Merge pull request #1243 from karalabe/instrument-downloader-sync

eth, eth/downloader: separate concerns, clean up test suite

eth/backend.go

@@ -193,7 +193,6 @@ type Ethereum struct {
 	whisper         *whisper.Whisper
 	pow             *ethash.Ethash
 	protocolManager *ProtocolManager
-	downloader      *downloader.Downloader
 	SolcPath        string
 	solc            *compiler.Solidity
 
@@ -290,14 +289,13 @@ func New(config *Config) (*Ethereum, error) {
 	if err != nil {
 		return nil, err
 	}
-	eth.downloader = downloader.New(eth.EventMux(), eth.chainManager.HasBlock, eth.chainManager.GetBlock)
 	eth.txPool = core.NewTxPool(eth.EventMux(), eth.chainManager.State, eth.chainManager.GasLimit)
 	eth.blockProcessor = core.NewBlockProcessor(stateDb, extraDb, eth.pow, eth.chainManager, eth.EventMux())
 	eth.chainManager.SetProcessor(eth.blockProcessor)
+	eth.protocolManager = NewProtocolManager(config.ProtocolVersion, config.NetworkId, eth.eventMux, eth.txPool, eth.chainManager)
+
 	eth.miner = miner.New(eth, eth.EventMux(), eth.pow)
 	eth.miner.SetGasPrice(config.GasPrice)
-
-	eth.protocolManager = NewProtocolManager(config.ProtocolVersion, config.NetworkId, eth.eventMux, eth.txPool, eth.chainManager, eth.downloader)
 	if config.Shh {
 		eth.whisper = whisper.New()
 		eth.shhVersionId = int(eth.whisper.Version())
@@ -447,7 +445,7 @@ func (s *Ethereum) ClientVersion() string                { return s.clientVersio
 func (s *Ethereum) EthVersion() int                      { return s.ethVersionId }
 func (s *Ethereum) NetVersion() int                      { return s.netVersionId }
 func (s *Ethereum) ShhVersion() int                      { return s.shhVersionId }
-func (s *Ethereum) Downloader() *downloader.Downloader   { return s.downloader }
+func (s *Ethereum) Downloader() *downloader.Downloader   { return s.protocolManager.downloader }
 
 // Start the ethereum
 func (s *Ethereum) Start() error {

eth/downloader/downloader.go

@@ -3,6 +3,7 @@ package downloader
 import (
 	"bytes"
 	"errors"
+	"math"
 	"math/rand"
 	"sync"
 	"sync/atomic"
@@ -28,32 +29,40 @@ var (
 	crossCheckCycle = time.Second      // Period after which to check for expired cross checks
 
 	maxBannedHashes = 4096 // Number of bannable hashes before phasing old ones out
+	maxBlockProcess = 256  // Number of blocks to import at once into the chain
 )
 
 var (
-	errLowTd            = errors.New("peers TD is too low")
+	errBusy              = errors.New("busy")
-	ErrBusy             = errors.New("busy")
+	errUnknownPeer       = errors.New("peer is unknown or unhealthy")
-	errUnknownPeer      = errors.New("peer is unknown or unhealthy")
+	errBadPeer           = errors.New("action from bad peer ignored")
-	ErrBadPeer          = errors.New("action from bad peer ignored")
+	errStallingPeer      = errors.New("peer is stalling")
-	ErrStallingPeer     = errors.New("peer is stalling")
+	errBannedHead        = errors.New("peer head hash already banned")
-	errBannedHead       = errors.New("peer head hash already banned")
+	errNoPeers           = errors.New("no peers to keep download active")
-	errNoPeers          = errors.New("no peers to keep download active")
+	errPendingQueue      = errors.New("pending items in queue")
-	ErrPendingQueue     = errors.New("pending items in queue")
+	errTimeout           = errors.New("timeout")
-	ErrTimeout          = errors.New("timeout")
+	errEmptyHashSet      = errors.New("empty hash set by peer")
-	ErrEmptyHashSet     = errors.New("empty hash set by peer")
+	errPeersUnavailable  = errors.New("no peers available or all peers tried for block download process")
-	errPeersUnavailable = errors.New("no peers available or all peers tried for block download process")
+	errAlreadyInPool     = errors.New("hash already in pool")
-	errAlreadyInPool    = errors.New("hash already in pool")
+	errInvalidChain      = errors.New("retrieved hash chain is invalid")
-	ErrInvalidChain     = errors.New("retrieved hash chain is invalid")
+	errCrossCheckFailed  = errors.New("block cross-check failed")
-	ErrCrossCheckFailed = errors.New("block cross-check failed")
+	errCancelHashFetch   = errors.New("hash fetching canceled (requested)")
-	errCancelHashFetch  = errors.New("hash fetching cancelled (requested)")
+	errCancelBlockFetch  = errors.New("block downloading canceled (requested)")
-	errCancelBlockFetch = errors.New("block downloading cancelled (requested)")
+	errCancelChainImport = errors.New("chain importing canceled (requested)")
-	errNoSyncActive     = errors.New("no sync active")
+	errNoSyncActive      = errors.New("no sync active")
 )
 
