The Rust memory management lifecycle

Computer programs can be modeled as finite state machines. A running program accepts different forms of inputs (for example, file inputs, command-line arguments, network calls, interrupts, and so on) and transitions from one state to another. Take the case of a device driver. It can be in either of the following states: uninitialized, active, or inactive. When a device driver is just booted up (loaded into memory), it is in the uninitialized state. When the device registers are initialized and ready to accept events, it goes into the active state. It can be put in suspended mode and not ready to accept inputs, in which case it goes into the inactive state. You can extend this concept further. For a communications device like a serial port, the device driver can be in the sending or receiving state. Interrupts can trigger the transitions from one state to another. Likewise, every kind of program, whether it is a kernel component, command-line tool...