Fix yaz URL
[yaz-moved-to-github.git] / include / yaz / shptr.h
1 /* This file is part of the YAZ toolkit.
2  * Copyright (C) 1995-2010 Index Data.
3  * All rights reserved.
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are met:
6  *
7  *     * Redistributions of source code must retain the above copyright
8  *       notice, this list of conditions and the following disclaimer.
9  *     * Redistributions in binary form must reproduce the above copyright
10  *       notice, this list of conditions and the following disclaimer in the
11  *       documentation and/or other materials provided with the distribution.
12  *     * Neither the name of Index Data nor the names of its contributors
13  *       may be used to endorse or promote products derived from this
14  *       software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27
28 /**
29  * \file shptr.h
30  * \brief Shared pointer macros
31  */
32
33 #ifndef YAZ_SHARED_PTR_H
34 #define YAZ_SHARED_PTR_H
35
36 #include <yaz/xmalloc.h>
37 #include <yaz/mutex.h>
38
39 YAZ_BEGIN_CDECL
40
41 #define YAZ_SHPTR_TYPE(type) \
42     struct type##_shptr \
43     {                          \
44     type ptr;                  \
45     int ref;                   \
46     YAZ_MUTEX mutex;           \
47     };  \
48     typedef struct type##_shptr *type##_shptr_t;
49
50 #define YAZ_SHPTR_INIT(p,n) {                   \
51         p = xmalloc(sizeof(*p));                \
52         p->ptr = n;                             \
53         p->ref = 1;                             \
54         p->mutex = 0;  \
55         yaz_mutex_create(&p->mutex);            \
56     }
57
58 #define YAZ_SHPTR_INC(p) {                      \
59         yaz_mutex_enter(p->mutex);              \
60         p->ref++;                               \
61         yaz_mutex_leave(p->mutex);              \
62     }
63
64 #define YAZ_SHPTR_DEC(p, destroy)  {             \
65     yaz_mutex_enter(p->mutex);                   \
66     if (--p->ref == 0) {                         \
67         yaz_mutex_leave(p->mutex);               \
68         destroy(p->ptr);                         \
69         yaz_mutex_destroy(&p->mutex);            \
70         xfree(p);                                \
71         p = 0;                                   \
72     } else { \
73     yaz_mutex_leave(p->mutex); \
74     } \
75     }
76
77 YAZ_END_CDECL
78
79 #endif
80 /*
81  * Local variables:
82  * c-basic-offset: 4
83  * c-file-style: "Stroustrup"
84  * indent-tabs-mode: nil
85  * End:
86  * vim: shiftwidth=4 tabstop=8 expandtab
87  */
88