+// hashCheckFn is a callback type for verifying a hash's presence in the local chain.
 type hashCheckFn func(common.Hash) bool
-type getBlockFn func(common.Hash) *types.Block
+
+// blockRetrievalFn is a callback type for retrieving a block from the local chain.
+type blockRetrievalFn func(common.Hash) *types.Block
+
+// chainInsertFn is a callback type to insert a batch of blocks into the local chain.
 type chainInsertFn func(types.Blocks) (int, error)
-type hashIterFn func() (common.Hash, error)
+
+// peerDropFn is a callback type for dropping a peer detected as malicious.
+type peerDropFn func(id string)
 
 type blockPack struct {
 	peerId string
@@ -85,12 +94,16 @@ type Downloader struct {
 	importLock  sync.Mutex
 
 	// Callbacks
-	hasBlock hashCheckFn
+	hasBlock    hashCheckFn      // Checks if a block is present in the chain
-	getBlock getBlockFn
+	getBlock    blockRetrievalFn // Retrieves a block from the chain
+	insertChain chainInsertFn    // Injects a batch of blocks into the chain
+	dropPeer    peerDropFn       // Retrieved the TD of our own chain
 
 	// Status
-	synchronising int32
+	synchroniseMock func(id string, hash common.Hash) error // Replacement for synchronise during testing
-	notified      int32
+	synchronising   int32
+	processing      int32
+	notified        int32
 
 	// Channels
 	newPeerCh chan *peer
@@ -107,17 +120,20 @@ type Block struct {
 	OriginPeer string
 }
 
-func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock getBlockFn) *Downloader {
+// New creates a new downloader to fetch hashes and blocks from remote peers.
+func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock blockRetrievalFn, insertChain chainInsertFn, dropPeer peerDropFn) *Downloader {
 	// Create the base downloader
 	downloader := &Downloader{
-		mux:       mux,
+		mux:         mux,
-		queue:     newQueue(),
+		queue:       newQueue(),
-		peers:     newPeerSet(),
+		peers:       newPeerSet(),
-		hasBlock:  hasBlock,
+		hasBlock:    hasBlock,
-		getBlock:  getBlock,
+		getBlock:    getBlock,
-		newPeerCh: make(chan *peer, 1),
+		insertChain: insertChain,
-		hashCh:    make(chan hashPack, 1),
+		dropPeer:    dropPeer,
-		blockCh:   make(chan blockPack, 1),
+		newPeerCh:   make(chan *peer, 1),
+		hashCh:      make(chan hashPack, 1),
+		blockCh:     make(chan blockPack, 1),
 	}
 	// Inject all the known bad hashes
 	downloader.banned = set.New()
@@ -150,7 +166,7 @@ func (d *Downloader) Stats() (pending int, cached int, importing int, estimate t
 	return
 }
 
-// Synchronising returns the state of the downloader
+// Synchronising returns whether the downloader is currently retrieving blocks.
 func (d *Downloader) Synchronising() bool {
 	return atomic.LoadInt32(&d.synchronising) > 0
 }
@@ -183,19 +199,47 @@ func (d *Downloader) UnregisterPeer(id string) error {
 	return nil
 }
 
-// Synchronise will select the peer and use it for synchronising. If an empty string is given
+// Synchronise tries to sync up our local block chain with a remote peer, both
+// adding various sanity checks as well as wrapping it with various log entries.
+func (d *Downloader) Synchronise(id string, head common.Hash) {
+	glog.V(logger.Detail).Infof("Attempting synchronisation: %v, 0x%x", id, head)
+
+	switch err := d.synchronise(id, head); err {
+	case nil:
+		glog.V(logger.Detail).Infof("Synchronisation completed")
+
+	case errBusy:
+		glog.V(logger.Detail).Infof("Synchronisation already in progress")
+
+	case errTimeout, errBadPeer, errStallingPeer, errBannedHead, errEmptyHashSet, errPeersUnavailable, errInvalidChain, errCrossCheckFailed:
+		glog.V(logger.Debug).Infof("Removing peer %v: %v", id, err)
+		d.dropPeer(id)
+
+	case errPendingQueue:
+		glog.V(logger.Debug).Infoln("Synchronisation aborted:", err)
+
+	default:
+		glog.V(logger.Warn).Infof("Synchronisation failed: %v", err)
+	}
+}
+
+// synchronise will select the peer and use it for synchronising. If an empty string is given
 // it will use the best peer possible and synchronize if it's TD is higher than our own. If any of the
 // checks fail an error will be returned. This method is synchronous
-func (d *Downloader) Synchronise(id string, hash common.Hash) error {
+func (d *Downloader) synchronise(id string, hash common.Hash) error {
+	// Mock out the synchonisation if testing
+	if d.synchroniseMock != nil {
+		return d.synchroniseMock(id, hash)
+	}
 	// Make sure only one goroutine is ever allowed past this point at once
 	if !atomic.CompareAndSwapInt32(&d.synchronising, 0, 1) {
-		return ErrBusy
+		return errBusy
 	}
 	defer atomic.StoreInt32(&d.synchronising, 0)
 
 	// If the head hash is banned, terminate immediately
 	if d.banned.Has(hash) {
-		return ErrInvalidChain
+		return errBannedHead
 	}
 	// Post a user notification of the sync (only once per session)
 	if atomic.CompareAndSwapInt32(&d.notified, 0, 1) {
@@ -209,7 +253,7 @@ func (d *Downloader) Synchronise(id string, hash common.Hash) error {
 
 	// Abort if the queue still contains some leftover data
 	if _, cached := d.queue.Size(); cached > 0 && d.queue.GetHeadBlock() != nil {
-		return ErrPendingQueue
+		return errPendingQueue
 	}
 	// Reset the queue and peer set to clean any internal leftover state
 	d.queue.Reset()
@@ -225,19 +269,6 @@ func (d *Downloader) Synchronise(id string, hash common.Hash) error {
 	return d.syncWithPeer(p, hash)
 }
 
-// TakeBlocks takes blocks from the queue and yields them to the caller.
-func (d *Downloader) TakeBlocks() []*Block {
-	blocks := d.queue.TakeBlocks()
-	if len(blocks) > 0 {
-		d.importLock.Lock()
-		d.importStart = time.Now()
-		d.importQueue = blocks
-		d.importDone = 0
-		d.importLock.Unlock()
-	}
-	return blocks
-}
-
 // Has checks if the downloader knows about a particular hash, meaning that its
 // either already downloaded of pending retrieval.
 func (d *Downloader) Has(hash common.Hash) bool {
@@ -272,34 +303,26 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash) (err error) {
 
 // Cancel cancels all of the operations and resets the queue. It returns true
 // if the cancel operation was completed.
-func (d *Downloader) Cancel() bool {
+func (d *Downloader) Cancel() {
-	// If we're not syncing just return.
-	hs, bs := d.queue.Size()
-	if atomic.LoadInt32(&d.synchronising) == 0 && hs == 0 && bs == 0 {
-		return false
-	}
 	// Close the current cancel channel
 	d.cancelLock.Lock()
-	select {
+	if d.cancelCh != nil {
-	case <-d.cancelCh:
+		select {
-		// Channel was already closed
+		case <-d.cancelCh:
-	default:
+			// Channel was already closed
-		close(d.cancelCh)
+		default:
+			close(d.cancelCh)
+		}
 	}
 	d.cancelLock.Unlock()
 
-	// Reset the queue and import statistics
+	// Reset the queue
 	d.queue.Reset()
-
-	d.importLock.Lock()
-	d.importQueue = nil
-	d.importDone = 0
-	d.importLock.Unlock()
-
-	return true
 }
 
