[Lldb-commits] [lldb] [lldb] Make `RegisterContextThreadMemory` thread safe (PR #134469)

[Felipe de Azevedo Piovezan via lldb-commits]

https://github.com/felipepiovezan created https://github.com/llvm/llvm-project/pull/134469

The UpdateRegisterContext method can be called from multiple threads.

>From ef59ad0f6522e5ca35cfeed562fc528b4732fb22 Mon Sep 17 00:00:00 2001
From: Felipe de Azevedo Piovezan <fpiovezan at apple.com>
Date: Fri, 4 Apr 2025 18:28:00 -0700
Subject: [PATCH] [lldb] Make `RegisterContextThreadMemory` thread safe

The UpdateRegisterContext method can be called from multiple threads.
---
 .../Plugins/Process/Utility/RegisterContextThreadMemory.cpp     | 2 ++
 .../Plugins/Process/Utility/RegisterContextThreadMemory.h       | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.cpp
index 75438550ce914..29927e3b5e4ed 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.cpp
@@ -25,6 +25,8 @@ RegisterContextThreadMemory::RegisterContextThreadMemory(
 RegisterContextThreadMemory::~RegisterContextThreadMemory() = default;
 
 void RegisterContextThreadMemory::UpdateRegisterContext() {
+  std::lock_guard<std::mutex> lock(m_update_register_ctx_lock);
+
   ThreadSP thread_sp(m_thread_wp.lock());
   if (thread_sp) {
     ProcessSP process_sp(thread_sp->GetProcess());
diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.h b/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.h
index 23f675508cf38..1df32bbc1f057 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.h
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextThreadMemory.h
@@ -99,6 +99,8 @@ class RegisterContextThreadMemory : public lldb_private::RegisterContext {
   RegisterContextThreadMemory(const RegisterContextThreadMemory &) = delete;
   const RegisterContextThreadMemory &
   operator=(const RegisterContextThreadMemory &) = delete;
+
+  std::mutex m_update_register_ctx_lock;
 };
 
 } // namespace lldb_private