diff options
Diffstat (limited to 'activesupport/lib/active_support/execution_wrapper.rb')
-rw-r--r-- | activesupport/lib/active_support/execution_wrapper.rb | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/execution_wrapper.rb b/activesupport/lib/active_support/execution_wrapper.rb new file mode 100644 index 0000000000..2bd1c01d35 --- /dev/null +++ b/activesupport/lib/active_support/execution_wrapper.rb @@ -0,0 +1,78 @@ +require 'active_support/callbacks' + +module ActiveSupport + class ExecutionWrapper + include ActiveSupport::Callbacks + + Null = Object.new # :nodoc: + def Null.complete! # :nodoc: + end + + define_callbacks :run + define_callbacks :complete + + def self.to_run(*args, &block) + set_callback(:run, *args, &block) + end + + def self.to_complete(*args, &block) + set_callback(:complete, *args, &block) + end + + # Run this execution. + # + # Returns an instance, whose +complete!+ method *must* be invoked + # after the work has been performed. + # + # Where possible, prefer +wrap+. + def self.run! + if active? + Null + else + new.tap(&:run!) + end + end + + # Perform the work in the supplied block as an execution. + def self.wrap + return yield if active? + + state = run! + begin + yield + ensure + state.complete! + end + end + + class << self # :nodoc: + attr_accessor :active + end + + def self.inherited(other) # :nodoc: + super + other.active = Concurrent::Hash.new + end + + self.active = Concurrent::Hash.new + + def self.active? # :nodoc: + @active[Thread.current] + end + + def run! # :nodoc: + self.class.active[Thread.current] = true + run_callbacks(:run) + end + + # Complete this in-flight execution. This method *must* be called + # exactly once on the result of any call to +run!+. + # + # Where possible, prefer +wrap+. + def complete! + run_callbacks(:complete) + ensure + self.class.active.delete Thread.current + end + end +end |