JRuby::Profiler::FlameGraphProfilePrinter

This is a JRuby Profiler Printer that will dump a profile into a form for usage with FlameGraph. It only builds a FlameGraph from the thread that wraps the profiler, because I'm not sure the JRuby profiler supports multiple threads right now.

$ gem install jruby-profiler-flame_graph_profile_printer

require "jruby/profiler/flame_graph_profile_printer"

def ok
  3 ** 3
end

def test
  ok ** 3
end

result = JRuby::Profiler.profile do
  # Do some expensive stuff.
  10_000.times do
     test ** 3
  end
end

printer = JRuby::Profiler::FlameGraphProfilePrinter.new(result)
printer.printProfile(STDOUT)

# Assuming you have the above example saved as "powers.rb".
jruby --profile.api powers.rb | ./FlameGraph/flamegraph.pl > output.svg

Where ./FlameGraph/flamegraph.pl is a cloned version of FlameGraph.

Here's a slightly more complex example:

Bug reports and pull requests are welcome on GitHub at https://github.com/film42/jruby-profiler-flame_graph_profile_printer. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.