-// XXX Make synchronous
+// fetchHahes starts retrieving hashes backwards from a specific peer and hash,
+// up until it finds a common ancestor. If the source peer times out, alternative
+// ones are tried for continuation.
 func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 	var (
 		start  = time.Now()
@@ -317,7 +340,7 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 	<-timeout.C // timeout channel should be initially empty.
 
 	getHashes := func(from common.Hash) {
-		active.getHashes(from)
+		go active.getHashes(from)
 		timeout.Reset(hashTTL)
 	}
 
@@ -342,7 +365,7 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 			// Make sure the peer actually gave something valid
 			if len(hashPack.hashes) == 0 {
 				glog.V(logger.Debug).Infof("Peer (%s) responded with empty hash set", active.id)
-				return ErrEmptyHashSet
+				return errEmptyHashSet
 			}
 			for index, hash := range hashPack.hashes {
 				if d.banned.Has(hash) {
@@ -352,7 +375,7 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 					if err := d.banBlocks(active.id, hash); err != nil {
 						glog.V(logger.Debug).Infof("Failed to ban batch of blocks: %v", err)
 					}
-					return ErrInvalidChain
+					return errInvalidChain
 				}
 			}
 			// Determine if we're done fetching hashes (queue up all pending), and continue if not done
@@ -369,12 +392,12 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 			inserts := d.queue.Insert(hashPack.hashes)
 			if len(inserts) == 0 && !done {
 				glog.V(logger.Debug).Infof("Peer (%s) responded with stale hashes", active.id)
-				return ErrBadPeer
+				return errBadPeer
 			}
 			if !done {
 				// Check that the peer is not stalling the sync
 				if len(inserts) < MinHashFetch {
-					return ErrStallingPeer
+					return errStallingPeer
 				}
 				// Try and fetch a random block to verify the hash batch
 				// Skip the last hash as the cross check races with the next hash fetch
@@ -386,9 +409,9 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 					expire: time.Now().Add(blockSoftTTL),
 					parent: parent,
 				}
-				active.getBlocks([]common.Hash{origin})
+				go active.getBlocks([]common.Hash{origin})
 
-				// Also fetch a fresh
+				// Also fetch a fresh batch of hashes
 				getHashes(head)
 				continue
 			}
@@ -408,7 +431,7 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 			block := blockPack.blocks[0]
 			if check, ok := d.checks[block.Hash()]; ok {
 				if block.ParentHash() != check.parent {
-					return ErrCrossCheckFailed
+					return errCrossCheckFailed
 				}
 				delete(d.checks, block.Hash())
 			}
@@ -418,7 +441,7 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 			for hash, check := range d.checks {
 				if time.Now().After(check.expire) {
 					glog.V(logger.Debug).Infof("Cross check timeout for %x", hash)
-					return ErrCrossCheckFailed
+					return errCrossCheckFailed
 				}
 			}
 
@@ -438,7 +461,7 @@ func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
 			// if all peers have been tried, abort the process entirely or if the hash is
 			// the zero hash.
 			if p == nil || (head == common.Hash{}) {
-				return ErrTimeout
+				return errTimeout
 			}
 			// set p to the active peer. this will invalidate any hashes that may be returned
 			// by our previous (delayed) peer.
@@ -495,12 +518,13 @@ out:
 						glog.V(logger.Detail).Infof("%s: no blocks delivered", peer)
 						break
 					}
-					// All was successful, promote the peer
+					// All was successful, promote the peer and potentially start processing
 					peer.Promote()
 					peer.SetIdle()
 					glog.V(logger.Detail).Infof("%s: delivered %d blocks", peer, len(blockPack.blocks))
+					go d.process()
 
-				case ErrInvalidChain:
+				case errInvalidChain:
 					// The hash chain is invalid (blocks are not ordered properly), abort
 					return err
 
@@ -617,7 +641,7 @@ func (d *Downloader) banBlocks(peerId string, head common.Hash) error {
 			return errCancelBlockFetch
 
 		case <-timeout:
-			return ErrTimeout
+			return errTimeout
 
 		case <-d.hashCh:
 			// Out of bounds hashes received, ignore them
@@ -674,6 +698,92 @@ func (d *Downloader) banBlocks(peerId string, head common.Hash) error {
 	}
 }
 
