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

samples/process.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 648 matching lines @@
 StringHttpRequest kSampleRequests[kSampleSize] = {
   StringHttpRequest("/process.cc", "localhost", "google.com", "firefox"),
   StringHttpRequest("/", "localhost", "google.net", "firefox"),
   StringHttpRequest("/", "localhost", "google.org", "safari"),
   StringHttpRequest("/", "localhost", "yahoo.com", "ie"),
   StringHttpRequest("/", "localhost", "yahoo.com", "safari"),
   StringHttpRequest("/", "localhost", "yahoo.com", "firefox")
 };
 
 
-bool ProcessEntries(HttpRequestProcessor* processor, int count,
-                    StringHttpRequest* reqs) {
+bool ProcessEntries(v8::Platform* platform, HttpRequestProcessor* processor,
+                    int count, StringHttpRequest* reqs) {
   for (int i = 0; i < count; i++) {
-    if (!processor->Process(&reqs[i]))
-      return false;
+    bool result = processor->Process(&reqs[i]);
+    while (v8::platform::PumpMessageLoop(platform, Isolate::GetCurrent()))
+      continue;
+    if (!result) return false;
   }
   return true;
 }
 
 
 void PrintMap(map<string, string>* m) {
   for (map<string, string>::iterator i = m->begin(); i != m->end(); i++) {
     pair<string, string> entry = *i;
     printf("%s: %s\n", entry.first.c_str(), entry.second.c_str());
   }
@@ skipping 22 matching lines @@
   if (!ReadFile(isolate, file).ToLocal(&source)) {
     fprintf(stderr, "Error reading '%s'.\n", file.c_str());
     return 1;
   }
   JsHttpRequestProcessor processor(isolate, source);
   map<string, string> output;
   if (!processor.Initialize(&options, &output)) {
     fprintf(stderr, "Error initializing processor.\n");
     return 1;
   }
-  if (!ProcessEntries(&processor, kSampleSize, kSampleRequests))
+  if (!ProcessEntries(platform, &processor, kSampleSize, kSampleRequests))
     return 1;
   PrintMap(&output);
 }