force -Xjit.max setting on JRuby <= 9.2.8

jit_max_force.rb

# force -Xjit.max setting on JRuby <= 9.2.8
#
# forcing is not perfect -
# counter for existing methods will still keep incrementing but compilation is expected to halt
#
# @note -Xjit.max has no effect on JRuby 9K - its only enforced since 9.2.9
#

(Class.new do

  JIT_MAX = ENV_JAVA['jruby.jit.max'].to_i

  if JRUBY_VERSION >= '9.2.9'
    fail "-Xjit.max enforcing no longer necessary on JRuby #{JRUBY_VERSION}, remove #{__FILE__}"
  end

  def self.start_thread
    return unless JIT_MAX > 0
    Thread.start do
      loop { sleep 90; new.check_and_force_jit_max }
    end
  end

  def check_and_force_jit_max
    success_count = mbean_server.getAttribute jit_compiler_mbean_name, 'SuccessCount'
    if success_count > JIT_MAX
      org.jruby.util.cli.Options::JIT_THRESHOLD.force '1000000000'
      warn "halting JRuby JIT by forcing JIT_THRESHOLD to #{org.jruby.util.cli.Options::JIT_THRESHOLD.load}"
      raise StopIteration
    end
  end

  def jit_compiler_mbean_name
    name = javax.management.ObjectName.getInstance("org.jruby:*,service=JITCompiler")
    mbean_server.queryNames(name, nil).first
  end

  def mbean_server
    java.lang.management.ManagementFactory.getPlatformMBeanServer
  end

end.start_thread) if defined?(JRUBY_VERSION)