diff --git a/eth/handler.go b/eth/handler.go
index b2d7412953f4b39e35ce2fe51c8555ab7130cbe3..835097d8432008e35d86417d7086404f966a54d0 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -47,9 +47,7 @@ type ProtocolManager struct {
txpool txPool
chainman *core.ChainManager
downloader *downloader.Downloader
-
- pmu sync.Mutex
- peers map[string]*peer
+ peers *peerSet
SubProtocol p2p.Protocol
@@ -73,7 +71,7 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
txpool: txpool,
chainman: chainman,
downloader: downloader,
- peers: make(map[string]*peer),
+ peers: newPeerSet(),
newPeerCh: make(chan *peer, 1),
quitSync: make(chan struct{}),
}
@@ -95,10 +93,14 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
}
func (pm *ProtocolManager) removePeer(peer *peer) {
- pm.pmu.Lock()
- defer pm.pmu.Unlock()
+ // Unregister the peer from the downloader
pm.downloader.UnregisterPeer(peer.id)
- delete(pm.peers, peer.id)
+
+ // Remove the peer from the Ethereum peer set too
+ glog.V(logger.Detail).Infoln("Removing peer", peer.id)
+ if err := pm.peers.Unregister(peer.id); err != nil {
+ glog.V(logger.Error).Infoln("Removal failed:", err)
+ }
}
func (pm *ProtocolManager) Start() {
@@ -136,31 +138,32 @@ func (pm *ProtocolManager) newPeer(pv, nv int, p *p2p.Peer, rw p2p.MsgReadWriter
}
func (pm *ProtocolManager) handle(p *peer) error {
+ // Execute the Ethereum handshake, short circuit if fails
if err := p.handleStatus(); err != nil {
return err
}
- pm.pmu.Lock()
- pm.peers[p.id] = p
- pm.pmu.Unlock()
-
- pm.downloader.RegisterPeer(p.id, p.recentHash, p.requestHashes, p.requestBlocks)
- defer func() {
- pm.removePeer(p)
- }()
+ // Register the peer locally and in the downloader too
+ glog.V(logger.Detail).Infoln("Adding peer", p.id)
+ if err := pm.peers.Register(p); err != nil {
+ glog.V(logger.Error).Infoln("Addition failed:", err)
+ return err
+ }
+ defer pm.removePeer(p)
+ if err := pm.downloader.RegisterPeer(p.id, p.recentHash, p.requestHashes, p.requestBlocks); err != nil {
+ return err
+ }
// propagate existing transactions. new transactions appearing
// after this will be sent via broadcasts.
if err := p.sendTransactions(pm.txpool.GetTransactions()); err != nil {
return err
}
-
// main loop. handle incoming messages.
for {
if err := pm.handleMsg(p); err != nil {
return err
}
}
-
return nil
}
@@ -346,18 +349,8 @@ func (pm *ProtocolManager) verifyTd(peer *peer, request newBlockMsgData) error {
// out which peers do not contain the block in their block set and will do a
// sqrt(peers) to determine the amount of peers we broadcast to.
func (pm *ProtocolManager) BroadcastBlock(hash common.Hash, block *types.Block) {
- pm.pmu.Lock()
- defer pm.pmu.Unlock()
-
- // Find peers who don't know anything about the given hash. Peers that
- // don't know about the hash will be a candidate for the broadcast loop
- var peers []*peer
- for _, peer := range pm.peers {
- if !peer.blockHashes.Has(hash) {
- peers = append(peers, peer)
- }
- }
- // Broadcast block to peer set
+ // Broadcast block to a batch of peers not knowing about it
+ peers := pm.peers.BlockLackingPeers(hash)
peers = peers[:int(math.Sqrt(float64(len(peers))))]
for _, peer := range peers {
peer.sendNewBlock(block)
@@ -369,18 +362,8 @@ func (pm *ProtocolManager) BroadcastBlock(hash common.Hash, block *types.Block)
// out which peers do not contain the block in their block set and will do a
// sqrt(peers) to determine the amount of peers we broadcast to.
