From 489566567073f697c619a61217ab5bd810bc833b Mon Sep 17 00:00:00 2001 From: gary rong Date: Mon, 25 Jun 2018 16:52:25 +0800 Subject: [PATCH] les: handle conn/disc/reg logic in the eventloop (#16981) * les: handle conn/disc/reg logic in the eventloop * les: try to dial before start eventloop * les: handle disconnect logic more safely * les: grammar fix --- les/serverpool.go | 209 ++++++++++++++++++++++++++++++---------------- 1 file changed, 135 insertions(+), 74 deletions(-) diff --git a/les/serverpool.go b/les/serverpool.go index a39f883554..1a4c752293 100644 --- a/les/serverpool.go +++ b/les/serverpool.go @@ -87,6 +87,27 @@ const ( initStatsWeight = 1 ) +// connReq represents a request for peer connection. +type connReq struct { + p *peer + ip net.IP + port uint16 + result chan *poolEntry +} + +// disconnReq represents a request for peer disconnection. +type disconnReq struct { + entry *poolEntry + stopped bool + done chan struct{} +} + +// registerReq represents a request for peer registration. +type registerReq struct { + entry *poolEntry + done chan struct{} +} + // serverPool implements a pool for storing and selecting newly discovered and already // known light server nodes. It received discovered nodes, stores statistics about // known nodes and takes care of always having enough good quality servers connected. @@ -105,10 +126,13 @@ type serverPool struct { discLookups chan bool entries map[discover.NodeID]*poolEntry - lock sync.Mutex timeout, enableRetry chan *poolEntry adjustStats chan poolStatAdjust + connCh chan *connReq + disconnCh chan *disconnReq + registerCh chan *registerReq + knownQueue, newQueue poolEntryQueue knownSelect, newSelect *weightedRandomSelect knownSelected, newSelected int @@ -125,6 +149,9 @@ func newServerPool(db ethdb.Database, quit chan struct{}, wg *sync.WaitGroup) *s timeout: make(chan *poolEntry, 1), adjustStats: make(chan poolStatAdjust, 100), enableRetry: make(chan *poolEntry, 1), + connCh: make(chan *connReq), + disconnCh: make(chan *disconnReq), + registerCh: make(chan *registerReq), knownSelect: newWeightedRandomSelect(), newSelect: newWeightedRandomSelect(), fastDiscover: true, @@ -147,9 +174,8 @@ func (pool *serverPool) start(server *p2p.Server, topic discv5.Topic) { pool.discLookups = make(chan bool, 100) go pool.server.DiscV5.SearchTopic(pool.topic, pool.discSetPeriod, pool.discNodes, pool.discLookups) } - - go pool.eventLoop() pool.checkDial() + go pool.eventLoop() } // connect should be called upon any incoming connection. If the connection has been @@ -158,83 +184,44 @@ func (pool *serverPool) start(server *p2p.Server, topic discv5.Topic) { // Note that whenever a connection has been accepted and a pool entry has been returned, // disconnect should also always be called. func (pool *serverPool) connect(p *peer, ip net.IP, port uint16) *poolEntry { - pool.lock.Lock() - defer pool.lock.Unlock() - entry := pool.entries[p.ID()] - if entry == nil { - entry = pool.findOrNewNode(p.ID(), ip, port) - } - p.Log().Debug("Connecting to new peer", "state", entry.state) - if entry.state == psConnected || entry.state == psRegistered { + log.Debug("Connect new entry", "enode", p.id) + req := &connReq{p: p, ip: ip, port: port, result: make(chan *poolEntry, 1)} + select { + case pool.connCh <- req: + case <-pool.quit: return nil } - pool.connWg.Add(1) - entry.peer = p - entry.state = psConnected - addr := &poolEntryAddress{ - ip: ip, - port: port, - lastSeen: mclock.Now(), - } - entry.lastConnected = addr - entry.addr = make(map[string]*poolEntryAddress) - entry.addr[addr.strKey()] = addr - entry.addrSelect = *newWeightedRandomSelect() - entry.addrSelect.update(addr) - return entry + return <-req.result } // registered should be called after a successful handshake func (pool *serverPool) registered(entry *poolEntry) { log.Debug("Registered new entry", "enode", entry.id) - pool.lock.Lock() - defer pool.lock.Unlock() - - entry.state = psRegistered - entry.regTime = mclock.Now() - if !entry.known { - pool.newQueue.remove(entry) - entry.known = true + req := ®isterReq{entry: entry, done: make(chan struct{})} + select { + case pool.registerCh <- req: + case <-pool.quit: + return } - pool.knownQueue.setLatest(entry) - entry.shortRetry = shortRetryCnt + <-req.done } // disconnect should be called when ending a connection. Service quality statistics // can be updated optionally (not updated if no registration happened, in this case // only connection statistics are updated, just like in case of timeout) func (pool *serverPool) disconnect(entry *poolEntry) { + stopped := false + select { + case <-pool.quit: + stopped = true + default: + } log.Debug("Disconnected old entry", "enode", entry.id) - pool.lock.Lock() - defer pool.lock.Unlock() + req := &disconnReq{entry: entry, stopped: stopped, done: make(chan struct{})} - if entry.state == psRegistered { - connTime := mclock.Now() - entry.regTime - connAdjust := float64(connTime) / float64(targetConnTime) - if connAdjust > 1 { - connAdjust = 1 - } - stopped := false - select { - case <-pool.quit: - stopped = true - default: - } - if stopped { - entry.connectStats.add(1, connAdjust) - } else { - entry.connectStats.add(connAdjust, 1) - } - } - - entry.state = psNotConnected - if entry.knownSelected { - pool.knownSelected-- - } else { - pool.newSelected-- - } - pool.setRetryDial(entry) - pool.connWg.Done() + // Block until disconnection request is served. + pool.disconnCh <- req + <-req.done } const ( @@ -277,25 +264,51 @@ func (pool *serverPool) eventLoop() { if pool.discSetPeriod != nil { pool.discSetPeriod <- time.Millisecond * 100 } + + // disconnect updates service quality statistics depending on the connection time + // and disconnection initiator. + disconnect := func(req *disconnReq, stopped bool) { + // Handle peer disconnection requests. + entry := req.entry + if entry.state == psRegistered { + connAdjust := float64(mclock.Now()-entry.regTime) / float64(targetConnTime) + if connAdjust > 1 { + connAdjust = 1 + } + if stopped { + // disconnect requested by ourselves. + entry.connectStats.add(1, connAdjust) + } else { + // disconnect requested by server side. + entry.connectStats.add(connAdjust, 1) + } + } + entry.state = psNotConnected + + if entry.knownSelected { + pool.knownSelected-- + } else { + pool.newSelected-- + } + pool.setRetryDial(entry) + pool.connWg.Done() + close(req.done) + } + for { select { case entry := <-pool.timeout: - pool.lock.Lock() if !entry.removed { pool.checkDialTimeout(entry) } - pool.lock.Unlock() case entry := <-pool.enableRetry: - pool.lock.Lock() if !entry.removed { entry.delayedRetry = false pool.updateCheckDial(entry) } - pool.lock.Unlock() case adj := <-pool.adjustStats: - pool.lock.Lock() switch adj.adjustType { case pseBlockDelay: adj.entry.delayStats.add(float64(adj.time), 1) @@ -305,13 +318,10 @@ func (pool *serverPool) eventLoop() { case pseResponseTimeout: adj.entry.timeoutStats.add(1, 1) } - pool.lock.Unlock() case node := <-pool.discNodes: - pool.lock.Lock() entry := pool.findOrNewNode(discover.NodeID(node.ID), node.IP, node.TCP) pool.updateCheckDial(entry) - pool.lock.Unlock() case conv := <-pool.discLookups: if conv { @@ -327,15 +337,66 @@ func (pool *serverPool) eventLoop() { } } + case req := <-pool.connCh: + // Handle peer connection requests. + entry := pool.entries[req.p.ID()] + if entry == nil { + entry = pool.findOrNewNode(req.p.ID(), req.ip, req.port) + } + if entry.state == psConnected || entry.state == psRegistered { + req.result <- nil + continue + } + pool.connWg.Add(1) + entry.peer = req.p + entry.state = psConnected + addr := &poolEntryAddress{ + ip: req.ip, + port: req.port, + lastSeen: mclock.Now(), + } + entry.lastConnected = addr + entry.addr = make(map[string]*poolEntryAddress) + entry.addr[addr.strKey()] = addr + entry.addrSelect = *newWeightedRandomSelect() + entry.addrSelect.update(addr) + req.result <- entry + + case req := <-pool.registerCh: + // Handle peer registration requests. + entry := req.entry + entry.state = psRegistered + entry.regTime = mclock.Now() + if !entry.known { + pool.newQueue.remove(entry) + entry.known = true + } + pool.knownQueue.setLatest(entry) + entry.shortRetry = shortRetryCnt + close(req.done) + + case req := <-pool.disconnCh: + // Handle peer disconnection requests. + disconnect(req, req.stopped) + case <-pool.quit: if pool.discSetPeriod != nil { close(pool.discSetPeriod) } - pool.connWg.Wait() + + // Spawn a goroutine to close the disconnCh after all connections are disconnected. + go func() { + pool.connWg.Wait() + close(pool.disconnCh) + }() + + // Handle all remaining disconnection requests before exit. + for req := range pool.disconnCh { + disconnect(req, true) + } pool.saveNodes() pool.wg.Done() return - } } }