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) 2001, 2002, 2003, 2004 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_pool_h
39 #define included_pool_h
41 #include <vppinfra/bitmap.h>
42 #include <vppinfra/error.h>
43 #include <vppinfra/mheap.h>
45 /* Pools are built from clib vectors and bitmaps. Use pools when
46 repeatedly allocating and freeing fixed-size data. Pools are
47 fast, and avoid memory fragmentation. */
50 /* Bitmap of indices of free objects. */
53 /* Vector of free indices. One element for each set bit in bitmap. */
57 /* Align pool header so that pointers are naturally aligned. */
58 #define pool_aligned_header_bytes \
59 vec_aligned_header_bytes (sizeof (pool_header_t), sizeof (void *))
61 /* Get pool header from user pool pointer */
62 always_inline pool_header_t * pool_header (void * v)
63 { return vec_aligned_header (v, sizeof (pool_header_t), sizeof (void *)); }
66 always_inline void pool_validate (void * v)
68 pool_header_t * p = pool_header (v);
69 uword i, n_free_bitmap;
74 n_free_bitmap = clib_bitmap_count_set_bits (p->free_bitmap);
75 ASSERT (n_free_bitmap == vec_len (p->free_indices));
76 for (i = 0; i < vec_len (p->free_indices); i++)
77 ASSERT (clib_bitmap_get (p->free_bitmap, p->free_indices[i]) == 1);
80 always_inline void pool_header_validate_index (void * v, uword index)
82 pool_header_t * p = pool_header (v);
85 vec_validate (p->free_bitmap, index / BITS (uword));
88 #define pool_validate_index(v,i) \
90 uword __pool_validate_index = (i); \
91 vec_validate_ha ((v), __pool_validate_index, \
92 pool_aligned_header_bytes, /* align */ 0); \
93 pool_header_validate_index ((v), __pool_validate_index); \
96 /* Number of active elements in a pool */
97 always_inline uword pool_elts (void * v)
99 uword ret = vec_len (v);
101 ret -= vec_len (pool_header (v)->free_indices);
105 /* Number of elements in pool vector
107 Note: you probably want to call pool_elts() instead
109 #define pool_len(p) vec_len(p)
110 /* Number of elements in pool vector (usable as an lvalue)
112 Note: you probably don't want to use this macro
114 #define _pool_len(p) _vec_len(p)
116 /*Memory usage of pool header */
118 pool_header_bytes (void * v)
120 pool_header_t * p = pool_header (v);
125 return vec_bytes (p->free_bitmap) + vec_bytes (p->free_indices);
128 /*Memory usage of pool */
129 #define pool_bytes(P) (vec_bytes (P) + pool_header_bytes (P))
131 /*Local variable naming macro. */
132 #define _pool_var(v) _pool_##v
134 /*Queries whether pool has at least N_FREE free elements. */
136 pool_free_elts (void * v)
138 pool_header_t * p = pool_header (v);
142 n_free += vec_len (p->free_indices);
144 /* Space left at end of vector? */
145 n_free += vec_capacity (v, sizeof (p[0])) - vec_len (v);
151 /* Allocate an object E from a pool P (general version)
153 First search free list. If nothing is free extend vector of objects
155 #define pool_get_aligned(P,E,A) \
157 pool_header_t * _pool_var (p) = pool_header (P); \
158 uword _pool_var (l); \
162 _pool_var (l) = vec_len (_pool_var (p)->free_indices); \
164 if (_pool_var (l) > 0) \
166 /* Return free element from free list. */ \
167 uword _pool_var (i) = _pool_var (p)->free_indices[_pool_var (l) - 1]; \
168 (E) = (P) + _pool_var (i); \
169 _pool_var (p)->free_bitmap = \
170 clib_bitmap_andnoti (_pool_var (p)->free_bitmap, _pool_var (i)); \
171 _vec_len (_pool_var (p)->free_indices) = _pool_var (l) - 1; \
175 /* Nothing on free list, make a new element and return it. */ \
176 P = _vec_resize (P, \
177 /* length_increment */ 1, \
178 /* new size */ (vec_len (P) + 1) * sizeof (P[0]), \
179 pool_aligned_header_bytes, \
181 E = vec_end (P) - 1; \
185 /* Allocate an object E from a pool P (unspecified alignment) */
186 #define pool_get(P,E) pool_get_aligned(P,E,0)
188 /* Use free bitmap to query whether given element is free */
189 #define pool_is_free(P,E) \
191 pool_header_t * _pool_var (p) = pool_header (P); \
192 uword _pool_var (i) = (E) - (P); \
