perf_hooks: fix gc elapsed time

theanarkh · danielleadams · commit 9fedf35d5eb2 · 2022-08-15T21:12:27.000-04:00
PR-URL: #44058 Refs: #44046 Reviewed-By: Chengzhong Wu <legendecas@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
diff --git a/src/node_perf.cc b/src/node_perf.cc
@@ -118,7 +118,13 @@ void MarkGarbageCollectionStart(
     GCCallbackFlags flags,
     void* data) {
   Environment* env = static_cast<Environment*>(data);
+  // Prevent gc callback from reentering with different type
+  // See https://github.com/nodejs/node/issues/44046
+  if (env->performance_state()->current_gc_type != 0) {
+    return;
+  }
   env->performance_state()->performance_last_gc_start_mark = PERFORMANCE_NOW();
+  env->performance_state()->current_gc_type = type;
 }
 
 MaybeLocal<Object> GCPerformanceEntryTraits::GetDetails(
@@ -155,6 +161,10 @@ void MarkGarbageCollectionEnd(
     void* data) {
   Environment* env = static_cast<Environment*>(data);
   PerformanceState* state = env->performance_state();
+  if (type != state->current_gc_type) {
+    return;
+  }
+  env->performance_state()->current_gc_type = 0;
   // If no one is listening to gc performance entries, do not create them.
   if (LIKELY(!state->observers[NODE_PERFORMANCE_ENTRY_TYPE_GC]))
     return;
@@ -179,14 +189,17 @@ void MarkGarbageCollectionEnd(
 
 void GarbageCollectionCleanupHook(void* data) {
   Environment* env = static_cast<Environment*>(data);
+  // Reset current_gc_type to 0
+  env->performance_state()->current_gc_type = 0;
   env->isolate()->RemoveGCPrologueCallback(MarkGarbageCollectionStart, data);
   env->isolate()->RemoveGCEpilogueCallback(MarkGarbageCollectionEnd, data);
 }
 
 static void InstallGarbageCollectionTracking(
     const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
-
+  // Reset current_gc_type to 0
+  env->performance_state()->current_gc_type = 0;
   env->isolate()->AddGCPrologueCallback(MarkGarbageCollectionStart,
                                         static_cast<void*>(env));
   env->isolate()->AddGCEpilogueCallback(MarkGarbageCollectionEnd,
diff --git a/src/node_perf_common.h b/src/node_perf_common.h
@@ -71,6 +71,7 @@ class PerformanceState {
   AliasedUint32Array observers;
 
   uint64_t performance_last_gc_start_mark = 0;
+  uint16_t current_gc_type = 0;
 
   void Mark(enum PerformanceMilestone milestone,
             uint64_t ts = PERFORMANCE_NOW());
