A gem to execute a block of code and ensure that one does not execute other code until the block has completed executing.
Add this line to your application's Gemfile:
gem 'with_locking'
Or install it yourself as:
$ gem install with_locking
A block of code can be executed like so:
WithLocking.run { puts "this code is locked!" }
Alternatively, run the block of code with an optional name (recommended), that way multiple WithLocking blocks with different names can be invoked without conflicting:
WithLocking.run(name: "sleeper") { sleep 60 }
WithLocking.run(name: "sleeper") do
puts "I won't execute and will return false because 'sleeper'
is still running the first block."
end
WithLocking.run(name: "other_name") do
puts "But I will run because 'other_name' isn't running!"
end
# => "But I will run because 'other_name' isn't running!"
To simply test if a named block is still running without executing a block use
the locked? method:
WithLocking.locked?("sleeper")
# => true or false
To raise an exception when the block isn't run (rather than simply returning
false), use the do! method:
WithLocking.run!(name: "sleeper") { puts "Blah" }
# => raises an error if 'sleeper' block is still running from before