inspector: track async stacks when necessary

With this change, we do async stack tracking only when explicitly
requested by the inspector client. This avoids unnecessary overhead
for clients that might not be interested in async stack traces.

PR-URL: https://github.com/nodejs/node/pull/16308
Fixes: https://github.com/nodejs/node/issues/16180
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/inspector_agent.h b/src/inspector_agent.h
index 9119e7263b2..24fae116f94 100644
--- a/src/inspector_agent.h
+++ b/src/inspector_agent.h
@@ -92,7 +92,12 @@ class Agent {
   DebugOptions& options() { return debug_options_; }
   void ContextCreated(v8::Local<v8::Context> context);
 
+  void EnableAsyncHook();
+  void DisableAsyncHook();
+
  private:
+  void ToggleAsyncHook(v8::Isolate* isolate, v8::Local<v8::Function> fn);
+
   node::Environment* parent_env_;
   std::unique_ptr<NodeInspectorClient> client_;
   std::unique_ptr<InspectorIo> io_;
@@ -102,6 +107,8 @@ class Agent {
   DebugOptions debug_options_;
   int next_context_number_;
 
+  bool pending_enable_async_hook_;
+  bool pending_disable_async_hook_;
   v8::Persistent<v8::Function> enable_async_hook_function_;
   v8::Persistent<v8::Function> disable_async_hook_function_;
 };