HandleScope enter/exit callbacks for peoper integration into uv loop

patches/handle_scope.patch

@@ -0,0 +1,47 @@
+diff --git forkSrcPrefix/deps/v8/src/api/api.cc forkDstPrefix/deps/v8/src/api/api.cc
+index 2dd476dda34f1cfe3a75b7895009af24963372f2..6476204733a8aa87c4681dbeb5fee12db54e529d 100644
+--- forkSrcPrefix/deps/v8/src/api/api.cc
++++ forkDstPrefix/deps/v8/src/api/api.cc
+@@ -883,7 +883,21 @@ void InternalFieldOutOfBounds(int index) {
+
+ // --- H a n d l e s ---
+
+-HandleScope::HandleScope(Isolate* v8_isolate) { Initialize(v8_isolate); }
++static std::function<void(Isolate*)> g_enterScopeCB;
++static std::function<void(Isolate*)> g_leaveScopeCB;
++
++V8_EXPORT void SetScopeHandler(const std::function<void(Isolate*)>& enter,
++                     const std::function<void(Isolate*)>& exit) {
++  g_enterScopeCB = enter;
++  g_leaveScopeCB = exit;
++}
++
++HandleScope::HandleScope(Isolate* v8_isolate) {
++  if(g_enterScopeCB) {
++    g_enterScopeCB(v8_isolate);
++  }
++  Initialize(v8_isolate);
++}
+
+ void HandleScope::Initialize(Isolate* v8_isolate) {
+   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+@@ -908,6 +922,9 @@ void HandleScope::Initialize(Isolate* v8_isolate) {
+ }
+
+ HandleScope::~HandleScope() {
++  if(g_leaveScopeCB) {
++    g_leaveScopeCB(reinterpret_cast<Isolate*>(i_isolate_));
++  }
+ #ifdef V8_ENABLE_CHECKS
+   CHECK_EQ(scope_level_, i_isolate_->handle_scope_data()->level);
+ #endif
+@@ -938,6 +955,9 @@ i::Address* HandleScope::CreateHandleForCurrentIsolate(i::Address value) {
+ #endif  // V8_ENABLE_DIRECT_LOCAL
+
+ EscapableHandleScopeBase::EscapableHandleScopeBase(Isolate* v8_isolate) {
++  if(g_enterScopeCB) {
++    g_enterScopeCB(v8_isolate);
++  }
+   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+   escape_slot_ = CreateHandle(
+       i_isolate, i::ReadOnlyRoots(i_isolate).the_hole_value().ptr());