SafeFlock

Thread-safe, transferable, flock-based file lock.

This helper solves mutual exclusion within niche constraints:

• A parent process must acquire a lock and transfer it to a child process.
• The parent may terminate before the child.
• Locks may be created within threads within the parent.

Installation

Add this line to your application's Gemfile:

gem 'safe_flock'

And then execute:

$ bundle

Or install it yourself as:

$ gem install safe_flock

Documentation

For documentation of the released gem, see rubydoc.info.

Usage

Simple example:

require "safe_flock"

SafeFlock.create("/var/run/myapp/myapp.lck") do
  # ... mutually excluded processing
end

The use case for which the helper was created:

require "safe_flock"

SafeFlock.create("/var/run/myapp/myapp.lck") do |lock|
  child = fork do

    # ... mutually excluded processing

    lock.unlock

    # ... non-critical processing

  end
end
Process.detach(child)

Development

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

To run the test suite, run bundle exec rake spec.

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 rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/starjuice/safe_flock.