Virtual Net: A Decentralized Architecture for Interaction in Mobile Virtual Worlds

Algorithm 6

Consensus.

1. 

2. Upon P ≠ ∅  ∧ CR = false ∧ LE = false

3.  For each () ∈P ∧ c∉Z,

4.   

5.   QUERY ← ()

6.   Reliably send QUERY to

7.

8. Upon QUERY_RESULT(epoch’, cid’, r, W_i) from r_i  ∧ epoch’ = epoch ∧

  cid’ = cid ∧ CR = false ∧ LE = false

9.  

10.

11. Upon G∩R⊆

12.  R’ ← Decide(c, Q)

13.  

14.  

15.  DECISION ← (epoch, cid, c, W’)

16.  Reliably broadcast DECISION to

17.

18.

19. Upon QUERY(epoch’, cid’, r,) from

    epoch’ = epoch ∧ cid’ = cid ∧ GR = false ∧ LE = false

20.  For each ,

21.   c’ = c – (Seq(s, c) – j)

22.   W ← W∪

23.  QUERY_RESULT ← (epoch, cid, c, W)

24.  Reliably send QUERY_RESULT to r_L

25.

26. Upon DECISION(epoch, cid’, c, W’) from r_L  ∧ epoch’ = epoch ∧ cid’ =

    cid ∧ GR = false ∧ LE = false

27.  E ← E ∪ W’

28.

29. Decide(c, Q)

30.  For each s∈S and ,

30.   If ∃e(s, j): e(s, j) ≠ ⊥ e(s, j) ∈, then

31.    W’ ← W’ ∪

32.   Else

33.    e← (s, j, Empty)

34.    W’ ← W’ ∪

31.  Return W’