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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:51:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 16:51:28 +0000 |
commit | 940b4d1848e8c70ab7642901a68594e8016caffc (patch) | |
tree | eb72f344ee6c3d9b80a7ecc079ea79e9fba8676d /unotools/source/i18n/readwritemutexguard.cxx | |
parent | Initial commit. (diff) | |
download | libreoffice-upstream.tar.xz libreoffice-upstream.zip |
Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'unotools/source/i18n/readwritemutexguard.cxx')
-rw-r--r-- | unotools/source/i18n/readwritemutexguard.cxx | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/unotools/source/i18n/readwritemutexguard.cxx b/unotools/source/i18n/readwritemutexguard.cxx new file mode 100644 index 000000000..134f06c35 --- /dev/null +++ b/unotools/source/i18n/readwritemutexguard.cxx @@ -0,0 +1,109 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <unotools/readwritemutexguard.hxx> +#include <tools/debug.hxx> + +namespace utl { + +ReadWriteGuard::ReadWriteGuard( ReadWriteMutex& rMutexP, + ReadWriteGuardMode nRequestMode ) + : rMutex( rMutexP ) +{ + // don't do anything until a pending write completed (or another + // ReadWriteGuard leaves the ctor phase) + ::osl::MutexGuard aGuard( rMutex.maWriteMutex ); + nMode = nRequestMode; + if ( nMode & ReadWriteGuardMode::Write ) + { + rMutex.maWriteMutex.acquire(); + // wait for any read to complete +// TODO: set up a waiting thread instead of a loop + bool bWait = true; + do + { + rMutex.maMutex.acquire(); + bWait = (rMutex.nReadCount != 0); + if ( nMode & ReadWriteGuardMode::CriticalChange ) + bWait |= (rMutex.nBlockCriticalCount != 0); + rMutex.maMutex.release(); + } while ( bWait ); + } + else if ( nMode & ReadWriteGuardMode::BlockCritical ) + { + rMutex.maMutex.acquire(); + ++rMutex.nBlockCriticalCount; + rMutex.maMutex.release(); + } + else + { + rMutex.maMutex.acquire(); + ++rMutex.nReadCount; + rMutex.maMutex.release(); + } +} + +ReadWriteGuard::~ReadWriteGuard() +{ + if ( nMode & ReadWriteGuardMode::Write ) + rMutex.maWriteMutex.release(); + else if ( nMode & ReadWriteGuardMode::BlockCritical ) + { + rMutex.maMutex.acquire(); + --rMutex.nBlockCriticalCount; + rMutex.maMutex.release(); + } + else + { + rMutex.maMutex.acquire(); + --rMutex.nReadCount; + rMutex.maMutex.release(); + } +} + +void ReadWriteGuard::changeReadToWrite() +{ + bool bOk = !(nMode & (ReadWriteGuardMode::Write | ReadWriteGuardMode::BlockCritical)); + DBG_ASSERT( bOk, "ReadWriteGuard::changeReadToWrite: can't" ); + if ( bOk ) + { + // MUST release read before acquiring write mutex or dead lock would + // occur if there was a write in another thread waiting for this read + // to complete. + rMutex.maMutex.acquire(); + --rMutex.nReadCount; + rMutex.maMutex.release(); + + rMutex.maWriteMutex.acquire(); + nMode |= ReadWriteGuardMode::Write; + // wait for any other read to complete +// TODO: set up a waiting thread instead of a loop + bool bWait = true; + do + { + rMutex.maMutex.acquire(); + bWait = (rMutex.nReadCount != 0); + rMutex.maMutex.release(); + } while ( bWait ); + } +} + +} // namespace utl + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |