FD.io VPP  v19.08.2-294-g37e99c22d
Vector Packet Processing
vec_bootstrap.h
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1 /*
2  * Copyright (c) 2015 Cisco and/or its affiliates.
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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
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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  _vec_len(v) = (l); \
168 } while (0)
169 #else /* __COVERITY__ */
170 #define vec_set_len(v, l) do { \
171  _vec_len(v) = (l); \
172 } while (0)
173 #endif /* __COVERITY__ */
174 
175 /** \brief Reset vector length to zero
176  NULL-pointer tolerant
177 */
178 #define vec_reset_length(v) do { if (v) vec_set_len (v, 0); } while (0)
179 
180 /** \brief End (last data address) of vector. */
181 #define vec_end(v) ((v) + vec_len (v))
182 
183 /** \brief True if given pointer is within given vector. */
184 #define vec_is_member(v,e) ((e) >= (v) && (e) < vec_end (v))
185 
186 /** \brief Get vector value at index i checking that i is in bounds. */
187 #define vec_elt_at_index(v,i) \
188 ({ \
189  ASSERT ((i) < vec_len (v)); \
190  (v) + (i); \
191 })
192 
193 /** \brief Get vector value at index i */
194 #define vec_elt(v,i) (vec_elt_at_index(v,i))[0]
195 
196 /** \brief Vector iterator */
197 #define vec_foreach(var,vec) for (var = (vec); var < vec_end (vec); var++)
198 
199 /** \brief Vector iterator (reverse) */
200 #define vec_foreach_backwards(var,vec) \
201 for (var = vec_end (vec) - 1; var >= (vec); var--)
202 
203 /** \brief Iterate over vector indices. */
204 #define vec_foreach_index(var,v) for ((var) = 0; (var) < vec_len (v); (var)++)
205 
206 /** \brief Iterate over vector indices (reverse). */
207 #define vec_foreach_index_backwards(var,v) \
208  for ((var) = vec_len((v)) - 1; (var) >= 0; (var)--)
209 
210 #endif /* included_clib_vec_bootstrap_h */
211 
212 /*
213  * fd.io coding-style-patch-verification: ON
214  *
215  * Local Variables:
216  * eval: (c-set-style "gnu")
217  * End:
218  */
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
#define always_inline
Definition: clib.h:99
unsigned int u32
Definition: types.h:88
static uword vec_aligned_header_bytes(uword header_bytes, uword align)
u8 len
Definition: ip_types.api:90
static void * vec_aligned_header(void *v, uword header_bytes, uword align)
static uword round_pow2(uword x, uword pow2)
Definition: clib.h:248
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.