+// process takes blocks from the queue and tries to import them into the chain.
+//
+// The algorithmic flow is as follows:
+//  - The `processing` flag is swapped to 1 to ensure singleton access
+//  - The current `cancel` channel is retrieved to detect sync abortions
+//  - Blocks are iteratively taken from the cache and inserted into the chain
+//  - When the cache becomes empty, insertion stops
+//  - The `processing` flag is swapped back to 0
+//  - A post-exit check is made whether new blocks became available
+//     - This step is important: it handles a potential race condition between
+//       checking for no more work, and releasing the processing "mutex". In
+//       between these state changes, a block may have arrived, but a processing
+//       attempt denied, so we need to re-enter to ensure the block isn't left
+//       to idle in the cache.
+func (d *Downloader) process() (err error) {
+	// Make sure only one goroutine is ever allowed to process blocks at once
+	if !atomic.CompareAndSwapInt32(&d.processing, 0, 1) {
+		return
+	}
+	// If the processor just exited, but there are freshly pending items, try to
+	// reenter. This is needed because the goroutine spinned up for processing
+	// the fresh blocks might have been rejected entry to to this present thread
+	// not yet releasing the `processing` state.
+	defer func() {
+		if err == nil && d.queue.GetHeadBlock() != nil {
+			err = d.process()
+		}
+	}()
+	// Release the lock upon exit (note, before checking for reentry!), and set
+	// the import statistics to zero.
+	defer func() {
+		d.importLock.Lock()
+		d.importQueue = nil
+		d.importDone = 0
+		d.importLock.Unlock()
+
+		atomic.StoreInt32(&d.processing, 0)
+	}()
+
+	// Fetch the current cancel channel to allow termination
+	d.cancelLock.RLock()
+	cancel := d.cancelCh
+	d.cancelLock.RUnlock()
+
+	// Repeat the processing as long as there are blocks to import
+	for {
+		// Fetch the next batch of blocks
+		blocks := d.queue.TakeBlocks()
+		if len(blocks) == 0 {
+			return nil
+		}
+		// Reset the import statistics
+		d.importLock.Lock()
+		d.importStart = time.Now()
+		d.importQueue = blocks
+		d.importDone = 0
+		d.importLock.Unlock()
+
+		// Actually import the blocks
+		glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())
+		for len(blocks) != 0 { // TODO: quit
+			// Check for any termination requests
+			select {
+			case <-cancel:
+				return errCancelChainImport
+			default:
+			}
+			// Retrieve the first batch of blocks to insert
+			max := int(math.Min(float64(len(blocks)), float64(maxBlockProcess)))
+			raw := make(types.Blocks, 0, max)
+			for _, block := range blocks[:max] {
+				raw = append(raw, block.RawBlock)
+			}
+			// Try to inset the blocks, drop the originating peer if there's an error
+			index, err := d.insertChain(raw)
+			if err != nil {
+				glog.V(logger.Debug).Infof("Block #%d import failed: %v", raw[index].NumberU64(), err)
+				d.dropPeer(blocks[index].OriginPeer)
+				d.Cancel()
+				return errCancelChainImport
+			}
+			blocks = blocks[max:]
+		}
+	}
+}
+
 // DeliverBlocks injects a new batch of blocks received from a remote node.
 // This is usually invoked through the BlocksMsg by the protocol handler.
 func (d *Downloader) DeliverBlocks(id string, blocks []*types.Block) error {

eth/downloader/peer.go

@@ -74,7 +74,7 @@ func (p *peer) Fetch(request *fetchRequest) error {
 	for hash, _ := range request.Hashes {
 		hashes = append(hashes, hash)
 	}
-	p.getBlocks(hashes)
+	go p.getBlocks(hashes)
 
 	return nil
 }

eth/downloader/queue.go

@@ -320,7 +320,7 @@ func (q *queue) Deliver(id string, blocks []*types.Block) (err error) {
 		// If a requested block falls out of the range, the hash chain is invalid
 		index := int(block.NumberU64()) - q.blockOffset
 		if index >= len(q.blockCache) || index < 0 {
-			return ErrInvalidChain
+			return errInvalidChain
 		}
 		// Otherwise merge the block and mark the hash block
 		q.blockCache[index] = &Block{