func (pm *ProtocolManager) BroadcastTx(hash common.Hash, tx *types.Transaction) {
- pm.pmu.Lock()
- defer pm.pmu.Unlock()
-
- // Find peers who don't know anything about the given hash. Peers that
- // don't know about the hash will be a candidate for the broadcast loop
- var peers []*peer
- for _, peer := range pm.peers {
- if !peer.txHashes.Has(hash) {
- peers = append(peers, peer)
- }
- }
- // Broadcast block to peer set
+ // Broadcast transaction to a batch of peers not knowing about it
+ peers := pm.peers.TxLackingPeers(hash)
//FIXME include this again: peers = peers[:int(math.Sqrt(float64(len(peers))))]
for _, peer := range peers {
peer.sendTransaction(tx)
diff --git a/eth/peer.go b/eth/peer.go
index 861efaaec60eb30082b5df77b3bfc782d43ad221..369e16221c1faf1d49708fa614672af63bd11d48 100644
--- a/eth/peer.go
+++ b/eth/peer.go
@@ -1,8 +1,10 @@
package eth
import (
+ "errors"
"fmt"
"math/big"
+ "sync"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
@@ -12,6 +14,11 @@ import (
"gopkg.in/fatih/set.v0"
)
+var (
+ errAlreadyRegistered = errors.New("peer is already registered")
+ errNotRegistered = errors.New("peer is not registered")
+)
+
type statusMsgData struct {
ProtocolVersion uint32
NetworkId uint32
@@ -25,16 +32,6 @@ type getBlockHashesMsgData struct {
Amount uint64
}
-func getBestPeer(peers map[string]*peer) *peer {
- var peer *peer
- for _, cp := range peers {
- if peer == nil || cp.td.Cmp(peer.td) > 0 {
- peer = cp
- }
- }
- return peer
-}
-
type peer struct {
*p2p.Peer
@@ -159,3 +156,115 @@ func (p *peer) handleStatus() error {
return <-errc
}
+
+// peerSet represents the collection of active peers currently participating in
+// the Ethereum sub-protocol.
+type peerSet struct {
+ peers map[string]*peer
+ lock sync.RWMutex
+}
+
+// newPeerSet creates a new peer set to track the active participants.
+func newPeerSet() *peerSet {
+ return &peerSet{
+ peers: make(map[string]*peer),
+ }
+}
+
+// Register injects a new peer into the working set, or returns an error if the
+// peer is already known.
+func (ps *peerSet) Register(p *peer) error {
+ ps.lock.Lock()
+ defer ps.lock.Unlock()
+
+ if _, ok := ps.peers[p.id]; ok {
+ return errAlreadyRegistered
+ }
+ ps.peers[p.id] = p
+ return nil
+}
+
+// Unregister removes a remote peer from the active set, disabling any further
+// actions to/from that particular entity.
+func (ps *peerSet) Unregister(id string) error {
+ ps.lock.Lock()
+ defer ps.lock.Unlock()
+
+ if _, ok := ps.peers[id]; !ok {
+ return errNotRegistered
+ }
+ delete(ps.peers, id)
+ return nil
+}
+
+// Peer retrieves the registered peer with the given id.
+func (ps *peerSet) Peer(id string) *peer {
+ ps.lock.RLock()
+ defer ps.lock.RUnlock()
+
+ return ps.peers[id]
+}
+
+// Len returns if the current number of peers in the set.
+func (ps *peerSet) Len() int {
+ ps.lock.RLock()
+ defer ps.lock.RUnlock()
+
+ return len(ps.peers)
+}
+
+// BlockLackingPeers retrieves a list of peers that do not have a given block
+// in their set of known hashes.
+func (ps *peerSet) BlockLackingPeers(hash common.Hash) []*peer {
+ ps.lock.RLock()
+ defer ps.lock.RUnlock()
+
+ list := make([]*peer, 0, len(ps.peers))
+ for _, p := range ps.peers {
+ if !p.blockHashes.Has(hash) {
+ list = append(list, p)
+ }
+ }
+ return list
+}
+
+// TxLackingPeers retrieves a list of peers that do not have a given transaction
+// in their set of known hashes.
