add "copy: true" option for Ractor.make_shareable

Ractor.make_shareable(obj) tries to make obj a shareable object
by changing the attribute of obj and traversable objects from obj
(mainly freeze them).

"copy: true" option is more conservative approach by make deep
copied object and make it sharable. It doesn't affect any existing
objects.

1 files changed, 16 insertions, 0 deletions

diff --git a/bootstraptest/test_ractor.rb b/bootstraptest/test_ractor.rb
index e81afb6fa3..c587c2c1eb 100644
--- a/bootstraptest/test_ractor.rb
+++ b/bootstraptest/test_ractor.rb
@@ -1176,6 +1176,22 @@ assert_equal 'can not make a Proc shareable because it accesses outer variables
   end
 }
 
+# Ractor.make_shareable(obj, copy: true) makes copied shareable object.
+assert_equal '[false, false, true, true]', %q{
+  r = []
+  o1 = [1, 2, ["3"]]
+
+  o2 = Ractor.make_shareable(o1, copy: true)
+  r << Ractor.shareable?(o1) # false
+  r << (o1.object_id == o2.object_id) # false
+
+  o3 = Ractor.make_shareable(o1)
+  r << Ractor.shareable?(o1) # true
+  r << (o1.object_id == o3.object_id) # false
+  r
+}
+
+
 # Ractor deep copies frozen objects (ary)
 assert_equal '[true, false]', %q{
   Ractor.new([[]].freeze) { |ary|