eth/downloader/queue_test.go

@@ -1,30 +0,0 @@
-package downloader
-
-import (
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/types"
-	"gopkg.in/fatih/set.v0"
-)
-
-func createHashSet(hashes []common.Hash) *set.Set {
-	hset := set.New()
-
-	for _, hash := range hashes {
-		hset.Add(hash)
-	}
-
-	return hset
-}
-
-func createBlocksFromHashSet(hashes *set.Set) []*types.Block {
-	blocks := make([]*types.Block, hashes.Size())
-
-	var i int
-	hashes.Each(func(v interface{}) bool {
-		blocks[i] = createBlock(i, common.Hash{}, v.(common.Hash))
-		i++
-		return true
-	})
-
-	return blocks
-}

eth/handler.go

@@ -68,12 +68,11 @@ type ProtocolManager struct {
 
 // NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
 // with the ethereum network.
-func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpool txPool, chainman *core.ChainManager, downloader *downloader.Downloader) *ProtocolManager {
+func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpool txPool, chainman *core.ChainManager) *ProtocolManager {
 	manager := &ProtocolManager{
 		eventMux:   mux,
 		txpool:     txpool,
 		chainman:   chainman,
-		downloader: downloader,
 		peers:      newPeerSet(),
 		newPeerCh:  make(chan *peer, 1),
 		newHashCh:  make(chan []*blockAnnounce, 1),
@@ -81,6 +80,7 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
 		txsyncCh:   make(chan *txsync),
 		quitSync:   make(chan struct{}),
 	}
+	manager.downloader = downloader.New(manager.eventMux, manager.chainman.HasBlock, manager.chainman.GetBlock, manager.chainman.InsertChain, manager.removePeer)
 	manager.SubProtocol = p2p.Protocol{
 		Name:    "eth",
 		Version: uint(protocolVersion),

eth/protocol_test.go

@@ -11,7 +11,6 @@ import (
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/p2p"
@@ -168,8 +167,7 @@ func newProtocolManagerForTesting(txAdded chan<- []*types.Transaction) *Protocol
 		db, _    = ethdb.NewMemDatabase()
 		chain, _ = core.NewChainManager(core.GenesisBlock(0, db), db, db, core.FakePow{}, em)
 		txpool   = &fakeTxPool{added: txAdded}
-		dl       = downloader.New(em, chain.HasBlock, chain.GetBlock)
+		pm       = NewProtocolManager(ProtocolVersion, 0, em, txpool, chain)
-		pm       = NewProtocolManager(ProtocolVersion, 0, em, txpool, chain, dl)
 	)
 	pm.Start()
 	return pm

eth/sync.go

@@ -1,14 +1,11 @@
 package eth
 
 import (
-	"math"
 	"math/rand"
-	"sync/atomic"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/p2p/discover"
@@ -16,12 +13,10 @@ import (
 
 const (
 	forceSyncCycle      = 10 * time.Second       // Time interval to force syncs, even if few peers are available
-	blockProcCycle      = 500 * time.Millisecond // Time interval to check for new blocks to process
 	notifyCheckCycle    = 100 * time.Millisecond // Time interval to allow hash notifies to fulfill before hard fetching
 	notifyArriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested
 	notifyFetchTimeout  = 5 * time.Second        // Maximum alloted time to return an explicitly requested block
 	minDesiredPeerCount = 5                      // Amount of peers desired to start syncing
-	blockProcAmount     = 256
 
 	// This is the target size for the packs of transactions sent by txsyncLoop.
 	// A pack can get larger than this if a single transactions exceeds this size.
@@ -176,7 +171,7 @@ func (pm *ProtocolManager) fetcher() {
 			// Send out all block requests
 			for peer, hashes := range request {
 				glog.V(logger.Debug).Infof("Explicitly fetching %d blocks from %s", len(hashes), peer.id)
-				peer.requestBlocks(hashes)
+				go peer.requestBlocks(hashes)
 			}
 			request = make(map[*peer][]common.Hash)
 
