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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
commited5640d8b587fbcfed7dd7967f3de04b37a76f26 (patch)
tree7a5f7c6c9d02226d7471cb3cc8fbbf631b415303 /include/tools/ref.hxx
parentInitial commit. (diff)
downloadlibreoffice-ed5640d8b587fbcfed7dd7967f3de04b37a76f26.tar.xz
libreoffice-ed5640d8b587fbcfed7dd7967f3de04b37a76f26.zip
Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/tools/ref.hxx')
-rw-r--r--include/tools/ref.hxx234
1 files changed, 234 insertions, 0 deletions
diff --git a/include/tools/ref.hxx b/include/tools/ref.hxx
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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 .
+ */
+#ifndef INCLUDED_TOOLS_REF_HXX
+#define INCLUDED_TOOLS_REF_HXX
+
+#include <sal/config.h>
+#include <cassert>
+#include <tools/toolsdllapi.h>
+#include <utility>
+
+/**
+ This implements similar functionality to boost::intrusive_ptr
+*/
+
+namespace tools {
+
+/** T must be a class that extends SvRefBase */
+template<typename T> class SAL_DLLPUBLIC_RTTI SvRef final {
+public:
+ SvRef(): pObj(nullptr) {}
+
+ SvRef(SvRef&& rObj) noexcept
+ {
+ pObj = rObj.pObj;
+ rObj.pObj = nullptr;
+ }
+
+ SvRef(SvRef const & rObj): pObj(rObj.pObj)
+ {
+ if (pObj != nullptr) pObj->AddNextRef();
+ }
+
+ SvRef(T * pObjP): pObj(pObjP)
+ {
+ if (pObj != nullptr) pObj->AddFirstRef();
+ }
+
+ ~SvRef()
+ {
+ if (pObj != nullptr) pObj->ReleaseRef();
+ }
+
+ void clear()
+ {
+ if (pObj != nullptr) {
+ T * pRefObj = pObj;
+ pObj = nullptr;
+ pRefObj->ReleaseRef();
+ }
+ }
+
+ SvRef & operator =(SvRef const & rObj)
+ {
+ if (rObj.pObj != nullptr) {
+ rObj.pObj->AddNextRef();
+ }
+ T * pRefObj = pObj;
+ pObj = rObj.pObj;
+ if (pRefObj != nullptr) {
+ pRefObj->ReleaseRef();
+ }
+ return *this;
+ }
+
+ SvRef & operator =(SvRef && rObj)
+ {
+ if (pObj != nullptr) {
+ pObj->ReleaseRef();
+ }
+ pObj = rObj.pObj;
+ rObj.pObj = nullptr;
+ return *this;
+ }
+
+ bool is() const { return pObj != nullptr; }
+
+ explicit operator bool() const { return is(); }
+
+ T * get() const { return pObj; }
+
+ T * operator ->() const { assert(pObj != nullptr); return pObj; }
+
+ T & operator *() const { assert(pObj != nullptr); return *pObj; }
+
+ bool operator ==(const SvRef<T> &rhs) const { return pObj == rhs.pObj; }
+ bool operator !=(const SvRef<T> &rhs) const { return !(*this == rhs); }
+
+private:
+ T * pObj;
+};
+
+/**
+ * This implements similar functionality to std::make_shared.
