Ractor-shareable JSON::Coder

Author: etiennebarrie

ext/json/ext/parser/parser.c

@@ -1555,6 +1555,11 @@ static size_t JSON_ParserConfig_memsize(const void *ptr)
     return sizeof(JSON_ParserConfig);
 }
 
+#ifndef HAVE_RB_EXT_RACTOR_SAFE
+#   undef RUBY_TYPED_FROZEN_SHAREABLE
+#   define RUBY_TYPED_FROZEN_SHAREABLE 0
+#endif
+
 static const rb_data_type_t JSON_ParserConfig_type = {
     "JSON::Ext::Parser/ParserConfig",
     {
@@ -1563,7 +1568,7 @@ static const rb_data_type_t JSON_ParserConfig_type = {
         JSON_ParserConfig_memsize,
     },
     0, 0,
-    RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE cJSON_parser_s_allocate(VALUE klass)

lib/json/common.rb

@@ -1051,6 +1051,12 @@ def initialize(options = nil, &as_json)
       @parser_config = Ext::Parser::Config.new(ParserOptions.prepare(options))
     end
 
+    def freeze
+      @state.freeze
+      @parser_config.freeze
+      super
+    end
+
     # call-seq:
     #   dump(object) -> String
     #   dump(object, io) -> io

test/json/ractor_test.rb

@@ -52,4 +52,68 @@ def test_generate
     _, status = Process.waitpid2(pid)
     assert_predicate status, :success?
   end
+
+  module Store
+    extend self
+    attr_accessor :coder
+  end
+
+  def test_coder
+    Store.coder = JSON::Coder.new.freeze
+    assert Ractor.shareable?(Store.coder)
+    pid = fork do
+      Warning[:experimental] = false
+      r = Ractor.new do
+        json = Store.coder.dump({
+          'a' => 2,
+          'b' => 3.141,
+          'c' => 'c',
+          'd' => [ 1, "b", 3.14 ],
+          'e' => { 'foo' => 'bar' },
+          'g' => "\"\0\037",
+          'h' => 1000.0,
+          'i' => 0.001
+        })
+        Store.coder.load(json)
+      end
+      expected_json = JSON.parse('{"a":2,"b":3.141,"c":"c","d":[1,"b",3.14],"e":{"foo":"bar"},' +
+                      '"g":"\\"\\u0000\\u001f","h":1000.0,"i":0.001}')
+      actual_json = r.value
+
+      if expected_json == actual_json
+        exit 0
+      else
+        puts "Expected:"
+        puts expected_json
+        puts "Actual:"
+        puts actual_json
+        puts
+        exit 1
+      end
+    end
+    _, status = Process.waitpid2(pid)
+    assert_predicate status, :success?
+  end
+
+  class NonNative
+    def initialize(value)
+      @value = value
+    end
+  end
+
+  def test_coder_proc
+    block = Ractor.shareable_proc { |value| value.as_json }
+    Store.coder = JSON::Coder.new(&block).freeze
+    assert Ractor.shareable?(Store.coder)
+
+    pid = fork do
+      Warning[:experimental] = false
+      assert_equal [{}], Ractor.new {
+        Store.coder.load('[{}]')
+      }.value
+    end
+
+    _, status = Process.waitpid2(pid)
+    assert_predicate status, :success?
+  end if Ractor.respond_to?(:shareable_proc)
 end if defined?(Ractor) && Process.respond_to?(:fork)