20、(N, N) 原子寄存器：原理、实现与性能分析

(N, N) 原子寄存器：原理、实现与性能分析

1. Read - Impose Write - Majority 算法

Read - Impose Write - Majority 算法的第二部分主要涉及写操作和回写操作，以下是其代码实现：

Algorithm 4.7: Read - Impose Write - Majority (part 2, write and write - back)
upon event ⟨onar, Write | v ⟩do
    rid := rid + 1;
    wts := wts + 1;
    acks := 0;
    trigger ⟨beb, Broadcast | [WRITE, rid, wts, v] ⟩;
upon event ⟨beb, Deliver | p, [WRITE, r, ts′, v′] ⟩do
    if ts′ > ts then
        (ts, val) := (ts′, v′);
        trigger ⟨pl, Send | p, [ACK, r] ⟩;
upon event ⟨pl, Deliver | q, [ACK, r] ⟩such that r = rid do
    acks := acks + 1;
    if acks > N/2 then
        acks := 0;
        if reading = TRUE then
            reading := FALSE;
            trigger ⟨onar, ReadReturn | readv