instiki/vendor/rails/activesupport/lib/active_support/core_ext/module/synchronization.rb
Jacques Distler 4e14ccc74d Instiki 0.16.3: Rails 2.3.0
Instiki now runs on the Rails 2.3.0 Candidate Release.
Among other improvements, this means that it now 
automagically selects between WEBrick and Mongrel.

Just run

    ./instiki --daemon
2009-02-04 14:26:08 -06:00

40 lines
1.8 KiB
Ruby

class Module
# Synchronize access around a method, delegating synchronization to a
# particular mutex. A mutex (either a Mutex, or any object that responds to
# #synchronize and yields to a block) must be provided as a final :with option.
# The :with option should be a symbol or string, and can represent a method,
# constant, or instance or class variable.
# Example:
# class SharedCache
# @@lock = Mutex.new
# def expire
# ...
# end
# synchronize :expire, :with => :@@lock
# end
def synchronize(*methods)
options = methods.extract_options!
unless options.is_a?(Hash) && with = options[:with]
raise ArgumentError, "Synchronization needs a mutex. Supply an options hash with a :with key as the last argument (e.g. synchronize :hello, :with => :@mutex)."
end
methods.each do |method|
aliased_method, punctuation = method.to_s.sub(/([?!=])$/, ''), $1
if method_defined?("#{aliased_method}_without_synchronization#{punctuation}")
raise ArgumentError, "#{method} is already synchronized. Double synchronization is not currently supported."
end
module_eval(<<-EOS, __FILE__, __LINE__)
def #{aliased_method}_with_synchronization#{punctuation}(*args, &block) # def expire_with_synchronization(*args, &block)
#{with}.synchronize do # @@lock.synchronize do
#{aliased_method}_without_synchronization#{punctuation}(*args, &block) # expire_without_synchronization(*args, &block)
end # end
end # end
EOS
alias_method_chain method, :synchronization
end
end
end