1 | /* GLIB - Library of useful routines for C programming |
2 | * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald |
3 | * |
4 | * SPDX-License-Identifier: LGPL-2.1-or-later |
5 | * |
6 | * This library is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public |
8 | * License as published by the Free Software Foundation; either |
9 | * version 2.1 of the License, or (at your option) any later version. |
10 | * |
11 | * This library 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 GNU |
14 | * Lesser General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
18 | */ |
19 | |
20 | /* |
21 | * Modified by the GLib Team and others 1997-2000. See the AUTHORS |
22 | * file for a list of people on the GLib Team. See the ChangeLog |
23 | * files for a list of changes. These files are distributed with |
24 | * GLib at ftp://ftp.gtk.org/pub/gtk/. |
25 | */ |
26 | |
27 | #ifndef __G_MEM_H__ |
28 | #define __G_MEM_H__ |
29 | |
30 | #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION) |
31 | #error "Only <glib.h> can be included directly." |
32 | #endif |
33 | |
34 | #include <glib/gutils.h> |
35 | #include <glib/glib-typeof.h> |
36 | |
37 | G_BEGIN_DECLS |
38 | |
39 | /** |
40 | * GMemVTable: |
41 | * @malloc: function to use for allocating memory. |
42 | * @realloc: function to use for reallocating memory. |
43 | * @free: function to use to free memory. |
44 | * @calloc: function to use for allocating zero-filled memory. |
45 | * @try_malloc: function to use for allocating memory without a default error handler. |
46 | * @try_realloc: function to use for reallocating memory without a default error handler. |
47 | * |
48 | * A set of functions used to perform memory allocation. The same #GMemVTable must |
49 | * be used for all allocations in the same program; a call to g_mem_set_vtable(), |
50 | * if it exists, should be prior to any use of GLib. |
51 | * |
52 | * This functions related to this has been deprecated in 2.46, and no longer work. |
53 | */ |
54 | typedef struct _GMemVTable GMemVTable; |
55 | |
56 | |
57 | #if GLIB_SIZEOF_VOID_P > GLIB_SIZEOF_LONG |
58 | /** |
59 | * G_MEM_ALIGN: |
60 | * |
61 | * Indicates the number of bytes to which memory will be aligned on the |
62 | * current platform. |
63 | */ |
64 | # define G_MEM_ALIGN GLIB_SIZEOF_VOID_P |
65 | #else /* GLIB_SIZEOF_VOID_P <= GLIB_SIZEOF_LONG */ |
66 | # define G_MEM_ALIGN GLIB_SIZEOF_LONG |
67 | #endif /* GLIB_SIZEOF_VOID_P <= GLIB_SIZEOF_LONG */ |
68 | |
69 | |
70 | /* Memory allocation functions |
71 | */ |
72 | |
73 | GLIB_AVAILABLE_IN_ALL |
74 | void (g_free) (gpointer mem); |
75 | GLIB_AVAILABLE_IN_2_76 |
76 | void g_free_sized (gpointer mem, |
77 | size_t size); |
78 | |
79 | GLIB_AVAILABLE_IN_2_34 |
80 | void g_clear_pointer (gpointer *pp, |
81 | GDestroyNotify destroy); |
82 | |
83 | GLIB_AVAILABLE_IN_ALL |
84 | gpointer g_malloc (gsize n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1); |
85 | GLIB_AVAILABLE_IN_ALL |
86 | gpointer g_malloc0 (gsize n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1); |
87 | GLIB_AVAILABLE_IN_ALL |
88 | gpointer g_realloc (gpointer mem, |
89 | gsize n_bytes) G_GNUC_WARN_UNUSED_RESULT; |
90 | GLIB_AVAILABLE_IN_ALL |
91 | gpointer g_try_malloc (gsize n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1); |
92 | GLIB_AVAILABLE_IN_ALL |
