33623f3117
Found with bin/find-unneeded-includes Only removal proposals are dealt with here. Change-Id: I444c43b9d549977039f25bec2b5bf666c3e15e0e Reviewed-on: https://gerrit.libreoffice.org/62041 Tested-by: Jenkins Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
102 lines
3.4 KiB
C++
102 lines
3.4 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/*
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* This file is part of the LibreOffice project.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* This file incorporates work covered by the following license notice:
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed
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* with this work for additional information regarding copyright
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* ownership. The ASF licenses this file to you under the Apache
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* License, Version 2.0 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy of
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* the License at http://www.apache.org/licenses/LICENSE-2.0 .
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*/
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#ifndef INCLUDED_UNOTOOLS_READWRITEMUTEXGUARD_HXX
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#define INCLUDED_UNOTOOLS_READWRITEMUTEXGUARD_HXX
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#include <osl/mutex.hxx>
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#include <o3tl/typed_flags_set.hxx>
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enum class ReadWriteGuardMode {
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ReadOnly = 0x00,
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Write = 0x01,
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CriticalChange = 0x02 | Write,
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BlockCritical = 0x04, // only a block, not a read, exclusive flag!
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};
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namespace o3tl {
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template<> struct typed_flags<ReadWriteGuardMode> : is_typed_flags<ReadWriteGuardMode, 0x7> {};
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}
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namespace utl {
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class ReadWriteMutex
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{
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friend class ReadWriteGuard;
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sal_uInt32 nReadCount;
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sal_uInt32 nBlockCriticalCount;
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::osl::Mutex maMutex;
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::osl::Mutex maWriteMutex;
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public:
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ReadWriteMutex()
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: nReadCount(0)
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, nBlockCriticalCount(0)
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{}
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};
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/** Enable multiple threads to read simultaneously, but a write blocks all
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other reads and writes, and a read blocks any write.
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Used in I18N wrappers to be able to maintain a single instance of a wrapper
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for the standard Office locale.
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NEVER construct a writing guard if there is already a reading guard in the
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same context, the following will dead lock EVEN IN THE SAME THREAD!
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void foo()
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{
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ReadWriteGuard aGuard1( aMutex );
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bar();
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}
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void bar()
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{
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// waits forever for aGuard1
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ReadWriteGuard aGuard2( aMutex, ReadWriteGuardMode::nWrite );
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}
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*/
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class ReadWriteGuard
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{
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ReadWriteMutex& rMutex;
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ReadWriteGuardMode nMode;
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public:
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ReadWriteGuard(
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ReadWriteMutex& rMutex,
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ReadWriteGuardMode nRequestMode = ReadWriteGuardMode::ReadOnly // read only
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);
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~ReadWriteGuard();
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/** Be careful with this, it does wait for ANY read to complete.
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The following will dead lock EVEN IN THE SAME THREAD!
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void foo()
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{
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ReadWriteGuard aGuard1( aMutex );
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bar();
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}
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void bar()
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{
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ReadWriteGuard aGuard2( aMutex );
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aGuard2.changeReadToWrite(); // waits forever for aGuard1
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}
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*/
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void changeReadToWrite();
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};
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} // namespace utl
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#endif // INCLUDED_UNOTOOLS_READWRITEMUTEXGUARD_HXX
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/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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