From 1b916f89c154e76b8733db51ab738f6eaec0ab39 Mon Sep 17 00:00:00 2001
From: Elad Nachmias <theman@elad.im>
Date: Wed, 16 Jan 2019 20:44:50 +0530
Subject: [PATCH 1/3] swarm/network: fix data race on TestService bucket caused
 by copying struct content without synchronisation

---
 p2p/simulations/events.go | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/p2p/simulations/events.go b/p2p/simulations/events.go
index 9b2a990e07e6..1f40c9437d6a 100644
--- a/p2p/simulations/events.go
+++ b/p2p/simulations/events.go
@@ -73,8 +73,7 @@ func NewEvent(v interface{}) *Event {
 	switch v := v.(type) {
 	case *Node:
 		event.Type = EventTypeNode
-		node := *v
-		event.Node = &node
+		event.Node = v
 	case *Conn:
 		event.Type = EventTypeConn
 		conn := *v

From f1a242793b5de24ed1c7d73a5308977a9a6ded34 Mon Sep 17 00:00:00 2001
From: Elad Nachmias <theman@elad.im>
Date: Fri, 18 Jan 2019 15:03:49 +0700
Subject: [PATCH 2/3] p2p/simulations: changed NewEvent function to be used
 under network lock to avoid possible data race

---
 p2p/simulations/events.go  |  3 ++-
 p2p/simulations/network.go | 15 ++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/p2p/simulations/events.go b/p2p/simulations/events.go
index 1f40c9437d6a..9b2a990e07e6 100644
--- a/p2p/simulations/events.go
+++ b/p2p/simulations/events.go
@@ -73,7 +73,8 @@ func NewEvent(v interface{}) *Event {
 	switch v := v.(type) {
 	case *Node:
 		event.Type = EventTypeNode
-		event.Node = v
+		node := *v
+		event.Node = &node
 	case *Conn:
 		event.Type = EventTypeConn
 		conn := *v
diff --git a/p2p/simulations/network.go b/p2p/simulations/network.go
index 86f7dc9bef44..ffe1f43a9d8d 100644
--- a/p2p/simulations/network.go
+++ b/p2p/simulations/network.go
@@ -168,7 +168,6 @@ func (net *Network) Start(id enode.ID) error {
 // snapshots
 func (net *Network) startWithSnapshots(id enode.ID, snapshots map[string][]byte) error {
 	net.lock.Lock()
-	defer net.lock.Unlock()
 
 	node := net.getNode(id)
 	if node == nil {
@@ -184,8 +183,10 @@ func (net *Network) startWithSnapshots(id enode.ID, snapshots map[string][]byte)
 	}
 	node.Up = true
 	log.Info("Started node", "id", id)
+	ev := NewEvent(node)
+	net.lock.Unlock()
 
-	net.events.Send(NewEvent(node))
+	net.events.Send(ev)
 
 	// subscribe to peer events
 	client, err := node.Client()
@@ -209,13 +210,14 @@ func (net *Network) watchPeerEvents(id enode.ID, events chan *p2p.PeerEvent, sub
 
 		// assume the node is now down
 		net.lock.Lock()
-		defer net.lock.Unlock()
 		node := net.getNode(id)
 		if node == nil {
 			return
 		}
 		node.Up = false
-		net.events.Send(NewEvent(node))
+		ev := NewEvent(node)
+		net.lock.Unlock()
+		net.events.Send(ev)
 	}()
 	for {
 		select {
@@ -270,7 +272,10 @@ func (net *Network) Stop(id enode.ID) error {
 		return err
 	}
 	log.Info("Stopped node", "id", id, "err", err)
-	net.events.Send(ControlEvent(node))
+	net.lock.Lock()
+	ev := ControlEvent(node)
+	net.lock.Unlock()
+	net.events.Send(ev)
 	return nil
 }
 

From 8ec258ab1d9403ed75d1a4d13f0d5e81a5bf07d4 Mon Sep 17 00:00:00 2001
From: Elad Nachmias <theman@elad.im>
Date: Fri, 18 Jan 2019 20:53:51 +0700
Subject: [PATCH 3/3] p2p/simulations: address data race pr comments

---
 p2p/simulations/network.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/p2p/simulations/network.go b/p2p/simulations/network.go
index ffe1f43a9d8d..6edcefc5320f 100644
--- a/p2p/simulations/network.go
+++ b/p2p/simulations/network.go
@@ -171,13 +171,16 @@ func (net *Network) startWithSnapshots(id enode.ID, snapshots map[string][]byte)
 
 	node := net.getNode(id)
 	if node == nil {
+		net.lock.Unlock()
 		return fmt.Errorf("node %v does not exist", id)
 	}
 	if node.Up {
+		net.lock.Unlock()
 		return fmt.Errorf("node %v already up", id)
 	}
 	log.Trace("Starting node", "id", id, "adapter", net.nodeAdapter.Name())
 	if err := node.Start(snapshots); err != nil {
+		net.lock.Unlock()
 		log.Warn("Node startup failed", "id", id, "err", err)
 		return err
 	}
@@ -210,13 +213,14 @@ func (net *Network) watchPeerEvents(id enode.ID, events chan *p2p.PeerEvent, sub
 
 		// assume the node is now down
 		net.lock.Lock()
+		defer net.lock.Unlock()
+
 		node := net.getNode(id)
 		if node == nil {
 			return
 		}
 		node.Up = false
 		ev := NewEvent(node)
-		net.lock.Unlock()
 		net.events.Send(ev)
 	}()
 	for {
@@ -256,9 +260,11 @@ func (net *Network) Stop(id enode.ID) error {
 	net.lock.Lock()
 	node := net.getNode(id)
 	if node == nil {
+		net.lock.Unlock()
 		return fmt.Errorf("node %v does not exist", id)
 	}
 	if !node.Up {
+		net.lock.Unlock()
 		return fmt.Errorf("node %v already down", id)
 	}
 	node.Up = false