From 5973fd406709fc2da5875ad2396e312cd060750a Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 10 Feb 2021 23:05:16 +0200
Subject: [PATCH] app/vmselect/promql: make a copy of EvalConfig when executing
 `q1` and `q2` in parallel for `q1 binary_op q2`

This should prevent from data races if the underlying functions modify EvalConfig contents.
---
 app/vmselect/promql/eval.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/app/vmselect/promql/eval.go b/app/vmselect/promql/eval.go
index 84bbd894e1..9768ddfae9 100644
--- a/app/vmselect/promql/eval.go
+++ b/app/vmselect/promql/eval.go
@@ -295,7 +295,8 @@ func evalExpr(ec *EvalConfig, e metricsql.Expr) ([]*timeseries, error) {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			tss, err := evalExpr(ec, be.Left)
+			ecCopy := *ec
+			tss, err := evalExpr(&ecCopy, be.Left)
 			mu.Lock()
 			if err != nil {
 				if errGlobal == nil {
@@ -308,7 +309,8 @@ func evalExpr(ec *EvalConfig, e metricsql.Expr) ([]*timeseries, error) {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			tss, err := evalExpr(ec, be.Right)
+			ecCopy := *ec
+			tss, err := evalExpr(&ecCopy, be.Right)
 			mu.Lock()
 			if err != nil {
 				if errGlobal == nil {