1 /*
2 * mem.h -- CoAP memory handling
3 *
4 * Copyright (C) 2010-2011,2014-2015 Olaf Bergmann <bergmann@tzi.org>
5 *
6 * This file is part of the CoAP library libcoap. Please see README for terms
7 * of use.
8 */
9
10 #ifndef _COAP_MEM_H_
11 #define _COAP_MEM_H_
12
13 #include <stdlib.h>
14
15 #ifndef WITH_LWIP
16 /**
17 * Initializes libcoap's memory management.
18 * This function must be called once before coap_malloc() can be used on
19 * constrained devices.
20 */
21 void coap_memory_init(void);
22 #endif /* WITH_LWIP */
23
24 /**
25 * Type specifiers for coap_malloc_type(). Memory objects can be typed to
26 * facilitate arrays of type objects to be used instead of dynamic memory
27 * management on constrained devices.
28 */
29 typedef enum {
30 COAP_STRING,
31 COAP_ATTRIBUTE_NAME,
32 COAP_ATTRIBUTE_VALUE,
33 COAP_PACKET,
34 COAP_NODE,
35 COAP_CONTEXT,
36 COAP_ENDPOINT,
37 COAP_PDU,
38 COAP_PDU_BUF,
39 COAP_RESOURCE,
40 COAP_RESOURCEATTR
41 } coap_memory_tag_t;
42
43 #ifndef WITH_LWIP
44
45 /**
46 * Allocates a chunk of @p size bytes and returns a pointer to the newly
47 * allocated memory. The @p type is used to select the appropriate storage
48 * container on constrained devices. The storage allocated by coap_malloc_type()
49 * must be released with coap_free_type().
50 *
51 * @param type The type of object to be stored.
52 * @param size The number of bytes requested.
53 * @return A pointer to the allocated storage or @c NULL on error.
54 */
55 void *coap_malloc_type(coap_memory_tag_t type, size_t size);
56
57 /**
58 * Releases the memory that was allocated by coap_malloc_type(). The type tag @p
59 * type must be the same that was used for allocating the object pointed to by
60 * @p .
61 *
62 * @param type The type of the object to release.
63 * @param p A pointer to memory that was allocated by coap_malloc_type().
64 */
65 void coap_free_type(coap_memory_tag_t type, void *p);
66
67 /**
68 * Wrapper function to coap_malloc_type() for backwards compatibility.
69 */
coap_malloc(size_t size)70 static inline void *coap_malloc(size_t size) {
71 return coap_malloc_type(COAP_STRING, size);
72 }
73
74 /**
75 * Wrapper function to coap_free_type() for backwards compatibility.
76 */
coap_free(void * object)77 static inline void coap_free(void *object) {
78 coap_free_type(COAP_STRING, object);
79 }
80
81 #endif /* not WITH_LWIP */
82
83 #ifdef WITH_LWIP
84
85 #include <lwip/memp.h>
86
87 /* no initialization needed with lwip (or, more precisely: lwip must be
88 * completely initialized anyway by the time coap gets active) */
coap_memory_init(void)89 static inline void coap_memory_init(void) {}
90
91 /* It would be nice to check that size equals the size given at the memp
92 * declaration, but i currently don't see a standard way to check that without
93 * sourcing the custom memp pools and becoming dependent of its syntax
94 */
95 #define coap_malloc_type(type, size) memp_malloc(MEMP_ ## type)
96 #define coap_free_type(type, p) memp_free(MEMP_ ## type, p)
97
98 /* Those are just here to make uri.c happy where string allocation has not been
99 * made conditional.
100 */
coap_malloc(size_t size)101 static inline void *coap_malloc(size_t size) {
102 LWIP_ASSERT("coap_malloc must not be used in lwIP", 0);
103 }
104
coap_free(void * pointer)105 static inline void coap_free(void *pointer) {
106 LWIP_ASSERT("coap_free must not be used in lwIP", 0);
107 }
108
109 #endif /* WITH_LWIP */
110
111 #endif /* _COAP_MEM_H_ */
112
