include/dbaccess/AsynchronousLink.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   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  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <mutex>
  23 #include <tools/link.hxx>
  24
  25 struct ImplSVEvent;
  26
  27 namespace dbaui
  28 {
  29
  30     // a helper for multi-threaded handling of async events
  31
  32     /** handles asynchronous links which may be called in multi-threaded environments
  33         If you use an instance of this class as member of your own class, it will handle
  34         several crucial points for you (for instance the case that somebody posts the
  35         event while another thread tries to delete this event in the _destructor_ of the
  36         class).
  37     */
  38     class OAsynchronousLink final
  39     {
  40         Link<void*,void>    m_aHandler;
  41         mutable std::mutex  m_aEventSafety;
  42         std::mutex          m_aDestructionSafety;
  43         ImplSVEvent *       m_nEventId;
  44         DECL_LINK(OnAsyncCall, void*, void);
  45
  46     public:
  47         /** constructs the object
  48             @param      _rHandler           The link to be called asynchronously
  49         */
  50         OAsynchronousLink( const Link<void*,void>& _rHandler );
  51         ~OAsynchronousLink();
  52
  53         bool    IsRunning() const
  54         {
  55             std::unique_lock aEventGuard(m_aEventSafety);
  56             return m_nEventId != nullptr;
  57         }
  58
  59         void Call( void* _pArgument = nullptr );
  60         void CancelCall();
  61     };
  62 }
  63
  64 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */