How long 120mg. well, the half-life of methadone can be up to 59-hours, so after 2 and half days you would still have 60mg's in your system. But this doesn't take into account multiple doses.
A third type of lock is a security lock. This lock is like a typical password, to prevent someone other than the owner from using the phone. If activated accidentally, the user manual or carrier customer service can usually tell you the default code.
/var/lock. Lock files. Many programs follow a convention to create a lock file in. to indicate that they are using a particular device or file. Other programs will notice the lock file and won't attempt to use the device or file.