MUTUAL EXCLUSION

Only one thing
may hold the resource.

The rule never says
it has to be
a driver.

acquire(wheel)

held

by one orange process
the scheduler has
no record of.

No PID.
No credentials.

One paw
within jurisdiction.

A request from behind
blocks.

Another would queue
behind that.

Given enough requests,
this becomes traffic.

PREEMPTION

preempt

pet

The holder acknowledges
the interrupt

and retains
ownership.

release()

not implemented
by this process.