From 8bd5db83b552a29b86badd4fb08c57ccf984fcce Mon Sep 17 00:00:00 2001
From: Vincenzo Eduardo Padulano <vincenzo.eduardo.padulano@cern.ch>
Date: Sun, 23 Jul 2023 22:28:25 +0200
Subject: [PATCH] [core] Lock interpreter in TCling::GetClassSharedLibs

Co-authored-by: Jonas Hahnfeld <jonas.hahnfeld@cern.ch>
---
 core/metacling/src/TCling.cxx | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/core/metacling/src/TCling.cxx b/core/metacling/src/TCling.cxx
index 7d4feb3fc2c5c..9a3c805252f35 100644
--- a/core/metacling/src/TCling.cxx
+++ b/core/metacling/src/TCling.cxx
@@ -7025,6 +7025,11 @@ static std::string GetClassSharedLibsForModule(const char *cls, cling::LookupHel
 const char* TCling::GetClassSharedLibs(const char* cls)
 {
    if (fCxxModulesEnabled) {
+      // Lock the interpreter mutex before interacting with cling.
+      // TODO: Can we move this further deep? In principle the lock should be in
+      // GetClassSharedLibsForModule, but it might be needed also for
+      // getLookupHelper?
+      R__LOCKGUARD(gInterpreterMutex);
       llvm::StringRef className = cls;
       // If we get a class name containing lambda, we cannot parse it and we
       // can exit early.