text: /*
   * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. 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 with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
   * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   * THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "config.h"
  #include "WebHeapAgent.h"
  
  #include <wtf/RunLoop.h>
  
  
  namespace WebCore {
  
  using namespace Inspector;
  
  struct GarbageCollectionData {
      Inspector::Protocol::Heap::GarbageCollection::Type type;
      double startTime;
      double endTime;
  };
  
  class SendGarbageCollectionEventsTask {
  public:
      SendGarbageCollectionEventsTask(WebHeapAgent&);
      void addGarbageCollection(GarbageCollectionData&&);
      void reset();
  private:
      void timerFired();
  
      WebHeapAgent& m_agent;
      Vector<GarbageCollectionData> m_collections;
      RunLoop::Timer<SendGarbageCollectionEventsTask> m_timer;
      Lock m_mutex;
  };
  
  SendGarbageCollectionEventsTask::SendGarbageCollectionEventsTask(WebHeapAgent& agent)
      : m_agent(agent)
      , m_timer(RunLoop::main(), this, &SendGarbageCollectionEventsTask::timerFired)
  {
  }
  
  void SendGarbageCollectionEventsTask::addGarbageCollection(GarbageCollectionData&& collection)
  {
      {
          std::lock_guard<Lock> lock(m_mutex);
          m_collections.append(WTFMove(collection));
      }
  
      if (!m_timer.isActive())
          m_timer.startOneShot(0_s);
  }
  
  void SendGarbageCollectionEventsTask::reset()
  {
      {
          std::lock_guard<Lock> lock(m_mutex);
          m_collections.clear();
      }
  
      m_timer.stop();
  }
  
  void SendGarbageCollectionEventsTask::timerFired()
  {
      Vector<GarbageCollectionData> collectionsToSend;
  
      {
          std::lock_guard<Lock> lock(m_mutex);
          m_collections.swap(collectionsToSend);
      }
  
      m_agent.dispatchGarbageCollectionEventsAfterDelay(WTFMove(collectionsToSend));
  }
  
  WebHeapAgent::WebHeapAgent(Inspector::AgentContext& context)
      : InspectorHeapAgent(context)
      , m_sendGarbageCollectionEventsTask(std::make_unique<SendGarbageCollectionEventsTask>(*this))
  {
  }
  
  WebHeapAgent::~WebHeapAgent()
  {
      m_sendGarbageCollectionEventsTask->reset();
  }
  
  void WebHeapAgent::disable(ErrorString& errorString)
  {
      m_sendGarbageCollectionEventsTask->reset();
  
      InspectorHeapAgent::disable(errorString);
  }
  
  void WebHeapAgent::dispatchGarbageCollectedEvent(Inspector::Protocol::Heap::GarbageCollection::Type type, double startTime, double endTime)
  {
      // Dispatch the event asynchronously because this method may be
      // called between collection and sweeping and we don't want to
      // create unexpected JavaScript allocations that the Sweeper does
      // not expect to encounter. JavaScript allocations could happen
      // with WebKitLegacy's in process inspector which shares the same
      // VM as the inspected page.
  
      GarbageCollectionData data = {type, startTime, endTime};
      m_sendGarbageCollectionEventsTask->addGarbageCollection(WTFMove(data));
  }
  
  void WebHeapAgent::dispatchGarbageCollectionEventsAfterDelay(Vector<GarbageCollectionData>&& collections)
  {
      for (auto& collection : collections)
          InspectorHeapAgent::dispatchGarbageCollectedEvent(collection.type, collection.startTime, collection.endTime);
  }
  
  } // namespace WebCore
  