distsys-nov-6-2018-p1.md

Some Midterm Solutions - DistSys Lecture - Nov 6th, 2018 (Part 1)

Spinlock

func (s *Spinlock) Lock() {
	for {
		test := 0
		Cmpxchg(&test, &s.held, 1)
		if test == 0 {
			break
		}
	}
}

func (s *Spinlock) Unlock() {
	// You don't need to use Cmpxchg here because
	// only one thread should have ownership of the
	// lock
	s.held = 0
}

Question 6

Since RPCs go across systems, we want to send the value that the pointer is pointing to.