class ConditionVariable

def timed_wait(mutex, secs)
	ruby_engine = defined?(RUBY_ENGINE) ? RUBY_ENGINE : "ruby"
	if secs > 100000000
		# NOTE: If one calls timeout() on FreeBSD 5 with an
		# argument of more than 100000000, then MRI will become
		# stuck in an infite loop, blocking all threads. It seems
		# that MRI uses select() to implement sleeping.
		# I think that a value of more than 100000000 overflows
		# select()'s data structures, causing it to behave incorrectly.
		# So we just make sure we can't sleep more than 100000000
		# seconds.
		secs = 100000000
	end
	if ruby_engine == "jruby"
		if secs > 0
			return wait(mutex, secs)
		else
			return wait(mutex)
		end
	elsif RUBY_VERSION >= '1.9.2'
		if secs > 0
			t1 = Time.now
			wait(mutex, secs)
			t2 = Time.now
			return t2.to_f - t1.to_f < secs
		else
			wait(mutex)
			return true
		end
	else
		if secs > 0
			Timeout.timeout(secs) do
				wait(mutex)
			end
		else
			wait(mutex)
		end
		return true
	end
rescue Timeout::Error
	return false
end

def timed_wait!(mutex, secs)
	ruby_engine = defined?(RUBY_ENGINE) ? RUBY_ENGINE : "ruby"
	if secs > 100000000
		# See the corresponding note for timed_wait().
		secs = 100000000
	end
	if ruby_engine == "jruby"
		if secs > 0
			if !wait(mutex, secs)
				raise Timeout::Error, "Timeout"
			end
		else
			wait(mutex)
		end
	elsif RUBY_VERSION >= '1.9.2'
		if secs > 0
			t1 = Time.now
			wait(mutex, secs)
			t2 = Time.now
			if t2.to_f - t1.to_f >= secs
				raise Timeout::Error, "Timeout"
			end
		else
			wait(mutex)
		end
	else
		if secs > 0
			Timeout.timeout(secs) do
				wait(mutex)
			end
		else
			wait(mutex)
		end
	end
	return nil
end