include/systools/win32/retry_if_failed.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 #include <type_traits>
  13 #include <systools/win32/uwinapi.h>
  14
  15 #pragma comment(lib, "Kernel32.lib") // for Sleep
  16
  17 namespace sal::systools
  18 {
  19 // Some system calls (e.g., clipboard access functions) may fail first time, because the resource
  20 // may only be accessed by one process at a time. This function allows to retry failed call up to
  21 // specified number of times with a specified timeout (in ms), until the call succeeds or the limit
  22 // of attempts is exceeded.
  23 // Usage:
  24 //     HRESULT hr = sal::systools::RetryIfFailed(10, 100, []{ return OleFlushClipboard(); });
  25 template <typename Func>
  26 std::enable_if_t<std::is_same_v<std::invoke_result_t<Func>, HRESULT>, HRESULT>
  27 RetryIfFailed(unsigned times, unsigned msTimeout, Func func)
  28 {
  29     for (unsigned i = 0;; ++i)
  30     {
  31         if (HRESULT hr = func(); SUCCEEDED(hr) || i >= times)
  32             return hr;
  33         Sleep(msTimeout);
  34     }
  35 }
  36 }
  37
  38 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */