# * George Moschovitis  <gm@navel.gr>
# (c) 2002-2005 Navel, all rights reserved.
# $Id: array.rb 282 2005-03-10 12:24:53Z gmosx $

require 'sync'

module N

# A thread-safe array. We use a sync object instead of a 
# mutex, because it is re-entrant. An exclusive lock is 
# needed when writing, a shared lock IS NEEDED when reading.

class SafeArray < Array
	
	attr :sync

	# gmosx: delegator is not used.
	
	def initialize(delegator = nil)
		@sync = Sync.new()
	end

	def << (value)
		return @sync.synchronize(Sync::SH) { super }		
	end
	
	def delete_if(&block) 
		return @sync.synchronize(Sync::SH) { super }				
	end
	
	def [](key)
		return @sync.synchronize(Sync::SH) { super }
	end

	def []=(key, value)
		return @sync.synchronize(Sync::EX) { super }
	end

	def delete(key)
		return @sync.synchronize(Sync::EX) { super }
	end

	def clear
		@sync.synchronize(Sync::EX) {	super }
	end

	def size
		return @sync.synchronize(Sync::SH) { super }
	end

	def shift
		return @sync.synchronize(::Sync::EX) { super }
	end

	def unshift(el)
		return @sync.synchronize(::Sync::EX) { super }
	end
		
end

end