GRASS GIS 8 Programmer's Manual 8.2.1RC1(2022)-exported
handler.c
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1/*!
2 \file lib/gis/handler.c
3
4 \brief GIS Library - Error handlers
5
6 (C) 2010-2011 by the GRASS Development Team
7
8 This program is free software under the GNU General Public
9 License (>=v2). Read the file COPYING that comes with GRASS
10 for details.
11
12 \author Glynn Clements
13*/
14
15#include <stddef.h>
16#include <grass/gis.h>
17
18/*!
19 \brief Error handler (see G_add_error_handler() for usage)
20*/
21struct handler {
22 /*!
23 \brief Pointer to the handler routine
24 */
25 void (*func)(void *);
26 /*!
27 \brief Pointer to closure data
28 */
29 void *closure;
30};
31
32static struct handler *handlers;
33
34static int num_handlers;
35static int max_handlers;
36
37static struct handler *alloc_handler(void)
38{
39 int i;
40
41 for (i = 0; i < num_handlers; i++) {
42 struct handler *h = &handlers[i];
43 if (!h->func)
44 return h;
45 }
46
47 if (num_handlers >= max_handlers) {
48 max_handlers += 10;
49 handlers = G_realloc(handlers, max_handlers * sizeof(struct handler));
50 }
51
52 return &handlers[num_handlers++];
53}
54
55/*!
56 \brief Add new error handler
57
58 Example
59 \code
60 static void error_handler(void *p) {
61 const char *map = (const char *) p;
62 Vect_delete(map);
63 }
64 G_add_error_handler(error_handler, new->answer);
65 \endcode
66
67 \param func handler to add
68 \param closure pointer to closure data
69*/
70void G_add_error_handler(void (*func)(void *), void *closure)
71{
72 struct handler *h = alloc_handler();
73
74 h->func = func;
75 h->closure = closure;
76}
77
78/*!
79 \brief Remove existing error handler
80
81 \param func handler to be remove
82 \param closure pointer to closure data
83*/
84void G_remove_error_handler(void (*func)(void *), void *closure)
85{
86 int i;
87
88 for (i = 0; i < num_handlers; i++) {
89 struct handler *h = &handlers[i];
90
91 if (h->func == func && h->closure == closure) {
92 h->func = NULL;
93 h->closure = NULL;
94 }
95 }
96}
97
98/*!
99 \brief Call available error handlers (internal use only)
100*/
102{
103 int i;
104
105 for (i = 0; i < num_handlers; i++) {
106 struct handler *h = &handlers[i];
107 if (h->func)
108 (*h->func)(h->closure);
109 }
110}
111
#define NULL
Definition: ccmath.h:32
void G_add_error_handler(void(*func)(void *), void *closure)
Add new error handler.
Definition: handler.c:70
void G__call_error_handlers(void)
Call available error handlers (internal use only)
Definition: handler.c:101
void G_remove_error_handler(void(*func)(void *), void *closure)
Remove existing error handler.
Definition: handler.c:84