diff options
Diffstat (limited to 'eth/block_pool.go')
-rw-r--r-- | eth/block_pool.go | 1239 |
1 files changed, 1239 insertions, 0 deletions
diff --git a/eth/block_pool.go b/eth/block_pool.go new file mode 100644 index 000000000..13016c694 --- /dev/null +++ b/eth/block_pool.go @@ -0,0 +1,1239 @@ +package eth + +import ( + "bytes" + "fmt" + "math" + "math/big" + "math/rand" + "sort" + "sync" + "time" + + "github.com/ethereum/go-ethereum/core/types" + "github.com/ethereum/go-ethereum/ethutil" + ethlogger "github.com/ethereum/go-ethereum/logger" + "github.com/ethereum/go-ethereum/pow" +) + +var poolLogger = ethlogger.NewLogger("Blockpool") + +const ( + blockHashesBatchSize = 256 + blockBatchSize = 64 + blocksRequestInterval = 500 // ms + blocksRequestRepetition = 1 + blockHashesRequestInterval = 500 // ms + blocksRequestMaxIdleRounds = 100 + blockHashesTimeout = 60 // seconds + blocksTimeout = 120 // seconds +) + +type poolNode struct { + lock sync.RWMutex + hash []byte + td *big.Int + block *types.Block + parent *poolNode + peer string + blockBy string +} + +type poolEntry struct { + node *poolNode + section *section + index int +} + +type BlockPool struct { + lock sync.RWMutex + chainLock sync.RWMutex + + pool map[string]*poolEntry + + peersLock sync.RWMutex + peers map[string]*peerInfo + peer *peerInfo + + quit chan bool + purgeC chan bool + flushC chan bool + wg sync.WaitGroup + procWg sync.WaitGroup + running bool + + // the minimal interface with blockchain + hasBlock func(hash []byte) bool + insertChain func(types.Blocks) error + verifyPoW func(pow.Block) bool +} + +type peerInfo struct { + lock sync.RWMutex + + td *big.Int + currentBlockHash []byte + currentBlock *types.Block + currentBlockC chan *types.Block + parentHash []byte + headSection *section + headSectionC chan *section + id string + + requestBlockHashes func([]byte) error + requestBlocks func([][]byte) error + peerError func(int, string, ...interface{}) + + sections map[string]*section + + quitC chan bool +} + +// structure to store long range links on chain to skip along +type section struct { + lock sync.RWMutex + parent *section + child *section + top *poolNode + bottom *poolNode + nodes []*poolNode + controlC chan *peerInfo + suicideC chan bool + blockChainC chan bool + forkC chan chan bool + offC chan bool +} + +func NewBlockPool(hasBlock func(hash []byte) bool, insertChain func(types.Blocks) error, verifyPoW func(pow.Block) bool, +) *BlockPool { + return &BlockPool{ + hasBlock: hasBlock, + insertChain: insertChain, + verifyPoW: verifyPoW, + } +} + +// allows restart +func (self *BlockPool) Start() { + self.lock.Lock() + if self.running { + self.lock.Unlock() + return + } + self.running = true + self.quit = make(chan bool) + self.flushC = make(chan bool) + self.pool = make(map[string]*poolEntry) + + self.lock.Unlock() + + self.peersLock.Lock() + self.peers = make(map[string]*peerInfo) + self.peersLock.Unlock() + + poolLogger.Infoln("Started") + +} + +func (self *BlockPool) Stop() { + self.lock.Lock() + if !self.running { + self.lock.Unlock() + return + } + self.running = false + + self.lock.Unlock() + + poolLogger.Infoln("Stopping...") + + close(self.quit) + //self.wg.Wait() + + self.peersLock.Lock() + self.peers = nil + self.peer = nil + self.peersLock.Unlock() + + self.lock.Lock() + self.pool = nil + self.lock.Unlock() + + poolLogger.Infoln("Stopped") +} + +func (self *BlockPool) Purge() { + self.lock.Lock() + if !self.running { + self.lock.Unlock() + return + } + self.lock.Unlock() + + poolLogger.Infoln("Purging...") + + close(self.purgeC) + self.wg.Wait() + + self.purgeC = make(chan bool) + + poolLogger.Infoln("Stopped") + +} + +func (self *BlockPool) Wait(t time.Duration) { + self.lock.Lock() + if !self.running { + self.lock.Unlock() + return + } + self.lock.Unlock() + + poolLogger.Infoln("Waiting for processes to complete...") + close(self.flushC) + w := make(chan bool) + go func() { + self.procWg.Wait() + close(w) + }() + + select { + case <-w: + poolLogger.Infoln("Processes complete") + case <-time.After(t): + poolLogger.Warnf("Timeout") + } + self.flushC = make(chan bool) +} + +// AddPeer is called by the eth protocol instance running on the peer after +// the status message