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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:51:28 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:51:28 +0000
commit940b4d1848e8c70ab7642901a68594e8016caffc (patch)
treeeb72f344ee6c3d9b80a7ecc079ea79e9fba8676d /unotools/source/i18n/readwritemutexguard.cxx
parentInitial commit. (diff)
downloadlibreoffice-940b4d1848e8c70ab7642901a68594e8016caffc.tar.xz
libreoffice-940b4d1848e8c70ab7642901a68594e8016caffc.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.cxx109
1 files changed, 109 insertions, 0 deletions
diff --git a/unotools/source/i18n/readwritemutexguard.cxx b/unotools/source/i18n/readwritemutexguard.cxx
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+/* -*- 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: */