node: count callouts to JS to reemit beforeExit

Author: indutny

src/async-wrap-inl.h

@@ -40,6 +40,7 @@ inline AsyncWrap::AsyncWrap(Environment* env,
   v8::TryCatch try_catch;
 
   v8::Local<v8::Value> n = v8::Int32::New(env->isolate(), provider);
+  env->inc_callout_count();
   env->async_hooks_init_function()->Call(object, 1, &n);
 
   if (try_catch.HasCaught())

src/async-wrap.cc

@@ -185,6 +185,7 @@ Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
   if (has_domain) {
     Local<Value> enter_v = domain->Get(env()->enter_string());
     if (enter_v->IsFunction()) {
+      env()->inc_callout_count();
       enter_v.As<Function>()->Call(domain, 0, nullptr);
       if (try_catch.HasCaught())
         return Undefined(env()->isolate());
@@ -193,12 +194,14 @@ Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
 
   if (has_async_queue()) {
     try_catch.SetVerbose(false);
+    env()->inc_callout_count();
     env()->async_hooks_pre_function()->Call(context, 0, nullptr);
     if (try_catch.HasCaught())
       FatalError("node::AsyncWrap::MakeCallback", "pre hook threw");
     try_catch.SetVerbose(true);
   }
 
+  env()->inc_callout_count();
   Local<Value> ret = cb->Call(context, argc, argv);
 
   if (try_catch.HasCaught()) {
@@ -207,6 +210,7 @@ Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
 
   if (has_async_queue()) {
     try_catch.SetVerbose(false);
+    env()->inc_callout_count();
     env()->async_hooks_post_function()->Call(context, 0, nullptr);
     if (try_catch.HasCaught())
       FatalError("node::AsyncWrap::MakeCallback", "post hook threw");
@@ -216,6 +220,7 @@ Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
   if (has_domain) {
     Local<Value> exit_v = domain->Get(env()->exit_string());
     if (exit_v->IsFunction()) {
+      env()->inc_callout_count();
       exit_v.As<Function>()->Call(domain, 0, nullptr);
       if (try_catch.HasCaught())
         return Undefined(env()->isolate());
@@ -239,6 +244,7 @@ Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
 
   tick_info->set_in_tick(true);
 
+  env()->inc_callout_count();
   env()->tick_callback_function()->Call(process, 0, nullptr);
 
   tick_info->set_in_tick(false);

src/env-inl.h

@@ -387,6 +387,21 @@ inline void Environment::set_http_parser_buffer(char* buffer) {
   http_parser_buffer_ = buffer;
 }
 
+
+inline unsigned int Environment::callout_count() const {
+  return callout_count_;
+}
+
+
+inline void Environment::reset_callout_count() {
+  callout_count_ = 0;
+}
+
+
+inline void Environment::inc_callout_count() {
+  callout_count_++;
+}
+
 inline Environment* Environment::from_cares_timer_handle(uv_timer_t* handle) {
   return ContainerOf(&Environment::cares_timer_handle_, handle);
 }

src/env.h

@@ -452,6 +452,10 @@ class Environment {
   inline char* http_parser_buffer() const;
   inline void set_http_parser_buffer(char* buffer);
 
+  inline unsigned int callout_count() const;
+  inline void reset_callout_count();
+  inline void inc_callout_count();
+
   inline void ThrowError(const char* errmsg);
   inline void ThrowTypeError(const char* errmsg);
   inline void ThrowRangeError(const char* errmsg);
@@ -551,6 +555,7 @@ class Environment {
   uint32_t* heap_statistics_buffer_ = nullptr;
 
   char* http_parser_buffer_;
+  unsigned int callout_count_ = 0;
 
 #define V(PropertyName, TypeName)                                             \
   v8::Persistent<TypeName> PropertyName ## _;

src/node.cc

@@ -1015,6 +1015,7 @@ void PromiseRejectCallback(PromiseRejectMessage message) {
   Local<Value> args[] = { event, promise, value };
   Local<Object> process = env->process_object();
 
+  env->inc_callout_count();
   callback->Call(process, ARRAY_SIZE(args), args);
 }
 
@@ -1068,24 +1069,28 @@ Local<Value> MakeCallback(Environment* env,
   if (has_domain) {
     Local<Value> enter_v = domain->Get(env->enter_string());
     if (enter_v->IsFunction()) {
-        enter_v.As<Function>()->Call(domain, 0, nullptr);
+      env->inc_callout_count();
+      enter_v.As<Function>()->Call(domain, 0, nullptr);
       if (try_catch.HasCaught())
         return Undefined(env->isolate());
     }
   }
 
   if (has_async_queue) {
     try_catch.SetVerbose(false);
+    env->inc_callout_count();
     env->async_hooks_pre_function()->Call(object, 0, nullptr);
     if (try_catch.HasCaught())
       FatalError("node::MakeCallback", "pre hook threw");
     try_catch.SetVerbose(true);
   }
 
+  env->inc_callout_count();
   Local<Value> ret = callback->Call(recv, argc, argv);
 
   if (has_async_queue) {
     try_catch.SetVerbose(false);
+    env->inc_callout_count();
     env->async_hooks_post_function()->Call(object, 0, nullptr);
     if (try_catch.HasCaught())
       FatalError("node::MakeCallback", "post hook threw");
@@ -1095,6 +1100,7 @@ Local<Value> MakeCallback(Environment* env,
   if (has_domain) {
     Local<Value> exit_v = domain->Get(env->exit_string());
     if (exit_v->IsFunction()) {
+      env->inc_callout_count();
       exit_v.As<Function>()->Call(domain, 0, nullptr);
       if (try_catch.HasCaught())
         return Undefined(env->isolate());
@@ -3971,17 +3977,11 @@ static void StartNodeInstance(void* arg) {
           v8::platform::PumpMessageLoop(default_platform, isolate);
           EmitBeforeExit(env);
 
-          // If there are only unrefed handles left, we need to run an
-          // extra event loop turn to purge the unrefed handles.
-          if (event_loop->active_handles == 0 &&
-              event_loop->handle_queue[0] != event_loop->handle_queue[1])
-            uv_run(event_loop, UV_RUN_NOWAIT);
-
           // Emit `beforeExit` if the loop became alive either after emitting
           // event, or after running some callbacks.
-          more = uv_loop_alive(event_loop);
-          if (uv_run(event_loop, UV_RUN_NOWAIT) != 0)
-            more = true;
+          env->reset_callout_count();
+          uv_run(event_loop, UV_RUN_NOWAIT);
+          more = uv_loop_alive(event_loop) || env->callout_count() != 0;
         }
       } while (more == true);
     }