Task system sample

task_example.cpp

static const std::filesystem::path testHTML{"../test_res/index.html"};
static const std::filesystem::path testCSS{"../test_res/style.css"};

using DataBuffer = std::unique_ptr<std::uint8_t[]>;

struct Document
{
  DataBuffer HTMLData;
  DataBuffer CSSData;
  std::mutex DataMut;

  void MakeDOM()
  {
    std::lock_guard<std::mutex> l{DataMut};
    assert(HTMLData && CSSData);
    
    // Pretend we do something useful here...

    std::cout << "Document created" << std::endl;
  }
};

void StartCreateDocument()
{
  std::shared_ptr<Document> result = std::make_shared<Document>();

  Enqueue(Work, [=]()
  {
      std::lock_guard<std::mutex> l{result->DataMut};
      result->HTMLData = std::move(ReadFile(testHTML));
      OnDocumentResourceLoaded(result);
  });
  Enqueue(Work, [=]()
  {
      std::lock_guard<std::mutex> l{result->DataMut};
      result->CSSData = std::move(ReadFile(testCSS));
      OnDocumentResourceLoaded(result);
  });
}

void OnDocumentResourcesLoaded(std::shared_ptr<Document>& result)
{
    if (result->HTMLData && result->CSSData)
    {
        Enqueue(Main, [=]()
        {
            result->MakeDOM();
        });
    }
}