From e785d6851c8b24f8ed87052e5603fca320fd00d3 Mon Sep 17 00:00:00 2001
From: ValarDragon <dojha12@gmail.com>
Date: Wed, 11 Jul 2018 22:55:20 -0700
Subject: [PATCH] Fix getting the start time so the first block is no longer
 empty

---
 tools/tm-bench/README.md     | 23 +++++++++++++++++------
 tools/tm-bench/main.go       | 15 ++++++++++++++-
 tools/tm-bench/transacter.go | 11 +++++++----
 3 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/tools/tm-bench/README.md b/tools/tm-bench/README.md
index 811141629..000f20f37 100644
--- a/tools/tm-bench/README.md
+++ b/tools/tm-bench/README.md
@@ -51,15 +51,26 @@ with the last command being in a seperate window.
 ## How stats are collected
 
 These stats are derived by having each connection send transactions at the
-specified rate (or as close as it can get) for the specified time. After the
-specified time, it iterates over all of the blocks that were created in that
-time. The average and stddev per second are computed based off of that, by
+specified rate (or as close as it can get) for the specified time.
+After the specified time, it iterates over all of the blocks that were created
+in that time.
+The average and stddev per second are computed based off of that, by
 grouping the data by second.
 
 To send transactions at the specified rate in each connection, we loop
-through the number of transactions. If its too slow, the loop stops at one second.
-If its too fast, we wait until the one second mark ends. The transactions per
-second stat is computed based off of what ends up in the block.
+through the number of transactions.
+If its too slow, the loop stops at one second.
+If its too fast, we wait until the one second mark ends.
+The transactions per second stat is computed based off of what ends up in the
+block.
+
+Note that there will be edge effects on the number of transactions in the first
+and last blocks.
+This is because transactions may start sending midway through when tendermint
+starts building the next block, so it only has half as much time to gather txs
+that tm-bench sends.
+Similarly the end of the duration will likely end mid-way through tendermint
+trying to build the next block.
 
 Each of the connections is handled via two separate goroutines. 
 
diff --git a/tools/tm-bench/main.go b/tools/tm-bench/main.go
index a9151404a..68b3bee16 100644
--- a/tools/tm-bench/main.go
+++ b/tools/tm-bench/main.go
@@ -101,7 +101,20 @@ Examples:
 		"broadcast_tx_"+broadcastTxMethod,
 	)
 
-	// record time start
+	// Wait until transacters have begun until we get the start time
+	for {
+		started := true
+		for _, t := range transacters {
+			for i := 0; i < t.Connections; i++ {
+				if !t.connsStarted[i] && !t.connsBroken[i] {
+					started = false
+				}
+			}
+		}
+		if started {
+			break
+		}
+	}
 	timeStart := time.Now()
 	logger.Info("Time last transacter started", "t", timeStart)
 
diff --git a/tools/tm-bench/transacter.go b/tools/tm-bench/transacter.go
index de408136d..f89c55b7b 100644
--- a/tools/tm-bench/transacter.go
+++ b/tools/tm-bench/transacter.go
@@ -34,10 +34,11 @@ type transacter struct {
 	Connections       int
 	BroadcastTxMethod string
 
-	conns       []*websocket.Conn
-	connsBroken []bool
-	wg          sync.WaitGroup
-	stopped     bool
+	conns        []*websocket.Conn
+	connsStarted []bool
+	connsBroken  []bool
+	wg           sync.WaitGroup
+	stopped      bool
 
 	logger log.Logger
 }
@@ -50,6 +51,7 @@ func newTransacter(target string, connections, rate int, size int, broadcastTxMe
 		Connections:       connections,
 		BroadcastTxMethod: broadcastTxMethod,
 		conns:             make([]*websocket.Conn, connections),
+		connsStarted:      make([]bool, connections),
 		connsBroken:       make([]bool, connections),
 		logger:            log.NewNopLogger(),
 	}
@@ -156,6 +158,7 @@ func (t *transacter) sendLoop(connIndex int) {
 			startTime := time.Now()
 			endTime := startTime.Add(time.Second)
 			numTxSent := t.Rate
+			t.connsStarted[connIndex] = true
 
 			for i := 0; i < t.Rate; i++ {
 				// each transaction embeds connection index, tx number and hash of the hostname