イグトランスの頭の中（のかけら）

#include <atomic>
#include <iostream>
#include <thread>
#include <windows.h>
#include <comdef.h>
 
MIDL_INTERFACE("c4230d66-43bb-42a9-9f70-f580f5b96866") IHoge : IUnknown
{
  STDMETHOD(Run)();
};
 
_COM_SMARTPTR_TYPEDEF(IHoge, __uuidof (IHoge));
 
class Hoge : public IHoge
{
  Hoge()
  {
    auto hr = CoCreateFreeThreadedMarshaler(this, &m_marshaler);
    if (FAILED(hr))
      throw _com_error(hr);
  }
 
public:
  static IHogePtr Create() { return new Hoge; }
 
  IFACEMETHOD(QueryInterface)(REFIID riid, void** ppv) override
  {
    if (ppv == nullptr)
    {
      return E_POINTER;
    }
    // IAgileObjectは追加のメソッドを持たないので
    // IUnknownと同じ値を返せば良い。
    if (riid == __uuidof (IHoge)
      || riid == __uuidof (IUnknown)
      || riid == __uuidof (IAgileObject))
    {
      *ppv = static_cast<IHoge*>(this);
      AddRef();
      return S_OK;
    }
    else if (riid == __uuidof (IMarshal))
    {
      // フリースレッドマーシャラに丸投げ。
      return m_marshaler->QueryInterface(riid, ppv);
    }
    *ppv = nullptr;
    return E_NOINTERFACE;
  }
 
  IFACEMETHOD_(ULONG, AddRef)() override
  {
    return ++m_count;
  }
 
  IFACEMETHOD_(ULONG, Release)() override
  {
    auto count = --m_count;
    if (count == 0)
    {
      delete this;
    }
    return count;
  }
 
  IFACEMETHOD(Run)()
  {
    std::cout << "Run: " << std::this_thread::get_id() << std::endl;
    return S_OK;
  }
 
private:
  IUnknownPtr m_marshaler;
  std::atomic<ULONG> m_count{};
};
 
void worker(_In_ IStream* s)
{
  try
  {
    _com_util::CheckError(CoInitializeEx(
      nullptr, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE));
 
    IHogePtr hoge;
    _com_util::CheckError(CoGetInterfaceAndReleaseStream(
      s, IID_PPV_ARGS(&hoge)));
 
    std::cout << "hoge in worker: " << hoge.GetInterfacePtr() << std::endl;
    std::cout << "worker thread: " << std::this_thread::get_id() << std::endl;
 
    hoge->Run();
  }
  catch(const _com_error& e)
  {
    std::cout << std::hex << std::showbase << e.Error() << std::endl;
  }
  CoUninitialize();
}
 
int main()
{
  try
  {
    _com_util::CheckError(CoInitializeEx(
      nullptr, COINIT_MULTITHREADED | COINIT_DISABLE_OLE1DDE));
 
    auto hoge = Hoge::Create();
    std::cout << "hoge in main: " << hoge.GetInterfacePtr() << std::endl;
    IStream* s;
    _com_util::CheckError(
      CoMarshalInterThreadInterfaceInStream(__uuidof (IUnknown), hoge, &s));
    std::thread(worker, s).join();
  }
  catch(const _com_error& e)
  {
    std::cout << std::hex << std::showbase << e.Error() << std::endl;
  }
 
  CoUninitialize();
}