summaryrefslogtreecommitdiff
path: root/include/cppuhelper/weak.hxx
blob: a1a920ce4193f0cb777fef991662fa52f4496a47 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/* -*- 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 .
 */

/*
 * This file is part of LibreOffice published API.
 */
#ifndef INCLUDED_CPPUHELPER_WEAK_HXX
#define INCLUDED_CPPUHELPER_WEAK_HXX

#include <cassert>
#include <cstddef>
#include "osl/interlck.h"
#include "rtl/alloc.h"
#include "com/sun/star/uno/XWeak.hpp"
#include "cppuhelper/cppuhelperdllapi.h"


namespace cppu
{

class OWeakConnectionPoint;

/** Base class to implement a UNO object supporting weak references, i.e. the object can be held
    weakly (by a css::uno::WeakReference).
    This implementation copes with reference counting.  Upon last release(), the virtual dtor
    is called.

    @derive
    Inherit from this class and delegate acquire()/ release() calls.
*/
class CPPUHELPER_DLLPUBLIC OWeakObject : public css::uno::XWeak
{
    friend class OWeakConnectionPoint;

protected:
    /** Virtual dtor.

        @attention
        Despite the fact that a RuntimeException is allowed to be thrown, you must not throw any
        exception upon destruction!
    */
    virtual ~OWeakObject() COVERITY_NOEXCEPT_FALSE;

    /** disposes and resets m_pWeakConnectionPoint
        @pre
            m_refCount equals 0
    */
    void    disposeWeakConnectionPoint();

    /** reference count.

        @attention
        Don't modify manually!  Use acquire() and release().
    */
    oslInterlockedCount m_refCount;

    /// @cond INTERNAL

    /** Container of all weak reference listeners and the connection point from the weak reference.
    */
    OWeakConnectionPoint * m_pWeakConnectionPoint;

    /** reserved for future use. do not use.
    */
    void * m_pReserved;

    /// @endcond

public:
    /// @cond INTERNAL
    // these are here to force memory de/allocation to sal lib.
    static void * SAL_CALL operator new( size_t nSize )
        { return ::rtl_allocateMemory( nSize ); }
    static void SAL_CALL operator delete( void * pMem )
        { ::rtl_freeMemory( pMem ); }
    static void * SAL_CALL operator new( size_t, void * pMem )
        { return pMem; }
    static void SAL_CALL operator delete( void *, void * )
        {}
    /// @endcond

    /** Default Constructor.  Sets the reference count to zero.
    */
    OWeakObject()
        : m_refCount( 0 )
        , m_pWeakConnectionPoint( NULL )
        , m_pReserved(NULL)
        {}

    /** Dummy copy constructor.  Set the reference count to zero.
    */
    OWeakObject( const OWeakObject & )
        : css::uno::XWeak()
        , m_refCount( 0 )
        , m_pWeakConnectionPoint( NULL )
        , m_pReserved(NULL)
        {}
    /** Dummy assignment operator. Does not affect reference count.

        @return this OWeakObject
    */
    OWeakObject & SAL_CALL operator = ( const OWeakObject &)
        { return *this; }

    /** Basic queryInterface() implementation supporting com::sun::star::uno::XWeak and
        com::sun::star::uno::XInterface.

        @param rType demanded type
        @return demanded type or empty any
    */
    virtual css::uno::Any SAL_CALL queryInterface(
        const css::uno::Type & rType ) SAL_OVERRIDE;
    /** increasing m_refCount
    */
    virtual void SAL_CALL acquire()
        SAL_NOEXCEPT SAL_OVERRIDE;
    /** decreasing m_refCount
    */
    virtual void SAL_CALL release()
        SAL_NOEXCEPT SAL_OVERRIDE;

    /** XWeak::queryAdapter() implementation

        @return a com::sun::star::uno::XAdapter reference
    */
    virtual css::uno::Reference< css::uno::XAdapter > SAL_CALL queryAdapter() SAL_OVERRIDE;

    /** Cast operator to XInterface reference.

        @return XInterface reference
    */
    SAL_CALL operator css::uno::Reference< css::uno::XInterface > ()
        { return this; }

#if defined LIBO_INTERNAL_ONLY
    css::uno::XWeak* getXWeak() { return this; }
#endif
};

/// @cond INTERNAL
/** Convenience function for constructor-based service implementations.

    To be used like:

    css::uno::XInterface * FOO_constructor_function(...) {
        return cppu::acquire(new FOO(...));
    }

    @param instance
    Newly created instance that should be acquired.
*/
static inline css::uno::XInterface * acquire(OWeakObject * instance)
{
    assert(instance != NULL);
    instance->acquire();
    return instance;
}

#if defined LIBO_INTERNAL_ONLY
static inline css::uno::XWeak* getXWeak(OWeakObject* instance) { return instance; }
#endif
/// @endcond

}

#endif

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */