Postpone interrupts while dipatching debugger events to listeners

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index de7cc2315d02397e85f54388772acf6f4da68b67..297156f563e0518c4f9a5e687324dc73c1378553 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -1815,6 +1815,7 @@ void Debug::OnException(Handle<Object> exception, Handle<Object> promise) {
 
 void Debug::OnCompileError(Handle<Script> script) {
   if (ignore_events()) return;
+  SuppressDebug while_processing(this);
 
   if (in_debug_scope()) {
     ProcessCompileEventInDebugScope(v8::CompileError, script);
@@ -1857,6 +1858,7 @@ void Debug::OnDebugBreak(Handle<Object> break_points_hit,
 
 void Debug::OnBeforeCompile(Handle<Script> script) {
   if (in_debug_scope() || ignore_events()) return;
+  SuppressDebug while_processing(this);
 
   HandleScope scope(isolate_);
   DebugScope debug_scope(this);
@@ -1878,6 +1880,7 @@ void Debug::OnBeforeCompile(Handle<Script> script) {
 // Handle debugger actions when a new script is compiled.
 void Debug::OnAfterCompile(Handle<Script> script) {
   if (ignore_events()) return;
+  SuppressDebug while_processing(this);
 
   if (in_debug_scope()) {
     ProcessCompileEventInDebugScope(v8::AfterCompile, script);
@@ -1974,6 +1977,9 @@ void Debug::CallEventCallback(v8::DebugEvent event,
                               Handle<Object> exec_state,
                               Handle<Object> event_data,
                               v8::Debug::ClientData* client_data) {
+  // Prevent other interrupts from triggering, for example API callbacks,
+  // while dispatching event listners.
+  PostponeInterruptsScope postpone(isolate_);
   bool previous = in_debug_event_listener_;
   in_debug_event_listener_ = true;
   if (event_listener_->IsForeign()) {
@@ -2007,7 +2013,6 @@ void Debug::ProcessCompileEventInDebugScope(v8::DebugEvent event,
                                             Handle<Script> script) {
   if (event_listener_.is_null()) return;
 
-  SuppressDebug while_processing(this);
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return;