Macro-transformed calls skip the recording
 # (because macro already knows about them)
-_acquire_impl!(pool, T, n)               # ← No marking
+_acquire_impl!(pool, T, n)               # ← No recording
 ```
 
 Each fixed-slot type maps to a bit in a `UInt16` bitmask via `_fixed_slot_bit(T)`.
-Non-fixed-slot types set a separate `_untracked_has_others` flag.
+Non-fixed-slot types set a separate `_touched_has_others` flag.
 
 ### Flow Diagram
 
@@ -144,7 +144,7 @@ Non-fixed-slot types set a separate `_untracked_has_others` flag.
     │   A = _acquire_impl!(...)          (macro-transformed, no mark)
     │   B = helper!(pool)
     │       └─► zeros!(pool, Float64, N)
-    │           └─► _mark_untracked!(pool, Float64)
+    │           └─► _record_type_touch!(pool, Float64)
     │               masks[2] |= 0x0001 (Float64 bit) ←───┐
     │                                                      │
     │   ... more code ...                                  │
@@ -161,9 +161,9 @@ end
 
 ### Why This Works
 
-1. **Macro-tracked calls**: Transformed to `_acquire_impl!` → no bitmask mark → typed path
-2. **Untracked calls**: Use public API → sets type-specific bitmask → subset check at rewind
-3. **Subset optimization**: If untracked types are a subset of tracked types, the typed path is still safe
+1. **Macro-tracked calls**: Transformed to `_acquire_impl!` → no bitmask touch → typed path
+2. **External calls**: Use public API → records type-specific bitmask → subset check at rewind
+3. **Subset optimization**: If touched types are a subset of tracked types, the typed path is still safe
 4. **Result**: Always safe, with finer-grained optimization than a single boolean flag
 
 ## Nested `@with_pool` Handling
@@ -191,14 +191,14 @@ end                                      depth: 2 → 1, bitmask checked
 struct AdaptiveArrayPool
     # ... type pools ...
     _current_depth::Int                     # Current scope depth (1 = global)
-    _untracked_fixed_masks::Vector{UInt16}  # Per-depth: which fixed slots untracked
-    _untracked_has_others::Vector{Bool}     # Per-depth: any non-fixed-slot untracked
+    _touched_type_masks::Vector{UInt16}     # Per-depth: which fixed slots were touched
+    _touched_has_others::Vector{Bool}       # Per-depth: any non-fixed-slot type touched
 end
 
 # Initialized with sentinel:
 _current_depth = 1                          # Global scope
-_untracked_fixed_masks = [UInt16(0)]        # Sentinel for depth=1
-_untracked_has_others = [false]             # Sentinel for depth=1
+_touched_type_masks = [UInt16(0)]           # Sentinel for depth=1
+_touched_has_others = [false]               # Sentinel for depth=1
 ```
 
 ## Performance Impact
@@ -256,7 +256,7 @@ end
 | `_extract_acquire_types(expr, pool_name)` | AST walk to find types |
 | `_filter_static_types(types, local_vars)` | Filter out locally-defined types |
 | `_transform_acquire_calls(expr, pool_name)` | Replace `acquire!` → `_acquire_impl!` |
-| `_mark_untracked!(pool, T)` | Set type-specific bitmask for current depth |
+| `_record_type_touch!(pool, T)` | Record type touch in bitmask for current depth |
 | `_can_use_typed_path(pool, mask)` | Bitmask subset check for typed vs full path |
 | `_tracked_mask_for_types(T...)` | Compile-time bitmask for tracked types |
 | `_generate_typed_checkpoint_call(pool, types)` | Generate bitmask-aware checkpoint |
diff --git a/test/test_backend_macro_expansion.jl b/test/test_backend_macro_expansion.jl
index f6bd192..9721cb0 100644
--- a/test/test_backend_macro_expansion.jl
+++ b/test/test_backend_macro_expansion.jl
@@ -58,8 +58,8 @@
             @test occursin("_get_pool_for_backend", expr_str)
             @test occursin("Val{:cuda}", expr_str)
             # Empty body → use_typed=false → dynamic selective mode
-            @test occursin("_depth_only_checkpoint!", expr_str)
-            @test occursin("_dynamic_selective_rewind!", expr_str)
+            @test occursin("_lazy_checkpoint!", expr_str)
+            @test occursin("_lazy_rewind!", expr_str)
         end
 
         @testset "Type extraction" begin
diff --git a/test/test_macro_expansion.jl b/test/test_macro_expansion.jl
index dd8ef8a..91cdc33 100644
--- a/test/test_macro_expansion.jl
+++ b/test/test_macro_expansion.jl
@@ -102,8 +102,8 @@
             # Should still have pool management (with gensym name).
             # Empty body → no acquire types → use_typed=false → dynamic selective mode.
             @test occursin("get_task_local_pool", expr_str)
-            @test occursin("_depth_only_checkpoint!", expr_str)
-            @test occursin("_dynamic_selective_rewind!", expr_str)
+            @test occursin("_lazy_checkpoint!", expr_str)
+            @test occursin("_lazy_rewind!", expr_str)
         end
 
         # Test @maybe_with_pool 1-arg
@@ -149,9 +149,9 @@
             expr_str = string(expr)
 
             # local_arr is detected as local → falls back to dynamic selective mode.
-            # Checkpoint is lightweight (_depth_only_checkpoint!), rewind is selective.
-            @test occursin("_depth_only_checkpoint!", expr_str)
-            @test occursin("_dynamic_selective_rewind!", expr_str)
+            # Checkpoint is lightweight (_lazy_checkpoint!), rewind is selective.
+            @test occursin("_lazy_checkpoint!", expr_str)
+            @test occursin("_lazy_rewind!", expr_str)
             # In dynamic mode acquire! is NOT transformed to _acquire_impl!
             @test !occursin("_acquire_impl!", expr_str)
         end
@@ -789,9 +789,9 @@ end
 
 @testset "Dynamic selective mode: macro expansion" begin
 
-    @testset "use_typed=false generates _depth_only_checkpoint! (dynamic selective)" begin
+    @testset "use_typed=false generates _lazy_checkpoint! (dynamic selective)" begin
         # Phase 3: when the macro cannot extract static types (local var), it uses
-        # _depth_only_checkpoint! instead of a full checkpoint of all 8 slots.
+        # _lazy_checkpoint! instead of a full checkpoint of all 8 slots.
         expr = @macroexpand @with_pool pool begin
             local_arr = rand(10)
             v = acquire!(pool, local_arr)  # eltype(local_arr) is dynamic → use_typed=false
@@ -801,13 +801,13 @@ end
         expr_str = string(expr)
 
         # Phase 3 behavior: depth-only checkpoint, selective rewind
-        @test occursin("_depth_only_checkpoint!", expr_str)
+        @test occursin("_lazy_checkpoint!", expr_str)
         @test !occursin("_can_use_typed_path", expr_str)       # only in typed path
     end
 
     @testset "use_typed=false does NOT transform acquire! → _acquire_impl! (dynamic mode)" begin
         # Phase 3: _transform_acquire_calls is skipped for dynamic-selective mode.
-        # acquire! stays as-is so _mark_untracked! is called and the selective rewind
+        # acquire! stays as-is so _record_type_touch! is called and the selective rewind
         # can see which types were actually touched.
         expr = @macroexpand @with_pool pool begin
             local_arr = rand(10)
@@ -838,8 +838,8 @@ end
     # RED tests: desired macro behavior after Phase 3.
     # ——————————————————————————————————————————————————————————————
 
-    @testset "GREEN: use_typed=false uses _depth_only_checkpoint!" begin
-        # Phase 3 complete: dynamic path emits _depth_only_checkpoint! instead of
+    @testset "GREEN: use_typed=false uses _lazy_checkpoint!" begin
+        # Phase 3 complete: dynamic path emits _lazy_checkpoint! instead of
         # the full checkpoint!(pool). This avoids the ~540ns full checkpoint cost.
         expr = @macroexpand @with_pool pool begin
             local_arr = rand(10)
@@ -849,13 +849,13 @@ end
 
         expr_str = string(expr)
 
-        @test occursin("_depth_only_checkpoint!", expr_str)
+        @test occursin("_lazy_checkpoint!", expr_str)
         # Full (eager) checkpoint must NOT appear; depth-only is the entry point
         @test !occursin("AdaptiveArrayPools.checkpoint!", expr_str)
     end
 
-    @testset "GREEN: use_typed=false uses _dynamic_selective_rewind!" begin
-        # Phase 3 complete: dynamic rewind path uses _dynamic_selective_rewind!,
+    @testset "GREEN: use_typed=false uses _lazy_rewind!" begin
+        # Phase 3 complete: dynamic rewind path uses _lazy_rewind!,
         # which selectively rewinds only typed pools that were actually touched.
         expr = @macroexpand @with_pool pool begin
             local_arr = rand(10)
@@ -865,7 +865,7 @@ end
 
         expr_str = string(expr)
 
-        @test occursin("_dynamic_selective_rewind!", expr_str)
+        @test occursin("_lazy_rewind!", expr_str)
         # Full rewind must NOT appear; selective rewind is the only rewind call
         @test !occursin("AdaptiveArrayPools.rewind!", expr_str)
     end
@@ -874,9 +874,9 @@ end
     # Phase 5: Typed-Fallback Optimization expansion tests (RED)
     # =========================================================================
 
-    @testset "Phase 5: use_typed=true false-branch emits _typed_checkpoint_with_lazy!" begin
+    @testset "Phase 5: use_typed=true false-branch emits _typed_lazy_checkpoint!" begin
         # After Phase 5: when _can_use_typed_path=false at runtime, the checkpoint
-        # side calls _typed_checkpoint_with_lazy! instead of full checkpoint!(pool).
+        # side calls _typed_lazy_checkpoint! instead of full checkpoint!(pool).
         expr = @macroexpand @with_pool pool begin
             v = acquire!(pool, Float64, 10)  # static type Float64 → use_typed=true
             v .= 1.0
@@ -884,13 +884,13 @@ end
         expr_str = string(expr)
 
         # Phase 5: else-branch uses lazy checkpoint
-        @test occursin("_typed_checkpoint_with_lazy!", expr_str)
+        @test occursin("_typed_lazy_checkpoint!", expr_str)
         # Full no-arg checkpoint!(pool) must NOT appear
         @test !occursin("AdaptiveArrayPools.checkpoint!(pool)", expr_str)
     end
 
-    @testset "Phase 5: use_typed=true false-branch emits _typed_selective_rewind!" begin
-        # After Phase 5: the rewind else-branch uses _typed_selective_rewind! instead of full rewind!(pool).
+    @testset "Phase 5: use_typed=true false-branch emits _typed_lazy_rewind!" begin
+        # After Phase 5: the rewind else-branch uses _typed_lazy_rewind! instead of full rewind!(pool).
         expr = @macroexpand @with_pool pool begin
             v = acquire!(pool, Float64, 10)
             v .= 1.0
@@ -898,7 +898,7 @@ end
         expr_str = string(expr)
 
         # Phase 5: else-branch uses selective rewind
-        @test occursin("_typed_selective_rewind!", expr_str)
+        @test occursin("_typed_lazy_rewind!", expr_str)
         # Full no-arg rewind!(pool) must NOT appear
         @test !occursin("AdaptiveArrayPools.rewind!(pool)", expr_str)
     end
diff --git a/test/test_macro_internals.jl b/test/test_macro_internals.jl
index e0ccf7b..ca3faeb 100644
--- a/test/test_macro_internals.jl
+++ b/test/test_macro_internals.jl
@@ -6,8 +6,8 @@
 # to ensure correct type extraction and filtering for optimized checkpoint/rewind.
 
 import AdaptiveArrayPools: _extract_local_assignments, _filter_static_types, _extract_acquire_types, _uses_local_var
-import AdaptiveArrayPools: _depth_only_checkpoint!, _dynamic_selective_rewind!
-import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind!, _tracked_mask_for_types
+import AdaptiveArrayPools: _lazy_checkpoint!, _lazy_rewind!
+import AdaptiveArrayPools: _typed_lazy_checkpoint!, _typed_lazy_rewind!, _tracked_mask_for_types
 
 @testset "Macro Internals" begin
 
@@ -1420,9 +1420,9 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
     # ==========================================================================
     # Dynamic selective mode: runtime correctness
-    # Phase 3: ensure n_active == 0 after _dynamic_selective_rewind! exits scope.
+    # Phase 3: ensure n_active == 0 after _lazy_rewind! exits scope.
     #
-    # NOTE: Uses _depth_only_checkpoint! + _dynamic_selective_rewind! directly
+    # NOTE: Uses _lazy_checkpoint! + _lazy_rewind! directly
     # with explicit fresh AdaptiveArrayPool() instances to avoid task-local pool
     # contamination from other tests. This mirrors what the macro generates for
     # the use_typed=false path, testing the state layer in isolation.
@@ -1432,49 +1432,49 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         @testset "Single type (Float64): n_active restored after dynamic scope" begin
             # Simulates: @with_pool pool begin; v = acquire!(pool, eltype(arr), 10); end
-            # where arr is a local var → macro emits _depth_only_checkpoint! +
-            # _dynamic_selective_rewind! (no _acquire_impl! transformation).
+            # where arr is a local var → macro emits _lazy_checkpoint! +
+            # _lazy_rewind! (no _acquire_impl! transformation).
             pool = AdaptiveArrayPool()
             local_arr = rand(Float64, 10)
-            _depth_only_checkpoint!(pool)
+            _lazy_checkpoint!(pool)
             try
-                v = acquire!(pool, eltype(local_arr), 10)  # _mark_untracked!(pool, Float64)
+                v = acquire!(pool, eltype(local_arr), 10)  # _record_type_touch!(pool, Float64)
                 v .= 1.0
                 @test pool.float64.n_active == 1
             finally
-                _dynamic_selective_rewind!(pool)
+                _lazy_rewind!(pool)
             end
             @test pool.float64.n_active == 0
         end
 
         @testset "similar!(pool, Float32 ref): n_active restored after dynamic scope" begin
-            # similar! calls _mark_untracked!(pool, eltype(ref)) directly, so the
+            # similar! calls _record_type_touch!(pool, eltype(ref)) directly, so the
             # dynamic selective rewind sees the type even without acquire! wrapping.
             pool = AdaptiveArrayPool()
             ref = rand(Float32, 5, 5)
-            _depth_only_checkpoint!(pool)
+            _lazy_checkpoint!(pool)
             try
-                m = similar!(pool, ref)  # _mark_untracked!(pool, Float32) + _acquire_impl!
+                m = similar!(pool, ref)  # _record_type_touch!(pool, Float32) + _acquire_impl!
                 m .= 0.0f0
                 @test pool.float32.n_active == 1
             finally
-                _dynamic_selective_rewind!(pool)
+                _lazy_rewind!(pool)
             end
             @test pool.float32.n_active == 0
         end
 
         @testset "Mixed types (Float64 + Float32): both n_active restored" begin
             # Simulates dynamic-mode block with two types: macro does NOT transform
-            # acquire! calls, so _mark_untracked! is called for each type via acquire!.
+            # acquire! calls, so _record_type_touch! is called for each type via acquire!.
             pool = AdaptiveArrayPool()
             local_arr = rand(Float32, 8)
-            _depth_only_checkpoint!(pool)
+            _lazy_checkpoint!(pool)
             try
-                v1 = acquire!(pool, Float64, 10)           # _mark_untracked!(pool, Float64)
-                v2 = acquire!(pool, eltype(local_arr), 8)  # _mark_untracked!(pool, Float32)
+                v1 = acquire!(pool, Float64, 10)           # _record_type_touch!(pool, Float64)
+                v2 = acquire!(pool, eltype(local_arr), 8)  # _record_type_touch!(pool, Float32)
                 v1 .= 0.0; v2 .= 0.0f0
             finally
-                _dynamic_selective_rewind!(pool)
+                _lazy_rewind!(pool)
             end
             @test pool.float64.n_active == 0
             @test pool.float32.n_active == 0
@@ -1484,26 +1484,26 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
             # Inner scope must only rewind its own depth entry, leaving the parent
             # scope's n_active intact until the outer scope calls its own rewind.
             pool = AdaptiveArrayPool()
-            _depth_only_checkpoint!(pool)                  # outer scope, depth 2
+            _lazy_checkpoint!(pool)                  # outer scope, depth 2
             try
                 outer_v = acquire!(pool, Float64, 10)      # lazy checkpoint for float64
                 outer_v .= 3.14
                 @test pool.float64.n_active == 1
 
-                _depth_only_checkpoint!(pool)              # inner scope, depth 3
+                _lazy_checkpoint!(pool)              # inner scope, depth 3
                 try
                     inner_v = acquire!(pool, Float64, 5)   # lazy checkpoint (first touch at depth 3)
                     inner_v .= 0.0
                     @test all(outer_v .== 3.14)            # parent array must survive
                     @test pool.float64.n_active == 2
                 finally
-                    _dynamic_selective_rewind!(pool)       # inner rewind: depth 3 → 2
+                    _lazy_rewind!(pool)       # inner rewind: depth 3 → 2
                 end
 
                 @test all(outer_v .== 3.14)                # outer_v survives inner rewind
                 @test pool.float64.n_active == 1           # only outer_v remains
             finally
-                _dynamic_selective_rewind!(pool)           # outer rewind: depth 2 → 1
+                _lazy_rewind!(pool)           # outer rewind: depth 2 → 1
             end
             @test pool.float64.n_active == 0
         end
@@ -1513,12 +1513,12 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
             # (NOT pool.bits, which is for BitArrays acquired via acquire!(pool, Bit, ...))
             pool = AdaptiveArrayPool()
             ref_bv = trues(64)  # BitVector, eltype = Bool
-            _depth_only_checkpoint!(pool)
+            _lazy_checkpoint!(pool)
             try
-                v = similar!(pool, ref_bv)   # _mark_untracked!(pool, Bool)
+                v = similar!(pool, ref_bv)   # _record_type_touch!(pool, Bool)
                 v .= false
             finally
-                _dynamic_selective_rewind!(pool)
+                _lazy_rewind!(pool)
             end
             @test pool.bool.n_active == 0
         end
@@ -1545,8 +1545,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         @test pool.int64.n_active == 1
 
         # Child scope: typed lazy checkpoint (Float64 tracked, but helper touches Int64)
-        # Simulates: _can_use_typed_path=false, macro emits _typed_checkpoint_with_lazy!
-        _typed_checkpoint_with_lazy!(pool, Float64)
+        # Simulates: _can_use_typed_path=false, macro emits _typed_lazy_checkpoint!
+        _typed_lazy_checkpoint!(pool, Float64)
         try
             child_float = acquire!(pool, Float64, 5)
             _phase5_extra_int64_helper!(pool)  # touches Int64 (untracked in child)
@@ -1554,7 +1554,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
             @test pool.float64.n_active >= 1
         finally
             tracked_mask = _tracked_mask_for_types(Float64)
-            _typed_selective_rewind!(pool, tracked_mask)
+            _typed_lazy_rewind!(pool, tracked_mask)
         end
 
         # Parent's Int64 must be intact (= 1)
diff --git a/test/test_state.jl b/test/test_state.jl
index d8f77fb..0b352ec 100644
--- a/test/test_state.jl
+++ b/test/test_state.jl
@@ -1,5 +1,5 @@
 # Phase 5 internal functions used in tests below
-import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind!, _tracked_mask_for_types
+import AdaptiveArrayPools: _typed_lazy_checkpoint!, _typed_lazy_rewind!, _tracked_mask_for_types
 
 @testset "State Management" begin
 
@@ -309,8 +309,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
             reset!(pool)
 
             @test pool._current_depth == 1
-            @test pool._untracked_fixed_masks == [UInt16(0)]
-            @test pool._untracked_has_others == [false]
+            @test pool._touched_type_masks == [UInt16(0)]
+            @test pool._touched_has_others == [false]
             @test pool.float64._checkpoint_n_active == [0]  # Sentinel only
             @test pool.float64._checkpoint_depths == [0]    # Sentinel only
         end
@@ -497,7 +497,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
             rewind!(pool)
             @test pool.float64.n_active == 0
             @test pool._current_depth == 1
-            @test pool._untracked_fixed_masks == [UInt16(0)]
+            @test pool._touched_type_masks == [UInt16(0)]
         end
 
         @testset "rewind! after reset!" begin
@@ -753,7 +753,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         v_parent = acquire!(pool, Int64, 10)
         v_parent .= 42  # Initialize
         @test pool.int64.n_active == 1
-        @test pool._untracked_fixed_masks[1] == AdaptiveArrayPools._fixed_slot_bit(Int64)
+        @test pool._touched_type_masks[1] == AdaptiveArrayPools._fixed_slot_bit(Int64)
 
         # Enter @with_pool - full checkpoint protects parent's Int64 arrays
         @with_pool pool begin
@@ -779,7 +779,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         v_parent = acquire!(pool, Int32, 7)
         v_parent .= Int32(123)
         @test pool.int32.n_active == 1
-        @test pool._untracked_fixed_masks[1] == AdaptiveArrayPools._fixed_slot_bit(Int32)
+        @test pool._touched_type_masks[1] == AdaptiveArrayPools._fixed_slot_bit(Int32)
 
         # Helper for Int32
         function int32_helper(p)
@@ -830,7 +830,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         pool = AdaptiveArrayPool()
 
         # No global untracked acquire
-        @test pool._untracked_fixed_masks[1] == UInt16(0)
+        @test pool._touched_type_masks[1] == UInt16(0)
 
         # Checkpoint/rewind with typed - should work normally
         checkpoint!(pool)
@@ -1005,7 +1005,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         @test pool.bool.n_active == 0
         @test pool.complexf64.n_active == 0
         @test pool._current_depth == 1
-        @test pool._untracked_fixed_masks == [UInt16(0)]
+        @test pool._touched_type_masks == [UInt16(0)]
 
         empty!(pool)
     end
@@ -1329,14 +1329,14 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         pool = AdaptiveArrayPool()
 
         # New fields exist
-        @test hasfield(AdaptiveArrayPool, :_untracked_fixed_masks)
-        @test hasfield(AdaptiveArrayPool, :_untracked_has_others)
+        @test hasfield(AdaptiveArrayPool, :_touched_type_masks)
+        @test hasfield(AdaptiveArrayPool, :_touched_has_others)
 
         # Sentinel values at depth=1 (global scope)
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
-        @test length(pool._untracked_fixed_masks) == 1
-        @test length(pool._untracked_has_others) == 1
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
+        @test length(pool._touched_type_masks) == 1
+        @test length(pool._touched_has_others) == 1
     end
 
     @testset "Bitmask metadata: checkpoint! pushes sentinels" begin
@@ -1344,15 +1344,15 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         # Full checkpoint
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 2
-        @test length(pool._untracked_has_others) == 2
-        @test pool._untracked_fixed_masks[2] == UInt16(0)
-        @test pool._untracked_has_others[2] == false
+        @test length(pool._touched_type_masks) == 2
+        @test length(pool._touched_has_others) == 2
+        @test pool._touched_type_masks[2] == UInt16(0)
+        @test pool._touched_has_others[2] == false
 
         # Another checkpoint
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 3
-        @test length(pool._untracked_has_others) == 3
+        @test length(pool._touched_type_masks) == 3
+        @test length(pool._touched_has_others) == 3
 
         # Cleanup
         rewind!(pool)
@@ -1364,18 +1364,18 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         # Single-type checkpoint
         checkpoint!(pool, Float64)
-        @test length(pool._untracked_fixed_masks) == 2
-        @test length(pool._untracked_has_others) == 2
-        @test pool._untracked_fixed_masks[2] == UInt16(0)
-        @test pool._untracked_has_others[2] == false
+        @test length(pool._touched_type_masks) == 2
+        @test length(pool._touched_has_others) == 2
+        @test pool._touched_type_masks[2] == UInt16(0)
+        @test pool._touched_has_others[2] == false
         rewind!(pool, Float64)
 
         # Multi-type checkpoint
         checkpoint!(pool, Float64, Float32)
-        @test length(pool._untracked_fixed_masks) == 2
-        @test length(pool._untracked_has_others) == 2
-        @test pool._untracked_fixed_masks[2] == UInt16(0)
-        @test pool._untracked_has_others[2] == false
+        @test length(pool._touched_type_masks) == 2
+        @test length(pool._touched_has_others) == 2
+        @test pool._touched_type_masks[2] == UInt16(0)
+        @test pool._touched_has_others[2] == false
         rewind!(pool, Float64, Float32)
     end
 
@@ -1383,33 +1383,33 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         pool = AdaptiveArrayPool()
 
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 2
-        @test length(pool._untracked_has_others) == 2
+        @test length(pool._touched_type_masks) == 2
+        @test length(pool._touched_has_others) == 2
 
         rewind!(pool)
-        @test length(pool._untracked_fixed_masks) == 1
-        @test length(pool._untracked_has_others) == 1
+        @test length(pool._touched_type_masks) == 1
+        @test length(pool._touched_has_others) == 1
         # Sentinel preserved
-        @test pool._untracked_fixed_masks[1] == UInt16(0)
-        @test pool._untracked_has_others[1] == false
+        @test pool._touched_type_masks[1] == UInt16(0)
+        @test pool._touched_has_others[1] == false
     end
 
     @testset "Bitmask metadata: typed rewind! pops" begin
         pool = AdaptiveArrayPool()
 
         checkpoint!(pool, Float64)
-        @test length(pool._untracked_fixed_masks) == 2
+        @test length(pool._touched_type_masks) == 2
 
         rewind!(pool, Float64)
-        @test length(pool._untracked_fixed_masks) == 1
-        @test length(pool._untracked_has_others) == 1
+        @test length(pool._touched_type_masks) == 1
+        @test length(pool._touched_has_others) == 1
 
         # Multi-type
         checkpoint!(pool, Float64, Int64)
-        @test length(pool._untracked_fixed_masks) == 2
+        @test length(pool._touched_type_masks) == 2
 
         rewind!(pool, Float64, Int64)
-        @test length(pool._untracked_fixed_masks) == 1
+        @test length(pool._touched_type_masks) == 1
     end
 
     @testset "Bitmask metadata: reset! restores sentinel" begin
@@ -1418,11 +1418,11 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         # Build up state
         checkpoint!(pool)
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 3
+        @test length(pool._touched_type_masks) == 3
 
         reset!(pool)
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
         @test pool._current_depth == 1
     end
 
@@ -1433,11 +1433,11 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         checkpoint!(pool)
         acquire!(pool, Float64, 10)
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 3
+        @test length(pool._touched_type_masks) == 3
 
         empty!(pool)
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
         @test pool._current_depth == 1
     end
 
@@ -1450,8 +1450,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         end
 
         # No stack leaks — should be back to sentinel only
-        @test length(pool._untracked_fixed_masks) == 1
-        @test length(pool._untracked_has_others) == 1
+        @test length(pool._touched_type_masks) == 1
+        @test length(pool._touched_has_others) == 1
         @test pool._current_depth == 1
     end
 
@@ -1460,25 +1460,25 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         # Depth 2
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 2
+        @test length(pool._touched_type_masks) == 2
 
         # Depth 3
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 3
+        @test length(pool._touched_type_masks) == 3
 
         # Depth 4
         checkpoint!(pool)
-        @test length(pool._untracked_fixed_masks) == 4
+        @test length(pool._touched_type_masks) == 4
 
         # Pop back
         rewind!(pool)
-        @test length(pool._untracked_fixed_masks) == 3
+        @test length(pool._touched_type_masks) == 3
 
         rewind!(pool)
-        @test length(pool._untracked_fixed_masks) == 2
+        @test length(pool._touched_type_masks) == 2
 
         rewind!(pool)
-        @test length(pool._untracked_fixed_masks) == 1
+        @test length(pool._touched_type_masks) == 1
     end
 
     # ==========================================================================
@@ -1510,78 +1510,78 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         @test all(b -> b != UInt16(0), bits)
     end
 
-    @testset "Typed _mark_untracked!: fixed-slot types set mask bits" begin
-        using AdaptiveArrayPools: _mark_untracked!, _fixed_slot_bit
+    @testset "Typed _record_type_touch!: fixed-slot types set mask bits" begin
+        using AdaptiveArrayPools: _record_type_touch!, _fixed_slot_bit
 
         pool = AdaptiveArrayPool()
         checkpoint!(pool)  # depth=2
 
         # Mark Float64 untracked
-        _mark_untracked!(pool, Float64)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64)
-        @test pool._untracked_has_others[2] == false
+        _record_type_touch!(pool, Float64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64)
+        @test pool._touched_has_others[2] == false
 
         # Mark Float32 additionally — bits accumulate
-        _mark_untracked!(pool, Float32)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Float32)
-        @test pool._untracked_has_others[2] == false
+        _record_type_touch!(pool, Float32)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Float32)
+        @test pool._touched_has_others[2] == false
 
         # Mark Float64 again — idempotent
-        _mark_untracked!(pool, Float64)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Float32)
+        _record_type_touch!(pool, Float64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Float32)
 
         rewind!(pool)
     end
 
-    @testset "Typed _mark_untracked!: non-fixed-slot types set has_others" begin
-        using AdaptiveArrayPools: _mark_untracked!, _fixed_slot_bit
+    @testset "Typed _record_type_touch!: non-fixed-slot types set has_others" begin
+        using AdaptiveArrayPools: _record_type_touch!, _fixed_slot_bit
 
         pool = AdaptiveArrayPool()
         checkpoint!(pool)  # depth=2
 
         # Mark UInt8 (not a fixed slot)
-        _mark_untracked!(pool, UInt8)
-        @test pool._untracked_fixed_masks[2] == UInt16(0)  # mask unchanged
-        @test pool._untracked_has_others[2] == true
+        _record_type_touch!(pool, UInt8)
+        @test pool._touched_type_masks[2] == UInt16(0)  # mask unchanged
+        @test pool._touched_has_others[2] == true
 
         rewind!(pool)
     end
 
-    @testset "Typed _mark_untracked!: mixed fixed + others" begin
-        using AdaptiveArrayPools: _mark_untracked!, _fixed_slot_bit
+    @testset "Typed _record_type_touch!: mixed fixed + others" begin
+        using AdaptiveArrayPools: _record_type_touch!, _fixed_slot_bit
 
         pool = AdaptiveArrayPool()
         checkpoint!(pool)
 
-        _mark_untracked!(pool, Float64)
-        _mark_untracked!(pool, UInt8)  # others
-        _mark_untracked!(pool, Int64)
+        _record_type_touch!(pool, Float64)
+        _record_type_touch!(pool, UInt8)  # others
+        _record_type_touch!(pool, Int64)
 
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Int64)
-        @test pool._untracked_has_others[2] == true
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Int64)
+        @test pool._touched_has_others[2] == true
 
         rewind!(pool)
     end
 
-    @testset "Typed _mark_untracked!: nested depth isolation" begin
-        using AdaptiveArrayPools: _mark_untracked!, _fixed_slot_bit
+    @testset "Typed _record_type_touch!: nested depth isolation" begin
+        using AdaptiveArrayPools: _record_type_touch!, _fixed_slot_bit
 
         pool = AdaptiveArrayPool()
 
         # Depth 2
         checkpoint!(pool)
-        _mark_untracked!(pool, Float64)
+        _record_type_touch!(pool, Float64)
 
         # Depth 3
         checkpoint!(pool)
-        _mark_untracked!(pool, Int32)
+        _record_type_touch!(pool, Int32)
 
         # Depth 3 has only Int32
-        @test pool._untracked_fixed_masks[3] == _fixed_slot_bit(Int32)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64)
+        @test pool._touched_type_masks[3] == _fixed_slot_bit(Int32)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64)
 
         # Depth 1 (sentinel) untouched
-        @test pool._untracked_fixed_masks[1] == UInt16(0)
+        @test pool._touched_type_masks[1] == UInt16(0)
 
         rewind!(pool)
         rewind!(pool)
@@ -1593,12 +1593,12 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         pool = AdaptiveArrayPool()
         checkpoint!(pool)  # depth=2
 
-        # acquire! outside @with_pool calls _mark_untracked!(pool, T)
+        # acquire! outside @with_pool calls _record_type_touch!(pool, T)
         acquire!(pool, Float64, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64)
 
         acquire!(pool, Int64, 5)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Int64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64) | _fixed_slot_bit(Int64)
 
         rewind!(pool)
     end
@@ -1610,7 +1610,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         checkpoint!(pool)
 
         unsafe_acquire!(pool, Float32, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float32)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float32)
 
         rewind!(pool)
     end
@@ -1623,37 +1623,37 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         # zeros! with explicit type
         checkpoint!(pool)
         zeros!(pool, Float64, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64)
         rewind!(pool)
 
         # zeros! without type → default_eltype → Float64
         checkpoint!(pool)
         zeros!(pool, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64)
         rewind!(pool)
 
         # ones! with type
         checkpoint!(pool)
         ones!(pool, Int32, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Int32)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Int32)
         rewind!(pool)
 
         # trues! → Bit type
         checkpoint!(pool)
         trues!(pool, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Bit)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Bit)
         rewind!(pool)
 
         # falses! → Bit type
         checkpoint!(pool)
         falses!(pool, 10)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Bit)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Bit)
         rewind!(pool)
 
         # similar! with template array
         checkpoint!(pool)
         similar!(pool, rand(Float32, 5))
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float32)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float32)
         rewind!(pool)
     end
 
@@ -1662,8 +1662,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         checkpoint!(pool)
         zeros!(pool, UInt8, 10)
-        @test pool._untracked_has_others[2] == true
-        @test pool._untracked_fixed_masks[2] == UInt16(0)
+        @test pool._touched_has_others[2] == true
+        @test pool._touched_type_masks[2] == UInt16(0)
         rewind!(pool)
     end
 
@@ -1712,27 +1712,27 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == true
 
         # Case 2: untracked Float64, tracked includes Float64 → subset → OK
-        pool._untracked_fixed_masks[2] = _fixed_slot_bit(Float64)
+        pool._touched_type_masks[2] = _fixed_slot_bit(Float64)
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == true
 
         # Case 3: untracked Float64, tracked is Float32 only → NOT subset → full
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float32)) == false
 
         # Case 4: untracked Float64|Float32, tracked Float64 only → partial → full
-        pool._untracked_fixed_masks[2] = _fixed_slot_bit(Float64) | _fixed_slot_bit(Float32)
+        pool._touched_type_masks[2] = _fixed_slot_bit(Float64) | _fixed_slot_bit(Float32)
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == false
 
         # Case 5: untracked Float64|Float32, tracked Float64|Float32 → exact match → OK
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64, Float32)) == true
 
         # Case 6: untracked Float64 + has_others → always full
-        pool._untracked_fixed_masks[2] = _fixed_slot_bit(Float64)
-        pool._untracked_has_others[2] = true
+        pool._touched_type_masks[2] = _fixed_slot_bit(Float64)
+        pool._touched_has_others[2] = true
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == false
 
         # Case 7: no fixed untracked but has_others → always full
-        pool._untracked_fixed_masks[2] = UInt16(0)
-        pool._untracked_has_others[2] = true
+        pool._touched_type_masks[2] = UInt16(0)
+        pool._touched_has_others[2] = true
         @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == false
 
         rewind!(pool)
@@ -1765,7 +1765,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
     @testset "Scenario B: selective rewind when untracked NOT ⊆ tracked" begin
         # Helper acquires Float32 while @with_pool only tracks Float64.
-        # Phase 5: _can_use_typed_path=false → _typed_selective_rewind! covers
+        # Phase 5: _can_use_typed_path=false → _typed_lazy_rewind! covers
         # tracked (Float64) | untracked (Float32), so both are rewound correctly.
         function _scenario_b_helper!(pool)
             acquire!(pool, Float32, 5)
@@ -1876,59 +1876,59 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
     # ==================================================================
     @testset "Phase 4: _untracked_flags field removed from AdaptiveArrayPool" begin
         # The legacy boolean _untracked_flags field has been replaced by
-        # bitmask-based tracking (_untracked_fixed_masks + _untracked_has_others).
+        # bitmask-based tracking (_touched_type_masks + _touched_has_others).
         # Verify it no longer exists as a struct field.
         @test !(:_untracked_flags in fieldnames(AdaptiveArrayPool))
 
         # Verify the bitmask fields ARE present (they are the replacement)
-        @test :_untracked_fixed_masks in fieldnames(AdaptiveArrayPool)
-        @test :_untracked_has_others in fieldnames(AdaptiveArrayPool)
+        @test :_touched_type_masks in fieldnames(AdaptiveArrayPool)
+        @test :_touched_has_others in fieldnames(AdaptiveArrayPool)
     end
 
     @testset "Phase 4: bitmask stacks have no stale state after lifecycle ops" begin
         pool = AdaptiveArrayPool()
 
         # Initial sentinel state
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
 
         # Checkpoint → mark → rewind cycle leaves no stale bits
         checkpoint!(pool)
-        _mark_untracked!(pool, Float64)
-        @test pool._untracked_fixed_masks[2] == _fixed_slot_bit(Float64)
+        _record_type_touch!(pool, Float64)
+        @test pool._touched_type_masks[2] == _fixed_slot_bit(Float64)
         rewind!(pool)
-        @test pool._untracked_fixed_masks == [UInt16(0)]  # back to sentinel
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]  # back to sentinel
+        @test pool._touched_has_others == [false]
 
         # Nested checkpoint → mark others → rewind cleans up
         checkpoint!(pool)  # depth 2
         checkpoint!(pool)  # depth 3
-        _mark_untracked!(pool, UInt8)  # others at depth 3
-        @test pool._untracked_has_others[3] == true
+        _record_type_touch!(pool, UInt8)  # others at depth 3
+        @test pool._touched_has_others[3] == true
         rewind!(pool)  # back to depth 2
-        @test length(pool._untracked_has_others) == 2
-        @test pool._untracked_has_others[2] == false  # depth 2 clean
+        @test length(pool._touched_has_others) == 2
+        @test pool._touched_has_others[2] == false  # depth 2 clean
         rewind!(pool)  # back to depth 1
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
 
         # reset! restores sentinel state after deep nesting
         checkpoint!(pool)
         checkpoint!(pool)
-        _mark_untracked!(pool, Float32)
-        _mark_untracked!(pool, Int64)
+        _record_type_touch!(pool, Float32)
+        _record_type_touch!(pool, Int64)
         reset!(pool)
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
         @test pool._current_depth == 1
 
         # empty! also restores sentinel state
         checkpoint!(pool)
-        _mark_untracked!(pool, ComplexF64)
-        _mark_untracked!(pool, UInt16)
+        _record_type_touch!(pool, ComplexF64)
+        _record_type_touch!(pool, UInt16)
         empty!(pool)
-        @test pool._untracked_fixed_masks == [UInt16(0)]
-        @test pool._untracked_has_others == [false]
+        @test pool._touched_type_masks == [UInt16(0)]
+        @test pool._touched_has_others == [false]
         @test pool._current_depth == 1
     end
 
@@ -1936,21 +1936,21 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
     # Dynamic Selective Mode — Phase 1: Characterization & Safety Locks
     # ==================================================================
 
-    @testset "Dynamic selective mode: _acquire_impl! bypasses _mark_untracked!" begin
+    @testset "Dynamic selective mode: _acquire_impl! bypasses _record_type_touch!" begin
         using AdaptiveArrayPools: _acquire_impl!, _fixed_slot_bit
         pool = AdaptiveArrayPool()
         checkpoint!(pool)
         depth = pool._current_depth  # = 2
 
-        # Internal _acquire_impl! does NOT call _mark_untracked! (by design).
+        # Internal _acquire_impl! does NOT call _record_type_touch! (by design).
         # This is the key reason a simple "combined mask" approach is insufficient:
         # macro-transformed calls won't appear in untracked bitmasks.
         _acquire_impl!(pool, Float64, 5)
-        @test pool._untracked_fixed_masks[depth] == UInt16(0)  # mask unchanged
+        @test pool._touched_type_masks[depth] == UInt16(0)  # mask unchanged
 
-        # Public acquire! DOES call _mark_untracked!
+        # Public acquire! DOES call _record_type_touch!
         acquire!(pool, Float32, 5)
-        @test pool._untracked_fixed_masks[depth] == _fixed_slot_bit(Float32)
+        @test pool._touched_type_masks[depth] == _fixed_slot_bit(Float32)
 
         rewind!(pool)
     end
@@ -2000,8 +2000,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         depth = pool._current_depth
 
         acquire!(pool, UInt8, 5)
-        @test pool._untracked_has_others[depth] == true
-        @test pool._untracked_fixed_masks[depth] == UInt16(0)
+        @test pool._touched_has_others[depth] == true
+        @test pool._touched_type_masks[depth] == UInt16(0)
 
         rewind!(pool)
         @test get_typed_pool!(pool, UInt8).n_active == 0
@@ -2016,7 +2016,7 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         # Record the stack length BEFORE entering the inner scope.
         # (global-scope bitmask at index 1 may be non-zero due to the acquire above.)
-        mask_before = pool._untracked_fixed_masks[1]
+        mask_before = pool._touched_type_masks[1]
 
         checkpoint!(pool)
         # no acquires in scope
@@ -2025,10 +2025,10 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         @test pool.float64.n_active == n_before
         @test pool._current_depth == 1
         # Stack has returned to exactly the sentinel (length 1)
-        @test length(pool._untracked_fixed_masks) == 1
-        @test length(pool._untracked_has_others) == 1
+        @test length(pool._touched_type_masks) == 1
+        @test length(pool._touched_has_others) == 1
         # Global-scope bitmask is unchanged from before we entered/exited the scope
-        @test pool._untracked_fixed_masks[1] == mask_before
+        @test pool._touched_type_masks[1] == mask_before
     end
 
     # ——————————————————————————————————————————————————————————————
@@ -2036,22 +2036,22 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
     # These will FAIL until Phase 2 is complete.
     # ——————————————————————————————————————————————————————————————
 
-    @testset "DESIRED [RED]: _depth_only_checkpoint! is exported/defined" begin
-        # Phase 2 will add _depth_only_checkpoint! to src/state.jl.
+    @testset "DESIRED [RED]: _lazy_checkpoint! is exported/defined" begin
+        # Phase 2 will add _lazy_checkpoint! to src/state.jl.
         # This test explicitly signals the missing implementation.
-        @test isdefined(AdaptiveArrayPools, :_depth_only_checkpoint!)
+        @test isdefined(AdaptiveArrayPools, :_lazy_checkpoint!)
     end
 
-    @testset "DESIRED [RED]: _depth_only_checkpoint! does not eagerly checkpoint typed pools" begin
+    @testset "DESIRED [RED]: _lazy_checkpoint! does not eagerly checkpoint typed pools" begin
         # A depth-only checkpoint should increment _current_depth and push bitmask
         # sentinels, but NOT save n_active for any typed pool.
         # The sentinel in _checkpoint_depths is always depth=0, so if no checkpoint
         # was saved at the current depth, _checkpoint_depths[end] will be < current_depth.
-        if !isdefined(AdaptiveArrayPools, :_depth_only_checkpoint!)
+        if !isdefined(AdaptiveArrayPools, :_lazy_checkpoint!)
             @test false  # RED: function not yet defined
         else
             pool = AdaptiveArrayPool()
-            AdaptiveArrayPools._depth_only_checkpoint!(pool)
+            AdaptiveArrayPools._lazy_checkpoint!(pool)
             depth = pool._current_depth  # = 2
 
             # No typed pool should have an eager checkpoint at this depth
@@ -2062,21 +2062,21 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
             # But depth metadata IS updated
             @test pool._current_depth == 2
-            @test length(pool._untracked_fixed_masks) == 2
-            @test length(pool._untracked_has_others) == 2
+            @test length(pool._touched_type_masks) == 2
+            @test length(pool._touched_has_others) == 2
         end
     end
 
     @testset "DESIRED [RED]: lazy first-touch checkpoint on acquire! in dynamic mode" begin
-        # In dynamic-selective mode, _mark_untracked! should lazily call
+        # In dynamic-selective mode, _record_type_touch! should lazily call
         # _checkpoint_typed_pool! on the FIRST acquire of each type per depth.
         # Only the touched pool gets checkpointed; others remain untouched.
-        if !isdefined(AdaptiveArrayPools, :_depth_only_checkpoint!)
+        if !isdefined(AdaptiveArrayPools, :_lazy_checkpoint!)
             @test false  # RED: prerequisite not implemented
         else
-            using AdaptiveArrayPools: _depth_only_checkpoint!
+            using AdaptiveArrayPools: _lazy_checkpoint!
             pool = AdaptiveArrayPool()
-            _depth_only_checkpoint!(pool)   # lightweight enter
+            _lazy_checkpoint!(pool)   # lightweight enter
             depth = pool._current_depth     # = 2
 
             # Before any acquire: no checkpoint for any pool at this depth
@@ -2097,14 +2097,14 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
     # Phase 5: Typed-Fallback Optimization
     # ==================================================================
 
-    @testset "Phase 5: _typed_checkpoint_with_lazy! sets bit 14 and checkpoints known types" begin
-        # _typed_checkpoint_with_lazy! must checkpoint known types AND set bit 14 for lazy mode.
+    @testset "Phase 5: _typed_lazy_checkpoint! sets bit 14 and checkpoints known types" begin
+        # _typed_lazy_checkpoint! must checkpoint known types AND set bit 14 for lazy mode.
         pool = AdaptiveArrayPool()
-        _typed_checkpoint_with_lazy!(pool, Float64)
+        _typed_lazy_checkpoint!(pool, Float64)
         d = pool._current_depth
         # Bit 14 (0x4000) must be set; bits 0-7 must be 0 (no acquires yet)
-        @test (pool._untracked_fixed_masks[d] & UInt16(0x4000)) != 0
-        @test (pool._untracked_fixed_masks[d] & UInt16(0x00FF)) == 0
+        @test (pool._touched_type_masks[d] & UInt16(0x4000)) != 0
+        @test (pool._touched_type_masks[d] & UInt16(0x00FF)) == 0
         # Float64 should be checkpointed at this depth
         @test pool.float64._checkpoint_depths[end] == d
         # Float32 should NOT be checkpointed at this depth
@@ -2132,14 +2132,14 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         # Child scope: typed checkpoint for Float64 only, but helper touches Int64
         # Simulates @with_pool with static type Float64 but _can_use_typed_path = false
-        _typed_checkpoint_with_lazy!(pool, Float64)
+        _typed_lazy_checkpoint!(pool, Float64)
         acquire!(pool, Float64, 5)        # tracked type
         _p0_helper_int64!(pool)           # untracked Int64 → triggers lazy first-touch checkpoint
         @test pool.int64.n_active == 2    # parent's 1 + helper's 1
 
         # Child scope exits via selective rewind
         tracked_mask = _tracked_mask_for_types(Float64)
-        _typed_selective_rewind!(pool, tracked_mask)
+        _typed_lazy_rewind!(pool, tracked_mask)
 
         # Parent's Int64 count must be restored to 1 (NOT 0)
         @test pool.int64.n_active == 1
@@ -2150,10 +2150,10 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
     end
 
     @testset "Phase 5: bit 14 enables lazy first-touch checkpoint for extra types" begin
-        # _mark_untracked! condition is (current_mask & 0xC000) != 0.
+        # _record_type_touch! condition is (current_mask & 0xC000) != 0.
         # With bit 14 set (typed lazy mode), extra-type first touch triggers _checkpoint_typed_pool!.
         pool = AdaptiveArrayPool()
-        _typed_checkpoint_with_lazy!(pool, Float64)  # typed chk + set bit 14
+        _typed_lazy_checkpoint!(pool, Float64)  # typed chk + set bit 14
         d = pool._current_depth
 
         # Before acquiring Int64: no Int64 checkpoint at this depth
@@ -2171,8 +2171,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
     @testset "Phase 5 (Issue #3): typed lazy mode preserves parent n_active for others types" begin
         # If a parent scope has an active others-type (UInt8) and a child uses
-        # _typed_checkpoint_with_lazy!, helpers touching the same type must NOT corrupt
-        # the parent's n_active. _typed_checkpoint_with_lazy! eagerly snapshots pool.others
+        # _typed_lazy_checkpoint!, helpers touching the same type must NOT corrupt
+        # the parent's n_active. _typed_lazy_checkpoint! eagerly snapshots pool.others
         # so Case A fires at rewind (not Case B with the wrong sentinel value).
         function _p5_helper_uint8!(pool)
             acquire!(pool, UInt8, 7)
@@ -2187,16 +2187,16 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         @test parent_others_pool.n_active == 1
 
         # Child scope: typed checkpoint for Float64 only; helper touches UInt8 (others)
-        # Without the fix: _typed_checkpoint_with_lazy! doesn't snapshot pool.others →
+        # Without the fix: _typed_lazy_checkpoint! doesn't snapshot pool.others →
         # rewind hits Case B → parent UInt8.n_active corrupted to 0.
-        _typed_checkpoint_with_lazy!(pool, Float64)
+        _typed_lazy_checkpoint!(pool, Float64)
         try
             acquire!(pool, Float64, 5)         # tracked type
             _p5_helper_uint8!(pool)            # untracked others type
             @test pool.others[UInt8].n_active == 2  # parent's 1 + helper's 1
         finally
             tracked_mask = _tracked_mask_for_types(Float64)
-            _typed_selective_rewind!(pool, tracked_mask)
+            _typed_lazy_rewind!(pool, tracked_mask)
         end
 
         # Parent's UInt8 count must be preserved (= 1, NOT 0)
@@ -2212,12 +2212,12 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
     # They should FAIL before the fix and PASS after.
     # ==================================================================
 
-    @testset "Issue #1: _depth_only_checkpoint! orphaned others stack leak" begin
-        # Bug: _depth_only_checkpoint! eagerly checkpoints pool.others entries,
-        # but sets _untracked_has_others[depth] = false. On _dynamic_selective_rewind!,
+    @testset "Issue #1: _lazy_checkpoint! orphaned others stack leak" begin
+        # Bug: _lazy_checkpoint! eagerly checkpoints pool.others entries,
+        # but sets _touched_has_others[depth] = false. On _lazy_rewind!,
         # the others loop is skipped (flag is false), leaving orphaned checkpoint entries.
         # In a loop, each iteration pushes one more stale entry → unbounded stack growth.
-        using AdaptiveArrayPools: _depth_only_checkpoint!, _dynamic_selective_rewind!
+        using AdaptiveArrayPools: _lazy_checkpoint!, _lazy_rewind!
 
         pool = AdaptiveArrayPool()
 
@@ -2231,8 +2231,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
         # Run 10 iterations of dynamic-selective scope without acquiring any others type
         for _ in 1:10
-            _depth_only_checkpoint!(pool)         # pushes checkpoint for others entries
-            _dynamic_selective_rewind!(pool)       # should pop it back
+            _lazy_checkpoint!(pool)         # pushes checkpoint for others entries
+            _lazy_rewind!(pool)       # should pop it back
         end
 
         # Checkpoint stack must NOT have grown (each entry should be popped by rewind)
@@ -2243,14 +2243,14 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
 
     @testset "Issue #2: double-checkpoint hazard when tracked type used by helper" begin
         # Bug: In typed-lazy mode (bit 14), when a tracked type T is:
-        #   1. Checkpointed by _typed_checkpoint_with_lazy!(pool, T) (saves n_active=0)
-        #   2. Acquired by macro-transformed _acquire_impl! (n_active → 1, no _mark_untracked!)
-        #   3. Re-acquired by a helper via acquire! → _mark_untracked!
+        #   1. Checkpointed by _typed_lazy_checkpoint!(pool, T) (saves n_active=0)
+        #   2. Acquired by macro-transformed _acquire_impl! (n_active → 1, no _record_type_touch!)
+        #   3. Re-acquired by a helper via acquire! → _record_type_touch!
         # Step 3 sees bit 14 set + T's bit unset → calls _checkpoint_typed_pool! again
         # with n_active=1 (wrong!). On rewind, restores n_active=1 instead of 0.
         using AdaptiveArrayPools: _acquire_impl!
 
-        # Helper that uses acquire! (goes through _mark_untracked!)
+        # Helper that uses acquire! (goes through _record_type_touch!)
         function _issue2_helper!(pool)
             acquire!(pool, Float64, 3)
         end
@@ -2258,20 +2258,20 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         pool = AdaptiveArrayPool()
 
         # Enter typed-lazy mode for Float64
-        _typed_checkpoint_with_lazy!(pool, Float64)
+        _typed_lazy_checkpoint!(pool, Float64)
         try
-            # Simulate macro-transformed code: bypasses _mark_untracked!
+            # Simulate macro-transformed code: bypasses _record_type_touch!
             _acquire_impl!(pool, Float64, 5)
             @test pool.float64.n_active == 1
 
-            # Helper: goes through acquire! → _mark_untracked!
-            # BUG: _mark_untracked! sees bit 14 + Float64 bit not yet set
+            # Helper: goes through acquire! → _record_type_touch!
+            # BUG: _record_type_touch! sees bit 14 + Float64 bit not yet set
             #      → redundant _checkpoint_typed_pool! with n_active=1
             _issue2_helper!(pool)
             @test pool.float64.n_active == 2
         finally
             tracked_mask = _tracked_mask_for_types(Float64)
-            _typed_selective_rewind!(pool, tracked_mask)
+            _typed_lazy_rewind!(pool, tracked_mask)
         end
 
         # After rewind, n_active should be 0 (parent state before scope entry)
@@ -2292,13 +2292,13 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         pool = AdaptiveArrayPool()
         initial_f32_stack = length(pool.float32._checkpoint_depths)  # 1 (sentinel)
 
-        _typed_checkpoint_with_lazy!(pool, Float32)
+        _typed_lazy_checkpoint!(pool, Float32)
         try
-            _acquire_impl!(pool, Float32, 5)     # n_active=1, no _mark_untracked!
-            _issue2b_helper!(pool)                # acquire! → _mark_untracked! → double checkpoint
+            _acquire_impl!(pool, Float32, 5)     # n_active=1, no _record_type_touch!
+            _issue2b_helper!(pool)                # acquire! → _record_type_touch! → double checkpoint
         finally
             tracked_mask = _tracked_mask_for_types(Float32)
-            _typed_selective_rewind!(pool, tracked_mask)
+            _typed_lazy_rewind!(pool, tracked_mask)
         end
 
         # The checkpoint stack should return to its initial length (sentinel only)
@@ -2325,25 +2325,25 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         end
     end
 
-    @testset "Issue #4: CUDA _depth_only_checkpoint! parity (has_others flag)" begin
-        # Bug: CUDA _depth_only_checkpoint! eagerly checkpoints pool.others but
-        # does NOT set _untracked_has_others = true, same as CPU Issue #1.
+    @testset "Issue #4: CUDA _lazy_checkpoint! parity (has_others flag)" begin
+        # Bug: CUDA _lazy_checkpoint! eagerly checkpoints pool.others but
+        # does NOT set _touched_has_others = true, same as CPU Issue #1.
         # Verify via source code inspection (no GPU needed).
         cuda_state_path = joinpath(@__DIR__, "..", "ext", "AdaptiveArrayPoolsCUDAExt", "state.jl")
         if isfile(cuda_state_path)
             code = read(cuda_state_path, String)
-            # Extract _depth_only_checkpoint! function body
+            # Extract _lazy_checkpoint! function body
             func_match = match(
-                r"function\s+AdaptiveArrayPools\._depth_only_checkpoint!\(pool::CuAdaptiveArrayPool\).*?^end"ms,
+                r"function\s+AdaptiveArrayPools\._lazy_checkpoint!\(pool::CuAdaptiveArrayPool\).*?^end"ms,
                 code
             )
             @test func_match !== nothing
             if func_match !== nothing
                 func_body = func_match.match
                 # If it eagerly checkpoints others (has `for p in values(pool.others)`),
-                # then it MUST also set _untracked_has_others[...] = true within the loop
+                # then it MUST also set _touched_has_others[...] = true within the loop
                 if contains(func_body, "values(pool.others)")
-                    @test occursin(r"_untracked_has_others\[.*\]\s*=\s*true", func_body)
+                    @test occursin(r"_touched_has_others\[.*\]\s*=\s*true", func_body)
                 end
             end
         else
@@ -2351,15 +2351,15 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
         end
     end
 
-    @testset "Issue #5: CUDA _typed_checkpoint_with_lazy! parity" begin
+    @testset "Issue #5: CUDA _typed_lazy_checkpoint! parity" begin
         # Bug: CUDA version is missing two features present in CPU version:
         # 1. Double-checkpoint guard: `_checkpoint_depths[end] != d`
-        # 2. has_others flag: `_untracked_has_others[d] = true`
+        # 2. has_others flag: `_touched_has_others[d] = true`
         cuda_state_path = joinpath(@__DIR__, "..", "ext", "AdaptiveArrayPoolsCUDAExt", "state.jl")
         if isfile(cuda_state_path)
             code = read(cuda_state_path, String)
             func_match = match(
-                r"function\s+AdaptiveArrayPools\._typed_checkpoint_with_lazy!\(pool::CuAdaptiveArrayPool.*?^end"ms,
+                r"function\s+AdaptiveArrayPools\._typed_lazy_checkpoint!\(pool::CuAdaptiveArrayPool.*?^end"ms,
                 code
             )
             @test func_match !== nothing
@@ -2369,8 +2369,8 @@ import AdaptiveArrayPools: _typed_checkpoint_with_lazy!, _typed_selective_rewind
                 # Must have double-checkpoint guard (like CPU version)
                 @test contains(func_body, "_checkpoint_depths[end]")
 
-                # Must set _untracked_has_others flag (like CPU version)
-                @test contains(func_body, "_untracked_has_others")
+                # Must set _touched_has_others flag (like CPU version)
+                @test contains(func_body, "_touched_has_others")
             end
         else
             @warn "CUDA extension not found, skipping parity test"

From e645a1c13500c5b8462f9ca668bdc75f114ee269 Mon Sep 17 00:00:00 2001
From: Min-Gu Yoo <mgyoo86@gmail.com>
Date: Wed, 18 Feb 2026 13:00:17 -0800
Subject: [PATCH 5/5] refactor(state): update comments and variable names to
 reflect type-touch tracking

---
 docs/design/naming_refactor_proposal.md | 429 ------------------------
 ext/AdaptiveArrayPoolsCUDAExt/state.jl  |  10 +-
 src/state.jl                            |   6 +-
 test/test_state.jl                      |  62 ++++
 4 files changed, 70 insertions(+), 437 deletions(-)
 delete mode 100644 docs/design/naming_refactor_proposal.md

diff --git a/docs/design/naming_refactor_proposal.md b/docs/design/naming_refactor_proposal.md
deleted file mode 100644
index 28085c6..0000000
--- a/docs/design/naming_refactor_proposal.md
+++ /dev/null
@@ -1,429 +0,0 @@
-# Naming & Refactoring Proposal: Post-Optimization Cleanup
-
-> **Status**: Brainstorm / RFC
-> **Context**: After Phase 3 (dynamic-selective) and Phase 5 (typed-fallback) optimizations,
-> many internal function names still reflect the original "untracked acquire detection" mental
-> model. This document proposes renaming to match the evolved architecture.
-
----
-
-## 1. Current Architecture: Three Execution Modes
-
-The `@with_pool` macro generates one of three checkpoint/rewind strategies:
-
-| Mode | Checkpoint | Acquire | Rewind | When |
-|------|-----------|---------|--------|------|
-| **Typed** | `checkpoint!(pool, T...)` | `_acquire_impl!(pool, T, ...)` | `rewind!(pool, T...)` | All types statically known |
-| **Dynamic-Selective** | `_depth_only_checkpoint!(pool)` | `acquire!(pool, T, ...)` *(unchanged)* | `_dynamic_selective_rewind!(pool)` | Types only known at runtime |
-| **Full** (manual) | `checkpoint!(pool)` | `acquire!(pool, T, ...)` | `rewind!(pool)` | User calls manually |
-
-Additionally, the **Typed** mode has a runtime fallback:
-- If `_can_use_typed_path()` is false → `_typed_checkpoint_with_lazy!` + `_typed_selective_rewind!`
-
----
-
-## 2. Naming Tensions
-
-### 2.1 `_mark_untracked!` — The Core Irony
-
-**Current name**: `_mark_untracked!`
-**What it does**: Records type usage in bitmask. Triggers lazy checkpoint on first touch.
-
-The word "untracked" is **doubly misleading**:
-1. The function **tracks** type usage (sets bitmask bits)
-2. The data it records is used to **selectively rewind** (the opposite of "untracked")
-
-The original semantics: "mark that this acquire happened in a path the macro doesn't track."
-The actual semantics now: "record that type T was touched at this depth, and lazily checkpoint if needed."
-
-#### Candidates
-
-| Candidate | Pros | Cons |
-|-----------|------|------|
-| `_record_type_touch!` | "touch" captures first-touch/lazy-checkpoint semantics; action-oriented | Doesn't convey the bitmask mechanism |
-| `_track_type_usage!` | Most literal description of what happens | "track" is overloaded (macro "tracks" types too) |
-| `_notify_acquire!` | Observer-pattern feel; captures side-effect (lazy checkpoint) | Too generic; doesn't convey type-specificity |
-| `_register_type!` | Clean, idiomatic ("register X in a registry") | Doesn't convey the "at this depth" scoping |
-| `_touch_type!` | Shortest; "touch" is a Unix/DB idiom for "first access triggers action" | Might be too terse for complex semantics |
-| `_mark_type_used!` | Simple and accurate | Still has "mark" which is vague |
-
-### 2.2 `_acquire_impl!` — The "Fast Path" Naming
-
-**Current name**: `_acquire_impl!`
-**What it does**: Core acquire logic without type tracking. Called by macro-transformed code.
-
-The `_impl!` suffix is conventional but **non-descriptive**. It doesn't convey *why* this variant
-exists (to skip tracking overhead when the macro already knows the types).
-
-#### Candidates
-
-| Candidate | Pros | Cons |
-|-----------|------|------|
-| `_acquire_direct!` | "direct" = no intermediary tracking step | Might imply "direct memory access" |
-| `_acquire_bare!` | "bare" = stripped of wrapper logic | Non-standard terminology |
-| `_acquire_core!` | "core" = the essential operation | Generic; doesn't explain *why* it's separate |
-| `_acquire_scoped!` | "scoped" = macro already manages this scope | Misleading — the function itself isn't scoped |
-| Keep `_acquire_impl!` | Well-understood `_impl` convention in Julia | Doesn't explain the tracking bypass |
-
-### 2.3 `_untracked_fixed_masks` / `_untracked_has_others` — Field Names
-
-**Current names**: Pool fields storing per-depth bitmask data.
-**What they store**: Which types were acquired at each depth (for selective rewind).
-
-These fields are the **runtime type tracking** data structure, yet named "untracked."
-
-#### Candidates
-
-| Candidate | Pros | Cons |
-|-----------|------|------|
-| `_touched_fixed_masks` / `_touched_has_others` | "touched" matches first-touch semantics | Might confuse with "dirty" bit patterns |
-| `_used_fixed_masks` / `_used_has_others` | Simplest, most literal | Too generic |
-| `_acquired_fixed_masks` / `_acquired_has_others` | Directly describes the event (acquire happened) | Slightly long |
-| `_runtime_fixed_masks` / `_runtime_has_others` | Contrasts with "compile-time" tracked types | Doesn't describe *what* is tracked |
-| Keep current names | Consistency with existing code, comments, tests | Perpetuates the "untracked" confusion |
-
-### 2.4 Mode-Specific Functions — Consistency
-
-The three modes don't follow a consistent naming pattern:
-
-```
-Typed:             checkpoint!(pool, T...)     / rewind!(pool, T...)
-  + fallback:      _typed_checkpoint_with_lazy!(pool, T...) / _typed_selective_rewind!(pool, mask)
-Dynamic-Selective: _depth_only_checkpoint!(pool) / _dynamic_selective_rewind!(pool)
-Full:              checkpoint!(pool)           / rewind!(pool)
-```
-
-**Observation**: The "typed" fallback functions have long compound names that mix the *mode*
-(`typed`) with the *mechanism* (`with_lazy`, `selective`).
-
-#### Possible Consistent Scheme
-
-Option A — Mode prefix:
-```
-_typed_checkpoint!          → checkpoint!(pool, T...)    (already clean)
-_typed_lazy_checkpoint!     → _typed_checkpoint_with_lazy!(pool, T...)
-_typed_selective_rewind!    → _typed_selective_rewind!(pool, mask)  (already clean)
-_dynamic_checkpoint!        → _depth_only_checkpoint!(pool)
-_dynamic_rewind!            → _dynamic_selective_rewind!(pool)
-```
-
-Option B — Mechanism suffix:
-```
-_checkpoint_typed!          (checkpoint the typed pools)
-_checkpoint_lazy!           (checkpoint with lazy first-touch)
-_checkpoint_depth_only!     (only increment depth)
-_rewind_typed!              (rewind typed pools)
-_rewind_selective!          (rewind based on bitmask)
-_rewind_dynamic!            (dynamic bitmask rewind)
-```
-
----
-
-## 3. Holistic Renaming Proposals
-
-### Proposal A: "Touch" Metaphor (First-Touch Semantics)
-
-The architecture's key insight is **first-touch tracking**: when a type is first used at a depth,
-it gets recorded (and lazily checkpointed). The "touch" metaphor captures this cleanly.
-
-```
-# Type tracking
-_mark_untracked!(pool, T)        → _touch_type!(pool, T)
-
-# Pool fields
-_untracked_fixed_masks           → _touched_fixed_masks
-_untracked_has_others            → _touched_has_others
-
-# Acquire internals (keep _impl convention)
-_acquire_impl!(pool, T, n)      → (keep as is, or _acquire_core!)
-_unsafe_acquire_impl!(...)      → (keep as is, or _unsafe_acquire_core!)
-
-# Dynamic mode (rename for symmetry)
-_depth_only_checkpoint!(pool)    → _lazy_checkpoint!(pool)       # "lazy" = defers to first touch
-_dynamic_selective_rewind!(pool) → _lazy_rewind!(pool)           # symmetric with checkpoint
-
-# Typed fallback (simplify)
-_typed_checkpoint_with_lazy!     → _typed_lazy_checkpoint!       # adjective before noun
-_typed_selective_rewind!         → _typed_lazy_rewind!           # symmetric pair
-
-# Macro generators (follow function names)
-_generate_dynamic_selective_checkpoint_call → _generate_lazy_checkpoint_call
-_generate_dynamic_selective_rewind_call    → _generate_lazy_rewind_call
-
-# Guards
-_can_use_typed_path              → (keep as is — already clear)
-_tracked_mask_for_types          → (keep as is — already clear)
-```
-
-**Pros**: Concise, consistent metaphor, captures the core mechanism.
-**Cons**: "lazy" is overloaded in CS (lazy evaluation, lazy initialization).
-
-### Proposal B: "Record/Direct" Pair (Action-Based)
-
-Focus on what each function *does* as an action:
-
-```
-# Type tracking
-_mark_untracked!(pool, T)        → _record_type_touch!(pool, T)
-
-# Pool fields
-_untracked_fixed_masks           → _acquired_type_masks
-_untracked_has_others            → _acquired_has_others
-
-# Acquire internals
-_acquire_impl!(pool, T, n)      → _acquire_direct!(pool, T, n)     # "direct" = no recording
-_unsafe_acquire_impl!(...)      → _unsafe_acquire_direct!(...)
-
-# All convenience _impl! follow:
-_zeros_impl!                     → _zeros_direct!
-_ones_impl!                      → _ones_direct!
-_similar_impl!                   → _similar_direct!
-
-# Dynamic mode
-_depth_only_checkpoint!(pool)    → _deferred_checkpoint!(pool)       # "deferred" = save later
-_dynamic_selective_rewind!(pool) → _deferred_selective_rewind!(pool) # rewind what was deferred
-
-# Typed fallback
-_typed_checkpoint_with_lazy!     → _typed_deferred_checkpoint!       # typed + deferred for extras
-_typed_selective_rewind!         → (keep — already descriptive)
-
-# Macro generators
-_generate_dynamic_selective_*    → _generate_deferred_*
-```
-
-**Pros**: Very descriptive, each name tells you exactly what happens.
-**Cons**: Longer names, "deferred" is less intuitive than "lazy."
-
-### Proposal C: "Scope" Metaphor (Inside/Outside Macro Scope)
-
-Frame the naming around the key architectural distinction: code inside `@with_pool` scope
-(macro-managed) vs outside (self-tracking):
-
-```
-# Type tracking — called from "outside scope" or "dynamic scope"
-_mark_untracked!(pool, T)        → _track_type!(pool, T)
-
-# Pool fields
-_untracked_fixed_masks           → _scope_type_masks      # per-scope tracking
-_untracked_has_others            → _scope_has_others
-
-# Acquire internals — used by "in-scope" (macro-managed) code
-_acquire_impl!(pool, T, n)      → _scoped_acquire!(pool, T, n)   # "scoped" = macro handles tracking
-_unsafe_acquire_impl!(...)      → _scoped_unsafe_acquire!(...)
-
-# Dynamic mode
-_depth_only_checkpoint!(pool)    → _open_scope!(pool)              # "open" a new tracking scope
-_dynamic_selective_rewind!(pool) → _close_scope!(pool)             # "close" and rewind the scope
-
-# Typed fallback
-_typed_checkpoint_with_lazy!     → _open_typed_scope_with_fallback!
-_typed_selective_rewind!         → _close_typed_scope_with_fallback!
-
-# Guards
-_can_use_typed_path              → _scope_is_typed_only
-```
-
-**Pros**: Captures the architectural mental model cleanly.
-**Cons**: "scope" semantics might clash with Julia's lexical scoping concepts.
-
-### Proposal D: Minimal Rename (Conservative)
-
-Only rename the most confusing items, keep everything else:
-
-```
-# The one truly misleading name:
-_mark_untracked!(pool, T)        → _record_type_touch!(pool, T)
-
-# The confusing fields:
-_untracked_fixed_masks           → _touched_type_masks
-_untracked_has_others            → _touched_has_others
-
-# Everything else stays as-is
-_acquire_impl!                   → (keep)
-_depth_only_checkpoint!          → (keep)
-_dynamic_selective_rewind!       → (keep)
-_typed_checkpoint_with_lazy!     → (keep)
-_typed_selective_rewind!         → (keep)
-```
-
-**Pros**: Minimal churn, only fixes the genuinely confusing names.
-**Cons**: Misses the opportunity for holistic consistency.
-
----
-
-## 4. Cross-Cutting Concerns
-
-### 4.1 Public API — Should NOT Change
-
-These are stable public APIs and should **never** be renamed:
-- `acquire!`, `unsafe_acquire!`, `acquire_view!`, `acquire_array!`
-- `checkpoint!`, `rewind!`, `reset!`, `empty!`
-- `zeros!`, `ones!`, `trues!`, `falses!`, `similar!`
-- `@with_pool`, `@maybe_with_pool`
-- `get_task_local_pool`
-
-### 4.2 CUDA Extension Parity
-
-Any rename must be mirrored in:
-- `ext/AdaptiveArrayPoolsCUDAExt/types.jl`
-- `ext/AdaptiveArrayPoolsCUDAExt/state.jl`
-- `ext/AdaptiveArrayPoolsCUDAExt/acquire.jl`
-
-### 4.3 Test Impact
-
-Renaming internal functions affects:
-- `test/test_macro_internals.jl` (directly calls `_depth_only_checkpoint!`, `_dynamic_selective_rewind!`, etc.)
-- `test/test_state.jl` (checkpoint/rewind tests)
-- `test/test_macroexpand.jl` (checks expanded code contains specific function names)
-- Any benchmarks referencing internal functions
-
-### 4.4 `Bit` 15 / Bit 14 Constants
-
-Currently the mode flags are raw hex literals (`0x8000`, `0x4000`). A related cleanup:
-```julia
-const _DYNAMIC_MODE_BIT   = UInt16(0x8000)  # bit 15
-const _LAZY_MODE_BIT      = UInt16(0x4000)  # bit 14
-const _MODE_BITS_MASK     = UInt16(0xC000)  # bits 14-15
-const _TYPE_BITS_MASK     = UInt16(0x00FF)  # bits 0-7
-```
-
-These constants would replace scattered magic numbers throughout `state.jl` and `acquire.jl`.
-
-### 4.5 The `_impl!` Convention — Keep or Replace?
-
-The `_impl!` suffix is a **widely understood Julia convention** (e.g., `Base._similar_impl`).
-Replacing it with `_direct!`, `_core!`, or `_scoped!` trades familiarity for specificity.
-
-Arguments for keeping `_impl!`:
-- Julia developers immediately understand it as "internal implementation"
-- No ambiguity about the function's role as a building block
-- Grep-friendly: `_*_impl!` finds all implementation functions
-
-Arguments for replacing:
-- `_impl!` doesn't explain *why* the split exists (tracking bypass)
-- New developers might not realize the critical difference between `acquire!` and `_acquire_impl!`
-
----
-
-## 5. Recommended Changes (for Discussion)
-
-### Tier 1: High Impact, Low Risk (Do First)
-
-| Current | Proposed | Rationale |
-|---------|----------|-----------|
-| `_mark_untracked!` | `_record_type_touch!` | Most misleading name; "touch" captures first-touch + lazy checkpoint |
-| `_untracked_fixed_masks` | `_touched_type_masks` | Field stores which types were *touched*, not which are "untracked" |
-| `_untracked_has_others` | `_touched_has_others` | Consistent with above |
-
-### Tier 2: Medium Impact, Medium Risk
-
-| Current | Proposed | Rationale |
-|---------|----------|-----------|
-| `_depth_only_checkpoint!` | `_lazy_checkpoint!` | "lazy" captures the deferred-to-first-touch semantics |
-| `_dynamic_selective_rewind!` | `_lazy_rewind!` | Symmetric with `_lazy_checkpoint!` |
-| `_typed_checkpoint_with_lazy!` | `_typed_lazy_checkpoint!` | Cleaner word order |
-| Magic numbers `0x8000`, `0x4000`, `0xC000`, `0x00FF` | Named constants (see 4.4) | Self-documenting code |
-
-### Tier 3: Low Impact, Higher Risk (Optional)
-
-| Current | Proposed | Rationale |
-|---------|----------|-----------|
-| `_acquire_impl!` | Keep as `_acquire_impl!` | Julia convention, well-understood |
-| `_generate_dynamic_selective_*` | `_generate_lazy_*` | Follows Tier 2 rename |
-| `_typed_selective_rewind!` | `_typed_lazy_rewind!` | Consistent with pair |
-
----
-
-## 6. Alternative: Do Nothing
-
-**Case for not renaming**: The current names work. They're documented. Tests pass.
-"Untracked" has a clear historical meaning in the codebase, and commit history explains
-the evolution. Renaming has a nonzero risk of introducing bugs (missed references,
-CUDA extension drift) and makes git blame harder to follow.
-
-**Counter-argument**: The package is pre-1.0 and has few external users. Now is the
-cheapest time to fix naming before the API surface solidifies.
-
----
-
-## 7. Open Questions
-
-1. **Should `_impl!` functions be renamed?** They work fine as a convention, but
-   `_acquire_direct!` or `_acquire_core!` would be more self-documenting.
-
-2. **Is "lazy" the right word?** In Julia, `lazy` is associated with `Lazy.jl` and
-   lazy evaluation. "Deferred" is more precise but longer.
-
-3. **Should mode names be formalized?** Currently modes are described in comments
-   as "typed", "dynamic-selective", "full". Should there be an enum or named constants?
-
-4. **How deep should the rename go?** Renaming `_mark_untracked!` alone fixes 80%
-   of the confusion. Is a holistic rename worth the churn?
-
-5. **Should the bitmask `_touched_type_masks` also track mode bits?** Currently
-   bits 0-7 = types, bits 14-15 = mode flags, all in the same field. Should mode
-   flags be a separate field for clarity?
-
----
-
-## Appendix: Complete Current → Proposed Mapping (Proposal A: "Touch/Lazy")
-
-```
-# === Type Tracking ===
-_mark_untracked!(pool, T)                    → _record_type_touch!(pool, T)
-
-# === Pool Fields ===
-_untracked_fixed_masks                       → _touched_type_masks
-_untracked_has_others                        → _touched_has_others
-
-# === Acquire (keep _impl convention) ===
-_acquire_impl!(pool, T, n)                   → (no change)
-_unsafe_acquire_impl!(pool, T, n)            → (no change)
-_zeros_impl!(pool, T, dims...)               → (no change)
-_ones_impl!(pool, T, dims...)                → (no change)
-_similar_impl!(pool, T, dims...)             → (no change)
-
-# === Dynamic-Selective Mode ===
-_depth_only_checkpoint!(pool)                → _lazy_checkpoint!(pool)
-_dynamic_selective_rewind!(pool)             → _lazy_rewind!(pool)
-
-# === Typed Fallback ===
-_typed_checkpoint_with_lazy!(pool, T...)     → _typed_lazy_checkpoint!(pool, T...)
-_typed_selective_rewind!(pool, mask)         → _typed_lazy_rewind!(pool, mask)
-
-# === Selective Rewind Helper ===
-_selective_rewind_fixed_slots!(pool, mask)   → (no change — already descriptive)
-
-# === Guards ===
-_can_use_typed_path(pool, mask)              → (no change)
-_tracked_mask_for_types(T...)                → (no change)
-
-# === Macro Generators ===
-_generate_dynamic_selective_checkpoint_call  → _generate_lazy_checkpoint_call
-_generate_dynamic_selective_rewind_call      → _generate_lazy_rewind_call
-_generate_typed_checkpoint_call              → (no change)
-_generate_typed_rewind_call                  → (no change)
-
-# === Constants (new) ===
-(raw 0x8000)                                 → _LAZY_MODE_BIT (or _DYNAMIC_MODE_BIT)
-(raw 0x4000)                                 → _TYPED_LAZY_BIT
-(raw 0xC000)                                 → _MODE_BITS_MASK
-(raw 0x00FF)                                 → _TYPE_BITS_MASK
-```
-
-### Files Affected
-
-| File | Changes |
-|------|---------|
-| `src/types.jl` | Field renames: `_untracked_*` → `_touched_*` |
-| `src/acquire.jl` | `_mark_untracked!` → `_record_type_touch!` |
-| `src/state.jl` | Mode functions, field references, constants |
-| `src/macros.jl` | Generator function renames, field references |
-| `src/convenience.jl` | `_mark_untracked!` calls |
-| `src/task_local_pool.jl` | (unlikely changes) |
-| `src/utils.jl` | (unlikely changes) |
-| `ext/AdaptiveArrayPoolsCUDAExt/*.jl` | Mirror all renames |
-| `test/test_macro_internals.jl` | Direct calls to renamed functions |
-| `test/test_state.jl` | Field references |
-| `test/test_macroexpand.jl` | String matching on expanded names |
-| `test/test_allocation.jl` | (unlikely changes) |
diff --git a/ext/AdaptiveArrayPoolsCUDAExt/state.jl b/ext/AdaptiveArrayPoolsCUDAExt/state.jl
index e800c9f..f5e572f 100644
--- a/ext/AdaptiveArrayPoolsCUDAExt/state.jl
+++ b/ext/AdaptiveArrayPoolsCUDAExt/state.jl
@@ -32,7 +32,7 @@ end
 # ==============================================================================
 
 function AdaptiveArrayPools.checkpoint!(pool::CuAdaptiveArrayPool)
-    # Increment depth and initialize untracked bitmask state
+    # Increment depth and initialize type-touch tracking state
     pool._current_depth += 1
     push!(pool._touched_type_masks, UInt16(0))
     push!(pool._touched_has_others, false)
@@ -223,14 +223,14 @@ end
     nothing
 end
 
-# _typed_lazy_rewind!: selective rewind of (tracked | untracked) mask.
+# _typed_lazy_rewind!: selective rewind of (tracked | touched) mask.
 # Uses direct field access with bit checks — foreach_fixed_slot is single-argument (no bit yield).
 # Bit 7: Float16 (CUDA-specific; lazy-checkpointed on first touch by _record_type_touch!).
 # has_others: genuine others types (UInt8, Int8, etc.) — eagerly checkpointed at scope entry.
 @inline function AdaptiveArrayPools._typed_lazy_rewind!(pool::CuAdaptiveArrayPool, tracked_mask::UInt16)
     d = pool._current_depth
-    untracked = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
-    combined = tracked_mask | untracked
+    touched = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
+    combined = tracked_mask | touched
     _has_bit(combined, Float64)    && _rewind_typed_pool!(pool.float64,    d)
     _has_bit(combined, Float32)    && _rewind_typed_pool!(pool.float32,    d)
     _has_bit(combined, Int64)      && _rewind_typed_pool!(pool.int64,      d)
@@ -238,7 +238,7 @@ end
     _has_bit(combined, ComplexF64) && _rewind_typed_pool!(pool.complexf64, d)
     _has_bit(combined, ComplexF32) && _rewind_typed_pool!(pool.complexf32, d)
     _has_bit(combined, Bool)       && _rewind_typed_pool!(pool.bool,       d)
-    # Float16: bit 7 is set by _record_type_touch! on first untracked touch (lazy first-touch).
+    # Float16: bit 7 is set by _record_type_touch! on first touch (lazy first-touch).
     # Also rewind when Float16 was a *tracked* type in the macro: _typed_lazy_checkpoint!
     # calls checkpoint!(pool, Float16) which pushes a checkpoint at depth d, but _acquire_impl!
     # (macro transform) bypasses _record_type_touch!, leaving bit 7 = 0.
diff --git a/src/state.jl b/src/state.jl
index 0eaea1e..86b27d9 100644
--- a/src/state.jl
+++ b/src/state.jl
@@ -312,8 +312,8 @@ guaranteed by the `_TYPED_LAZY_BIT` mode set in `_typed_lazy_checkpoint!`.
 """
 @inline function _typed_lazy_rewind!(pool::AdaptiveArrayPool, tracked_mask::UInt16)
     d = pool._current_depth
-    untracked = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
-    combined = tracked_mask | untracked
+    touched = @inbounds(pool._touched_type_masks[d]) & _TYPE_BITS_MASK
+    combined = tracked_mask | touched
     _selective_rewind_fixed_slots!(pool, combined)
     if @inbounds(pool._touched_has_others[d])
         for tp in values(pool.others)
@@ -587,7 +587,7 @@ in `touched_mask` is also set in `tracked_mask`.
 """
 @inline function _can_use_typed_path(pool::AbstractArrayPool, tracked_mask::UInt16)
     depth = pool._current_depth
-    touched_mask = @inbounds pool._touched_type_masks[depth]
+    touched_mask = @inbounds(pool._touched_type_masks[depth]) & _TYPE_BITS_MASK
     has_others = @inbounds pool._touched_has_others[depth]
     return (touched_mask & ~tracked_mask) == UInt16(0) && !has_others
 end
diff --git a/test/test_state.jl b/test/test_state.jl
index 0b352ec..a0f67b3 100644
--- a/test/test_state.jl
+++ b/test/test_state.jl
@@ -1738,6 +1738,68 @@ import AdaptiveArrayPools: _typed_lazy_checkpoint!, _typed_lazy_rewind!, _tracke
         rewind!(pool)
     end
 
+    @testset "_can_use_typed_path: mode bits do not pollute subset check" begin
+        # Issue: _can_use_typed_path reads raw _touched_type_masks[depth] which may
+        # contain mode bits (14-15) from _lazy_checkpoint! or _typed_lazy_checkpoint!.
+        # These mode bits leak into the subset check `(touched_mask & ~tracked_mask) == 0`,
+        # causing false negatives: the typed fast path is rejected even when only
+        # tracked types were touched.
+        using AdaptiveArrayPools: _can_use_typed_path, _tracked_mask_for_types,
+              _lazy_checkpoint!, _lazy_rewind!, _LAZY_MODE_BIT, _TYPED_LAZY_BIT,
+              _acquire_impl!
+
+        # --- Case 1: _LAZY_MODE_BIT (bit 15) should be ignored ---
+        pool = AdaptiveArrayPool()
+        checkpoint!(pool)  # depth 2
+        pool._touched_type_masks[2] = _LAZY_MODE_BIT  # simulate lazy parent scope
+        # Only mode bit set, no type bits → typed path should be safe
+        @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == true
+
+        # Mode bit + tracked type bit → still safe (type is tracked)
+        pool._touched_type_masks[2] = _LAZY_MODE_BIT | _fixed_slot_bit(Float64)
+        @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == true
+
+        # Mode bit + untracked type bit → correctly fails
+        pool._touched_type_masks[2] = _LAZY_MODE_BIT | _fixed_slot_bit(Int32)
+        @test _can_use_typed_path(pool, _tracked_mask_for_types(Float64)) == false
+        rewind!(pool)
+
+        # --- Case 2: _TYPED_LAZY_BIT (bit 14) should be ignored ---
+        pool2 = AdaptiveArrayPool()
+        checkpoint!(pool2)
+        pool2._touched_type_masks[2] = _TYPED_LAZY_BIT
+        @test _can_use_typed_path(pool2, _tracked_mask_for_types(Float64)) == true
+
+        pool2._touched_type_masks[2] = _TYPED_LAZY_BIT | _fixed_slot_bit(Float64)
+        @test _can_use_typed_path(pool2, _tracked_mask_for_types(Float64)) == true
+        rewind!(pool2)
+
+        # --- Case 3: Both mode bits set (bits 14+15) should be ignored ---
+        pool3 = AdaptiveArrayPool()
+        checkpoint!(pool3)
+        pool3._touched_type_masks[2] = _LAZY_MODE_BIT | _TYPED_LAZY_BIT
+        @test _can_use_typed_path(pool3, _tracked_mask_for_types(Float64)) == true
+        rewind!(pool3)
+
+        # --- Case 4: End-to-end — nested typed scope inside lazy scope ---
+        pool4 = AdaptiveArrayPool()
+        _lazy_checkpoint!(pool4)  # outer lazy scope (depth 2, mask has _LAZY_MODE_BIT)
+
+        # Before entering inner typed scope, macro calls _can_use_typed_path at parent depth
+        tracked_mask = _tracked_mask_for_types(Float64)
+        @test _can_use_typed_path(pool4, tracked_mask) == true  # parent has no extra type bits
+
+        # Enter inner typed scope
+        checkpoint!(pool4, Float64)  # depth 3
+        a = _acquire_impl!(pool4, Float64, 10)
+        a .= 1.0
+        # At rewind time: inner mask is clean (no mode bits from checkpoint!)
+        @test _can_use_typed_path(pool4, tracked_mask) == true
+
+        rewind!(pool4, Float64)
+        _lazy_rewind!(pool4)
+    end
+
     # ==================================================================
     # Phase 3: End-to-end runtime scenarios
     # ==================================================================