include/cppuhelper/weak.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  14  *   ownership. The ASF licenses this file to you under the Apache
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  18  */
  19 #ifndef INCLUDED_CPPUHELPER_WEAK_HXX
  20 #define INCLUDED_CPPUHELPER_WEAK_HXX
  21
  22 #include <cassert>
  23 #include <osl/interlck.h>
  24 #include <rtl/alloc.h>
  25 #include <com/sun/star/uno/XWeak.hpp>
  26 #include <cppuhelper/cppuhelperdllapi.h>
  27
  28
  29 namespace cppu
  30 {
  31
  32 class OWeakConnectionPoint;
  33
  34 /** Base class to implement an UNO object supporting weak references, i.e. the object can be held
  35     weakly (by a ::com::sun::star::uno::WeakReference).
  36     This implementation copes with reference counting.  Upon last release(), the virtual dtor
  37     is called.
  38
  39     @derive
  40     Inherit from this class and delegate acquire()/ release() calls.
  41 */
  42 class CPPUHELPER_DLLPUBLIC OWeakObject : public ::com::sun::star::uno::XWeak
  43 {
  44     friend class OWeakConnectionPoint;
  45
  46 protected:
  47     /** Virtual dtor.
  48
  49         @attention
  50         Despite the fact that a RuntimeException is allowed to be thrown, you must not throw any
  51         exception upon destruction!
  52     */
  53     virtual ~OWeakObject();
  54
  55     /** disposes and resets m_pWeakConnectionPoint
  56         @pre
  57             m_refCount equals 0
  58     */
  59     void    disposeWeakConnectionPoint();
  60
  61     /** reference count.
  62
  63         @attention
  64         Don't modify manually!  Use acquire() and release().
  65     */
  66     oslInterlockedCount m_refCount;
  67
  68     /// @cond INTERNAL
  69
  70     /** Container of all weak reference listeners and the connection point from the weak reference.
  71     */
  72     OWeakConnectionPoint * m_pWeakConnectionPoint;
  73
  74     /** reserved for future use. do not use.
  75     */
  76     void * m_pReserved;
  77
  78     /// @endcond
  79
  80 public:
  81     /// @cond INTERNAL
  82     // these are here to force memory de/allocation to sal lib.
  83     inline static void * SAL_CALL operator new( size_t nSize )
  84         { return ::rtl_allocateMemory( nSize ); }
  85     inline static void SAL_CALL operator delete( void * pMem )
  86         { ::rtl_freeMemory( pMem ); }
  87     inline static void * SAL_CALL operator new( size_t, void * pMem )
  88         { return pMem; }
  89     inline static void SAL_CALL operator delete( void *, void * )
  90         {}
  91     /// @endcond
  92
  93 #ifdef _MSC_VER
  94     /** Default Constructor.  Sets the reference count to zero.
  95         Accidentally occurs in msvc mapfile = > had to be outlined.
  96     */
  97     OWeakObject();
  98 #else
  99     /** Default Constructor.  Sets the reference count to zero.
 100     */
 101     inline OWeakObject()
 102         : m_refCount( 0 )
 103         , m_pWeakConnectionPoint( 0 )
 104         , m_pReserved(0)
 105         {}
 106 #endif
 107     /** Dummy copy constructor.  Set the reference count to zero.
 108
 109         @param rObj dummy param
 110     */
 111     inline OWeakObject( const OWeakObject & rObj )
 112         : com::sun::star::uno::XWeak()
 113         , m_refCount( 0 )
 114         , m_pWeakConnectionPoint( 0 )
 115         , m_pReserved(0)
 116         {
 117             (void) rObj;
 118         }
 119     /** Dummy assignment operator. Does not affect reference count.
 120
 121         @return this OWeakObject
 122     */
 123     inline OWeakObject & SAL_CALL operator = ( const OWeakObject &)
 124         { return *this; }
 125
 126     /** Basic queryInterface() implementation supporting \::com::sun::star::uno::XWeak and
 127         \::com::sun::star::uno::XInterface.
 128
 129         @param rType demanded type
 130         @return demanded type or empty any
 131     */
 132     virtual ::com::sun::star::uno::Any SAL_CALL queryInterface(
 133         const ::com::sun::star::uno::Type & rType )
 134         throw (::com::sun::star::uno::RuntimeException, std::exception) SAL_OVERRIDE;
 135     /** increasing m_refCount
 136     */
 137     virtual void SAL_CALL acquire()
 138         throw () SAL_OVERRIDE;
 139     /** decreasing m_refCount
 140     */
 141     virtual void SAL_CALL release()
 142         throw () SAL_OVERRIDE;
 143
 144     /** XWeak::queryAdapter() implementation
 145
 146         @return a \::com::sun::star::uno::XAdapter reference
 147     */
 148     virtual ::com::sun::star::uno::Reference< ::com::sun::star::uno::XAdapter > SAL_CALL queryAdapter()
 149         throw (::com::sun::star::uno::RuntimeException, std::exception) SAL_OVERRIDE;
 150
 151     /** Cast operator to XInterface reference.
 152
 153         @return XInterface reference
 154     */
 155     inline SAL_CALL operator ::com::sun::star::uno::Reference< ::com::sun::star::uno::XInterface > ()
 156         { return this; }
 157 };
 158
 159 /// @cond INTERNAL
 160 /** Convenience function for constructor-based service implementations.
 161
 162     To be used like:
 163
 164     css::uno::XInterface * FOO_constructor_function(...) {
 165         return cppu::acquire(new FOO(...));
 166     }
 167
 168     @param instance
 169     Newly created instance that should be acquired.
 170 */
 171 static inline ::com::sun::star::uno::XInterface * acquire(OWeakObject * instance)
 172 {
 173     assert(instance != 0);
 174     instance->acquire();
 175     return instance;
 176 }
 177 /// @endcond
 178
 179 }
 180
 181 #endif
 182
 183 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */