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.
Call DECLARE_LOCK(name) to create a lock definition, LOCK(name) to acquire the lock, and UNLOCK(name) to release it. The LOCK macro will spin until the lock is released before continuing. This code makes use of intrisics specific to GCC, but it also compiles on Clang.