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author | Ton Voon <tonvoon@users.sourceforge.net> | 2007-01-24 22:47:25 +0000 |
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committer | Ton Voon <tonvoon@users.sourceforge.net> | 2007-01-24 22:47:25 +0000 |
commit | fe856aa957978504137c1d425815d4ed8a22be40 (patch) | |
tree | a5bb46ce0e64b2056f75700eadbf27aba7c39418 /gl/xalloc.h | |
parent | 210f39bc84cfbb21cd72dc054e43f13815ee0616 (diff) | |
download | monitoring-plugins-fe856aa957978504137c1d425815d4ed8a22be40.tar.gz |
Sync with gnulib - lots of extraneous code removed in preference to GNU code
git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1580 f882894a-f735-0410-b71e-b25c423dba1c
Diffstat (limited to 'gl/xalloc.h')
-rw-r--r-- | gl/xalloc.h | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/gl/xalloc.h b/gl/xalloc.h new file mode 100644 index 00000000..17ab5142 --- /dev/null +++ b/gl/xalloc.h | |||
@@ -0,0 +1,267 @@ | |||
1 | /* xalloc.h -- malloc with out-of-memory checking | ||
2 | |||
3 | Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | ||
4 | 1999, 2000, 2003, 2004, 2006 Free Software Foundation, Inc. | ||
5 | |||
6 | This program is free software; you can redistribute it and/or modify | ||
7 | it under the terms of the GNU General Public License as published by | ||
8 | the Free Software Foundation; either version 2, or (at your option) | ||
9 | any later version. | ||
10 | |||
11 | This program is distributed in the hope that it will be useful, | ||
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | GNU General Public License for more details. | ||
15 | |||
16 | You should have received a copy of the GNU General Public License | ||
17 | along with this program; if not, write to the Free Software Foundation, | ||
18 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | ||
19 | |||
20 | #ifndef XALLOC_H_ | ||
21 | # define XALLOC_H_ | ||
22 | |||
23 | # include <stddef.h> | ||
24 | |||
25 | |||
26 | # ifdef __cplusplus | ||
27 | extern "C" { | ||
28 | # endif | ||
29 | |||
30 | |||
31 | # ifndef __attribute__ | ||
32 | # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__ | ||
33 | # define __attribute__(x) | ||
34 | # endif | ||
35 | # endif | ||
36 | |||
37 | # ifndef ATTRIBUTE_NORETURN | ||
38 | # define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__)) | ||
39 | # endif | ||
40 | |||
41 | /* This function is always triggered when memory is exhausted. | ||
42 | It must be defined by the application, either explicitly | ||
43 | or by using gnulib's xalloc-die module. This is the | ||
44 | function to call when one wants the program to die because of a | ||
45 | memory allocation failure. */ | ||
46 | extern void xalloc_die (void) ATTRIBUTE_NORETURN; | ||
47 | |||
48 | void *xmalloc (size_t s); | ||
49 | void *xzalloc (size_t s); | ||
50 | void *xcalloc (size_t n, size_t s); | ||
51 | void *xrealloc (void *p, size_t s); | ||
52 | void *x2realloc (void *p, size_t *pn); | ||
53 | void *xmemdup (void const *p, size_t s); | ||
54 | char *xstrdup (char const *str); | ||
55 | |||
56 | /* Return 1 if an array of N objects, each of size S, cannot exist due | ||
57 | to size arithmetic overflow. S must be positive and N must be | ||
58 | nonnegative. This is a macro, not an inline function, so that it | ||
59 | works correctly even when SIZE_MAX < N. | ||
60 | |||
61 | By gnulib convention, SIZE_MAX represents overflow in size | ||
62 | calculations, so the conservative dividend to use here is | ||