+func (ps *peerSet) TxLackingPeers(hash common.Hash) []*peer {
+ ps.lock.RLock()
+ defer ps.lock.RUnlock()
+
+ list := make([]*peer, 0, len(ps.peers))
+ for _, p := range ps.peers {
+ if !p.txHashes.Has(hash) {
+ list = append(list, p)
+ }
+ }
+ return list
+}
+
+// AllPeers retrieves a flat list of all the peers within the set.
+func (ps *peerSet) AllPeers() []*peer {
+ ps.lock.RLock()
+ defer ps.lock.RUnlock()
+
+ list := make([]*peer, 0, len(ps.peers))
+ for _, p := range ps.peers {
+ list = append(list, p)
+ }
+ return list
+}
+
+// BestPeer retrieves the known peer with the currently highest total difficulty.
+func (ps *peerSet) BestPeer() *peer {
+ ps.lock.RLock()
+ defer ps.lock.RUnlock()
+
+ var best *peer
+ for _, p := range ps.peers {
+ if best == nil || p.td.Cmp(best.td) > 0 {
+ best = p
+ }
+ }
+ return best
+}
diff --git a/eth/sync.go b/eth/sync.go
index aa7ebc77b8de4f309ad8891ab3bddd1ab9ea04a6..62d08acb6859ebcd8febfe695566f18d3553618c 100644
--- a/eth/sync.go
+++ b/eth/sync.go
@@ -10,8 +10,8 @@ import (
"github.com/ethereum/go-ethereum/logger/glog"
)
-// Sync contains all synchronisation code for the eth protocol
-
+// update periodically tries to synchronise with the network, both downloading
+// hashes and blocks as well as retrieving cached ones.
func (pm *ProtocolManager) update() {
forceSync := time.Tick(forceSyncCycle)
blockProc := time.Tick(blockProcCycle)
@@ -20,22 +20,16 @@ func (pm *ProtocolManager) update() {
for {
select {
case <-pm.newPeerCh:
- // Meet the `minDesiredPeerCount` before we select our best peer
- if len(pm.peers) < minDesiredPeerCount {
+ // Make sure we have peers to select from, then sync
+ if pm.peers.Len() < minDesiredPeerCount {
break
}
- // Find the best peer and synchronise with it
- peer := getBestPeer(pm.peers)
- if peer == nil {
- glog.V(logger.Debug).Infoln("Sync attempt canceled. No peers available")
- }
- go pm.synchronise(peer)
+ go pm.synchronise(pm.peers.BestPeer())
case <-forceSync:
// Force a sync even if not enough peers are present
- if peer := getBestPeer(pm.peers); peer != nil {
- go pm.synchronise(peer)
- }
+ go pm.synchronise(pm.peers.BestPeer())
+
case <-blockProc:
// Try to pull some blocks from the downloaded
if atomic.CompareAndSwapInt32(&blockProcPend, 0, 1) {
@@ -51,10 +45,9 @@ func (pm *ProtocolManager) update() {
}
}
-// processBlocks will attempt to reconstruct a chain by checking the first item and check if it's
-// a known parent. The first block in the chain may be unknown during downloading. When the
-// downloader isn't downloading blocks will be dropped with an unknown parent until either it
-// has depleted the list or found a known parent.
+// 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()
@@ -79,15 +72,24 @@ func (pm *ProtocolManager) processBlocks() error {
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) {
+ // Short circuit if no peers are available
+ if peer == nil {
+ glog.V(logger.Debug).Infoln("Synchronisation canceled: no peers available")
+ return
+ }
// Make sure the peer's TD is higher than our own. If not drop.
if peer.td.Cmp(pm.chainman.Td()) <= 0 {
+ glog.V(logger.Debug).Infoln("Synchronisation canceled: peer TD too small")
return
}
// FIXME if we have the hash in our chain and the TD of the peer is
// much higher than ours, something is wrong with us or the peer.
// Check if the hash is on our own chain
if pm.chainman.HasBlock(peer.recentHash) {
+ glog.V(logger.Debug).Infoln("Synchronisation canceled: head already known")
return
}
// Get the hashes from the peer (synchronously)