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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
16 Copyright (c) 2005 Eliot Dresselhaus
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:
26 The above copyright notice and this permission notice shall be
27 included in all copies or substantial portions of the Software.
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.
38 #ifndef included_fifo_h
39 #define included_fifo_h
41 #include <vppinfra/cache.h>
42 #include <vppinfra/error.h> /* for ASSERT */
43 #include <vppinfra/vec.h>
46 /* First index of valid data in fifo. */
49 /* One beyond last index in fifo. */
53 always_inline clib_fifo_header_t *
54 clib_fifo_header (void * f)
55 { return vec_header (f, sizeof (clib_fifo_header_t)); }
58 #define clib_fifo_len(v) vec_len(v)
59 #define _clib_fifo_len(v) _vec_len(v)
60 #define clib_fifo_end(v) vec_end(v)
63 clib_fifo_elts (void * v)
66 clib_fifo_header_t * f = clib_fifo_header (v);
71 l = _clib_fifo_len (v);
72 r = (word) f->tail_index - (word) f->head_index;
73 r = r < 0 ? r + l : r;
74 ASSERT (r >= 0 && r <= l);
79 clib_fifo_free_elts (void * v)
80 { return clib_fifo_len (v) - clib_fifo_elts (v); }
83 clib_fifo_reset (void * v)
85 clib_fifo_header_t * f = clib_fifo_header (v);
88 f->head_index = f->tail_index = 0;
93 /* External resize function. */
94 void * _clib_fifo_resize (void * v, uword n_elts, uword elt_bytes);
96 #define clib_fifo_resize(f,n_elts) \
97 f = _clib_fifo_resize ((f), (n_elts), sizeof ((f)[0]))
100 _clib_fifo_validate (void * v, uword n_elts, uword elt_bytes)
102 if (clib_fifo_free_elts (v) < n_elts)
103 v = _clib_fifo_resize (v, n_elts, elt_bytes);
107 #define clib_fifo_validate(f,n_elts) \
108 f = _clib_fifo_validate ((f), (n_elts), sizeof (f[0]))
110 /* Advance tail pointer by N_ELTS which can be either positive or negative. */
112 _clib_fifo_advance_tail (void * v, word n_elts, uword elt_bytes,
116 clib_fifo_header_t * f;
118 n_free = clib_fifo_free_elts (v);
121 v = _clib_fifo_resize (v, n_elts, elt_bytes);
122 n_free = clib_fifo_free_elts (v);
125 ASSERT (n_free >= n_elts);
128 f = clib_fifo_header (v);
129 l = _clib_fifo_len (v);
134 /* Mark fifo full. */
135 f->tail_index = f->head_index + l;
139 word n = f->tail_index + n_elts;
144 ASSERT (n >= 0 && n < l);
148 ASSERT (clib_fifo_free_elts (v) == n_free);
151 *tail_return = n_elts > 0 ? i : f->tail_index;
156 #define clib_fifo_advance_tail(f,n_elts) \
159 (f) = _clib_fifo_advance_tail ((f), (n_elts), sizeof ((f)[0]), &_i); \
164 clib_fifo_advance_head (void * v, uword n_elts)
166 clib_fifo_header_t * f;
169 ASSERT (clib_fifo_elts (v) >= n_elts);
170 f = clib_fifo_header (v);
171 l = _clib_fifo_len (v);
173 /* If fifo was full, restore tail pointer. */
174 if (f->tail_index == f->head_index + l)
175 f->tail_index = f->head_index;
177 n = i = f->head_index;
179 n = n >= l ? n - l : n;
186 /* Add given element to fifo. */
187 #define clib_fifo_add1(f,e) \
190 (f) = _clib_fifo_advance_tail ((f), 1, sizeof ((f)[0]), &_i); \
194 /* Add element to fifo; return pointer to new element. */
195 #define clib_fifo_add2(f,p) \
198 (f) = _clib_fifo_advance_tail ((f), 1, sizeof ((f)[0]), &_i); \
202 /* Add several elements to fifo. */
203 #define clib_fifo_add(f,e,n) \
205 uword _i, _l; word _n0, _n1; \
208 (f) = _clib_fifo_advance_tail ((f), _n0, sizeof ((f)[0]), &_i); \
209 _l = clib_fifo_len (f); \
210 _n1 = _i + _n0 - _l; \
211 _n1 = _n1 < 0 ? 0 : _n1; \
213 memcpy ((f) + _i, (e), _n0 * sizeof ((f)[0])); \
215 memcpy ((f) + 0, (e) + _n0, _n1 * sizeof ((f)[0])); \
218 /* Subtract element from fifo. */
219 #define clib_fifo_sub1(f,e) \
222 ASSERT (clib_fifo_elts (f) >= 1); \
223 _i = clib_fifo_advance_head ((f), 1); \
227 #define clib_fifo_sub2(f,p) \
230 ASSERT (clib_fifo_elts (f) >= 1); \
231 _i = clib_fifo_advance_head ((f), 1); \
236 clib_fifo_head_index (void * v)
238 clib_fifo_header_t * f = clib_fifo_header (v);
239 return v ? f->head_index : 0;
243 clib_fifo_tail_index (void * v)
245 clib_fifo_header_t * f = clib_fifo_header (v);
246 return v ? f->tail_index : 0;
249 #define clib_fifo_head(v) ((v) + clib_fifo_head_index (v))
250 #define clib_fifo_tail(v) ((v) + clib_fifo_tail_index (v))
252 #define clib_fifo_free(f) vec_free_h((f),sizeof(clib_fifo_header_t))
255 clib_fifo_elt_index (void * v, uword i)
257 clib_fifo_header_t * f = clib_fifo_header (v);
260 ASSERT (i < clib_fifo_elts (v));
264 result = f->head_index + i;
265 if (result >= _vec_len (v))
266 result -= _vec_len (v);
272 #define clib_fifo_elt_at_index(v,i) ((v) + clib_fifo_elt_index (v, (i)))
274 #define clib_fifo_foreach(v,f,body) \
278 _i = clib_fifo_head_index (f); \
279 _l = clib_fifo_len (f); \
280 _n = clib_fifo_elts (f); \
284 do { body; } while (0); \
287 _i = _i >= _l ? 0 : _i; \
291 #endif /* included_fifo_h */