fix deadlock issue in AddBlock

- add peer switch channel arg to activateChain - no peer locking within
- proper locking in AddBlock - fixes deadlock issue
- comment out TD check and skip incorrect TD test again for hotfix

1 files changed, 17 insertions, 14 deletions

diff --git a/blockpool/peers.go b/blockpool/peers.go
index d95c348a8..7e6d281bb 100644
--- a/blockpool/peers.go
+++ b/blockpool/peers.go
@@ -114,10 +114,8 @@ func (self *peers) addToBlacklist(id string) {
 	self.blacklist[id] = time.Now()
 }
 
-// suspended checks if peer is still suspended
+// suspended checks if peer is still suspended, caller should hold peers.lock
 func (self *peers) suspended(id string) (s bool) {
-	self.lock.Lock()
-	defer self.lock.Unlock()
 	if suspendedAt, ok := self.blacklist[id]; ok {
 		if s = suspendedAt.Add(self.bp.Config.PeerSuspensionInterval).After(time.Now()); !s {
 			// no longer suspended, delete entry
@@ -205,13 +203,14 @@ func (self *peers) addPeer(
 	peerError func(*errs.Error),
 ) (best bool, suspended bool) {
 
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
 	var previousBlockHash common.Hash
 	if self.suspended(id) {
 		suspended = true
 		return
 	}
-	self.lock.Lock()
-	defer self.lock.Unlock()
 	p, found := self.peers[id]
 	if found {
 		// when called on an already connected peer, it means a newBlockMsg is received
@@ -255,7 +254,7 @@ func (self *peers) addPeer(
 			p.headSectionC <- nil
 			if entry := self.bp.get(previousBlockHash); entry != nil {
 				plog.DebugDetailf("addPeer: <%s> previous head : %v found in pool, activate", id, hex(previousBlockHash))
-				self.bp.activateChain(entry.section, p, nil)
+				self.bp.activateChain(entry.section, p, p.switchC, nil)
 				p.sections = append(p.sections, previousBlockHash)
 			}
 		}
@@ -265,8 +264,8 @@ func (self *peers) addPeer(
 		currentTD := self.bp.getTD()
 		bestpeer := self.best
 		if bestpeer != nil {
-			bestpeer.lock.Lock()
-			defer bestpeer.lock.Unlock()
+			bestpeer.lock.RLock()
+			defer bestpeer.lock.RUnlock()
 			currentTD = self.best.td
 		}
 		if td.Cmp(currentTD) > 0 {
@@ -362,14 +361,14 @@ func (self *BlockPool) switchPeer(oldp, newp *peer) {
 			if connected[hash] == nil {
 				// if not deleted, then reread from pool (it can be orphaned top half of a split section)
 				if entry := self.get(hash); entry != nil {
-					self.activateChain(entry.section, newp, connected)
+					self.activateChain(entry.section, newp, newp.switchC, connected)
 					connected[hash] = entry.section
 					sections = append(sections, hash)
 				}
 			}
 		}
 		plog.DebugDetailf("<%s> section processes (%v non-contiguous sequences, was %v before)", newp.id, len(sections), len(newp.sections))
-		// need to lock now that newp is exposed to section processes
+		// need to lock now that newp is exposed to section processesr
 		newp.lock.Lock()
 		newp.sections = sections
 		newp.lock.Unlock()
@@ -457,6 +456,8 @@ func (self *peer) getCurrentBlock(currentBlock *types.Block) {
 }
 
 func (self *peer) getBlockHashes() bool {
+	self.lock.Lock()
+	defer self.lock.Unlock()
 	//if connecting parent is found
 	if self.bp.hasBlock(self.parentHash) {
 		plog.DebugDetailf("HeadSection: <%s> parent block %s found in blockchain", self.id, hex(self.parentHash))
@@ -470,10 +471,10 @@ func (self *peer) getBlockHashes() bool {
 			self.bp.status.badPeers[self.id]++
 		} else {
 			// XXX added currentBlock check (?)
-			if self.currentBlock != nil && self.currentBlock.Td != nil {
+			if self.currentBlock != nil && self.currentBlock.Td != nil && !self.currentBlock.Queued() {
 				if self.td.Cmp(self.currentBlock.Td) != 0 {
-					//self.addError(ErrIncorrectTD, "on block %x", self.currentBlockHash)
-					//self.bp.status.badPeers[self.id]++
+					// self.addError(ErrIncorrectTD, "on block %x", self.currentBlockHash)
+					// self.bp.status.badPeers[self.id]++
 				}
 			}
 			headKey := self.parentHash
@@ -499,7 +500,7 @@ func (self *peer) getBlockHashes() bool {
 				self.bp.newSection([]*node{n}).activate(self)
 			} else {
 				plog.DebugDetailf("HeadSection: <%s> connecting parent %s found in pool...head section [%s] exists...not requesting hashes", self.id, hex(self.parentHash), sectionhex(parent.section))
-				self.bp.activateChain(parent.section, self, nil)
+				self.bp.activateChain(parent.section, self, self.switchC, nil)
 			}
 		} else {
 			plog.DebugDetailf("HeadSection: <%s> section [%s] requestBlockHashes", self.id, sectionhex(self.headSection))
@@ -523,6 +524,7 @@ func (self *peer) run() {
 
 	self.lock.RLock()
 	switchC := self.switchC
+	plog.Debugf("HeadSection: <%s> section process for head %s started", self.id, hex(self.currentBlockHash))
 	self.lock.RUnlock()
 
 	self.blockHashesRequestTimer = nil
@@ -589,6 +591,7 @@ LOOP:
 			plog.Debugf("HeadSection: <%s> (headsection [%s]) quit channel closed : timed out without providing new blocks...quitting", self.id, sectionhex(self.headSection))
 		}
 	}
+
 	if !self.idle {
 		self.idle = true
 		self.bp.wg.Done()