include/o3tl/safeCoInitUninit.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #pragma once
  11
  12 #if defined _WIN32
  13 #include <prewin.h>
  14
  15 // for CoInitializeEx / CoUninitialize
  16 #include <combaseapi.h>
  17
  18 #include <postwin.h>
  19
  20 // for std::abort
  21 #include <cstdlib>
  22
  23 namespace o3tl
  24 {
  25 // Helpers for safe calls to CoInitializeEx and CoUninitialize in MSVC
  26 // Indeed if a thread has been already initialized with a concurrency model
  27 // (in LO case COINIT_APARTMENTTHREADED or COINIT_MULTITHREADED)
  28 // CoInitializeEx can't succeed without calling first CoUninitialize
  29 // also, CoUninitialize must be called the number of times CoInitializeEx has been called
  30 inline HRESULT safeCoInitializeEx(DWORD dwCoInit, int& nbReinit)
  31 {
  32     HRESULT hr;
  33     while ((hr = CoInitializeEx(nullptr, dwCoInit)) == RPC_E_CHANGED_MODE)
  34     {
  35         // so we're in RPC_E_CHANGED_MODE case
  36         // the pb was it was already initialized with a different concurrency model
  37         // close this init
  38         CoUninitialize();
  39         // and increment counter for dtr part
  40         ++nbReinit;
  41
  42         // and keep on the loop if there were multi initializations
  43     }
  44     if (FAILED(hr))
  45         std::abort();
  46     return hr;
  47 }
  48
  49 inline void safeCoUninitializeReinit(DWORD dwCoInit, int nbReinit)
  50 {
  51     CoUninitialize();
  52     // Put back all the inits, if there were, before the use of the caller to safeCoInitializeEx
  53     for (int i = 0; i < nbReinit; ++i)
  54         CoInitializeEx(nullptr, dwCoInit);
  55 }
  56 }
  57 #endif
  58 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */