From 3978f0a525c299aba40b3d1968fcb1b02ece90eb Mon Sep 17 00:00:00 2001
From: Robert Buessow <robert.buessow@relational.ai>
Date: Tue, 26 May 2026 11:41:10 +0000
Subject: [PATCH 1/2] Remove CDataHandle finalizer and leak counter

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/cdatainterface.jl  | 24 +-----------------------
 test/cdatainterface.jl | 38 --------------------------------------
 2 files changed, 1 insertion(+), 61 deletions(-)

diff --git a/src/cdatainterface.jl b/src/cdatainterface.jl
index 3f376856..3c2938e4 100644
--- a/src/cdatainterface.jl
+++ b/src/cdatainterface.jl
@@ -77,8 +77,6 @@ const CDATA_FLAG_MAP_KEYS_SORTED = Int64(4)
 
 Holds C-side pointers for an imported Arrow C Data Interface pair.
 Call `Arrow.release_c_data` to release C resources explicitly.
-If the handle is garbage-collected without being released, an error is logged
-and `Arrow.UNRELEASED_HANDLE_COUNT` is incremented.
 """
 mutable struct CDataHandle
     schema_ptr::Ptr{ArrowSchema}
@@ -86,27 +84,7 @@ mutable struct CDataHandle
     released::Bool
 end
 
-# Counts CDataHandles that were GC'd without an explicit release_c_data call.
-const UNRELEASED_HANDLE_COUNT = Threads.Atomic{Int}(0)
-
-function _warn_unreleased(h::CDataHandle)
-    h.released && return
-    Threads.atomic_add!(UNRELEASED_HANDLE_COUNT, 1)
-    # Use jl_safe_printf since task switches are forbidden in finalizers.
-    ccall(
-        :jl_safe_printf,
-        Cvoid,
-        (Cstring,),
-        "Arrow.CDataHandle GC'd without explicit release_c_data — resource leak detected\n",
-    )
-    _release_cdata_handle(h)
-end
-
-function CDataHandle(sp::Ptr{ArrowSchema}, ap::Ptr{ArrowArray})
-    h = CDataHandle(sp, ap, false)
-    finalizer(_warn_unreleased, h)
-    return h
-end
+CDataHandle(sp::Ptr{ArrowSchema}, ap::Ptr{ArrowArray}) = CDataHandle(sp, ap, false)
 
 function _release_cdata_handle(h::CDataHandle)
     h.released && return
diff --git a/test/cdatainterface.jl b/test/cdatainterface.jl
index 319f4366..ffcafc4c 100644
--- a/test/cdatainterface.jl
+++ b/test/cdatainterface.jl
@@ -15,8 +15,6 @@
 # limitations under the License.
 
 @testset "Arrow C Data Interface" begin
-    _initial_count = Arrow.UNRELEASED_HANDLE_COUNT[]
-
     @testset "struct sizes" begin
         @test sizeof(Arrow.ArrowSchema) == 9 * 8
         @test sizeof(Arrow.ArrowArray) == 10 * 8
@@ -756,36 +754,6 @@
         end
     end
 
-    # ── Finalizer / leak counter ──────────────────────────────────────────────
-
-    @testset "finalizer: increments leak counter when not released" begin
-        before = Arrow.UNRELEASED_HANDLE_COUNT[]
-        redirect_stderr(devnull) do
-            let
-                av = to_arrow(Int32[1, 2, 3])
-                s_ref, a_ref = Arrow.to_c_data(av)
-                Arrow.from_c_data(_cptr(s_ref), _cptr(a_ref))
-                # CImportedArray and its CDataHandle go out of scope here
-            end
-            GC.gc(true)
-            GC.gc(true)
-        end
-        @test Arrow.UNRELEASED_HANDLE_COUNT[] == before + 1
-    end
-
-    @testset "finalizer: does NOT increment counter when released explicitly" begin
-        before = Arrow.UNRELEASED_HANDLE_COUNT[]
-        let
-            av = to_arrow(Int32[1, 2, 3])
-            s_ref, a_ref = Arrow.to_c_data(av)
-            col = Arrow.from_c_data(_cptr(s_ref), _cptr(a_ref))
-            Arrow.release_c_data(col)
-        end
-        GC.gc(true)
-        GC.gc(true)
-        @test Arrow.UNRELEASED_HANDLE_COUNT[] == before
-    end
-
     # ── Empty arrays ─────────────────────────────────────────────────────────
 
     @testset "round-trip: empty Int32 array" begin
@@ -829,10 +797,4 @@
         @test isequal(collect(imported), data)
         Arrow.release_c_data(imported)
     end
-
-    @testset "no unexpected resource leaks" begin
-        GC.gc(true)
-        GC.gc(true)
-        @test Arrow.UNRELEASED_HANDLE_COUNT[] == _initial_count + 1  # +1 for the intentional leak test
-    end
 end # @testset "Arrow C Data Interface"

From c8ac0d27b3ca6fe17a4b40952c05ec20b3bdbdcc Mon Sep 17 00:00:00 2001
From: Robert Buessow <robert.buessow@relational.ai>
Date: Tue, 26 May 2026 11:41:27 +0000
Subject: [PATCH 2/2] bumb version

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index b87ff796..a2928b83 100644
--- a/Project.toml
+++ b/Project.toml
@@ -17,7 +17,7 @@
 name = "Arrow"
 uuid = "69666777-d1a9-59fb-9406-91d4454c9d45"
 authors = ["quinnj <quinn.jacobd@gmail.com>"]
-version = "2.8.1"
+version = "2.9.0"
 
 [deps]
 ArrowTypes = "31f734f8-188a-4ce0-8406-c8a06bd891cd"