simulator for HyParView protocol bootstraping

hyparview_bootstraping_simulator.go

package main

import (
	"fmt"
	"math/rand"
	"sync/atomic"
	"time"
)

var makeup int32
var breakup int32
var messageSent int32

type member struct {
	fanout        int
	totalPool     []*member
	id            int
	friends       []int
	makeup        chan int
	breakup       chan int
	needNewFriend chan bool
}

func (m *member) run() {
	for {
		select {
		case id := <-m.makeup:
			atomic.AddInt32(&makeup, 1)
			if len(m.friends) < m.fanout+2 {
				m.friends = append(m.friends, id)
			} else {
				vindex := rand.Intn(len(m.friends))
				victim := m.friends[vindex]
				m.totalPool[victim].breakup <- m.id
				m.friends[vindex] = id
			}
		case id := <-m.breakup:
			atomic.AddInt32(&breakup, 1)
			index := -1
			for i := range m.friends {
				if m.friends[i] == id {
					index = i
					break
				}
			}
			if index >= 0 {
				// Slot found for making new friends
				newFriend := rand.Intn(len(m.totalPool))
				m.friends[index] = newFriend
				m.totalPool[newFriend].makeup <- m.id
			}
		case <-m.needNewFriend:
			if len(m.friends) < m.fanout {
				newFriend := rand.Intn(len(m.totalPool))
				m.friends = append(m.friends, newFriend)
				m.totalPool[newFriend].makeup <- m.id
			}
			if len(m.friends) < m.fanout {
				m.needNewFriend <- true
			}
		}
		atomic.AddInt32(&messageSent, 1)
	}
}

func main() {
	n := 10000
	fan := 5
	m := make([]*member, n)

	for i := range m {
		m[i] = &member{
			totalPool:     m,
			fanout:        fan,
			id:            i,
			friends:       make([]int, 0, fan),
			makeup:        make(chan int, 1024),
			breakup:       make(chan int, 1024),
			needNewFriend: make(chan bool, 1024),
		}
	}
	for i := range m {
		m[i].needNewFriend <- true
		go m[i].run()
	}

	for j := 0; ; j++ {
		select {
		case <-time.After(time.Millisecond):
			fmt.Println("round ", j)
			for i := range m {
				fmt.Println(i, ": ", m[i].friends)
			}
			fmt.Println("makeup: ", makeup, "breakup: ", breakup)
			atomic.StoreInt32(&makeup, 0)
			atomic.StoreInt32(&breakup, 0)
		}
	}
}