ruby/zjit.rb

# frozen_string_literal: true

# This module allows for introspection of \ZJIT, CRuby's just-in-time compiler.
# Everything in the module is highly implementation specific and the API might
# be less stable compared to the standard library.
#
# This module may not exist if \ZJIT does not support the particular platform
# for which CRuby is built.
module RubyVM::ZJIT
  # Avoid calling a Ruby method here to avoid interfering with compilation tests
  if Primitive.rb_zjit_stats_enabled_p
    at_exit { print_stats }
  end
end

class << RubyVM::ZJIT
  # Check if \ZJIT is enabled
  def enabled?
    Primitive.cexpr! 'RBOOL(rb_zjit_enabled_p)'
  end

  # Return \ZJIT statistics as a Hash
  def stats
    stats = Primitive.rb_zjit_stats

    if stats.key?(:vm_insns_count) && stats.key?(:zjit_insns_count)
      stats[:total_insns_count] = stats[:vm_insns_count] + stats[:zjit_insns_count]
      stats[:ratio_in_zjit] = 100.0 * stats[:zjit_insns_count] / stats[:total_insns_count]
    end

    stats
  end

  # Get the summary of \ZJIT statistics as a String
  def stats_string
    buf = +''
    stats = self.stats

    [
      :total_insns_count,
      :vm_insns_count,
      :zjit_insns_count,
      :ratio_in_zjit,
    ].each do |key|
      value = stats[key]
      if key == :ratio_in_zjit
        value = '%0.1f%%' % value
      end
      buf << "#{'%-18s' % "#{key}:"} #{value}\n"
    end
    buf
  end

  # Assert that any future ZJIT compilation will return a function pointer
  def assert_compiles # :nodoc:
    Primitive.rb_zjit_assert_compiles
  end

  # :stopdoc:
  private

  # Print ZJIT stats
  def print_stats
    $stderr.write stats_string
  end
end