Memprof2 is a Ruby memory profiler for >= Ruby 2.1.0.

Execute

$ gem install memprof2

or ddd the following to your Gemfile:

gem 'memprof2'

And then execute:

$ bundle

Memprof2.start
12.times{ "abc" }
Memprof2.report(out: "/path/to/file")
Memprof2.stop

Start tracking file/line memory size (bytes) information for objects created after calling Memprof2.start, and print out a summary of file:line:class pairs created.

480 file.rb:2:String

Note: Call Memprof2.report again after GC.start to see which objects are cleaned up by the garbage collector:

Memprof2.start
10.times{ $last_str = "abc" }

puts '=== Before GC'
Memprof2.report

puts '=== After GC'
GC.start
Memprof2.report

Memprof2.stop

After GC.start, only the very last instance of "abc" will still exist:

=== Before GC
400 file.rb:2:String
=== After GC
40 file.rb:2:String

Note: Use Memprof2.report! to clear out tracking data after printing out results.

Use trace and ignore options to restrict files to report. You can write patterns by regular expressions:

Memprof2.start
10.times{ $last_str = "abc" }
GC.start
Memprof2.report!(trace: /file\.rb/, ignore: /ignore_me/, out: "/path/to/file")
Memprof2.stop

A shorthand for Memprof2.start/stop that will start/stop memprof around a given block of ruby code.

Memprof2.run do
  100.times{ "abc" }
  100.times{ 1.23 + 1 }
  100.times{ Module.new }
  Memprof2.report(out: "/path/to/file")
end

For the block of ruby code, print out file:line:class pairs for ruby objects created.

4000  file.rb:2:String
4000  file.rb:3:Float
4000  file.rb:4:Module

Note: You can call GC.start at the end of the block to print out only objects that are 'leaking' (i.e. objects that still have inbound references).

A shorthand for Memprof2.start/report/stop.

Following codes work exactly same with the above example.

Memprof2.run_with_report(out: "/path/to/file") do
  100.times{ "abc" }
  100.times{ 1.23 + 1 }
  100.times{ Module.new }
end

See CHANGELOG.md for details.

• Ruby でラインメモリプロファイラ (Japanese)

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Copyright (c) 2014 Naotoshi Seo. See LICENSE.txt for details.