I think two processes set up a file in /var/lock to see (by the presence of the file) if they are attempting to grab the same resource. If the directory itself isn't there the "is this device in use" function fails.
I think two processes set up a file in /var/lock to see (by the presence of the file) if they are attempting to grab the same resource. If the directory itself isn't there the "is this device in use" function fails.