add read lock in destroy
add read lock in destroy

Signed-off-by: Alex Suraci <a8053324ea51f0cc533cfe7b17f8bee3c920919f@pivotallabs.com>

shashidharatd/garden-linux,cloudfoundry-incubator/garden-linux,cloudfoundry-incubator/garden-linux,shashidharatd/garden-linux,cloudfoundry-incubator/garden-linux,shashidharatd/garden-linux,shashidharatd/garden-linux