From a77e0e471380252653df2bbeeff8e895fc030e4f Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Fri, 15 Dec 2017 13:41:53 -0800
Subject: [PATCH] fix races in testnet

ConnectTo can be called concurrently from within bitswap.

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>
---
 exchange/bitswap/testnet/virtual.go | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/exchange/bitswap/testnet/virtual.go b/exchange/bitswap/testnet/virtual.go
index c3debc90d..97d251992 100644
--- a/exchange/bitswap/testnet/virtual.go
+++ b/exchange/bitswap/testnet/virtual.go
@@ -3,6 +3,7 @@ package bitswap
 import (
 	"context"
 	"errors"
+	"sync"
 
 	bsmsg "github.com/ipfs/go-ipfs/exchange/bitswap/message"
 	bsnet "github.com/ipfs/go-ipfs/exchange/bitswap/network"
@@ -29,6 +30,7 @@ func VirtualNetwork(rs mockrouting.Server, d delay.D) Network {
 }
 
 type network struct {
+	mu            sync.Mutex
 	clients       map[peer.ID]bsnet.Receiver
 	routingserver mockrouting.Server
 	delay         delay.D
@@ -36,6 +38,9 @@ type network struct {
 }
 
 func (n *network) Adapter(p testutil.Identity) bsnet.BitSwapNetwork {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
 	client := &networkClient{
 		local:   p.ID(),
 		network: n,
@@ -46,6 +51,9 @@ func (n *network) Adapter(p testutil.Identity) bsnet.BitSwapNetwork {
 }
 
 func (n *network) HasPeer(p peer.ID) bool {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
 	_, found := n.clients[p]
 	return found
 }
@@ -58,6 +66,9 @@ func (n *network) SendMessage(
 	to peer.ID,
 	message bsmsg.BitSwapMessage) error {
 
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
 	receiver, ok := n.clients[to]
 	if !ok {
 		return errors.New("Cannot locate peer on network")
@@ -161,18 +172,26 @@ func (nc *networkClient) SetDelegate(r bsnet.Receiver) {
 }
 
 func (nc *networkClient) ConnectTo(_ context.Context, p peer.ID) error {
-	if !nc.network.HasPeer(p) {
+	nc.network.mu.Lock()
+
+	otherClient, ok := nc.network.clients[p]
+	if !ok {
+		nc.network.mu.Unlock()
 		return errors.New("no such peer in network")
 	}
+
 	tag := tagForPeers(nc.local, p)
 	if _, ok := nc.network.conns[tag]; ok {
+		nc.network.mu.Unlock()
 		log.Warning("ALREADY CONNECTED TO PEER (is this a reconnect? test lib needs fixing)")
 		return nil
 	}
 	nc.network.conns[tag] = struct{}{}
+	nc.network.mu.Unlock()
+
 	// TODO: add handling for disconnects
 
-	nc.network.clients[p].PeerConnected(nc.local)
+	otherClient.PeerConnected(nc.local)
 	nc.Receiver.PeerConnected(p)
 	return nil
 }