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MasterLock is a Ruby library for interprocess locking using Redis. Critical sections of code can be wrapped in a MasterLock block that ensures only one thread will run the code at a time. The locks are resilient to process failures by expiring after the thread obtaining them dies.


Add this line to your application's Gemfile:

gem 'master_lock'

And then execute:

$ bundle

Or install it yourself as:

$ gem install master_lock


def perform_safe_operation
  MasterLock.synchronize("perform_safe_operation") do
    # Code executes within locked context

# Call MasterLock.start when your application boots up.
# This starts a background thread to prevent locks from expiring.

See documentation for advanced usage.


After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to


Bug reports and pull requests are welcome on GitHub at


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