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, 23 insertions, 4 deletions

diff --git a/ractor.rb b/ractor.rb
index 2196a93352..e4fbdfe102 100644
--- a/ractor.rb
+++ b/ractor.rb
@@ -214,9 +214,28 @@ class Ractor
     }
   end
 
-  def self.make_shareable obj
-    __builtin_cexpr! %q{
-      rb_ractor_make_shareable(obj);
-    }
+  # make obj sharable.
+  #
+  # Basically, traverse referring objects from obj and freeze them.
+  # 
+  # When a sharable object is found in traversing, stop traversing
+  # from this shareable object.
+  #
+  # If copy keyword is true, it makes a deep copied object
+  # and make it sharable. This is safer option (but it can take more time).
+  #
+  # Note that the specification and implementation of this method are not
+  # matured and can be changed in a future.
+  #
+  def self.make_shareable obj, copy: false
+    if copy
+      __builtin_cexpr! %q{
+        rb_ractor_make_copy_shareable(obj);
+      }
+    else
+      __builtin_cexpr! %q{
+        rb_ractor_make_shareable(obj);
+      }
+    end
   end
 end