framework/inc/helper/shareablemutex.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.
   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  * 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 <osl/interlck.h>
  23 #include <osl/mutex.hxx>
  24
  25 namespace framework
  26 {
  27
  28 /**
  29  * This acts like a rtl::Reference<osl::Mutex>
  30  */
  31 class ShareableMutex
  32 {
  33     public:
  34         ShareableMutex();
  35         ShareableMutex( const ShareableMutex& rShareableMutex );
  36         ShareableMutex& operator=( const ShareableMutex& rShareableMutex );
  37
  38         ~ShareableMutex() { m_pMutexRef->release(); }
  39
  40         /** acquire the shared mutex */
  41         void acquire();
  42         /** release the shared mutex */
  43         void release();
  44
  45     private:
  46         /* ShareableMutex::MutexRef will destroy itself when the last ShareableMutex pointing to it is destroyed */
  47         struct MutexRef
  48         {
  49             MutexRef() : m_refCount(0) {}
  50             void acquire()
  51             {
  52                 osl_atomic_increment( &m_refCount );
  53             }
  54
  55             void release()
  56             {
  57                 if ( osl_atomic_decrement( &m_refCount ) == 0 )
  58                     delete this;
  59             }
  60
  61             oslInterlockedCount m_refCount;
  62             osl::Mutex          m_oslMutex;
  63         };
  64
  65         MutexRef* m_pMutexRef;
  66 };
  67
  68 class ShareGuard
  69 {
  70     public:
  71         explicit ShareGuard( ShareableMutex& rShareMutex ) :
  72             m_rShareMutex( rShareMutex )
  73         {
  74             m_rShareMutex.acquire();
  75         }
  76
  77         ~ShareGuard()
  78         {
  79             m_rShareMutex.release();
  80         }
  81
  82     private:
  83         ShareGuard& operator=( const ShareGuard& ) = delete;
  84
  85         ShareableMutex& m_rShareMutex;
  86 };
  87
  88 }
  89
  90 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */