src: add Env::profiler_idle_notifier_started()

Refs: ayojs/ayo#93
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>

PR-URL: #20876
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Shingo Inoue <leko.noor@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>

src/env-inl.h

@@ -322,6 +322,10 @@ inline Environment* Environment::GetThreadLocalEnv() {
   return static_cast<Environment*>(uv_key_get(&thread_local_env));
 }
 
+inline bool Environment::profiler_idle_notifier_started() const {
+  return profiler_idle_notifier_started_;
+}
+
 inline v8::Isolate* Environment::isolate() const {
   return isolate_;
 }

src/env.cc

@@ -263,6 +263,11 @@ void Environment::CleanupHandles() {
 }
 
 void Environment::StartProfilerIdleNotifier() {
+  if (profiler_idle_notifier_started_)
+    return;
+
+  profiler_idle_notifier_started_ = true;
+
   uv_prepare_start(&idle_prepare_handle_, [](uv_prepare_t* handle) {
     Environment* env = ContainerOf(&Environment::idle_prepare_handle_, handle);
     env->isolate()->SetIdle(true);
@@ -275,6 +280,7 @@ void Environment::StartProfilerIdleNotifier() {
 }
 
 void Environment::StopProfilerIdleNotifier() {
+  profiler_idle_notifier_started_ = false;
   uv_prepare_stop(&idle_prepare_handle_);
   uv_check_stop(&idle_check_handle_);
 }

src/env.h

@@ -615,6 +615,7 @@ class Environment {
 
   void StartProfilerIdleNotifier();
   void StopProfilerIdleNotifier();
+  inline bool profiler_idle_notifier_started() const;
 
   inline v8::Isolate* isolate() const;
   inline tracing::Agent* tracing_agent() const;
@@ -840,6 +841,7 @@ class Environment {
   uv_idle_t immediate_idle_handle_;
   uv_prepare_t idle_prepare_handle_;
   uv_check_t idle_check_handle_;
+  bool profiler_idle_notifier_started_ = false;
 
   AsyncHooks async_hooks_;
   ImmediateInfo immediate_info_;