93 | gpointer g_try_malloc0 (gsize n_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE(1); |
94 | GLIB_AVAILABLE_IN_ALL |
95 | gpointer g_try_realloc (gpointer mem, |
96 | gsize n_bytes) G_GNUC_WARN_UNUSED_RESULT; |
97 | |
98 | GLIB_AVAILABLE_IN_ALL |
99 | gpointer g_malloc_n (gsize n_blocks, |
100 | gsize n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2); |
101 | GLIB_AVAILABLE_IN_ALL |
102 | gpointer g_malloc0_n (gsize n_blocks, |
103 | gsize n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2); |
104 | GLIB_AVAILABLE_IN_ALL |
105 | gpointer g_realloc_n (gpointer mem, |
106 | gsize n_blocks, |
107 | gsize n_block_bytes) G_GNUC_WARN_UNUSED_RESULT; |
108 | GLIB_AVAILABLE_IN_ALL |
109 | gpointer g_try_malloc_n (gsize n_blocks, |
110 | gsize n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2); |
111 | GLIB_AVAILABLE_IN_ALL |
112 | gpointer g_try_malloc0_n (gsize n_blocks, |
113 | gsize n_block_bytes) G_GNUC_MALLOC G_GNUC_ALLOC_SIZE2(1,2); |
114 | GLIB_AVAILABLE_IN_ALL |
115 | gpointer g_try_realloc_n (gpointer mem, |
116 | gsize n_blocks, |
117 | gsize n_block_bytes) G_GNUC_WARN_UNUSED_RESULT; |
118 | |
119 | GLIB_AVAILABLE_IN_2_72 |
120 | gpointer g_aligned_alloc (gsize n_blocks, |
121 | gsize n_block_bytes, |
122 | gsize alignment) G_GNUC_WARN_UNUSED_RESULT G_GNUC_ALLOC_SIZE2(1,2); |
123 | GLIB_AVAILABLE_IN_2_72 |
124 | gpointer g_aligned_alloc0 (gsize n_blocks, |
125 | gsize n_block_bytes, |
126 | gsize alignment) G_GNUC_WARN_UNUSED_RESULT G_GNUC_ALLOC_SIZE2(1,2); |
127 | GLIB_AVAILABLE_IN_2_72 |
128 | void g_aligned_free (gpointer mem); |
129 | GLIB_AVAILABLE_IN_2_76 |
130 | void g_aligned_free_sized (gpointer mem, |
131 | size_t alignment, |
132 | size_t size); |
133 | |
134 | #if defined(glib_typeof) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_58 |
135 | #define g_clear_pointer(pp, destroy) \ |
136 | G_STMT_START \ |
137 | { \ |
138 | G_STATIC_ASSERT (sizeof *(pp) == sizeof (gpointer)); \ |
139 | glib_typeof ((pp)) _pp = (pp); \ |
140 | glib_typeof (*(pp)) _ptr = *_pp; \ |
141 | *_pp = NULL; \ |
142 | if (_ptr) \ |
143 | (destroy) (_ptr); \ |
144 | } \ |
145 | G_STMT_END \ |
146 | GLIB_AVAILABLE_MACRO_IN_2_34 |
147 | #else /* __GNUC__ */ |
148 | #define g_clear_pointer(pp, destroy) \ |
149 | G_STMT_START { \ |
150 | G_STATIC_ASSERT (sizeof *(pp) == sizeof (gpointer)); \ |
151 | /* Only one access, please; work around type aliasing */ \ |
152 | union { char *in; gpointer *out; } _pp; \ |
153 | gpointer _p; \ |
154 | /* This assignment is needed to avoid a gcc warning */ \ |
155 | GDestroyNotify _destroy = (GDestroyNotify) (destroy); \ |
156 | \ |
157 | _pp.in = (char *) (pp); \ |
158 | _p = *_pp.out; \ |
159 | if (_p) \ |
160 | { \ |
161 | *_pp.out = NULL; \ |
162 | _destroy (_p); \ |
163 | } \ |
164 | } G_STMT_END \ |
165 | GLIB_AVAILABLE_MACRO_IN_2_34 |
166 | #endif /* __GNUC__ */ |
167 | |
168 | |
169 | #if G_GNUC_CHECK_VERSION (4, 1) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_78 && defined(G_HAVE_FREE_SIZED) |
170 | |
171 | #define g_free(mem) \ |
172 | (__builtin_object_size ((mem), 0) != ((size_t) - 1)) ? \ |
173 | g_free_sized (mem, __builtin_object_size ((mem), 0)) : (g_free) (mem) |
174 | |
175 | #endif /* G_GNUC_CHECK_VERSION (4, 1) && && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_78 && defined(G_HAVE_FREE_SIZED) */ |
176 | |
177 | /** |
178 | * g_steal_pointer: |
179 | * @pp: (not nullable): a pointer to a pointer |
180 | * |
181 | * Sets @pp to %NULL, returning the value that was there before. |
182 | * |
183 | * Conceptually, this transfers the ownership of the pointer from the |
184 | * referenced variable to the "caller" of the macro (ie: "steals" the |
185 | * reference). |
186 | * |
187 | * The return value will be properly typed, according to the type of |
188 | * @pp. |
189 | * |
190 | * This can be very useful when combined with g_autoptr() to prevent the |
191 | * return value of a function from being automatically freed. Consider |
192 | * the following example (which only works on GCC and clang): |
193 | * |
194 | * |[ |
195 | * GObject * |
196 | * create_object (void) |
197 | * { |
198 | * g_autoptr(GObject) obj = g_object_new (G_TYPE_OBJECT, NULL); |
199 | * |
200 | * if (early_error_case) |
201 | * return NULL; |
202 | * |
203 | * return g_steal_pointer (&obj); |
204 | * } |
205 | * ]| |
206 | * |
207 | * It can also be used in similar ways for 'out' parameters and is |
208 | * particularly useful for dealing with optional out parameters: |
209 | * |
210 | * |[ |
211 | * gboolean |
212 | * get_object (GObject **obj_out) |
213 | * { |
214 | * g_autoptr(GObject) obj = g_object_new (G_TYPE_OBJECT, NULL); |
215 | * |
216 | * if (early_error_case) |
217 | * return FALSE; |
218 | * |
219 | * if (obj_out) |
220 | * *obj_out = g_steal_pointer (&obj); |
221 | * |
222 | * return TRUE; |
223 | * } |
224 | * ]| |
225 | * |
226 | * In the above example, the object will be automatically freed in the |
227 | * early error case and also in the case that %NULL was given for |
228 | * @obj_out. |
229 | * |
230 | * Since: 2.44 |
231 | */ |
232 | GLIB_AVAILABLE_STATIC_INLINE_IN_2_44 |
233 | static inline gpointer |
234 | g_steal_pointer (gpointer pp) |
235 | { |
236 | gpointer *ptr = (gpointer *) pp; |
237 | gpointer ref; |
238 | |
239 | ref = *ptr; |
240 | *ptr = NULL; |
241 | |
242 | return ref; |
243 | } |
244 | |
245 | /* type safety */ |
246 | #if defined(glib_typeof) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_58 |
247 | #define g_steal_pointer(pp) ((glib_typeof (*pp)) (g_steal_pointer) (pp)) |
248 | #else /* __GNUC__ */ |
249 | /* This version does not depend on gcc extensions, but gcc does not warn |
250 | * about incompatible-pointer-types: */ |
251 | #define g_steal_pointer(pp) \ |
252 | (0 ? (*(pp)) : (g_steal_pointer) (pp)) |
253 | #endif /* __GNUC__ */ |
254 | |
255 | /* Optimise: avoid the call to the (slower) _n function if we can |
256 | * determine at compile-time that no overflow happens. |
257 | */ |
258 | #if defined (__GNUC__) && (__GNUC__ >= 2) && defined (__OPTIMIZE__) |
259 | # define _G_NEW(struct_type, n_structs, func) \ |
260 | (struct_type *) (G_GNUC_EXTENSION ({ \ |
261 | gsize __n = (gsize) (n_structs); \ |
262 | gsize __s = sizeof (struct_type); \ |
263 | gpointer __p; \ |
264 | if (__s == 1) \ |
265 | __p = g_##func (__n); \ |
266 | else if (__builtin_constant_p (__n) && \ |
267 | (__s == 0 || __n <= G_MAXSIZE / __s)) \ |
268 | __p = g_##func (__n * __s); \ |
269 | else \ |
270 | __p = g_##func##_n (__n, __s); \ |
271 | __p; \ |
272 | })) |
273 | # define _G_RENEW(struct_type, mem, n_structs, func) \ |
274 | (struct_type *) (G_GNUC_EXTENSION ({ \ |
275 | gsize __n = (gsize) (n_structs); \ |
276 | gsize __s = sizeof (struct_type); \ |
277 | gpointer __p = (gpointer) (mem); \ |
278 | if (__s == 1) \ |
279 | __p = g_##func (__p, __n); \ |
280 | else if (__builtin_constant_p (__n) && \ |
281 | (__s == 0 || __n <= G_MAXSIZE / __s)) \ |
282 | __p = g_##func (__p, __n * __s); \ |
283 | else \ |
284 | __p = g_##func##_n (__p, __n, __s); \ |
285 | __p; \ |
286 | })) |
287 | |
288 | #else |
289 | |
290 | /* Unoptimised version: always call the _n() function. */ |
291 | |
292 | #define _G_NEW(struct_type, n_structs, func) \ |
293 | ((struct_type *) g_##func##_n ((n_structs), sizeof (struct_type))) |
294 | #define _G_RENEW(struct_type, mem, n_structs, func) \ |
295 | ((struct_type *) g_##func##_n (mem, (n_structs), sizeof (struct_type))) |
296 | |
297 | #endif |
298 | |
299 | /** |
300 | * g_new: |
301 | * @struct_type: the type of the elements to allocate |
302 | * @n_structs: the number of elements to allocate |
303 | * |
304 | * Allocates @n_structs elements of type @struct_type. |
305 | * The returned pointer is cast to a pointer to the given type. |
306 | * If @n_structs is 0 it returns %NULL. |
307 | * Care is taken to avoid overflow when calculating the size of the allocated block. |
308 | * |
309 | * Since the returned pointer is already casted to the right type, |
310 | * it is normally unnecessary to cast it explicitly, and doing |
311 | * so might hide memory allocation errors. |
312 | * |
313 | * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type |
314 | */ |
315 | #define g_new(struct_type, n_structs) _G_NEW (struct_type, n_structs, malloc) |
316 | /** |
317 | * g_new0: |
318 | * @struct_type: the type of the elements to allocate. |
319 | * @n_structs: the number of elements to allocate. |
320 | * |
321 | * Allocates @n_structs elements of type @struct_type, initialized to 0's. |
322 | * The returned pointer is cast to a pointer to the given type. |
323 | * If @n_structs is 0 it returns %NULL. |
324 | * Care is taken to avoid overflow when calculating the size of the allocated block. |
325 | * |
326 | * Since the returned pointer is already casted to the right type, |
327 | * it is normally unnecessary to cast it explicitly, and doing |
328 | * so might hide memory allocation errors. |
329 | * |
330 | * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type. |
331 | */ |
332 | #define g_new0(struct_type, n_structs) _G_NEW (struct_type, n_structs, malloc0) |
333 | /** |
334 | * g_renew: |
335 | * @struct_type: the type of the elements to allocate |
336 | * @mem: the currently allocated memory |
337 | * @n_structs: the number of elements to allocate |
338 | * |
339 | * Reallocates the memory pointed to by @mem, so that it now has space for |
340 | * @n_structs elements of type @struct_type. It returns the new address of |
341 | * the memory, which may have been moved. |
342 | * Care is taken to avoid overflow when calculating the size of the allocated block. |
343 | * |
344 | * Returns: a pointer to the new allocated memory, cast to a pointer to @struct_type |
345 | */ |
346 | #define g_renew(struct_type, mem, n_structs) _G_RENEW (struct_type, mem, n_structs, realloc) |
347 | /** |
348 | * g_try_new: |
349 | * @struct_type: the type of the elements to allocate |
