[api] Introduce MicrotasksScope::IsRunningMicrotasks

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 1840 matching lines @@
       deferred_handles_head_(NULL),
       optimizing_compile_dispatcher_(NULL),
       stress_deopt_count_(0),
       virtual_handler_register_(NULL),
       virtual_slot_register_(NULL),
       next_optimization_id_(0),
       js_calls_from_api_counter_(0),
 #if TRACE_MAPS
       next_unique_sfi_id_(0),
 #endif
+      is_running_microtasks_(false),
       use_counter_callback_(NULL),
       basic_block_profiler_(NULL),
       cancelable_task_manager_(new CancelableTaskManager()),
       abort_on_uncaught_exception_callback_(NULL) {
   {
     base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
     CHECK(thread_data_table_);
   }
   id_ = base::NoBarrier_AtomicIncrement(&isolate_counter_, 1);
   TRACE_ISOLATE(constructor);
@@ skipping 902 matching lines @@
   DCHECK(queue->get(num_tasks)->IsUndefined());
   queue->set(num_tasks, *microtask);
   set_pending_microtask_count(num_tasks + 1);
 }
 
 
 void Isolate::RunMicrotasks() {
   // Increase call depth to prevent recursive callbacks.
   v8::Isolate::SuppressMicrotaskExecutionScope suppress(
       reinterpret_cast<v8::Isolate*>(this));
+  is_running_microtasks_ = true;
   RunMicrotasksInternal();
+  is_running_microtasks_ = false;
   FireMicrotasksCompletedCallback();
 }
 
 
 void Isolate::RunMicrotasksInternal() {
   while (pending_microtask_count() > 0) {
     HandleScope scope(this);
     int num_tasks = pending_microtask_count();
     Handle<FixedArray> queue(heap()->microtask_queue(), this);
     DCHECK(num_tasks <= queue->length());
@@ skipping 200 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8