From bbf1a116f6cbed04715f00d63e1ae5671f67e0a3 Mon Sep 17 00:00:00 2001
From: Daniel Nephin <dnephin@hashicorp.com>
Date: Wed, 23 Dec 2020 12:59:05 -0500
Subject: [PATCH] xds: Fix data race

TestEnvoy.Close used e.stream.recvCh == nil to indicate the channel had already
been closed, so that TestEnvoy.Close can be called multiple times. The recvCh
was not protected by a lock, so setting it to nil caused a data race with any
goroutine trying to read from the channel.

Instead set the stream to nil. The stream is guarded by a lock, so it does not race.

This change allows us to test the agent/xds package using -race.
---
 .circleci/config.yml | 2 +-
 agent/xds/testing.go | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index a178514d5..d095bd366 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -237,7 +237,7 @@ jobs:
           command: |
             mkdir -p $TEST_RESULTS_DIR /tmp/jsonfile
             pkgs="$(go list ./... | \
-              grep -E -v '^github.com/hashicorp/consul/agent(/consul|/local|/xds|/routine-leak-checker)?$' | \
+              grep -E -v '^github.com/hashicorp/consul/agent(/consul|/local|/routine-leak-checker)?$' | \
               grep -E -v '^github.com/hashicorp/consul/command/')"
             gotestsum \
               --jsonfile /tmp/jsonfile/go-test-race.log \
diff --git a/agent/xds/testing.go b/agent/xds/testing.go
index 8a635114a..7fb9b224c 100644
--- a/agent/xds/testing.go
+++ b/agent/xds/testing.go
@@ -189,7 +189,7 @@ func (e *TestEnvoy) Close() error {
 	// unblock the recv chan to simulate recv error when client disconnects
 	if e.stream != nil && e.stream.recvCh != nil {
 		close(e.stream.recvCh)
-		e.stream.recvCh = nil
+		e.stream = nil
 	}
 	if e.cancel != nil {
 		e.cancel()