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