From e1b4acfb6e6a0f930afeb79749ac56c381609258 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Tue, 1 Nov 2016 12:53:33 +0200
Subject: [PATCH] eth/downloader: clear pending requests when switching trie
 root

---
 eth/downloader/queue.go | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/eth/downloader/queue.go b/eth/downloader/queue.go
index eb730a723..b7ad92099 100644
--- a/eth/downloader/queue.go
+++ b/eth/downloader/queue.go
@@ -362,20 +362,20 @@ func (q *queue) Schedule(headers []*types.Header, from uint64) []*types.Header {
 		// Make sure chain order is honoured and preserved throughout
 		hash := header.Hash()
 		if header.Number == nil || header.Number.Uint64() != from {
-			glog.V(logger.Warn).Infof("Header #%v [%x] broke chain ordering, expected %d", header.Number, hash[:4], from)
+			glog.V(logger.Warn).Infof("Header #%v [%x…] broke chain ordering, expected %d", header.Number, hash[:4], from)
 			break
 		}
 		if q.headerHead != (common.Hash{}) && q.headerHead != header.ParentHash {
-			glog.V(logger.Warn).Infof("Header #%v [%x] broke chain ancestry", header.Number, hash[:4])
+			glog.V(logger.Warn).Infof("Header #%v [%x…] broke chain ancestry", header.Number, hash[:4])
 			break
 		}
 		// Make sure no duplicate requests are executed
 		if _, ok := q.blockTaskPool[hash]; ok {
-			glog.V(logger.Warn).Infof("Header #%d [%x] already scheduled for block fetch", header.Number.Uint64(), hash[:4])
+			glog.V(logger.Warn).Infof("Header #%d [%x…] already scheduled for block fetch", header.Number.Uint64(), hash[:4])
 			continue
 		}
 		if _, ok := q.receiptTaskPool[hash]; ok {
-			glog.V(logger.Warn).Infof("Header #%d [%x] already scheduled for receipt fetch", header.Number.Uint64(), hash[:4])
+			glog.V(logger.Warn).Infof("Header #%d [%x…] already scheduled for receipt fetch", header.Number.Uint64(), hash[:4])
 			continue
 		}
 		// Queue the header for content retrieval
@@ -388,7 +388,16 @@ func (q *queue) Schedule(headers []*types.Header, from uint64) []*types.Header {
 			q.receiptTaskQueue.Push(header, -float32(header.Number.Uint64()))
 		}
 		if q.mode == FastSync && header.Number.Uint64() == q.fastSyncPivot {
-			// Pivoting point of the fast sync, retrieve the state tries
+			// Pivoting point of the fast sync, switch the state retrieval to this
+			glog.V(logger.Debug).Infof("Switching state downloads to %d [%x…]", header.Number.Uint64(), header.Hash().Bytes()[:4])
+
+			q.stateTaskIndex = 0
+			q.stateTaskPool = make(map[common.Hash]int)
+			q.stateTaskQueue.Reset()
+			for _, req := range q.statePendPool {
+				req.Hashes = make(map[common.Hash]int) // Make sure executing requests fail, but don't disappear
+			}
+
 			q.stateSchedLock.Lock()
 			q.stateScheduler = state.NewStateSync(header.Root, q.stateDatabase)
 			q.stateSchedLock.Unlock()
@@ -866,10 +875,10 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 	accepted := len(headers) == MaxHeaderFetch
 	if accepted {
 		if headers[0].Number.Uint64() != request.From {
-			glog.V(logger.Detail).Infof("Peer %s: first header #%v [%x] broke chain ordering, expected %d", id, headers[0].Number, headers[0].Hash().Bytes()[:4], request.From)
+			glog.V(logger.Detail).Infof("Peer %s: first header #%v [%x…] broke chain ordering, expected %d", id, headers[0].Number, headers[0].Hash().Bytes()[:4], request.From)
 			accepted = false
 		} else if headers[len(headers)-1].Hash() != target {
-			glog.V(logger.Detail).Infof("Peer %s: last header #%v [%x] broke skeleton structure, expected %x", id, headers[len(headers)-1].Number, headers[len(headers)-1].Hash().Bytes()[:4], target[:4])
+			glog.V(logger.Detail).Infof("Peer %s: last header #%v [%x…] broke skeleton structure, expected %x", id, headers[len(headers)-1].Number, headers[len(headers)-1].Hash().Bytes()[:4], target[:4])
 			accepted = false
 		}
 	}
@@ -877,12 +886,12 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 		for i, header := range headers[1:] {
 			hash := header.Hash()
 			if want := request.From + 1 + uint64(i); header.Number.Uint64() != want {
-				glog.V(logger.Warn).Infof("Peer %s: header #%v [%x] broke chain ordering, expected %d", id, header.Number, hash[:4], want)
+				glog.V(logger.Warn).Infof("Peer %s: header #%v [%x…] broke chain ordering, expected %d", id, header.Number, hash[:4], want)
 				accepted = false
 				break
 			}
 			if headers[i].Hash() != header.ParentHash {
-				glog.V(logger.Warn).Infof("Peer %s: header #%v [%x] broke chain ancestry", id, header.Number, hash[:4])
+				glog.V(logger.Warn).Infof("Peer %s: header #%v [%x…] broke chain ancestry", id, header.Number, hash[:4])
 				accepted = false
 				break
 			}