From 63ad0394687bde6dba5dd271ba76231140759eeb Mon Sep 17 00:00:00 2001
From: Laurent Demailly <ldemailly@gmail.com>
Date: Wed, 2 Oct 2024 13:37:51 -0700
Subject: [PATCH] Race in setting Config.Level: Add failing test

---
 logger_test.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/logger_test.go b/logger_test.go
index 8e9d5a9..63b5a05 100644
--- a/logger_test.go
+++ b/logger_test.go
@@ -957,6 +957,21 @@ func TestInvalidFile(t *testing.T) {
 	}
 }
 
+func TestConcurrentLevelSet(t *testing.T) {
+	// This test is to make sure that setting the log level concurrently
+	// doesn't cause a -race failure. Shows up in dflag/ for instance with configmap changes.
+	var wg sync.WaitGroup
+	wg.Add(int(Fatal - Verbose))
+	for i := Verbose; i < Fatal; i++ {
+		go func() {
+			SetLogLevel(i)
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+	SetLogLevel(Info)
+}
+
 // --- Benchmarks
 
 // This `discard` is like io.Discard, except that io.Discard is checked explicitly