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 #include "libcoap.h"
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 #ifdef HAVE_LIBTINYDTLS
42 COAP_DTLS_SESSION,
43 #endif
44 COAP_SESSION,
45 COAP_OPTLIST,
46 } coap_memory_tag_t;
47
48 #ifndef WITH_LWIP
49
50 /**
51 * Allocates a chunk of @p size bytes and returns a pointer to the newly
52 * allocated memory. The @p type is used to select the appropriate storage
53 * container on constrained devices. The storage allocated by coap_malloc_type()
54 * must be released with coap_free_type().
55 *
56 * @param type The type of object to be stored.
57 * @param size The number of bytes requested.
58 * @return A pointer to the allocated storage or @c NULL on error.
59 */
60 void *coap_malloc_type(coap_memory_tag_t type, size_t size);
61
62 /**
63 * Releases the memory that was allocated by coap_malloc_type(). The type tag @p
64 * type must be the same that was used for allocating the object pointed to by
65 * @p .
66 *
67 * @param type The type of the object to release.
68 * @param p A pointer to memory that was allocated by coap_malloc_type().
69 */
70 void coap_free_type(coap_memory_tag_t type, void *p);
71
72 /**
73 * Wrapper function to coap_malloc_type() for backwards compatibility.
74 */
coap_malloc(size_t size)75 COAP_STATIC_INLINE void *coap_malloc(size_t size) {
76 return coap_malloc_type(COAP_STRING, size);
77 }
78
79 /**
80 * Wrapper function to coap_free_type() for backwards compatibility.
81 */
coap_free(void * object)82 COAP_STATIC_INLINE void coap_free(void *object) {
83 coap_free_type(COAP_STRING, object);
84 }
85
86 #endif /* not WITH_LWIP */
87
88 #ifdef WITH_LWIP
89
90 #include <lwip/memp.h>
91 #include <lwip/mem.h>
92
93 /* no initialization needed with lwip (or, more precisely: lwip must be
94 * completely initialized anyway by the time coap gets active) */
coap_memory_init(void)95 COAP_STATIC_INLINE void coap_memory_init(void) {}
96
97 /* It would be nice to check that size equals the size given at the memp
98 * declaration, but i currently don't see a standard way to check that without
99 * sourcing the custom memp pools and becoming dependent of its syntax
100 */
101 #define coap_malloc_type(type, size) memp_malloc(MEMP_ ## type)
102 #define coap_free_type(type, p) memp_free(MEMP_ ## type, p)
103
104 /* Those are just here to make uri.c happy where string allocation has not been
105 * made conditional.
106 */
coap_malloc(size_t size)107 COAP_STATIC_INLINE void *coap_malloc(size_t size) {
108 LWIP_ASSERT("coap_malloc must not be used in lwIP", 0);
109 return mem_malloc(size);
110 }
111
coap_free(void * pointer)112 COAP_STATIC_INLINE void coap_free(void *pointer) {
113 LWIP_ASSERT("coap_free must not be used in lwIP", 0);
114 mem_free(pointer);
115 }
116
117 #endif /* WITH_LWIP */
118
119 #endif /* COAP_MEM_H_ */
120