+ */
+template<typename T, typename... Args>
+SvRef<T> make_ref(Args&& ... args)
+{
+ return SvRef<T>(new T(std::forward<Args>(args)...));
+}
+
+}
+
+/** Classes that want to be referenced-counted via SvRef<T>, should extend this base class */
+class TOOLS_DLLPUBLIC SvRefBase
+{
+ // work around a clang 3.5 optimization bug: if the bNoDelete is *first*
+ // it mis-compiles "if (--nRefCount == 0)" and never deletes any object
+ unsigned int nRefCount : 31;
+ // the only reason this is not bool is because MSVC cannot handle mixed type bitfields
+ unsigned int bNoDelete : 1;
+
+protected:
+ virtual ~SvRefBase() COVERITY_NOEXCEPT_FALSE;
+
+public:
+ SvRefBase() : nRefCount(0), bNoDelete(1) {}
+ SvRefBase(const SvRefBase &) : nRefCount(0), bNoDelete(1) {}
+
+ SvRefBase & operator=(const SvRefBase &) { return *this; }
+
+ void RestoreNoDelete()
+ { bNoDelete = 1; }
+
+ void AddNextRef()
+ {
+ assert( nRefCount < (1 << 30) && "Do not add refs to dead objects" );
+ ++nRefCount;
+ }
+
+ void AddFirstRef()
+ {
+ assert( nRefCount < (1 << 30) && "Do not add refs to dead objects" );
+ if( bNoDelete )
+ bNoDelete = 0;
+ ++nRefCount;
+ }
+
+ void ReleaseRef()
+ {
+ assert( nRefCount >= 1);
+ if( --nRefCount == 0 && !bNoDelete)
+ {
+ // I'm not sure about the original purpose of this line, but right now
+ // it serves the purpose that anything that attempts to do an AddRef()
+ // after an object is deleted will trip an assert.
+ nRefCount = 1 << 30;
+ delete this;
+ }
+ }
+
+ unsigned int GetRefCount() const
+ { return nRefCount; }
+};
+
+template<typename T>
+class SvCompatWeakBase;
+
+/** SvCompatWeakHdl acts as an intermediary between SvCompatWeakRef<T> and T.
+*/
+template<typename T>
+class SvCompatWeakHdl final : public SvRefBase
+{
+ friend class SvCompatWeakBase<T>;
+ T* _pObj;
+
+ SvCompatWeakHdl( T* pObj ) : _pObj( pObj ) {}
+
+public:
+ void ResetWeakBase( ) { _pObj = nullptr; }
+ T* GetObj() { return _pObj; }
+};
+
+/** We only have one place that extends this, in include/sfx2/frame.hxx, class SfxFrame.
+ Its function is to notify the SvCompatWeakHdl when an SfxFrame object is deleted.
+*/
+template<typename T>
+class SvCompatWeakBase
+{
+ tools::SvRef< SvCompatWeakHdl<T> > _xHdl;
+
+public:
+ /** Does not use initializer due to compiler warnings,
+ because the lifetime of the _xHdl object can exceed the lifetime of this class.
+ */
+ SvCompatWeakBase( T* pObj ) { _xHdl = new SvCompatWeakHdl<T>( pObj ); }
+
+ ~SvCompatWeakBase() { _xHdl->ResetWeakBase(); }
+
+ SvCompatWeakHdl<T>* GetHdl() { return _xHdl.get(); }
+};
+
+/** We only have one weak reference in LO, in include/sfx2/frame.hxx, class SfxFrameWeak.
+*/
+template<typename T>
+class SAL_WARN_UNUSED SvCompatWeakRef
+{
+ tools::SvRef< SvCompatWeakHdl<T> > _xHdl;
+public:
+ SvCompatWeakRef( ) {}
+ SvCompatWeakRef( T* pObj )
+ { if( pObj ) _xHdl = pObj->GetHdl(); }
+#if defined(__COVERITY__)
+ ~SvCompatWeakRef() COVERITY_NOEXCEPT_FALSE {}
+#endif
+ SvCompatWeakRef& operator = ( T * pObj )
+ { _xHdl = pObj ? pObj->GetHdl() : nullptr; return *this; }
+ bool is() const
+ { return _xHdl.is() && _xHdl->GetObj(); }
+ explicit operator bool() const { return is(); }
+ T* operator -> () const
+ { return _xHdl.is() ? _xHdl->GetObj() : nullptr; }
+ operator T* () const
+ { return _xHdl.is() ? _xHdl->GetObj() : nullptr; }
+};
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */