From de3130ede1a2db7bbe9e129f21856ee80de0f8cb Mon Sep 17 00:00:00 2001
From: Sutou Kouhei <kou@clear-code.com>
Date: Mon, 8 Jan 2024 07:21:00 +0900
Subject: [PATCH] GH-39488: [Ruby] Add support for ChunkedArray in Ractor
 (#39490)

### Rationale for this change

We can't use `@ cache ||= build_cache` idiom in Ractor because Ractor requires that shared objects are immutable.

### What changes are included in this PR?

Compute caches before making ChunkedArray immutable.

### Are these changes tested?

Yes.

### Are there any user-facing changes?

Yes.
* Closes: #39488

Authored-by: Sutou Kouhei <kou@clear-code.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>
---
 ruby/red-arrow/lib/arrow/chunked-array.rb |  8 ++++++
 ruby/red-arrow/test/helper/omittable.rb   |  5 ++++
 ruby/red-arrow/test/test-ractor.rb        | 34 +++++++++++++++++++++++
 3 files changed, 47 insertions(+)
 create mode 100644 ruby/red-arrow/test/test-ractor.rb

diff --git a/ruby/red-arrow/lib/arrow/chunked-array.rb b/ruby/red-arrow/lib/arrow/chunked-array.rb
index 7d83becc6deb3..0cdd9b6a6d2f0 100644
--- a/ruby/red-arrow/lib/arrow/chunked-array.rb
+++ b/ruby/red-arrow/lib/arrow/chunked-array.rb
@@ -24,6 +24,14 @@ class ChunkedArray
     include GenericTakeable
     include InputReferable
 
+    def freeze
+      unless frozen?
+        # Ensure caching
+        chunks
+      end
+      super
+    end
+
     def to_arrow
       self
     end
diff --git a/ruby/red-arrow/test/helper/omittable.rb b/ruby/red-arrow/test/helper/omittable.rb
index a1c0334b63a2b..8e1564be47879 100644
--- a/ruby/red-arrow/test/helper/omittable.rb
+++ b/ruby/red-arrow/test/helper/omittable.rb
@@ -17,6 +17,11 @@
 
 module Helper
   module Omittable
+    def require_ruby(major, minor, micro=0)
+      return if (RUBY_VERSION <=> "#{major}.#{minor}.#{micro}") >= 0
+      omit("Require Ruby #{major}.#{minor}.#{micro} or later: #{RUBY_VERSION}")
+    end
+
     def require_gi_bindings(major, minor, micro)
       return if GLib.check_binding_version?(major, minor, micro)
       message =
diff --git a/ruby/red-arrow/test/test-ractor.rb b/ruby/red-arrow/test/test-ractor.rb
new file mode 100644
index 0000000000000..daf674d135257
--- /dev/null
+++ b/ruby/red-arrow/test/test-ractor.rb
@@ -0,0 +1,34 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+class RactorTest < Test::Unit::TestCase
+  include Helper::Omittable
+
+  ractor
+  test("ChunkedArray") do
+    require_ruby(3, 1, 0)
+    array = Arrow::Array.new([1, 2, 3])
+    chunked_array = Arrow::ChunkedArray.new([array])
+    Ractor.make_shareable(chunked_array)
+    ractor = Ractor.new do
+      recived_chunked_array = Ractor.receive
+      recived_chunked_array.chunks
+    end
+    ractor.send(chunked_array)
+    assert_equal([array], ractor.take)
+  end
+end