350 | * @n_structs: the number of elements to allocate |
351 | * |
352 | * Attempts to allocate @n_structs elements of type @struct_type, and returns |
353 | * %NULL on failure. Contrast with g_new(), which aborts the program on failure. |
354 | * The returned pointer is cast to a pointer to the given type. |
355 | * The function returns %NULL when @n_structs is 0 of if an overflow occurs. |
356 | * |
357 | * Since: 2.8 |
358 | * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type |
359 | */ |
360 | #define g_try_new(struct_type, n_structs) _G_NEW (struct_type, n_structs, try_malloc) |
361 | /** |
362 | * g_try_new0: |
363 | * @struct_type: the type of the elements to allocate |
364 | * @n_structs: the number of elements to allocate |
365 | * |
366 | * Attempts to allocate @n_structs elements of type @struct_type, initialized |
367 | * to 0's, and returns %NULL on failure. Contrast with g_new0(), which aborts |
368 | * the program on failure. |
369 | * The returned pointer is cast to a pointer to the given type. |
370 | * The function returns %NULL when @n_structs is 0 or if an overflow occurs. |
371 | * |
372 | * Since: 2.8 |
373 | * Returns: a pointer to the allocated memory, cast to a pointer to @struct_type |
374 | */ |
375 | #define g_try_new0(struct_type, n_structs) _G_NEW (struct_type, n_structs, try_malloc0) |
376 | /** |
377 | * g_try_renew: |
378 | * @struct_type: the type of the elements to allocate |
379 | * @mem: the currently allocated memory |
380 | * @n_structs: the number of elements to allocate |
381 | * |
382 | * Attempts to reallocate the memory pointed to by @mem, so that it now has |
383 | * space for @n_structs elements of type @struct_type, and returns %NULL on |
384 | * failure. Contrast with g_renew(), which aborts the program on failure. |
385 | * It returns the new address of the memory, which may have been moved. |
386 | * The function returns %NULL if an overflow occurs. |
387 | * |
388 | * Since: 2.8 |
389 | * Returns: a pointer to the new allocated memory, cast to a pointer to @struct_type |
390 | */ |
391 | #define g_try_renew(struct_type, mem, n_structs) _G_RENEW (struct_type, mem, n_structs, try_realloc) |
392 | |
393 | |
394 | /* Memory allocation virtualization for debugging purposes |
395 | * g_mem_set_vtable() has to be the very first GLib function called |
396 | * if being used |
397 | */ |
398 | struct _GMemVTable { |
399 | gpointer (*malloc) (gsize n_bytes); |
400 | gpointer (*realloc) (gpointer mem, |
401 | gsize n_bytes); |
402 | void (*free) (gpointer mem); |
403 | /* optional; set to NULL if not used ! */ |
404 | gpointer (*calloc) (gsize n_blocks, |
405 | gsize n_block_bytes); |
406 | gpointer (*try_malloc) (gsize n_bytes); |
407 | gpointer (*try_realloc) (gpointer mem, |
408 | gsize n_bytes); |
409 | }; |
410 | GLIB_DEPRECATED_IN_2_46 |
411 | void g_mem_set_vtable (GMemVTable *vtable); |
412 | GLIB_DEPRECATED_IN_2_46 |
413 | gboolean g_mem_is_system_malloc (void); |
414 | |
415 | GLIB_VAR gboolean g_mem_gc_friendly; |
416 | |
417 | /* Memory profiler and checker, has to be enabled via g_mem_set_vtable() |
418 | */ |
419 | GLIB_VAR GMemVTable *glib_mem_profiler_table; |
420 | GLIB_DEPRECATED_IN_2_46 |
421 | void g_mem_profile (void); |
422 | |
423 | G_END_DECLS |
424 | |
425 | #endif /* __G_MEM_H__ */ |
426 | |