chef

https://github.com/opscode/chef

Ruby

A systems integration framework, built to bring the benefits of configuration management to your entire infrastructure.

Chef::RunLock#acquire

Acquire the system-wide lock. Will block indefinitely if another process
already has the lock and Chef::Config[:run_lock_timeout] is
not set. Otherwise will block for Chef::Config[:run_lock_timeout]
seconds and exit if the lock is not acquired.

Each call to acquire should have a corresponding call to #release.

The implementation is based on File#flock (see also: flock(2)).

Either acquire() or test() methods should be called in order to
get the ownership of run_lock.

Source | Google | Stack overflow

Edit

git clone [email protected]:opscode/chef.git
cd chef
open lib/chef/run_lock.rb

Contribute

# Make a new branch

git checkout -b -your-name--update-docs-Chef--RunLock-acquire-for-pr

# Commit to git

git add lib/chef/run_lock.rbgit commit -m "better docs for Chef::RunLock#acquire"

# Open pull request

gem install hub # on a mac you can `brew install hub`

hub fork

git push <your name> -your-name--update-docs-Chef--RunLock-acquire-for-pr

hub pull-request

# Celebrate!