src: allow optional Isolate termination in node::Stop()

src/env.cc

@@ -911,10 +911,11 @@ void Environment::InitializeLibuv() {
   StartProfilerIdleNotifier();
 }
 
-void Environment::ExitEnv() {
+void Environment::ExitEnv(StopFlags::Flags flags) {
   // Should not access non-thread-safe methods here.
   set_stopping(true);
-  isolate_->TerminateExecution();
+  if ((flags & StopFlags::kDoNotTerminateIsolate) == 0)
+    isolate_->TerminateExecution();
   SetImmediateThreadsafe([](Environment* env) {
     env->set_can_call_into_js(false);
     uv_stop(env->event_loop());

src/env.h

@@ -636,7 +636,7 @@ class Environment : public MemoryRetainer {
   void RegisterHandleCleanups();
   void CleanupHandles();
   void Exit(ExitCode code);
-  void ExitEnv();
+  void ExitEnv(StopFlags::Flags flags);
 
   // Register clean-up cb to be called on environment destruction.
   inline void RegisterHandleCleanup(uv_handle_t* handle,

src/node.cc

@@ -1254,7 +1254,11 @@ int Start(int argc, char** argv) {
 }
 
 int Stop(Environment* env) {
-  env->ExitEnv();
+  return Stop(env, StopFlags::kNoFlags);
+}
+
+int Stop(Environment* env, StopFlags::Flags flags) {
+  env->ExitEnv(flags);
   return 0;
 }
 

src/node.h

@@ -273,6 +273,15 @@ enum Flags : uint32_t {
 }  // namespace ProcessInitializationFlags
 namespace ProcessFlags = ProcessInitializationFlags;  // Legacy alias.
 
+namespace StopFlags {
+enum Flags : uint32_t {
+  kNoFlags = 0,
+  // Do not explicitly terminate the Isolate
+  // when exiting the Environment.
+  kDoNotTerminateIsolate = 1 << 0,
+};
+}  // namespace StopFlags
+
 class NODE_EXTERN InitializationResult {
  public:
   virtual ~InitializationResult();
@@ -309,6 +318,7 @@ NODE_EXTERN int Start(int argc, char* argv[]);
 // Tear down Node.js while it is running (there are active handles
 // in the loop and / or actively executing JavaScript code).
 NODE_EXTERN int Stop(Environment* env);
+NODE_EXTERN int Stop(Environment* env, StopFlags::Flags flags);
 
 // Set up per-process state needed to run Node.js. This will consume arguments
 // from argv, fill exec_argv, and possibly add errors resulting from parsing