1 /*
2 * Allocation and free functions for aligned memory
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2 or later.
5 * See the COPYING file in the top-level directory.
6 */
7
8 #ifndef QEMU_MEMALIGN_H
9 #define QEMU_MEMALIGN_H
10
11 /**
12 * qemu_try_memalign: Allocate aligned memory
13 * @alignment: required alignment, in bytes
14 * @size: size of allocation, in bytes
15 *
16 * Allocate memory on an aligned boundary (i.e. the returned
17 * address will be an exact multiple of @alignment).
18 * @alignment must be a power of 2, or the function will assert().
19 * On success, returns allocated memory; on failure, returns NULL.
20 *
21 * The memory allocated through this function must be freed via
22 * qemu_vfree() (and not via free()).
23 */
24 void *qemu_try_memalign(size_t alignment, size_t size);
25 /**
26 * qemu_memalign: Allocate aligned memory, without failing
27 * @alignment: required alignment, in bytes
28 * @size: size of allocation, in bytes
29 *
30 * Allocate memory in the same way as qemu_try_memalign(), but
31 * abort() with an error message if the memory allocation fails.
32 *
33 * The memory allocated through this function must be freed via
34 * qemu_vfree() (and not via free()).
35 */
36 void *qemu_memalign(size_t alignment, size_t size);
37 /**
38 * qemu_vfree: Free memory allocated through qemu_memalign
39 * @ptr: memory to free
40 *
41 * This function must be used to free memory allocated via qemu_memalign()
42 * or qemu_try_memalign(). (Using the wrong free function will cause
43 * subtle bugs on Windows hosts.)
44 */
45 void qemu_vfree(void *ptr);
46 /*
47 * It's an analog of GLIB's g_autoptr_cleanup_generic_gfree(), used to define
48 * g_autofree macro.
49 */
qemu_cleanup_generic_vfree(void * p)50 static inline void qemu_cleanup_generic_vfree(void *p)
51 {
52 void **pp = (void **)p;
53 qemu_vfree(*pp);
54 }
55
56 /*
57 * Analog of g_autofree, but qemu_vfree is called on cleanup instead of g_free.
58 */
59 #define QEMU_AUTO_VFREE __attribute__((cleanup(qemu_cleanup_generic_vfree)))
60
61 #endif
62