63 | SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value. | ||
64 | However, malloc (SIZE_MAX) fails on all known hosts where | ||
65 | sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for | ||
66 | exactly-SIZE_MAX allocations on such hosts; this avoids a test and | ||
67 | branch when S is known to be 1. */ | ||
68 | # define xalloc_oversized(n, s) \ | ||
69 | ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n)) | ||
70 | |||
71 | |||
72 | /* In the following macros, T must be an elementary or structure/union or | ||
73 | typedef'ed type, or a pointer to such a type. To apply one of the | ||
74 | following macros to a function pointer or array type, you need to typedef | ||
75 | it first and use the typedef name. */ | ||
76 | |||
77 | /* Allocate an object of type T dynamically, with error checking. */ | ||
78 | /* extern t *XMALLOC (typename t); */ | ||
79 | # define XMALLOC(t) ((t *) xmalloc (sizeof (t))) | ||
80 | |||
81 | /* Allocate memory for N elements of type T, with error checking. */ | ||
82 | /* extern t *XNMALLOC (size_t n, typename t); */ | ||
83 | # define XNMALLOC(n, t) \ | ||
84 | ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t)))) | ||
85 | |||
86 | /* Allocate an object of type T dynamically, with error checking, | ||
87 | and zero it. */ | ||
88 | /* extern t *XZALLOC (typename t); */ | ||
89 | # define XZALLOC(t) ((t *) xzalloc (sizeof (t))) | ||
90 | |||
91 | /* Allocate memory for N elements of type T, with error checking, | ||
92 | and zero it. */ | ||
93 | /* extern t *XCALLOC (size_t n, typename t); */ | ||
94 | # define XCALLOC(n, t) \ | ||
95 | ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t)))) | ||
96 | |||
97 | |||
98 | # if HAVE_INLINE | ||
99 | # define static_inline static inline | ||
100 | # else | ||
101 | void *xnmalloc (size_t n, size_t s); | ||
102 | void *xnrealloc (void *p, size_t n, size_t s); | ||
103 | void *x2nrealloc (void *p, size_t *pn, size_t s); | ||
104 | char *xcharalloc (size_t n); | ||
105 | # endif | ||
106 | |||
107 | # ifdef static_inline | ||
108 | |||
109 | /* Allocate an array of N objects, each with S bytes of memory, | ||
110 | dynamically, with error checking. S must be nonzero. */ | ||
111 | |||
112 | static_inline void * | ||
113 | xnmalloc (size_t n, size_t s) | ||
114 | { | ||
115 | if (xalloc_oversized (n, s)) | ||
116 | xalloc_die (); | ||
117 | return xmalloc (n * s); | ||
118 | } | ||
119 | |||
120 | /* Change the size of an allocated block of memory P to an array of N | ||
121 | objects each of S bytes, with error checking. S must be nonzero. */ | ||
122 | |||
123 | static_inline void * | ||
124 | xnrealloc (void *p, size_t n, size_t s) | ||
125 | { | ||
126 | if (xalloc_oversized (n, s)) | ||
127 | xalloc_die (); | ||
128 | return xrealloc (p, n * s); | ||
129 | } | ||
130 | |||
131 | /* If P is null, allocate a block of at least *PN such objects; | ||
132 | otherwise, reallocate P so that it contains more than *PN objects | ||
133 | each of S bytes. *PN must be nonzero unless P is null, and S must | ||
134 | be nonzero. Set *PN to the new number of objects, and return the | ||
135 | pointer to the new block. *PN is never set to zero, and the | ||
136 | returned pointer is never null. | ||
137 | |||
138 | Repeated reallocations are guaranteed to make progress, either by | ||
139 | allocating an initial block with a nonzero size, or by allocating a | ||
140 | larger block. | ||
141 | |||
142 | In the following implementation, nonzero sizes are doubled so that | ||
143 | repeated reallocations have O(N log N) overall cost rather than | ||
