src: add optional keep-alive object to SetImmediate

Adds the possibility to keep a strong persistent reference to
a JS object while a `SetImmediate()` call is in effect.

PR-URL: https://github.com/nodejs/node/pull/17183
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/env.h b/src/env.h
index f5161b9f8a..1e0175946e 100644
--- a/src/env.h
+++ b/src/env.h
@@ -686,7 +686,11 @@ class Environment {
   bool EmitNapiWarning();
 
   typedef void (*native_immediate_callback)(Environment* env, void* data);
-  inline void SetImmediate(native_immediate_callback cb, void* data);
+  // cb will be called as cb(env, data) on the next event loop iteration.
+  // obj will be kept alive between now and after the callback has run.
+  inline void SetImmediate(native_immediate_callback cb,
+                           void* data,
+                           v8::Local<v8::Object> obj = v8::Local<v8::Object>());
   // This needs to be available for the JS-land setImmediate().
   void ActivateImmediateCheck();
 
@@ -751,6 +755,7 @@ class Environment {
   struct NativeImmediateCallback {
     native_immediate_callback cb_;
     void* data_;
+    std::unique_ptr<v8::Persistent<v8::Object>> keep_alive_;
   };
   std::vector<NativeImmediateCallback> native_immediate_callbacks_;
   void RunAndClearNativeImmediates();