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: */