ruby/test/objspace/test_ractor.rb

require "test/unit"

class TestObjSpaceRactor < Test::Unit::TestCase
  def test_tracing_does_not_crash
    assert_ractor(<<~RUBY, require: 'objspace')
      ObjectSpace.trace_object_allocations do
        r = Ractor.new do
          _obj = 'a' * 1024
        end

        r.join
      end
    RUBY
  end

  # dump_all / memsize_of_all cover every Ractor's objspace, including other Ractors'
  # unshareable objects
  def test_dump_all_covers_all_ractors
    assert_ractor(<<~'RUBY', require: 'objspace')
      ready = Ractor::Port.new
      ch = Ractor.new(ready) do |port|
        marker = +"DUMP_ALL_MARKER_FOREIGN"
        port << :built
        Ractor.receive
        marker.size
      end
      ready.receive

      dump = ObjectSpace.dump_all(output: :string)
      assert_include dump, "DUMP_ALL_MARKER_FOREIGN"

      ch.send(:go)
      ch.value
    RUBY
  end

  def test_undefine_finalizer
    assert_ractor(<<~'RUBY', timeout: 20, require: 'objspace', signal: :SEGV)
      def fin
        ->(id) { }
      end
      ractors = 5.times.map do
        Ractor.new do
          10_000.times do
            o = Object.new
            ObjectSpace.define_finalizer(o, fin)
            ObjectSpace.undefine_finalizer(o)
          end
        end
      end

      ractors.each(&:join)
    RUBY
  end

  def test_copy_finalizer
    assert_ractor(<<~'RUBY', require: 'objspace')
      def fin
        ->(id) { }
      end
      OBJ = Object.new
      ObjectSpace.define_finalizer(OBJ, fin)
      OBJ.freeze

      ractors = 5.times.map do
        Ractor.new do
          10_000.times do
            OBJ.clone
          end
        end
      end

      ractors.each(&:join)
    RUBY
  end

  # A joined-but-not-valued Ractor keeps its objspace as a zombie.
  # ObjectSpace.dump_all should still walk it for shareables.
  def test_dump_all_includes_zombie_objspace
    assert_ractor(<<~'RUBY', require: ['objspace', 'json'])
      port = Ractor::Port.new
      ch = Ractor.new(port) do |port|
        port << Object.new.freeze
        Ractor.receive
      end
      obj = port.receive
      ch.send(:go)
      ch.join
      loop until ch.inspect =~ /terminated/ # unfortunate

      needle = JSON.parse(ObjectSpace.dump(obj))["address"] # relies on non-moving collector
      found = ObjectSpace.dump_all(output: :string).each_line.any? do |line|
        json = JSON.parse(line) rescue nil
        json && json["address"] == needle
      end
      assert found, "zombie objspace object missing from dump_all"
    RUBY
  end

  def test_trace_object_allocations_with_ractor_tracepoint
    # Test that ObjectSpace.trace_object_allocations works globally across all Ractors
    assert_ractor(<<~'RUBY', require: 'objspace')
      ObjectSpace.trace_object_allocations do
        obj1 = Object.new; line1 = __LINE__
        assert_equal __FILE__, ObjectSpace.allocation_sourcefile(obj1)
        assert_equal line1, ObjectSpace.allocation_sourceline(obj1)

        r = Ractor.new {
          obj = Object.new; line = __LINE__
          [line, obj]
        }

        obj2 = Object.new; line2 = __LINE__
        assert_equal __FILE__, ObjectSpace.allocation_sourcefile(obj2)
        assert_equal line2, ObjectSpace.allocation_sourceline(obj2)

        expected_line, ractor_obj = r.value
        assert_equal __FILE__, ObjectSpace.allocation_sourcefile(ractor_obj)
        assert_equal expected_line, ObjectSpace.allocation_sourceline(ractor_obj)

        obj3 = Object.new; line3 = __LINE__
        assert_equal __FILE__, ObjectSpace.allocation_sourcefile(obj3)
        assert_equal line3, ObjectSpace.allocation_sourceline(obj3)
      end
    RUBY
  end
end