metasploit-framework/lib/rex/sync/ref.rb

require 'thread'

module Rex

###
#
# This module provides a uniform reference counted interface for classes to
# use.
#
###
module Ref

	#
	# Initializes the reference count to one.
	#
	def refinit
		@_references       = 1
		@_references_mutex = Mutex.new

		self
	end

	#
	# Increments the total number of references.
	#
	def ref
		@_references_mutex.synchronize {
			@_references += 1
		}

		self
	end

	#
	# Decrements the total number of references.  If the reference count
	# reaches zero, true is returned.  Otherwise, false is returned.
	#
	def deref
		@_references_mutex.synchronize {
			if ((@_references -= 1) == 0)
				cleanup

				true
			else
				false
			end
		}
	end

	#
	# Called to clean up resources once the ref count drops to zero.
	#
	def cleanup
	end

end
end