has been received with total difficulty and current block hash +// AddPeer can only be used once, RemovePeer needs to be called when the peer disconnects +func (self *BlockPool) AddPeer(td *big.Int, currentBlockHash []byte, peerId string, requestBlockHashes func([]byte) error, requestBlocks func([][]byte) error, peerError func(int, string, ...interface{})) (best bool) { + + self.peersLock.Lock() + defer self.peersLock.Unlock() + peer, ok := self.peers[peerId] + if ok { + if bytes.Compare(peer.currentBlockHash, currentBlockHash) != 0 { + poolLogger.Debugf("Update peer %v with td %v and current block %s", peerId, td, name(currentBlockHash)) + peer.lock.Lock() + peer.td = td + peer.currentBlockHash = currentBlockHash + peer.currentBlock = nil + peer.parentHash = nil + peer.headSection = nil + peer.lock.Unlock() + } + } else { + peer = &peerInfo{ + td: td, + currentBlockHash: currentBlockHash, + id: peerId, //peer.Identity().Pubkey() + requestBlockHashes: requestBlockHashes, + requestBlocks: requestBlocks, + peerError: peerError, + sections: make(map[string]*section), + currentBlockC: make(chan *types.Block), + headSectionC: make(chan *section), + } + self.peers[peerId] = peer + poolLogger.Debugf("add new peer %v with td %v and current block %x", peerId, td, currentBlockHash[:4]) + } + // check peer current head + if self.hasBlock(currentBlockHash) { + // peer not ahead + return false + } + + if self.peer == peer { + // new block update + // peer is already active best peer, request hashes + poolLogger.Debugf("[%s] already the best peer. Request new head section info from %s", peerId, name(currentBlockHash)) + peer.headSectionC <- nil + best = true + } else { + currentTD := ethutil.Big0 + if self.peer != nil { + currentTD = self.peer.td + } + if td.Cmp(currentTD) > 0 { + poolLogger.Debugf("peer %v promoted best peer", peerId) + self.switchPeer(self.peer, peer) + self.peer = peer + best = true + } + } + return +} + +func (self *BlockPool) requestHeadSection(peer *peerInfo) { + self.wg.Add(1) + self.procWg.Add(1) + poolLogger.Debugf("[%s] head section at [%s] requesting info", peer.id, name(peer.currentBlockHash)) + + go func() { + var idle bool + peer.lock.RLock() + quitC := peer.quitC + currentBlockHash := peer.currentBlockHash + peer.lock.RUnlock() + blockHashesRequestTimer := time.NewTimer(0) + blocksRequestTimer := time.NewTimer(0) + suicide := time.NewTimer(blockHashesTimeout * time.Second) + blockHashesRequestTimer.Stop() + defer blockHashesRequestTimer.Stop() + defer blocksRequestTimer.Stop() + + entry := self.get(currentBlockHash) + if entry != nil { + entry.node.lock.RLock() + currentBlock := entry.node.block + entry.node.lock.RUnlock() + if currentBlock != nil { + peer.lock.Lock() + peer.currentBlock = currentBlock + peer.parentHash = currentBlock.ParentHash() + poolLogger.Debugf("[%s] head block [%s] found", peer.id, name(currentBlockHash)) + peer.lock.Unlock() + blockHashesRequestTimer.Reset(0) + blocksRequestTimer.Stop() + } + } + + LOOP: + for { + + select { + case <-self.quit: + break LOOP + + case <-quitC: + poolLogger.Debugf("[%s] head section at [%s] incomplete - quit request loop", peer.id, name(currentBlockHash)) + break LOOP + + case headSection := <-peer.headSectionC: + peer.lock.Lock() + peer.headSection = headSection + if headSection == nil { + oldBlockHash := currentBlockHash + currentBlockHash = peer.currentBlockHash + poolLogger.Debugf("[%s] head section changed [%s] -> [%s]", peer.id, name(oldBlockHash), name(currentBlockHash)) + if idle { + idle = false + suicide.Reset(blockHashesTimeout * time.Second) + self.procWg.Add(1) + } + blocksRequestTimer.Reset(blocksRequestInterval * time.Millisecond) + } else { + poolLogger.DebugDetailf("[%s] head section at [%s] created", peer.id, name(currentBlockHash)) + if !idle { + idle = true + suicide.Stop() + self.procWg.Done() + } + } + peer.lock.Unlock() + blockHashesRequestTimer.Stop() + + case <-blockHashesRequestTimer.C: + poolLogger.DebugDetailf("[%s] head section at [%s] not found, requesting block hashes", peer.id, name(currentBlockHash)) + peer.requestBlockHashes(currentBlockHash) + blockHashesRequestTimer.Reset(blockHashesRequestInterval * time.Millisecond) + + case currentBlock := <-peer.currentBlockC: + peer.lock.Lock() + peer.currentBlock = currentBlock + peer.parentHash = currentBlock.ParentHash() + poolLogger.DebugDetailf("[%s] head block [%s] found", peer.id, name(currentBlockHash)) + peer.lock.Unlock() + if self.hasBlock(currentBlock.ParentHash()) { + if err := self.insertChain(types.Blocks([]*types.Block{currentBlock})); err != nil { + peer.peerError(ErrInvalidBlock, "%v", err) + } + if !idle { + idle = true + suicide.Stop() + self.procWg.Done() + } + } else { + blockHashesRequestTimer.Reset(0) + } + blocksRequestTimer.Stop() + + case <-blocksRequestTimer.C: + peer.lock.RLock() + poolLogger.DebugDetailf("[%s] head block [%s] not found, requesting", peer.id, name(currentBlockHash)) + peer.requestBlocks([][]byte{peer.currentBlockHash}) + peer.lock.RUnlock() + blocksRequestTimer.Reset(blocksRequestInterval * time.Millisecond) + + case <-suicide.C: + peer.peerError(ErrInsufficientChainInfo, "peer failed to provide block hashes or head block for block hash %x", currentBlockHash) + break LOOP + } + } + self.wg.Done() + if !idle { + self.procWg.Done() + } + }() +} + +// RemovePeer is called by the eth protocol when the peer disconnects +func (self *BlockPool) RemovePeer(peerId string) { + self.peersLock.Lock() + defer self.peersLock.Unlock() + peer, ok := self.peers[peerId] + if !ok { + return + } + delete(self.peers, peerId) + poolLogger.Debugf("remove peer %v", peerId) + + // if current best peer is removed, need find a better one + if self.peer == peer { + var newPeer *peerInfo + max := ethutil.Big0 + // peer with the highest self-acclaimed TD is chosen + for _, info := range self.peers { + if info.td.Cmp(max) > 0 { + max = info.td + newPeer = info + } + } + if newPeer != nil { + poolLogger.Debugf("peer %v with td %v promoted to best peer", newPeer.id, newPeer.td) + } else { + poolLogger.Warnln("no peers") + } + self.peer = newPeer + self.switchPeer(peer, newPeer) + } +} + +// Entry point for eth protocol to add block hashes received via BlockHashesMsg +// only hashes from the best peer is handled +// this method is always responsible to initiate further hash requests until +// a known parent is reached unless cancelled by a peerChange event +// this process also launches all request processes on each chain section +// this function needs to run asynchronously for one peer since the message is discarded??? +func (self *BlockPool) AddBlockHashes(next func() ([]byte, bool), peerId string) { + + // register with peer manager loop + + peer, best := self.getPeer(peerId) + if !best { + return + } + // peer is still the best + + var size, n int + var hash []byte + var ok, headSection bool + var sec, child, parent *section + var entry *poolEntry + var nodes []*poolNode + bestPeer := peer + + hash, ok = next() + peer.lock.Lock() + if bytes.Compare(peer.parentHash, hash) == 0 { + if self.hasBlock(peer.currentBlockHash) { + return + } + poolLogger.Debugf("adding hashes at chain head for best peer %s starting from [%s]", peerId, name(peer.currentBlockHash)) + headSection = true + + if entry := self.get(peer.currentBlockHash); entry == nil { + node := &poolNode{ + hash: peer.currentBlockHash, + block: peer.currentBlock, + peer: peerId, + blockBy: peerId, + } + if size == 0 { + sec = newSection() + } + nodes = append(nodes, node) + size++ + n++ + } else { + child = entry.section + } + } else { + poolLogger.Debugf("adding hashes for best peer %s starting from [%s]", peerId, name(hash)) + } + quitC := peer.quitC + peer.lock.Unlock() + +LOOP: + // iterate using next (rlp stream lazy decoder) feeding hashesC + for ; ok; hash, ok = next() { + n++ + select { + case <-self.quit: + return + case <-quitC: + // if the peer is demoted, no more hashes taken + bestPeer = nil + break LOOP + default: + } + if self.hasBlock(hash) { + // check if known block connecting the downloaded chain to our blockchain + poolLogger.DebugDetailf("[%s] known block", name(hash)) + // mark child as absolute pool root with parent known to blockchain + if sec != nil { + self.connectToBlockChain(sec) + } else { + if child != nil { + self.connectToBlockChain(child) + } + } + break LOOP + } + // look up node in pool + entry = self.get(hash) + if entry != nil { + // reached a known chain in the pool + if entry.node == entry.section.bottom && n == 1 { + // the first block hash received is an orphan in the pool, so rejoice and continue + poolLogger.DebugDetailf("[%s] connecting child section", sectionName(entry.section)) + child = entry.section + continue LOOP + } + poolLogger.DebugDetailf("[%s] reached blockpool chain", name(hash)) + parent = entry.section + break LOOP + } + // if node for block hash does not exist, create it and index in the pool + node := &poolNode{ + hash: hash, + peer: peerId, + } + if size == 0 { + sec = newSection() + } + nodes = append(nodes, node) + size++ + } //for + + self.chainLock.Lock() + + poolLogger.DebugDetailf("added %v hashes sent by %s", n, peerId) + + if parent != nil && entry != nil && entry.node != parent.top { + poolLogger.DebugDetailf("[%s] split section at fork", sectionName(parent)) + parent.controlC <- nil + waiter := make(chan bool) + parent.forkC <- waiter + chain := parent.nodes + parent.nodes = chain[entry.index:] + parent.top = parent.nodes[0] + orphan := newSection() + self.link(orphan, parent.child) + self.processSection(orphan, chain[0:entry.index]) + orphan.controlC <- nil + close(waiter) + } + + if size > 0 { + self.processSection(sec, nodes) + poolLogger.DebugDetailf("[%s]->[%s](%v)->[%s] new chain section", sectionName(parent), sectionName(sec), size, sectionName(child)) + self.link(parent, sec) + self.link(sec, child) + } else { + poolLogger.DebugDetailf("[%s]->[%s] connecting known sections", sectionName(parent), sectionName(child)) + self.link(parent, child) + } + + self.chainLock.Unlock() + + if parent != nil && bestPeer != nil { + self.activateChain(parent, peer) + poolLogger.Debugf("[%s] activate parent section [%s]", name(parent.top.hash), sectionName(parent)) + } + + if sec != nil { + peer.addSection(sec.top.hash, sec) + // request next section here once, only repeat if bottom block arrives, + // otherwise no way to check if it arrived + peer.requestBlockHashes(sec.bottom.hash) + sec.controlC <- bestPeer + poolLogger.Debugf("[%s] activate new section", sectionName(sec)) + } + + if headSection { + var headSec *section + switch { + case sec != nil: + headSec = sec + case child != nil: + headSec = child + default: + headSec = parent + } + peer.headSectionC <- headSec + } +} + +func name(hash []byte) (name string) { + if hash == nil { + name = "" + } else { + name = fmt.Sprintf("%x", hash[:4]) + } + return +} + +func sectionName(section *section) (name string) { + if section == nil { + name = "" + } else { + name = fmt.Sprintf("%x-%x", section.bottom.hash[:4], section.top.hash[:4]) + } + return +} + +// AddBlock is the entry point for the eth protocol when blockmsg is received upon requests +// It has a strict interpretation of the protocol in that if the block received has not been requested, it results in an error (which can be ignored) +// block is checked for PoW +// only the first PoW-valid block for a hash is considered legit +func (self *BlockPool) AddBlock(block *types.Block, peerId string) { + hash := block.Hash() + self.peersLock.Lock() + peer := self.peer + self.peersLock.Unlock() + + entry := self.get(hash) + if bytes.Compare(hash, peer.currentBlockHash) == 0 { + poolLogger.Debugf("add head block [%s] for peer %s", name(hash), peerId) + peer.currentBlockC <- block + } else { + if entry == nil { + poolLogger.Warnf("unrequested block [%s] by peer %s", name(hash), peerId) + self.peerError(peerId, ErrUnrequestedBlock, "%x", hash) + } + } + if entry == nil { + return + } + + node := entry.node + node.lock.Lock() + defer node.lock.Unlock() + + // check if block already present + if node.block != nil { + poolLogger.DebugDetailf("block [%s] already sent by %s", name(hash), node.blockBy) + return + } + + if self.hasBlock(hash) { + poolLogger.DebugDetailf("block [%s] already known", name(hash)) + } else { + + // validate block for PoW + if !self.verifyPoW(block) { + poolLogger.Warnf("invalid pow on block [%s %v] by peer %s", name(hash), block.Number(), peerId) + self.peerError(peerId, ErrInvalidPoW, "%x", hash) + return + } + } + poolLogger.DebugDetailf("added block [%s] sent by peer %s", name(hash), peerId) + node.block = block + node.blockBy = peerId + +} + +func (self *BlockPool) connectToBlockChain(section *section) { + select { + case <-section.offC: + self.addSectionToBlockChain(section) + case <-section.blockChainC: + default: + close(section.blockChainC) + } +} + +func (self *BlockPool) addSectionToBlockChain(section *section) (rest int, err error) { + + var blocks types.Blocks + var node *poolNode + var keys []string + rest = len(section.nodes) + for rest > 0 { + rest-- + node = section.nodes[rest] + node.lock.RLock() + block := node.block + node.lock.RUnlock() + if block == nil { + break + } + keys = append(keys, string(node.hash)) + blocks = append(blocks, block) + } + + self.lock.Lock() + for _, key := range keys { + delete(self.pool, key) + } + self.lock.Unlock() + + poolLogger.Infof("insert %v blocks into blockchain", len(blocks)) + err = self.insertChain(blocks) + if err != nil { + // TODO: not clear which peer we need to address + // peerError should dispatch to peer if still connected and disconnect + self.peerError(node.blockBy, ErrInvalidBlock, "%v", err) + poolLogger.Warnf("invalid block %x", node.hash) + poolLogger.Warnf("penalise peers %v (hash), %v (block)", node.peer, node.blockBy) + // penalise peer in node.blockBy + // self.disconnect() + } + return +} + +func (self *BlockPool) activateChain(section *section, peer *peerInfo) { + poolLogger.DebugDetailf("[%s] activate known chain for peer %s", sectionName(section), peer.id) + i := 0 +LOOP: + for section != nil { + // register this section with the peer and quit if registered + poolLogger.DebugDetailf("[%s] register section with peer %s", sectionName(section), peer.id) + if peer.addSection(section.top.hash, section) == section { + return + } + poolLogger.DebugDetailf("[%s] activate section process", sectionName(section)) + select { + case section.controlC <- peer: + case <-section.offC: + } + i++ + section = self.getParent(section) + select { + case <-peer.quitC: + break LOOP + case <-self.quit: + break LOOP + default: + } + } +} + +// main worker thread on each section in the poolchain +// - kills the section if there are blocks missing after an absolute time +// - kills the section if there are maxIdleRounds of idle rounds of block requests with no response +// - periodically polls the chain section for missing blocks which are then requested from peers +// - registers the process controller on the peer so that if the peer is promoted as best peer the second time (after a disconnect of a better one), all active processes are switched back on unless they expire and killed () +// - when turned off (if peer disconnects and new peer connects with alternative chain), no blockrequests are made but absolute expiry timer is ticking +// - when turned back on it recursively calls itself on the root of the next chain section +// - when exits, signals to +func (self *BlockPool) processSection(sec *section, nodes []*poolNode) { + + for i, node := range nodes { + entry := &poolEntry{node: node, section: sec, index: i} + self.set(node.hash, entry) + } + + sec.bottom = nodes[len(nodes)-1] + sec.top = nodes[0] + sec.nodes = nodes + poolLogger.DebugDetailf("[%s] setup section process", sectionName(sec)) + + self.wg.Add(1) + go func() { + + // absolute time after which sub-chain is killed if not complete (some blocks are missing) + suicideTimer := time.After(blocksTimeout * time.Second) + + var peer, newPeer *peerInfo + + var blocksRequestTimer, blockHashesRequestTimer <-chan time.Time + var blocksRequestTime, blockHashesRequestTime bool + var blocksRequests, blockHashesRequests int + var blocksRequestsComplete, blockHashesRequestsComplete bool + + // node channels for the section + var missingC, processC, offC chan *poolNode + // container for missing block hashes + var hashes [][]byte + + var i, missing, lastMissing, depth int + var idle int + var init, done, same, ready bool + var insertChain bool + var quitC chan bool + + var blockChainC = sec.blockChainC + + var parentHash []byte + + LOOP: + for { + + if insertChain { + insertChain = false + rest, err := self.addSectionToBlockChain(sec) + if err != nil { + close(sec.suicideC) + continue LOOP + } + if rest == 0 { + blocksRequestsComplete = true + child := self.getChild(sec) + if child != nil { + self.connectToBlockChain(child) + } + } + } + + if blockHashesRequestsComplete && blocksRequestsComplete { + // not waiting for hashes any more + poolLogger.Debugf("[%s] section complete %v blocks retrieved (%v attempts), hash requests complete on root (%v attempts)", sectionName(sec), depth, blocksRequests, blockHashesRequests) + break LOOP + } // otherwise suicide if no hashes coming + + if done { + // went through all blocks in section + if missing == 0 { + // no missing blocks + poolLogger.DebugDetailf("[%s] got all blocks. process complete (%v total blocksRequests): missing %v/%v/%v", sectionName(sec), blocksRequests, missing, lastMissing, depth) + blocksRequestsComplete = true + blocksRequestTimer = nil + blocksRequestTime = false + } else { + poolLogger.DebugDetailf("[%s] section checked: missing %v/%v/%v", sectionName(sec), missing, lastMissing, depth) + // some missing blocks + blocksRequests++ + if len(hashes) > 0 { + // send block requests to peers + self.requestBlocks(blocksRequests, hashes) + hashes = nil + } + if missing == lastMissing { + // idle round + if same { + // more than once + idle++ + // too many idle rounds + if idle >= blocksRequestMaxIdleRounds { + poolLogger.DebugDetailf("[%s] block requests had %v idle rounds (%v total attempts): missing %v/%v/%v\ngiving up...", sectionName(sec), idle, blocksRequests, missing, lastMissing, depth) + close(sec.suicideC) + } + } else { + idle = 0 + } + same = true + } else { + same = false + } + } + lastMissing = missing + ready = true + done = false + // save a new processC (blocks still missing) + offC = missingC + missingC = processC + // put processC offline + processC = nil + } + // + + if ready && blocksRequestTime && !blocksRequestsComplete { + poolLogger.DebugDetailf("[%s] check if new blocks arrived (attempt %v): missing %v/%v/%v", sectionName(sec), blocksRequests, missing, lastMissing, depth) + blocksRequestTimer = time.After(blocksRequestInterval * time.Millisecond) + blocksRequestTime = false + processC = offC + } + + if blockHashesRequestTime { + var parentSection = self.getParent(sec) + if parentSection == nil { + if parent := self.get(parentHash); parent != nil { + parentSection = parent.section + self.chainLock.Lock() + self.link(parentSection, sec) + self.chainLock.Unlock() + } else { + if self.hasBlock(parentHash) { + insertChain = true + blockHashesRequestTime = false + blockHashesRequestTimer = nil + blockHashesRequestsComplete = true + continue LOOP + } + } + } + if parentSection != nil { + // if not root of chain, switch off + poolLogger.DebugDetailf("[%s] parent found, hash requests deactivated (after %v total attempts)\n", sectionName(sec), blockHashesRequests) + blockHashesRequestTimer = nil + blockHashesRequestsComplete = true + } else { + blockHashesRequests++ + poolLogger.Debugf("[%s] hash request on root (%v total attempts)\n", sectionName(sec), blockHashesRequests) + peer.requestBlockHashes(sec.bottom.hash) + blockHashesRequestTimer = time.After(blockHashesRequestInterval * time.Millisecond) + } + blockHashesRequestTime = false + } + + select { + case <-self.quit: + break LOOP + + case <-quitC: + // peer quit or demoted, put section in idle mode + quitC = nil + go func() { + sec.controlC <- nil + }() + + case <-self.purgeC: + suicideTimer = time.After(0) + + case <-suicideTimer: + close(sec.suicideC) + poolLogger.Debugf("[%s] timeout. (%v total attempts): missing %v/%v/%v", sectionName(sec), blocksRequests, missing, lastMissing, depth) + + case <-sec.suicideC: + poolLogger.Debugf("[%s] suicide", sectionName(sec)) + + // first delink from child and parent under chainlock + self.chainLock.Lock() + self.link(nil, sec) + self.link(sec, nil) + self.chainLock.Unlock() + // delete node entries from pool index under pool lock + self.lock.Lock() + for _, node := range sec.nodes { + delete(self.pool, string(node.hash)) + } + self.lock.Unlock() + + break LOOP + + case <-blocksRequestTimer: + poolLogger.DebugDetailf("[%s] block request time", sectionName(sec)) + blocksRequestTime = true + + case <-blockHashesRequestTimer: + poolLogger.DebugDetailf("[%s] hash request time", sectionName(sec)) + blockHashesRequestTime = true + + case newPeer = <-sec.controlC: + + // active -> idle + if peer != nil && newPeer == nil { + self.procWg.Done() + if init { + poolLogger.Debugf("[%s] idle mode (%v total attempts): missing %v/%v/%v", sectionName(sec), blocksRequests, missing, lastMissing, depth) + } + blocksRequestTime = false + blocksRequestTimer = nil + blockHashesRequestTime = false + blockHashesRequestTimer = nil + if processC != nil { + offC = processC + processC = nil + } + } + + // idle -> active + if peer == nil && newPeer != nil { + self.procWg.Add(1) + + poolLogger.Debugf("[%s] active mode", sectionName(sec)) + if !blocksRequestsComplete { + blocksRequestTime = true + } + if !blockHashesRequestsComplete && parentHash != nil { + blockHashesRequestTime = true + } + if !init { + processC = make(chan *poolNode, blockHashesBatchSize) + missingC = make(chan *poolNode, blockHashesBatchSize) + i = 0 + missing = 0 + self.wg.Add(1) + self.procWg.Add(1) + depth = len(sec.nodes) + lastMissing = depth + // if not run at least once fully, launch iterator + go func() { + var node *poolNode + IT: + for _, node = range sec.nodes { + select { + case processC <- node: + case <-self.quit: + break IT + } + } + close(processC) + self.wg.Done() + self.procWg.Done() + }() + } else { + poolLogger.Debugf("[%s] restore earlier state", sectionName(sec)) + processC = offC + } + } + // reset quitC to current best peer + if newPeer != nil { + quitC = newPeer.quitC + } + peer = newPeer + + case waiter := <-sec.forkC: + // this case just blocks the process until section is split at the fork + <-waiter + init = false + done = false + ready = false + + case node, ok := <-processC: + if !ok && !init { + // channel closed, first iteration finished + init = true + done = true + processC = make(chan *poolNode, missing) + poolLogger.DebugDetailf("[%s] section initalised: missing %v/%v/%v", sectionName(sec), missing, lastMissing, depth) + continue LOOP + } + if ready { + i = 0 + missing = 0 + ready = false + } + i++ + // if node has no block + node.lock.RLock() + block := node.block + node.lock.RUnlock() + if block == nil { + missing++ + hashes = append(hashes, node.hash) + if len(hashes) == blockBatchSize { + poolLogger.Debugf("[%s] request %v missing blocks", sectionName(sec), len(hashes)) + self.requestBlocks(blocksRequests, hashes) + hashes = nil + } + missingC <- node + } else { + if i == lastMissing { + if blockChainC == nil { + insertChain = true + } else { + if parentHash == nil { + parentHash = block.ParentHash() + poolLogger.Debugf("[%s] found root block [%s]", sectionName(sec), name(parentHash)) + blockHashesRequestTime = true + } + } + } + } + if i == lastMissing && init { + done = true + } + + case <-blockChainC: + // closed blockChain channel indicates that the blockpool is reached + // connected to the blockchain, insert the longest chain of blocks + poolLogger.Debugf("[%s] reached blockchain", sectionName(sec)) + blockChainC = nil + // switch off hash requests in case they were on + blockHashesRequestTime = false + blockHashesRequestTimer = nil + blockHashesRequestsComplete = true + // section root has block + if len(sec.nodes) > 0 && sec.nodes[len(sec.nodes)-1].block != nil { + insertChain = true + } + continue LOOP + + } // select + } // for + + close(sec.offC) + + self.wg.Done() + if peer != nil { + self.procWg.Done() + } + }() + return +} + +func (self *BlockPool) peerError(peerId string, code int, format string, params ...interface{}) { + self.peersLock.RLock() + defer self.peersLock.RUnlock() + peer, ok := self.peers[peerId] + if ok { + peer.peerError(code, format, params...) + } +} + +func (self *BlockPool) requestBlocks(attempts int, hashes [][]byte) { + self.wg.Add(1) + self.procWg.Add(1) + go func() { + // distribute block request among known peers + self.peersLock.Lock() + defer self.peersLock.Unlock() + peerCount := len(self.peers) + // on first attempt use the best peer + if attempts == 0 { + poolLogger.Debugf("request %v missing blocks from best peer %s", len(hashes), self.peer.id) + self.peer.requestBlocks(hashes) + return + } + repetitions := int(math.Min(float64(peerCount), float64(blocksRequestRepetition))) + i := 0 + indexes := rand.Perm(peerCount)[0:repetitions] + sort.Ints(indexes) + poolLogger.Debugf("request %v missing blocks from %v/%v peers: chosen %v", len(hashes), repetitions, peerCount, indexes) + for _, peer := range self.peers { + if i == indexes[0] { + poolLogger.Debugf("request %v missing blocks [%x/%x] from peer %s", len(hashes), hashes[0][:4], hashes[len(hashes)-1][:4], peer.id) + peer.requestBlocks(hashes) + indexes = indexes[1:] + if len(indexes) == 0 { + break + } + } + i++ + } + self.wg.Done() + self.procWg.Done() + }() +} + +func (self *BlockPool) getPeer(peerId string) (*peerInfo, bool) { + self.peersLock.RLock() + defer self.peersLock.RUnlock() + if self.peer != nil && self.peer.id == peerId { + return self.peer, true + } + info, ok := self.peers[peerId] + if !ok { + return nil, false + } + return info, false +} + +func (self *peerInfo) addSection(hash []byte, section *section) (found *section) { + self.lock.Lock() + defer self.lock.Unlock() + key := string(hash) + found = self.sections[key] + poolLogger.DebugDetailf("[%s] section process stored for %s", sectionName(section), self.id) + self.sections[key] = section + return +} + +func (self *BlockPool) switchPeer(oldPeer, newPeer *peerInfo) { + if newPeer != nil { + newPeer.quitC = make(chan bool) + poolLogger.DebugDetailf("[%s] activate section processes", newPeer.id) + var addSections []*section + for hash, section := range newPeer.sections { + // split sections get reorganised here + if string(section.top.hash) != hash { + addSections = append(addSections, section) + if entry := self.get([]byte(hash)); entry != nil { + addSections = append(addSections, entry.section) + } + } + } + for _, section := range addSections { + newPeer.sections[string(section.top.hash)] = section + } + for hash, section := range newPeer.sections { + // this will block if section process is waiting for peer lock + select { + case <-section.offC: + poolLogger.DebugDetailf("[%s][%x] section process complete - remove", newPeer.id, hash[:4]) + delete(newPeer.sections, hash) + case section.controlC <- newPeer: + poolLogger.DebugDetailf("[%s][%x] activates section [%s]", newPeer.id, hash[:4], sectionName(section)) + } + } + newPeer.lock.Lock() + headSection := newPeer.headSection + currentBlockHash := newPeer.currentBlockHash + newPeer.lock.Unlock() + if headSection == nil { + poolLogger.DebugDetailf("[%s] head section for [%s] not created, requesting info", newPeer.id, name(currentBlockHash)) + self.requestHeadSection(newPeer) + } else { + if entry := self.get(currentBlockHash); entry != nil { + headSection = entry.section + } + poolLogger.DebugDetailf("[%s] activate chain at head section [%s] for current head [%s]", newPeer.id, sectionName(headSection), name(currentBlockHash)) + self.activateChain(headSection, newPeer) + } + } + if oldPeer != nil { + poolLogger.DebugDetailf("[%s] quit section processes", oldPeer.id) + close(oldPeer.quitC) + } +} + +func (self *BlockPool) getParent(sec *section) *section { + self.chainLock.RLock() + defer self.chainLock.RUnlock() + return sec.parent +} + +func (self *BlockPool) getChild(sec *section) *section { + self.chainLock.RLock() + defer self.chainLock.RUnlock() + return sec.child +} + +func newSection() (sec *section) { + sec = §ion{ + controlC: make(chan *peerInfo), + suicideC: make(chan bool), + blockChainC: make(chan bool), + offC: make(chan bool), + forkC: make(chan chan bool), + } + return +} + +// link should only be called under chainLock +func (self *BlockPool) link(parent *section, child *section) { + if parent != nil { + exChild := parent.child + parent.child = child + if exChild != nil && exChild != child { + poolLogger.Debugf("[%s] chain fork [%s] -> [%s]", sectionName(parent), sectionName(exChild), sectionName(child)) + exChild.parent = nil + } + } + if child != nil { + exParent := child.parent + if exParent != nil && exParent != parent { + poolLogger.Debugf("[%s] chain reverse fork [%s] -> [%s]", sectionName(child), sectionName(exParent), sectionName(parent)) + exParent.child = nil + } + child.parent = parent + } +} + +func (self *BlockPool) get(hash []byte) (node *poolEntry) { + self.lock.RLock() + defer self.lock.RUnlock() + return self.pool[string(hash)] +} + +func (self *BlockPool) set(hash []byte, node *poolEntry) { + self.lock.Lock() + defer self.lock.Unlock() + self.pool[string(hash)] = node +} |