FD.io VPP  v20.01-9-g24064d02a
Vector Packet Processing
vec_bootstrap.h
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2015 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 /*
16  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus
17 
18  Permission is hereby granted, free of charge, to any person obtaining
19  a copy of this software and associated documentation files (the
20  "Software"), to deal in the Software without restriction, including
21  without limitation the rights to use, copy, modify, merge, publish,
22  distribute, sublicense, and/or sell copies of the Software, and to
23  permit persons to whom the Software is furnished to do so, subject to
24  the following conditions:
25 
26  The above copyright notice and this permission notice shall be
27  included in all copies or substantial portions of the Software.
28 
29  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
30  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
31  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
32  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
33  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
34  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
35  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
36 */
37 
38 #ifndef included_clib_vec_bootstrap_h
39 #define included_clib_vec_bootstrap_h
40 
41 /** \file
42  Vector bootstrap header file
43 */
44 
45 /* Bootstrap include so that #include <vppinfra/mem.h> can include e.g.
46  <vppinfra/mheap.h> which depends on <vppinfra/vec.h>. */
47 
48 /** \brief vector header structure
49 
50  Bookkeeping header preceding vector elements in memory.
51  User header information may preceed standard vec header.
52  If you change u32 len -> u64 len, single vectors can
53  exceed 2**32 elements. Clib heaps are vectors. */
54 
55 typedef struct
56 {
57 #if CLIB_VEC64 > 0
58  u64 len;
59 #else
60  u32 len; /**< Number of elements in vector (NOT its allocated length). */
61  u32 dlmalloc_header_offset; /**< offset to memory allocator offset */
62 #endif
63  u8 vector_data[0]; /**< Vector data . */
64 } vec_header_t;
65 
66 /** \brief Find the vector header
67 
68  Given the user's pointer to a vector, find the corresponding
69  vector header
70 
71  @param v pointer to a vector
72  @return pointer to the vector's vector_header_t
73 */
74 #define _vec_find(v) ((vec_header_t *) (v) - 1)
75 
76 #define _vec_round_size(s) \
77  (((s) + sizeof (uword) - 1) &~ (sizeof (uword) - 1))
78 
80 vec_header_bytes (uword header_bytes)
81 {
82  return round_pow2 (header_bytes + sizeof (vec_header_t),
83  sizeof (vec_header_t));
84 }
85 
86 /** \brief Find a user vector header
87 
88  Finds the user header of a vector with unspecified alignment given
89  the user pointer to the vector.
90 */
91 
92 always_inline void *
93 vec_header (void *v, uword header_bytes)
94 {
95  return v - vec_header_bytes (header_bytes);
96 }
97 
98 /** \brief Find the end of user vector header
99 
100  Finds the end of the user header of a vector with unspecified
101  alignment given the user pointer to the vector.
102 */
103 
104 always_inline void *
105 vec_header_end (void *v, uword header_bytes)
106 {
107  return v + vec_header_bytes (header_bytes);
108 }
109 
111 vec_aligned_header_bytes (uword header_bytes, uword align)
112 {
113  return round_pow2 (header_bytes + sizeof (vec_header_t), align);
114 }
115 
116 always_inline void *
117 vec_aligned_header (void *v, uword header_bytes, uword align)
118 {
119  return v - vec_aligned_header_bytes (header_bytes, align);
120 }
121 
122 always_inline void *
123 vec_aligned_header_end (void *v, uword header_bytes, uword align)
124 {
125  return v + vec_aligned_header_bytes (header_bytes, align);
126 }
127 
128 
129 /** \brief Number of elements in vector (lvalue-capable)
130 
131  _vec_len (v) does not check for null, but can be used as a lvalue
132  (e.g. _vec_len (v) = 99).
133 */
134 
135 #define _vec_len(v) (_vec_find(v)->len)
136 
137 /** \brief Number of elements in vector (rvalue-only, NULL tolerant)
138 
139  vec_len (v) checks for NULL, but cannot be used as an lvalue.
