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>
47 /* First index of valid data in fifo. */
50 /* One beyond last index in fifo. */
54 always_inline clib_fifo_header_t *
55 clib_fifo_header (void *f)
57 return vec_header (f);
61 #define clib_fifo_len(v) vec_len(v)
62 #define _clib_fifo_len(v) _vec_len(v)
63 #define clib_fifo_end(v) vec_end(v)
66 clib_fifo_elts (void *v)
69 clib_fifo_header_t *f = clib_fifo_header (v);
74 l = _clib_fifo_len (v);
75 r = (word) f->tail_index - (word) f->head_index;
76 r = r < 0 ? r + l : r;
77 ASSERT (r >= 0 && r <= l);
82 clib_fifo_free_elts (void *v)
84 return clib_fifo_len (v) - clib_fifo_elts (v);
88 clib_fifo_reset (void *v)
90 clib_fifo_header_t *f = clib_fifo_header (v);
93 f->head_index = f->tail_index = 0;
98 /* External resize function. */
99 void *_clib_fifo_resize (void *v, uword n_elts, uword align, uword elt_bytes);
101 #define clib_fifo_resize(f, n_elts) \
102 f = _clib_fifo_resize ((f), (n_elts), _vec_align (f, 0), _vec_elt_sz (f))
105 _clib_fifo_validate (void *v, uword n_elts, uword align, uword elt_bytes)
107 if (clib_fifo_free_elts (v) < n_elts)
108 v = _clib_fifo_resize (v, n_elts, align, elt_bytes);
112 #define clib_fifo_validate(f, n_elts) \
113 f = _clib_fifo_validate ((f), (n_elts), _vec_align (f, 0), _vec_elt_sz (f))
115 /* Advance tail pointer by N_ELTS which can be either positive or negative. */
117 _clib_fifo_advance_tail (void *v, word n_elts, uword align, uword elt_bytes,
121 clib_fifo_header_t *f;
123 n_free = clib_fifo_free_elts (v);
126 v = _clib_fifo_resize (v, n_elts, align, elt_bytes);
127 n_free = clib_fifo_free_elts (v);
130 ASSERT (n_free >= n_elts);
133 f = clib_fifo_header (v);
134 l = _clib_fifo_len (v);
139 /* Mark fifo full. */
140 f->tail_index = f->head_index + l;
144 word n = f->tail_index + n_elts;
149 ASSERT (n >= 0 && n < l);
153 ASSERT (clib_fifo_free_elts (v) == n_free);
156 *tail_return = n_elts > 0 ? i : f->tail_index;
161 #define clib_fifo_advance_tail(f, n_elts) \
164 (f) = _clib_fifo_advance_tail ((f), (n_elts), _vec_align (f, 0), \
165 _vec_elt_sz (f), &_i); \
170 clib_fifo_advance_head (void *v, uword n_elts)
172 clib_fifo_header_t *f;
175 ASSERT (clib_fifo_elts (v) >= n_elts);
176 f = clib_fifo_header (v);
177 l = _clib_fifo_len (v);
179 /* If fifo was full, restore tail pointer. */
180 if (f->tail_index == f->head_index + l)
181 f->tail_index = f->head_index;
183 n = i = f->head_index;
185 n = n >= l ? n - l : n;
192 /* Add given element to fifo. */
193 #define clib_fifo_add1(f, e) \
197 (f) = _clib_fifo_advance_tail ((f), 1, _vec_align (f, 0), \
198 _vec_elt_sz (f), &_i); \
203 /* Add element to fifo; return pointer to new element. */
204 #define clib_fifo_add2(f, p) \
208 (f) = _clib_fifo_advance_tail ((f), 1, _vec_align (f, 0), \
209 _vec_elt_sz (f), &_i); \
214 /* Add several elements to fifo. */
215 #define clib_fifo_add(f, e, n) \
222 (f) = _clib_fifo_advance_tail ((f), _n0, _vec_align (f, 0), \
223 _vec_elt_sz (f), &_i); \
224 _l = clib_fifo_len (f); \
225 _n1 = _i + _n0 - _l; \
226 _n1 = _n1 < 0 ? 0 : _n1; \
228 clib_memcpy_fast ((f) + _i, (e), _n0 * sizeof ((f)[0])); \
230 clib_memcpy_fast ((f) + 0, (e) + _n0, _n1 * sizeof ((f)[0])); \
234 /* Subtract element from fifo. */
235 #define clib_fifo_sub1(f,e) \
238 ASSERT (clib_fifo_elts (f) >= 1); \
239 _i = clib_fifo_advance_head ((f), 1); \
243 #define clib_fifo_sub2(f,p) \
246 ASSERT (clib_fifo_elts (f) >= 1); \
247 _i = clib_fifo_advance_head ((f), 1); \
252 clib_fifo_head_index (void *v)
254 clib_fifo_header_t *f = clib_fifo_header (v);
255 return v ? f->head_index : 0;
259 clib_fifo_tail_index (void *v)
261 clib_fifo_header_t *f = clib_fifo_header (v);
262 return v ? f->tail_index : 0;
265 #define clib_fifo_head(v) ((v) + clib_fifo_head_index (v))
266 #define clib_fifo_tail(v) ((v) + clib_fifo_tail_index (v))
268 #define clib_fifo_free(f) vec_free ((f))
271 clib_fifo_elt_index (void *v, uword i)
273 clib_fifo_header_t *f = clib_fifo_header (v);
276 ASSERT (i < clib_fifo_elts (v));
280 result = f->head_index + i;
281 if (result >= _vec_len (v))
282 result -= _vec_len (v);
288 #define clib_fifo_elt_at_index(v, i) ((v) + (i))
290 #define clib_fifo_foreach(v,f,body) \
294 _i = clib_fifo_head_index (f); \
295 _l = clib_fifo_len (f); \
296 _n = clib_fifo_elts (f); \
300 do { body; } while (0); \
303 _i = _i >= _l ? 0 : _i; \
307 #endif /* included_fifo_h */
310 * fd.io coding-style-patch-verification: ON
313 * eval: (c-set-style "gnu")