package blockchain import ( "bytes" "errors" "fmt" "reflect" "sync/atomic" "time" "github.com/tendermint/tendermint/binary" . "github.com/tendermint/tendermint/common" "github.com/tendermint/tendermint/events" "github.com/tendermint/tendermint/p2p" sm "github.com/tendermint/tendermint/state" "github.com/tendermint/tendermint/types" ) const ( BlockchainChannel = byte(0x40) defaultChannelCapacity = 100 defaultSleepIntervalMS = 500 trySyncIntervalMS = 100 // stop syncing when last block's time is // within this much of the system time. // stopSyncingDurationMinutes = 10 // ask for best height every 10s statusUpdateIntervalSeconds = 10 // check if we should switch to consensus reactor switchToConsensusIntervalSeconds = 10 ) type consensusReactor interface { // for when we switch from blockchain reactor and fast sync to // the consensus machine SwitchToConsensus(*sm.State) } // BlockchainReactor handles long-term catchup syncing. type BlockchainReactor struct { sw *p2p.Switch state *sm.State store *BlockStore pool *BlockPool sync bool requestsCh chan BlockRequest timeoutsCh chan string lastBlock *types.Block quit chan struct{} running uint32 evsw events.Fireable } func NewBlockchainReactor(state *sm.State, store *BlockStore, sync bool) *BlockchainReactor { // SANITY CHECK if state.LastBlockHeight != store.Height() && state.LastBlockHeight != store.Height()-1 { // XXX double check this logic. panic(Fmt("state (%v) and store (%v) height mismatch", state.LastBlockHeight, store.Height())) } // SANITY CHECK END requestsCh := make(chan BlockRequest, defaultChannelCapacity) timeoutsCh := make(chan string, defaultChannelCapacity) pool := NewBlockPool( store.Height()+1, requestsCh, timeoutsCh, ) bcR := &BlockchainReactor{ state: state, store: store, pool: pool, sync: sync, requestsCh: requestsCh, timeoutsCh: timeoutsCh, quit: make(chan struct{}), running: uint32(0), } return bcR } // Implements Reactor func (bcR *BlockchainReactor) Start(sw *p2p.Switch) { if atomic.CompareAndSwapUint32(&bcR.running, 0, 1) { log.Info("Starting BlockchainReactor") bcR.sw = sw if bcR.sync { bcR.pool.Start() go bcR.poolRoutine() } } } // Implements Reactor func (bcR *BlockchainReactor) Stop() { if atomic.CompareAndSwapUint32(&bcR.running, 1, 0) { log.Info("Stopping BlockchainReactor") close(bcR.quit) bcR.pool.Stop() } } // Implements Reactor func (bcR *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor { return []*p2p.ChannelDescriptor{ &p2p.ChannelDescriptor{ Id: BlockchainChannel, Priority: 5, SendQueueCapacity: 100, }, } } // Implements Reactor func (bcR *BlockchainReactor) AddPeer(peer *p2p.Peer) { // Send peer our state. peer.Send(BlockchainChannel, &bcStatusResponseMessage{bcR.store.Height()}) } // Implements Reactor func (bcR *BlockchainReactor) RemovePeer(peer *p2p.Peer, reason interface{}) { // Remove peer from the pool. bcR.pool.RemovePeer(peer.Key) } // Implements Reactor func (bcR *BlockchainReactor) Receive(chId byte, src *p2p.Peer, msgBytes []byte) { _, msg, err := DecodeMessage(msgBytes) if err != nil { log.Warn("Error decoding message", "error", err) return } log.Info("Received message", "msg", msg) switch msg := msg.(type) { case *bcBlockRequestMessage: // Got a request for a block. Respond with block if we have it. block := bcR.store.LoadBlock(msg.Height) if block != nil { msg := &bcBlockResponseMessage{Block: block} queued := src.TrySend(BlockchainChannel, msg) if !queued { // queue is full, just ignore. } } else { // TODO peer is asking for things we don't have. } case *bcBlockResponseMessage: // Got a block. bcR.pool.AddBlock(msg.Block, src.Key) case *bcStatusRequestMessage: // Send peer our state. queued := src.TrySend(BlockchainChannel, &bcStatusResponseMessage{bcR.store.Height()}) if !queued { // sorry } case *bcStatusResponseMessage: // Got a peer status. Unverified. bcR.pool.SetPeerHeight(src.Key, msg.Height) default: log.Warn(Fmt("Unknown message type %v", reflect.TypeOf(msg))) } } // Handle messages from the poolReactor telling the reactor what to do. // NOTE: Don't sleep in the FOR_LOOP or otherwise slow it down! // (Except for the SYNC_LOOP, which is the primary purpose and must be synchronous.) func (bcR *BlockchainReactor) poolRoutine() { trySyncTicker := time.NewTicker(trySyncIntervalMS * time.Millisecond) statusUpdateTicker := time.NewTicker(statusUpdateIntervalSeconds * time.Second) switchToConsensusTicker := time.NewTicker(switchToConsensusIntervalSeconds * time.Second) FOR_LOOP: for { select { case request := <-bcR.requestsCh: // chan BlockRequest peer := bcR.sw.Peers().Get(request.PeerId) if peer == nil { // We can't assign the request. continue FOR_LOOP } msg := &bcBlockRequestMessage{request.Height} queued := peer.TrySend(BlockchainChannel, msg) if !queued { // We couldn't make the request, send-queue full. // The pool handles retries, so just let it go. continue FOR_LOOP } case peerId := <-bcR.timeoutsCh: // chan string // Peer timed out. peer := bcR.sw.Peers().Get(peerId) if peer != nil { bcR.sw.StopPeerForError(peer, errors.New("BlockchainReactor Timeout")) } case _ = <-statusUpdateTicker.C: // ask for status updates go bcR.BroadcastStatusRequest() case _ = <-switchToConsensusTicker.C: // not thread safe access for numUnassigned and numPending but should be fine // TODO make threadsafe and use exposed functions outbound, inbound, _ := bcR.sw.NumPeers() log.Debug("Consensus ticker", "numUnassigned", bcR.pool.numUnassigned, "numPending", bcR.pool.numPending, "total", len(bcR.pool.requests), "outbound", outbound, "inbound", inbound) // NOTE: this condition is very strict right now. may need to weaken // If all `maxPendingRequests` requests are unassigned // and we have some peers (say >= 3), then we're caught up maxPending := bcR.pool.numPending == maxPendingRequests allUnassigned := bcR.pool.numPending == bcR.pool.numUnassigned enoughPeers := outbound+inbound >= 3 if maxPending && allUnassigned && enoughPeers { log.Info("Time to switch to consensus reactor!", "height", bcR.pool.height) bcR.pool.Stop() conR := bcR.sw.Reactor("CONSENSUS").(consensusReactor) conR.SwitchToConsensus(bcR.state) break FOR_LOOP } case _ = <-trySyncTicker.C: // chan time // This loop can be slow as long as it's doing syncing work. SYNC_LOOP: for i := 0; i < 10; i++ { // See if there are any blocks to sync. first, second := bcR.pool.PeekTwoBlocks() //log.Debug("TrySync peeked", "first", first, "second", second) if first == nil || second == nil { // We need both to sync the first block. break SYNC_LOOP } firstParts := first.MakePartSet() firstPartsHeader := firstParts.Header() // Finally, verify the first block using the second's validation. err := bcR.state.BondedValidators.VerifyValidation( bcR.state.ChainID, first.Hash(), firstPartsHeader, first.Height, second.LastValidation) if err != nil { log.Debug("error in validation", "error", err) bcR.pool.RedoRequest(first.Height) break SYNC_LOOP } else { bcR.pool.PopRequest() err := sm.ExecBlock(bcR.state, first, firstPartsHeader) if err != nil { // TODO This is bad, are we zombie? panic(Fmt("Failed to process committed block: %v", err)) } bcR.store.SaveBlock(first, firstParts, second.LastValidation) bcR.state.Save() } } continue FOR_LOOP case <-bcR.quit: break FOR_LOOP } } } func (bcR *BlockchainReactor) BroadcastStatusResponse() error { bcR.sw.Broadcast(BlockchainChannel, &bcStatusResponseMessage{bcR.store.Height()}) return nil } func (bcR *BlockchainReactor) BroadcastStatusRequest() error { bcR.sw.Broadcast(BlockchainChannel, &bcStatusRequestMessage{bcR.store.Height()}) return nil } // implements events.Eventable func (bcR *BlockchainReactor) SetFireable(evsw events.Fireable) { bcR.evsw = evsw } //----------------------------------------------------------------------------- // Messages const ( msgTypeBlockRequest = byte(0x10) msgTypeBlockResponse = byte(0x11) msgTypeStatusResponse = byte(0x20) msgTypeStatusRequest = byte(0x21) ) type BlockchainMessage interface{} var _ = binary.RegisterInterface( struct{ BlockchainMessage }{}, binary.ConcreteType{&bcBlockRequestMessage{}, msgTypeBlockRequest}, binary.ConcreteType{&bcBlockResponseMessage{}, msgTypeBlockResponse}, binary.ConcreteType{&bcStatusResponseMessage{}, msgTypeStatusResponse}, binary.ConcreteType{&bcStatusRequestMessage{}, msgTypeStatusRequest}, ) func DecodeMessage(bz []byte) (msgType byte, msg BlockchainMessage, err error) { msgType = bz[0] n := new(int64) r := bytes.NewReader(bz) msg = binary.ReadBinary(struct{ BlockchainMessage }{}, r, n, &err).(struct{ BlockchainMessage }).BlockchainMessage return } //------------------------------------- type bcBlockRequestMessage struct { Height int } func (m *bcBlockRequestMessage) String() string { return fmt.Sprintf("[bcBlockRequestMessage %v]", m.Height) } //------------------------------------- type bcBlockResponseMessage struct { Block *types.Block } func (m *bcBlockResponseMessage) String() string { return fmt.Sprintf("[bcBlockResponseMessage %v]", m.Block.Height) } //------------------------------------- type bcStatusRequestMessage struct { Height int } func (m *bcStatusRequestMessage) String() string { return fmt.Sprintf("[bcStatusRequestMessage %v]", m.Height) } //------------------------------------- type bcStatusResponseMessage struct { Height int } func (m *bcStatusResponseMessage) String() string { return fmt.Sprintf("[bcStatusResponseMessage %v]", m.Height) }