4 files changed, 40 insertions, 3 deletions
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
index dc64139..1dd0a9e 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.cpp
@@ -10,9 +10,9 @@
 #include "llvm/Support/FormatVariadic.h"
 
 using namespace lldb_private;
+using namespace lldb;
 
 llvm::Error Lua::Run(llvm::StringRef buffer) {
-  std::lock_guard<std::mutex> lock(m_mutex);
   int error =
       luaL_loadbuffer(m_lua_state, buffer.data(), buffer.size(), "buffer") ||
       lua_pcall(m_lua_state, 0, 0, 0);
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
index ed1d159..adc6c61 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/Lua.h
@@ -9,6 +9,7 @@
 #ifndef liblldb_Lua_h_
 #define liblldb_Lua_h_
 
+#include "lldb/lldb-types.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Error.h"
 
@@ -38,7 +39,6 @@ public:
   llvm::Error Run(llvm::StringRef buffer);
 
 private:
-  std::mutex m_mutex;
   lua_State *m_lua_state;
 };
 
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
index d5423b7..e46851c 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp
@@ -27,7 +27,13 @@ public:
       : IOHandlerEditline(debugger, IOHandler::Type::LuaInterpreter, "lua",
                           ">>> ", "..> ", true, debugger.GetUseColor(), 0,
                           *this, nullptr),
-        m_script_interpreter(script_interpreter) {}
+        m_script_interpreter(script_interpreter) {
+    llvm::cantFail(m_script_interpreter.EnterSession(debugger.GetID()));
+  }
+
+  ~IOHandlerLuaInterpreter() {
+    llvm::cantFail(m_script_interpreter.LeaveSession());
+  }
 
   void IOHandlerInputComplete(IOHandler &io_handler,
                               std::string &data) override {
@@ -89,6 +95,33 @@ void ScriptInterpreterLua::Initialize() {
 
 void ScriptInterpreterLua::Terminate() {}
 
+llvm::Error ScriptInterpreterLua::EnterSession(user_id_t debugger_id) {
+  if (m_session_is_active)
+    return llvm::Error::success();
+
+  const char *fmt_str =
+      "lldb.debugger = lldb.SBDebugger.FindDebuggerWithID({0}); "
+      "lldb.target = lldb.debugger:GetSelectedTarget(); "
+      "lldb.process = lldb.target:GetProcess(); "
+      "lldb.thread = lldb.process:GetSelectedThread(); "
+      "lldb.frame = lldb.thread:GetSelectedFrame()";
+  return m_lua->Run(llvm::formatv(fmt_str, debugger_id).str());
+}
+
+llvm::Error ScriptInterpreterLua::LeaveSession() {
+  if (!m_session_is_active)
+    return llvm::Error::success();
+
+  m_session_is_active = false;
+
+  llvm::StringRef str = "lldb.debugger = nil; "
+                        "lldb.target = nil; "
+                        "lldb.process = nil; "
+                        "lldb.thread = nil; "
+                        "lldb.frame = nil";
+  return m_lua->Run(str);
+}
+
 lldb::ScriptInterpreterSP
 ScriptInterpreterLua::CreateInstance(Debugger &debugger) {
   return std::make_shared<ScriptInterpreterLua>(debugger);
diff --git a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
index b34c7d0..550e1035 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h
@@ -43,8 +43,12 @@ public:
 
   Lua &GetLua();
 
+  llvm::Error EnterSession(lldb::user_id_t debugger_id);
+  llvm::Error LeaveSession();
+
 private:
   std::unique_ptr<Lua> m_lua;
+  bool m_session_is_active = false;
 };
 
 } // namespace lldb_private