144 | O(N**2) cost, but the specification for this function does not | ||
145 | guarantee that sizes are doubled. | ||
146 | |||
147 | Here is an example of use: | ||
148 | |||
149 | int *p = NULL; | ||
150 | size_t used = 0; | ||
151 | size_t allocated = 0; | ||
152 | |||
153 | void | ||
154 | append_int (int value) | ||
155 | { | ||
156 | if (used == allocated) | ||
157 | p = x2nrealloc (p, &allocated, sizeof *p); | ||
158 | p[used++] = value; | ||
159 | } | ||
160 | |||
161 | This causes x2nrealloc to allocate a block of some nonzero size the | ||
162 | first time it is called. | ||
163 | |||
164 | To have finer-grained control over the initial size, set *PN to a | ||
165 | nonzero value before calling this function with P == NULL. For | ||
166 | example: | ||
167 | |||
168 | int *p = NULL; | ||
169 | size_t used = 0; | ||
170 | size_t allocated = 0; | ||
171 | size_t allocated1 = 1000; | ||
172 | |||
173 | void | ||
174 | append_int (int value) | ||
175 | { | ||
176 | if (used == allocated) | ||
177 | { | ||
178 | p = x2nrealloc (p, &allocated1, sizeof *p); | ||
179 | allocated = allocated1; | ||
180 | } | ||
181 | p[used++] = value; | ||
182 | } | ||
183 | |||
184 | */ | ||
185 | |||
186 | static_inline void * | ||
187 | x2nrealloc (void *p, size_t *pn, size_t s) | ||
188 | { | ||
189 | size_t n = *pn; | ||
190 | |||
191 | if (! p) | ||
192 | { | ||
193 | if (! n) | ||
194 | { | ||
195 | /* The approximate size to use for initial small allocation | ||
196 | requests, when the invoking code specifies an old size of | ||
197 | zero. 64 bytes is the largest "small" request for the | ||
198 | GNU C library malloc. */ | ||
199 | enum { DEFAULT_MXFAST = 64 }; | ||
200 | |||
201 | n = DEFAULT_MXFAST / s; | ||
202 | n += !n; | ||
203 | } | ||
204 | } | ||
205 | else | ||
206 | { | ||
207 | if (((size_t) -1) / 2 / s < n) | ||
208 | xalloc_die (); | ||
209 | n *= 2; | ||
210 | } | ||
211 | |||
212 | *pn = n; | ||
213 | return xrealloc (p, n * s); | ||
214 | } | ||
215 | |||
216 | /* Return a pointer to a new buffer of N bytes. This is like xmalloc, | ||
217 | except it returns char *. */ | ||
218 | |||
219 | static_inline char * | ||
220 | xcharalloc (size_t n) | ||
221 | { | ||
222 | return XNMALLOC (n, char); | ||
223 | } | ||
224 | |||
225 | # endif | ||
226 | |||
227 | # ifdef __cplusplus | ||
228 | } | ||
229 | |||
230 | /* C++ does not allow conversions from void * to other pointer types | ||
231 | without a cast. Use templates to work around the problem when | ||
232 | possible. */ | ||
233 | |||
234 | template <typename T> inline T * | ||
235 | xrealloc (T *p, size_t s) | ||
236 | { | ||
237 | return (T *) xrealloc ((void *) p, s); | ||
238 | } | ||
239 | |||
240 | template <typename T> inline T * | ||
241 | xnrealloc (T *p, size_t n, size_t s) | ||
242 | { | ||
243 | return (T *) xnrealloc ((void *) p, n, s); | ||
244 | } | ||
245 | |||
246 | template <typename T> inline T * | ||
247 | x2realloc (T *p, size_t *pn) | ||
248 | { | ||
249 | return (T *) x2realloc ((void *) p, pn); | ||
250 | } | ||
251 | |||
252 | template <typename T> inline T * | ||
253 | x2nrealloc (T *p, size_t *pn, size_t s) | ||
254 | { | ||
255 | return (T *) x2nrealloc ((void *) p, pn, s); | ||
256 | } | ||
257 | |||
258 | template <typename T> inline T * | ||
259 | xmemdup (T const *p, size_t s) | ||
260 | { | ||
261 | return (T *) xmemdup ((void const *) p, s); | ||
262 | } | ||
263 | |||
264 | # endif | ||
265 | |||
266 | |||
267 | #endif /* !XALLOC_H_ */ | ||