@@ -219,7 +214,7 @@ func (pm *ProtocolManager) fetcher() {
 				if announce := pending[hash]; announce != nil {
 					// Drop the block if it surely cannot fit
 					if pm.chainman.HasBlock(hash) || !pm.chainman.HasBlock(block.ParentHash()) {
-						delete(pending, hash)
+						// delete(pending, hash) // if we drop, it will re-fetch it, wait for timeout?
 						continue
 					}
 					// Otherwise accumulate for import
@@ -255,10 +250,10 @@ func (pm *ProtocolManager) fetcher() {
 // syncer is responsible for periodically synchronising with the network, both
 // downloading hashes and blocks as well as retrieving cached ones.
 func (pm *ProtocolManager) syncer() {
-	forceSync := time.Tick(forceSyncCycle)
+	// Abort any pending syncs if we terminate
-	blockProc := time.Tick(blockProcCycle)
+	defer pm.downloader.Cancel()
-	blockProcPend := int32(0)
 
+	forceSync := time.Tick(forceSyncCycle)
 	for {
 		select {
 		case <-pm.newPeerCh:
@@ -272,55 +267,12 @@ func (pm *ProtocolManager) syncer() {
 			// Force a sync even if not enough peers are present
 			go pm.synchronise(pm.peers.BestPeer())
 
-		case <-blockProc:
-			// Try to pull some blocks from the downloaded
-			if atomic.CompareAndSwapInt32(&blockProcPend, 0, 1) {
-				go func() {
-					pm.processBlocks()
-					atomic.StoreInt32(&blockProcPend, 0)
-				}()
-			}
-
 		case <-pm.quitSync:
 			return
 		}
 	}
 }
 
-// processBlocks retrieves downloaded blocks from the download cache and tries
-// to construct the local block chain with it. Note, since the block retrieval
-// order matters, access to this function *must* be synchronized/serialized.
-func (pm *ProtocolManager) processBlocks() error {
-	pm.wg.Add(1)
-	defer pm.wg.Done()
-
-	// Short circuit if no blocks are available for insertion
-	blocks := pm.downloader.TakeBlocks()
-	if len(blocks) == 0 {
-		return nil
-	}
-	glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())
-
-	for len(blocks) != 0 && !pm.quit {
-		// Retrieve the first batch of blocks to insert
-		max := int(math.Min(float64(len(blocks)), float64(blockProcAmount)))
-		raw := make(types.Blocks, 0, max)
-		for _, block := range blocks[:max] {
-			raw = append(raw, block.RawBlock)
-		}
-		// Try to inset the blocks, drop the originating peer if there's an error
-		index, err := pm.chainman.InsertChain(raw)
-		if err != nil {
-			glog.V(logger.Debug).Infoln("Downloaded block import failed:", err)
-			pm.removePeer(blocks[index].OriginPeer)
-			pm.downloader.Cancel()
-			return err
-		}
-		blocks = blocks[max:]
-	}
-	return nil
-}
-
 // synchronise tries to sync up our local block chain with a remote peer, both
 // adding various sanity checks as well as wrapping it with various log entries.
 func (pm *ProtocolManager) synchronise(peer *peer) {
@@ -332,33 +284,6 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 	if peer.Td().Cmp(pm.chainman.Td()) <= 0 {
 		return
 	}
-	// FIXME if we have the hash in our chain and the TD of the peer is
+	// Otherwise try to sync with the downloader
-	// much higher than ours, something is wrong with us or the peer.
+	pm.downloader.Synchronise(peer.id, peer.Head())
-	// Check if the hash is on our own chain
-	head := peer.Head()
-	if pm.chainman.HasBlock(head) {
-		glog.V(logger.Debug).Infoln("Synchronisation canceled: head already known")
-		return
-	}
-	// Get the hashes from the peer (synchronously)
-	glog.V(logger.Detail).Infof("Attempting synchronisation: %v, 0x%x", peer.id, head)
-
-	err := pm.downloader.Synchronise(peer.id, head)
-	switch err {
-	case nil:
-		glog.V(logger.Detail).Infof("Synchronisation completed")
-
-	case downloader.ErrBusy:
-		glog.V(logger.Detail).Infof("Synchronisation already in progress")
-
-	case downloader.ErrTimeout, downloader.ErrBadPeer, downloader.ErrEmptyHashSet, downloader.ErrInvalidChain, downloader.ErrCrossCheckFailed:
-		glog.V(logger.Debug).Infof("Removing peer %v: %v", peer.id, err)
-		pm.removePeer(peer.id)
-
-	case downloader.ErrPendingQueue:
-		glog.V(logger.Debug).Infoln("Synchronisation aborted:", err)
-
-	default:
-		glog.V(logger.Warn).Infof("Synchronisation failed: %v", err)
-	}
 }