140  If in doubt, use vec_len...
141 */
142 
143 #define vec_len(v) ((v) ? _vec_len(v) : 0)
144 
145 /** \brief Number of data bytes in vector. */
146 
147 #define vec_bytes(v) (vec_len (v) * sizeof (v[0]))
148 
149 /** \brief Total number of bytes that can fit in vector with current allocation. */
150 
151 #define vec_capacity(v,b) \
152 ({ \
153  void * _vec_capacity_v = (void *) (v); \
154  uword _vec_capacity_b = (b); \
155  _vec_capacity_b = sizeof (vec_header_t) + _vec_round_size (_vec_capacity_b); \
156  _vec_capacity_v ? clib_mem_size (_vec_capacity_v - _vec_capacity_b) : 0; \
157 })
158 
159 /** \brief Total number of elements that can fit into vector. */
160 #define vec_max_len(v) (vec_capacity(v,0) / sizeof (v[0]))
161 
162 /** \brief Set vector length to a user-defined value */
163 #ifndef __COVERITY__ /* Coverity gets confused by ASSERT() */
164 #define vec_set_len(v, l) do { \
165  ASSERT(v); \
166  ASSERT((l) <= vec_max_len(v)); \
167  CLIB_MEM_POISON_LEN((void *)(v), _vec_len(v) * sizeof((v)[0]), (l) * sizeof((v)[0])); \
168  _vec_len(v) = (l); \
169 } while (0)
170 #else /* __COVERITY__ */
171 #define vec_set_len(v, l) do { \
172  _vec_len(v) = (l); \
173 } while (0)
174 #endif /* __COVERITY__ */
175 
176 /** \brief Reset vector length to zero
177  NULL-pointer tolerant
178 */
179 #define vec_reset_length(v) do { if (v) vec_set_len (v, 0); } while (0)
180 
181 /** \brief End (last data address) of vector. */
182 #define vec_end(v) ((v) + vec_len (v))
183 
184 /** \brief True if given pointer is within given vector. */
185 #define vec_is_member(v,e) ((e) >= (v) && (e) < vec_end (v))
186 
187 /** \brief Get vector value at index i checking that i is in bounds. */
188 #define vec_elt_at_index(v,i) \
189 ({ \
190  ASSERT ((i) < vec_len (v)); \
191  (v) + (i); \
192 })
193 
194 /** \brief Get vector value at index i */
195 #define vec_elt(v,i) (vec_elt_at_index(v,i))[0]
196 
197 /** \brief Vector iterator */
198 #define vec_foreach(var,vec) for (var = (vec); var < vec_end (vec); var++)
199 
200 /** \brief Vector iterator (reverse) */
201 #define vec_foreach_backwards(var,vec) \
202 for (var = vec_end (vec) - 1; var >= (vec); var--)
203 
204 /** \brief Iterate over vector indices. */
205 #define vec_foreach_index(var,v) for ((var) = 0; (var) < vec_len (v); (var)++)
206 
207 /** \brief Iterate over vector indices (reverse). */
208 #define vec_foreach_index_backwards(var,v) \
209  for ((var) = vec_len((v)) - 1; (var) >= 0; (var)--)
210 
211 #endif /* included_clib_vec_bootstrap_h */
212 
213 /*
214  * fd.io coding-style-patch-verification: ON
215  *
216  * Local Variables:
217  * eval: (c-set-style "gnu")
218  * End:
219  */
unsigned long u64
Definition: types.h:89
unsigned char u8
Definition: types.h:56
static uword vec_header_bytes(uword header_bytes)
Definition: vec_bootstrap.h:80
u32 dlmalloc_header_offset
offset to memory allocator offset
Definition: vec_bootstrap.h:61
unsigned int u32
Definition: types.h:88
static uword vec_aligned_header_bytes(uword header_bytes, uword align)
#define always_inline
Definition: ipsec.h:28
u8 len
Definition: ip_types.api:91
static void * vec_aligned_header(void *v, uword header_bytes, uword align)
static uword round_pow2(uword x, uword pow2)
Definition: clib.h:241
u32 len
Number of elements in vector (NOT its allocated length).
Definition: vec_bootstrap.h:60
vector header structure
Definition: vec_bootstrap.h:55
u64 uword
Definition: types.h:112
static void * vec_aligned_header_end(void *v, uword header_bytes, uword align)
static void * vec_header(void *v, uword header_bytes)
Find a user vector header.
Definition: vec_bootstrap.h:93
static void * vec_header_end(void *v, uword header_bytes)
Find the end of user vector header.