Let the second pass phantom callbacks run in a separate task on the foreground thread.

test/cctest/test-api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 18 matching lines @@
 #include <csignal>
 #include <map>
 #include <string>
 
 #include "test/cctest/test-api.h"
 
 #if V8_OS_POSIX
 #include <unistd.h>  // NOLINT
 #endif
 
+#include "include/libplatform/libplatform.h"
 #include "include/v8-util.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/platform/platform.h"
 #include "src/compilation-cache.h"
 #include "src/debug.h"
 #include "src/execution.h"
 #include "src/objects.h"
 #include "src/parser.h"
 #include "src/smart-pointers.h"
@@ skipping 32 matching lines @@
 using ::v8::Value;
 
 
 #define THREADED_PROFILED_TEST(Name)                                 \
   static void Test##Name();                                          \
   TEST(Name##WithProfiler) {                                         \
     RunWithProfiler(&Test##Name);                                    \
   }                                                                  \
   THREADED_TEST(Name)
 
+#define ENSURE_TASKS_HAVE_BEEN_RUN(isolate)                                    \
+  while (v8::platform::PumpMessageLoop(v8::internal::V8::GetCurrentPlatform(), \
+                                       (isolate)))                             \
+    ;
+
 
 void RunWithProfiler(void (*test)()) {
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());
   v8::Local<v8::String> profile_name =
       v8::String::NewFromUtf8(env->GetIsolate(), "my_profile1");
   v8::CpuProfiler* cpu_profiler = env->GetIsolate()->GetCpuProfiler();
 
   cpu_profiler->StartProfiling(profile_name);
   (*test)();
@@ skipping 3167 matching lines @@
 TEST(TwoPassPhantomCallbacks) {
   auto isolate = CcTest::isolate();
   const size_t kLength = 20;
   int instance_counter = 0;
   for (size_t i = 0; i < kLength; ++i) {
     auto data = new TwoPassCallbackData(isolate, &instance_counter);
     data->SetWeak();
   }
   CHECK_EQ(static_cast<int>(kLength), instance_counter);
   CcTest::heap()->CollectAllGarbage();
+  ENSURE_TASKS_HAVE_BEEN_RUN(isolate);
   CHECK_EQ(0, instance_counter);
 }
 
 
 TEST(TwoPassPhantomCallbacksNestedGc) {
   auto isolate = CcTest::isolate();
   const size_t kLength = 20;
   TwoPassCallbackData* array[kLength];
   int instance_counter = 0;
   for (size_t i = 0; i < kLength; ++i) {
     array[i] = new TwoPassCallbackData(isolate, &instance_counter);
     array[i]->SetWeak();
   }
   array[5]->MarkTriggerGc();
   array[10]->MarkTriggerGc();
   array[15]->MarkTriggerGc();
   CHECK_EQ(static_cast<int>(kLength), instance_counter);
   CcTest::heap()->CollectAllGarbage();
+  ENSURE_TASKS_HAVE_BEEN_RUN(isolate);
   CHECK_EQ(0, instance_counter);
 }
 
 
 namespace {
 
 void* IntKeyToVoidPointer(int key) { return reinterpret_cast<void*>(key << 1); }
 
 
 Local<v8::Object> NewObjectForIntKey(
@@ skipping 3493 matching lines @@
       FlagAndPersistent object;
       {
         v8::HandleScope handle_scope(isolate);
         object.handle.Reset(isolate, v8::Object::New(isolate));
       }
       object.flag = false;
       object.handle.SetWeak(&object, gc_forcing_callback[inner_gc],
                             v8::WeakCallbackType::kParameter);
       object.handle.MarkIndependent();
       invoke_gc[outer_gc]();
+      ENSURE_TASKS_HAVE_BEEN_RUN(isolate);
       CHECK(object.flag);
     }
   }
 }
 
 
 v8::Handle<Function> args_fun;
 
 
 static void ArgumentsTestCallback(
@@ skipping 14836 matching lines @@
   CHECK(set->Has(env.local(), set).FromJust());
 
   CHECK(set->Delete(env.local(), set).FromJust());
   CHECK_EQ(2U, set->Size());
   CHECK(!set->Has(env.local(), set).FromJust());
   CHECK(!set->Delete(env.local(), set).FromJust());
 
   set->Clear();
   CHECK_EQ(0U, set->Size());
 }