From 808887da84a67e0f254fba57bd2d8d59a339fce8 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Sat, 4 Nov 2017 22:25:18 +0100
Subject: [PATCH] src: use unrefed async for GC tracking

Do not let an internal handle keep the event loop alive.

Fixes: https://github.com/nodejs/node/issues/16210
---
 src/node_perf.cc                     | 1 +
 test/parallel/test-performance-gc.js | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/src/node_perf.cc b/src/node_perf.cc
index f5aafbab63a781..155f1e66e46bb9 100644
--- a/src/node_perf.cc
+++ b/src/node_perf.cc
@@ -215,6 +215,7 @@ void MarkGarbageCollectionEnd(Isolate* isolate,
   uv_async_t* async = new uv_async_t();  // coverity[leaked_storage]
   if (uv_async_init(env->event_loop(), async, PerformanceGCCallback))
     return delete async;
+  uv_unref(reinterpret_cast<uv_handle_t*>(async));
   async->data =
       new PerformanceEntry::Data(env, "gc", "gc",
                                  performance_last_gc_start_mark_,
diff --git a/test/parallel/test-performance-gc.js b/test/parallel/test-performance-gc.js
index 1ff4c9ae629942..89a9041c1c1159 100644
--- a/test/parallel/test-performance-gc.js
+++ b/test/parallel/test-performance-gc.js
@@ -48,4 +48,6 @@ const kinds = [
   }));
   obs.observe({ entryTypes: ['gc'] });
   global.gc();
+  // Keep the event loop alive to witness the GC async callback happen.
+  setImmediate(() => setImmediate(() => 0));
 }