Takes as argument the process id of the process to be resumed.
Returns an error value if argument is not a valid process id or is not in the suspended state.
Puts the process in the ready list.
Asks for rescheduling. (why?)
Stores the value of the priority of the resumed process before the process is rescheduled (why does this value have to be stored?).
Disables interrupts while accessing the process table to read the
priority of the resumed process.
If interrupts are not disabled,
a clock interrupt may ask for rescheduling.
Thus some other process may change the priority of the resumed process
before the resuming process has a chance to read the priority.