From 057c8ef400089e23e7f2562ee314df80dfe07732 Mon Sep 17 00:00:00 2001
From: Jae Kwon <jae@tendermint.com>
Date: Thu, 28 May 2015 03:18:13 -0700
Subject: [PATCH] waiting back to pending

---
 blockchain/pool.go    | 42 +++++++++++++++---------------------------
 blockchain/reactor.go | 21 +++++++++++----------
 2 files changed, 26 insertions(+), 37 deletions(-)

diff --git a/blockchain/pool.go b/blockchain/pool.go
index 1c38e876e..0503c8ebb 100644
--- a/blockchain/pool.go
+++ b/blockchain/pool.go
@@ -13,7 +13,7 @@ const (
 	maxTries              = 3
 	inputsChannelCapacity = 200
 	requestIntervalMS     = 500
-	maxWaitingRequests    = 200
+	maxPendingRequests    = 200
 	maxTotalRequests      = 300
 	maxRequestsPerPeer    = 300
 )
@@ -39,7 +39,7 @@ type BlockPool struct {
 	requests      map[uint]*bpRequest
 	height        uint  // the lowest key in requests.
 	numUnassigned int32 // number of requests not yet assigned to a peer
-	numWaiting    int32 // number of requests awaiting response from a peer
+	numPending    int32 // number of requests pending assignment or block response
 
 	// peers
 	peersMtx sync.Mutex
@@ -59,7 +59,7 @@ func NewBlockPool(start uint, requestsCh chan<- BlockRequest, timeoutsCh chan<-
 		requests:      make(map[uint]*bpRequest),
 		height:        start,
 		numUnassigned: 0,
-		numWaiting:    0,
+		numPending:    0,
 
 		requestsCh: requestsCh,
 		timeoutsCh: timeoutsCh,
@@ -94,8 +94,8 @@ RUN_LOOP:
 		if atomic.LoadInt32(&pool.running) == 0 {
 			break RUN_LOOP
 		}
-		_, numWaiting := pool.GetStatus()
-		if numWaiting >= maxWaitingRequests {
+		_, numPending := pool.GetStatus()
+		if numPending >= maxPendingRequests {
 			// sleep for a bit.
 			time.Sleep(requestIntervalMS * time.Millisecond)
 		} else if len(pool.requests) >= maxTotalRequests {
@@ -103,8 +103,7 @@ RUN_LOOP:
 			time.Sleep(requestIntervalMS * time.Millisecond)
 		} else {
 			// request for more blocks.
-			height := pool.nextHeight()
-			pool.makeRequest(height)
+			pool.makeNextRequest()
 		}
 	}
 }
@@ -113,7 +112,7 @@ func (pool *BlockPool) GetStatus() (uint, int32) {
 	pool.requestsMtx.Lock() // Lock
 	defer pool.requestsMtx.Unlock()
 
-	return pool.height, pool.numWaiting
+	return pool.height, pool.numPending
 }
 
 // We need to see the second block's Validation to validate the first block.
@@ -160,7 +159,7 @@ func (pool *BlockPool) RedoRequest(height uint) {
 	pool.RemovePeer(request.peerId) // Lock on peersMtx.
 	request.block = nil
 	request.peerId = ""
-	pool.numWaiting++
+	pool.numPending++
 	pool.numUnassigned++
 
 	go requestRoutine(pool, height)
@@ -213,7 +212,7 @@ func (pool *BlockPool) AddBlock(block *types.Block, peerId string) {
 		return
 	}
 	request.block = block
-	pool.numWaiting--
+	pool.numPending--
 }
 
 func (pool *BlockPool) getPeer(peerId string) *bpPeer {
@@ -279,33 +278,22 @@ func (pool *BlockPool) decrPeer(peerId string) {
 	peer.numRequests--
 }
 
-func (pool *BlockPool) nextHeight() uint {
-	pool.requestsMtx.Lock() // Lock
-	defer pool.requestsMtx.Unlock()
-
-	// we make one request per height.
-	return pool.height + uint(len(pool.requests))
-}
-
-func (pool *BlockPool) makeRequest(height uint) {
+func (pool *BlockPool) makeNextRequest() {
 	pool.requestsMtx.Lock() // Lock
 	defer pool.requestsMtx.Unlock()
 
+	nextHeight := pool.height + uint(len(pool.requests)) + 1
 	request := &bpRequest{
-		height: height,
+		height: nextHeight,
 		peerId: "",
 		block:  nil,
 	}
-	pool.requests[height] = request
 
+	pool.requests[nextHeight] = request
 	pool.numUnassigned++
+	pool.numPending++
 
-	nextHeight := pool.height + uint(len(pool.requests))
-	if nextHeight == height {
-		pool.numWaiting++
-	}
-
-	go requestRoutine(pool, height)
+	go requestRoutine(pool, nextHeight)
 }
 
 func (pool *BlockPool) sendRequest(height uint, peerId string) {
diff --git a/blockchain/reactor.go b/blockchain/reactor.go
index 7d0d4b84e..793183375 100644
--- a/blockchain/reactor.go
+++ b/blockchain/reactor.go
@@ -197,18 +197,19 @@ FOR_LOOP:
 			// ask for status updates
 			go bcR.BroadcastStatusRequest()
 		case _ = <-switchToConsensusTicker.C:
-			// not thread safe access for numUnassigned and numWaiting but should be fine
+			// not thread safe access for numUnassigned and numPending but should be fine
 			// TODO make threadsafe and use exposed functions
-			log.Debug("Consensus ticker", "numUnassigned", bcR.pool.numUnassigned, "numWaiting", bcR.pool.numWaiting, "total", len(bcR.pool.requests))
+			outbound, inbound, _ := bcR.sw.NumPeers()
+			log.Debug("Consensus ticker", "numUnassigned", bcR.pool.numUnassigned, "numPending", bcR.pool.numPending,
+				"total", len(bcR.pool.requests), "outbound", outbound, "inbound", inbound)
 			// NOTE: this condition is very strict right now. may need to weaken
-			// if the max amount of requests are waiting and numUnassigned
-			// and we have some peers (say > 5), then we're caught up
-			maxWaiting := bcR.pool.numWaiting == maxWaitingRequests
-			peersUnavailable := bcR.pool.numWaiting == bcR.pool.numUnassigned
-			o, i, _ := bcR.sw.NumPeers()
-			enoughPeers := o+i >= 5
-			if maxWaiting && peersUnavailable && enoughPeers {
-				log.Warn("Time to switch to consensus reactor!", "height", bcR.pool.height)
+			// If all `maxPendingRequests` requests are unassigned
+			// and we have some peers (say >= 3), then we're caught up
+			maxPending := bcR.pool.numPending == maxPendingRequests
+			allUnassigned := bcR.pool.numPending == bcR.pool.numUnassigned
+			enoughPeers := outbound+inbound >= 3
+			if maxPending && allUnassigned && enoughPeers {
+				log.Info("Time to switch to consensus reactor!", "height", bcR.pool.height)
 				bcR.pool.Stop()
 				stateDB := dbm.GetDB("state")
 				state := sm.LoadState(stateDB)