# frozen_string_literal: true
require "active_support/core_ext/module/delegation"
module ActiveSupport
module PerThreadRegistry
def self.extended(object)
object.instance_variable_set "@per_thread_registry_key", object.name.freeze
end
def instance
Thread.current[@per_thread_registry_key] ||= new
end
private
def method_missing(name, *args, &block)
# Caches the method definition as a singleton method of the receiver.
#
# By letting #delegate handle it, we avoid an enclosure that'll capture args.
singleton_class.delegate name, to: :instance
send(name, *args, &block)
end
end
end
用于在类里保存当前线程的变量信息，也就是说一个类extend了PerThreadRegistry,那么这个类的变量将只在这个线程里共享。
