therubyracer freezes, if used in webservice

sinatra-nodejs.ru

##### freezes after a couple of requests...
# OS: osx 10.9.1, libv8 (3.16.14.3 x86_64-darwin-13), therubyracer (0.12.1)
# gem install sinatra therubyracer json puma
# rackup sinatra-nodejs.ru
# wrk -t 2 -d 3 http://0.0.0.0:9292/am
# webserver (puma/webrick) does not make any difference


require 'sinatra/base'
require 'json'
require 'v8'


SUGGESTIONS = []
File.foreach("/usr/share/dict/words") do |line|
  SUGGESTIONS << line
  break if SUGGESTIONS.size > 200
end

class HelloWord < Sinatra::Base
  get '/:q' do
    matches = get_matches(params[:q])
    halt 200, {'Content-Type' => 'text/json'}, matches.to_json
  end

  def get_matches(q)
    matches = nil
    with_proper_vm_lock do
      ctx                = V8::Context.new
      ctx['suggestions'] = SUGGESTIONS
      ctx['q']           = q
      matches = Array(ctx.eval(<<-eojs
      suggestions.filter(function(suggestion) {
              return suggestion.search(q) > -1;
          }).slice(0,10);
      eojs
      ))
      ctx.dispose()
    end
    matches
  end

  def with_proper_vm_lock
    V8::C::Locker() do
      V8::C::HandleScope() do
        @cxt = V8::C::Context::New()
        begin
          @cxt.Enter()
          yield
        ensure
          @cxt.Exit()
        end
      end
    end
  end
end

run HelloWord

sinatra-v8-connection-pool.ru

##### v.2, with connection_pool.... still freezes.
##### freezes after a couple of requests...
# gem install sinatra therubyracer json puma
# rackup sinatra-v8-connection-pool.ru
# wrk -t 2 -d 3 http://0.0.0.0:9292/am
# webserver (puma/webrick) does not make any difference


require 'sinatra/base'
require 'json'
require 'connection_pool'
require 'v8'
require 'execjs'


SUGGESTIONS = []
File.foreach("/usr/share/dict/words") do |line|
  SUGGESTIONS << line
  break if SUGGESTIONS.size > 200
end


class Renderer
  class << self
    attr_accessor :pool

    def setup!
      @pool.shutdown{} if @pool
      @pool = ConnectionPool.new(:size => 10, :timeout => 20) { self.new }
    end

    def render(q)
      @pool.with do |renderer|
        renderer.render(q)
      end
    end
  end

  def context
    @context ||= ExecJS.compile('1+1')
  end

  def render(q)
    jscode = <<-JS
      function() {
        var q = '#{q}';
        var suggestions = #{SUGGESTIONS.to_json}
        return suggestions.filter(function(suggestion) {
          return suggestion.search(q) > -1;
        }).slice(0,10);
      }()
    JS
    context.eval(jscode)
  rescue ExecJS::ProgramError => e
    "[Renderer] #{e.message}"
  end
end
Renderer.setup!

class HelloWord < Sinatra::Base
  get '/:q' do
    matches = get_matches(params[:q])
    halt 200, {'Content-Type' => 'text/json'}, matches.to_json
  end

  def get_matches(q)
    Renderer.render(q)
  end
end

run HelloWord

Did you make any headway figuring out why? I am wanting to do something similar on running js on the server and trying to decide between just using node directly or therubyracer within sinatra/rails. Also considered elixir, but it doesn't have the power of therubyracer.