Fixed data race in logger ydb/log/WithNames

ydb-platform · Apr 18, 2024 · 668e3c4 · 668e3c4
1 parent 35a861a
commit 668e3c4
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,5 @@
+* Fixed data race in logger ydb/log/WithNames 
+
 ## v3.65.1
 * Updated dependency `ydb-go-genproto`
 * Added processing of `Ydb.StatusIds_EXTERNAL_ERROR` in `retry.Retry`

diff --git a/log/context.go b/log/context.go
@@ -1,6 +1,8 @@
 package log
 
-import "context"
+import (
+	"context"
+)
 
 type (
 	ctxLevelKey struct{}
@@ -18,7 +20,11 @@ func LevelFromContext(ctx context.Context) Level {
 }
 
 func WithNames(ctx context.Context, names ...string) context.Context {
-	return context.WithValue(ctx, ctxNamesKey{}, append(NamesFromContext(ctx), names...))
+	// trim capacity for force allocate new memory for new slice and prevent data race
+	oldNames := NamesFromContext(ctx)
+	oldNames = oldNames[:len(oldNames):len(oldNames)]
+
+	return context.WithValue(ctx, ctxNamesKey{}, append(oldNames, names...))
 }
 
 func NamesFromContext(ctx context.Context) []string {
@@ -27,7 +33,7 @@ func NamesFromContext(ctx context.Context) []string {
 		return []string{}
 	}
 
-	return v
+	return v[:len(v):len(v)] // prevent re
 }
 
 func with(ctx context.Context, lvl Level, names ...string) context.Context {