xref: /nrf52832-nimble/rt-thread/components/net/uip/lib/memb.h (revision 104654410c56c573564690304ae786df310c91fc)
1*10465441SEvalZero /*
2*10465441SEvalZero  * Copyright (c) 2004, Swedish Institute of Computer Science.
3*10465441SEvalZero  * All rights reserved.
4*10465441SEvalZero  *
5*10465441SEvalZero  * Redistribution and use in source and binary forms, with or without
6*10465441SEvalZero  * modification, are permitted provided that the following conditions
7*10465441SEvalZero  * are met:
8*10465441SEvalZero  * 1. Redistributions of source code must retain the above copyright
9*10465441SEvalZero  *    notice, this list of conditions and the following disclaimer.
10*10465441SEvalZero  * 2. Redistributions in binary form must reproduce the above copyright
11*10465441SEvalZero  *    notice, this list of conditions and the following disclaimer in the
12*10465441SEvalZero  *    documentation and/or other materials provided with the distribution.
13*10465441SEvalZero  * 3. Neither the name of the Institute nor the names of its contributors
14*10465441SEvalZero  *    may be used to endorse or promote products derived from this software
15*10465441SEvalZero  *    without specific prior written permission.
16*10465441SEvalZero  *
17*10465441SEvalZero  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18*10465441SEvalZero  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*10465441SEvalZero  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*10465441SEvalZero  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21*10465441SEvalZero  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*10465441SEvalZero  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*10465441SEvalZero  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*10465441SEvalZero  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*10465441SEvalZero  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*10465441SEvalZero  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*10465441SEvalZero  * SUCH DAMAGE.
28*10465441SEvalZero  *
29*10465441SEvalZero  * This file is part of the uIP TCP/IP stack
30*10465441SEvalZero  *
31*10465441SEvalZero  * Author: Adam Dunkels <[email protected]>
32*10465441SEvalZero  *
33*10465441SEvalZero  * $Id: memb.h,v 1.1 2006/06/12 08:21:43 adam Exp $
34*10465441SEvalZero  */
35*10465441SEvalZero 
36*10465441SEvalZero /**
37*10465441SEvalZero  * \defgroup memb Memory block management functions
38*10465441SEvalZero  *
39*10465441SEvalZero  * The memory block allocation routines provide a simple yet powerful
40*10465441SEvalZero  * set of functions for managing a set of memory blocks of fixed
41*10465441SEvalZero  * size. A set of memory blocks is statically declared with the
42*10465441SEvalZero  * MEMB() macro. Memory blocks are allocated from the declared
43*10465441SEvalZero  * memory by the memb_alloc() function, and are deallocated with the
44*10465441SEvalZero  * memb_free() function.
45*10465441SEvalZero  *
46*10465441SEvalZero  * \note Because of namespace clashes only one MEMB() can be
47*10465441SEvalZero  * declared per C module, and the name scope of a MEMB() memory
48*10465441SEvalZero  * block is local to each C module.
49*10465441SEvalZero  *
50*10465441SEvalZero  * The following example shows how to declare and use a memory block
51*10465441SEvalZero  * called "cmem" which has 8 chunks of memory with each memory chunk
52*10465441SEvalZero  * being 20 bytes large.
53*10465441SEvalZero  *
54*10465441SEvalZero  * @{
55*10465441SEvalZero  */
56*10465441SEvalZero 
57*10465441SEvalZero 
58*10465441SEvalZero /**
59*10465441SEvalZero  * \file
60*10465441SEvalZero  *         Memory block allocation routines.
61*10465441SEvalZero  * \author
62*10465441SEvalZero  *         Adam Dunkels <[email protected]>
63*10465441SEvalZero  *
64*10465441SEvalZero  */
65*10465441SEvalZero 
66*10465441SEvalZero #ifndef __MEMB_H__
67*10465441SEvalZero #define __MEMB_H__
68*10465441SEvalZero 
69*10465441SEvalZero /*
70*10465441SEvalZero  * Here we define a C preprocessing macro for concatenating to
71*10465441SEvalZero  * strings. We need use two macros in order to allow concatenation of
72*10465441SEvalZero  * two #defined macros.
73*10465441SEvalZero  */
74*10465441SEvalZero #define MEMB_CONCAT2(s1, s2) s1##s2
75*10465441SEvalZero #define MEMB_CONCAT(s1, s2) MEMB_CONCAT2(s1, s2)
76*10465441SEvalZero 
77*10465441SEvalZero /**
78*10465441SEvalZero  * Declare a memory block.
79*10465441SEvalZero  *
80*10465441SEvalZero  * This macro is used to staticall declare a block of memory that can
81*10465441SEvalZero  * be used by the block allocation functions. The macro statically
82*10465441SEvalZero  * declares a C array with a size that matches the specified number of
83*10465441SEvalZero  * blocks and their individual sizes.
84*10465441SEvalZero  *
85*10465441SEvalZero  * Example:
86*10465441SEvalZero  \code
87*10465441SEvalZero MEMB(connections, sizeof(struct connection), 16);
88*10465441SEvalZero  \endcode
89*10465441SEvalZero  *
90*10465441SEvalZero  * \param name The name of the memory block (later used with
91*10465441SEvalZero  * memb_init(), memb_alloc() and memb_free()).
92*10465441SEvalZero  *
93*10465441SEvalZero  * \param size The size of each memory chunk, in bytes.
94*10465441SEvalZero  *
95*10465441SEvalZero  * \param num The total number of memory chunks in the block.
96*10465441SEvalZero  *
97*10465441SEvalZero  */
98*10465441SEvalZero #define MEMB(name, structure, num) \
99*10465441SEvalZero         static char MEMB_CONCAT(name,_memb_count)[num]; \
100*10465441SEvalZero         static structure MEMB_CONCAT(name,_memb_mem)[num]; \
101*10465441SEvalZero         static struct memb_blocks name = {sizeof(structure), num, \
102*10465441SEvalZero                                           MEMB_CONCAT(name,_memb_count), \
103*10465441SEvalZero                                           (void *)MEMB_CONCAT(name,_memb_mem)}
104*10465441SEvalZero 
105*10465441SEvalZero struct memb_blocks {
106*10465441SEvalZero   unsigned short size;
107*10465441SEvalZero   unsigned short num;
108*10465441SEvalZero   char *count;
109*10465441SEvalZero   void *mem;
110*10465441SEvalZero };
111*10465441SEvalZero 
112*10465441SEvalZero /**
113*10465441SEvalZero  * Initialize a memory block that was declared with MEMB().
114*10465441SEvalZero  *
115*10465441SEvalZero  * \param m A memory block previosly declared with MEMB().
116*10465441SEvalZero  */
117*10465441SEvalZero void  memb_init(struct memb_blocks *m);
118*10465441SEvalZero 
119*10465441SEvalZero /**
120*10465441SEvalZero  * Allocate a memory block from a block of memory declared with MEMB().
121*10465441SEvalZero  *
122*10465441SEvalZero  * \param m A memory block previosly declared with MEMB().
123*10465441SEvalZero  */
124*10465441SEvalZero void *memb_alloc(struct memb_blocks *m);
125*10465441SEvalZero 
126*10465441SEvalZero /**
127*10465441SEvalZero  * Deallocate a memory block from a memory block previously declared
128*10465441SEvalZero  * with MEMB().
129*10465441SEvalZero  *
130*10465441SEvalZero  * \param m m A memory block previosly declared with MEMB().
131*10465441SEvalZero  *
132*10465441SEvalZero  * \param ptr A pointer to the memory block that is to be deallocated.
133*10465441SEvalZero  *
134*10465441SEvalZero  * \return The new reference count for the memory block (should be 0
135*10465441SEvalZero  * if successfully deallocated) or -1 if the pointer "ptr" did not
136*10465441SEvalZero  * point to a legal memory block.
137*10465441SEvalZero  */
138*10465441SEvalZero char  memb_free(struct memb_blocks *m, void *ptr);
139*10465441SEvalZero 
140*10465441SEvalZero /** @} */
141*10465441SEvalZero 
142*10465441SEvalZero #endif /* __MEMB_H__ */
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