From 25fcf69c0662b09fbd9dc1c0446b7679ae020ed5 Mon Sep 17 00:00:00 2001
From: Vincenzo Eduardo Padulano <v.e.padulano@gmail.com>
Date: Sat, 8 Oct 2022 03:12:06 +0200
Subject: [PATCH] [core] Guard gInterpreterMutex in TClingClassInfo::IsEnum

Fixes https://github.com/root-project/root/issues/11515

This method leads to contention in some specific scenarios (see linked
issue).

Co-authored-by: Philippe Canal <pcanal@fnal.gov>
---
 core/metacling/src/TClingClassInfo.cxx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/core/metacling/src/TClingClassInfo.cxx b/core/metacling/src/TClingClassInfo.cxx
index c0c061dfcafed..ce6e82d388156 100644
--- a/core/metacling/src/TClingClassInfo.cxx
+++ b/core/metacling/src/TClingClassInfo.cxx
@@ -815,6 +815,7 @@ bool TClingClassInfo::IsBase(const char *name) const
 
 bool TClingClassInfo::IsEnum(cling::Interpreter *interp, const char *name)
 {
+   R__LOCKGUARD(gInterpreterMutex);
    // Note: This is a static member function.
    TClingClassInfo info(interp, name);
    if (info.IsValid() && (info.Property() & kIsEnum)) {