193 (_pool_var (i) < vec_len (P)) ? clib_bitmap_get (_pool_var (p)->free_bitmap, _pool_i) : 1; \
196 /* Use free bitmap to query whether given index is free */
197 #define pool_is_free_index(P,I) pool_is_free((P),(P)+(I))
199 /* Free an object E in pool P */
200 #define pool_put(P,E) \
202 pool_header_t * _pool_var (p) = pool_header (P); \
203 uword _pool_var (l) = (E) - (P); \
204 ASSERT (vec_is_member (P, E)); \
205 ASSERT (! pool_is_free (P, E)); \
207 /* Add element to free bitmap and to free list. */ \
208 _pool_var (p)->free_bitmap = \
209 clib_bitmap_ori (_pool_var (p)->free_bitmap, _pool_var (l)); \
210 vec_add1 (_pool_var (p)->free_indices, _pool_var (l)); \
213 /* Free pool element with given index. */
214 #define pool_put_index(p,i) \
216 typeof (p) _e = (p) + (i); \
220 /* Allocate N more free elements to pool (general version) */
221 #define pool_alloc_aligned(P,N,A) \
223 pool_header_t * _p; \
224 (P) = _vec_resize ((P), 0, (vec_len (P) + (N)) * sizeof (P[0]), \
225 pool_aligned_header_bytes, \
227 _p = pool_header (P); \
228 vec_resize (_p->free_indices, (N)); \
229 _vec_len (_p->free_indices) -= (N); \
232 /* Allocate N more free elements to pool (unspecified alignment) */
233 #define pool_alloc(P,N) pool_alloc_aligned(P,N,0)
235 /* low-level free pool operator (do not call directly) */
236 always_inline void * _pool_free (void * v)
238 pool_header_t * p = pool_header (v);
241 clib_bitmap_free (p->free_bitmap);
242 vec_free (p->free_indices);
243 vec_free_h (v, pool_aligned_header_bytes);
248 #define pool_free(p) (p) = _pool_free(p)
250 /* Optimized iteration through pool
252 @param LO pointer to first element in chunk
253 @param HI pointer to last element in chunk
254 @param POOL pool to iterate across
255 @param BODY operation to perform
257 Optimized version which assumes that BODY is smart enough to
258 process multiple (LOW,HI) chunks. See also pool_foreach().
260 #define pool_foreach_region(LO,HI,POOL,BODY) \
262 uword _pool_var (i), _pool_var (lo), _pool_var (hi), _pool_var (len); \
263 uword _pool_var (bl), * _pool_var (b); \
264 pool_header_t * _pool_var (p); \
266 _pool_var (p) = pool_header (POOL); \
267 _pool_var (b) = (POOL) ? _pool_var (p)->free_bitmap : 0; \
268 _pool_var (bl) = vec_len (_pool_var (b)); \
269 _pool_var (len) = vec_len (POOL); \
270 _pool_var (lo) = 0; \
272 for (_pool_var (i) = 0; \
273 _pool_var (i) <= _pool_var (bl); \
276 uword _pool_var (m), _pool_var (f); \
277 _pool_var (m) = (_pool_var (i) < _pool_var (bl) \
278 ? _pool_var (b) [_pool_var (i)] \
280 while (_pool_var (m) != 0) \
282 _pool_var (f) = first_set (_pool_var (m)); \
283 _pool_var (hi) = (_pool_var (i) * BITS (_pool_var (b)[0]) \
284 + min_log2 (_pool_var (f))); \
285 _pool_var (hi) = (_pool_var (i) < _pool_var (bl) \
286 ? _pool_var (hi) : _pool_var (len)); \
287 _pool_var (m) ^= _pool_var (f); \
288 if (_pool_var (hi) > _pool_var (lo)) \
290 (LO) = _pool_var (lo); \
291 (HI) = _pool_var (hi); \
292 do { BODY; } while (0); \
294 _pool_var (lo) = _pool_var (hi) + 1; \
299 /* Iterate through pool
301 @param VAR variable of same type as pool vector
302 @param POOL pool to iterate across
303 @param BODY operation to perform. See the example below.
305 call BODY with each active pool element.
308 proc_t *procs; // a pool of processes <br>
309 proc_t *proc; // pointer to one process <br>
311 pool_foreach (proc, procs, ({
313 if (proc->state != PROC_STATE_RUNNING)<br>
314 continue;
316 <i>check a running proc in some way</i><br>
319 It is a bad idea to allocate or free pool element from within
320 pool_foreach. Build a vector of indices and dispose of them later.
322 Because pool_foreach is a macro, syntax errors can be difficult to
323 find inside BODY, let alone actual code bugs. One can temporarily
324 split a complex pool_foreach into a trivial pool_foreach which
325 builds a vector of active indices, and a vec_foreach() (or plain
326 for-loop) to walk the active index vector.
328 #define pool_foreach(VAR,POOL,BODY) \
330 uword _pool_foreach_lo, _pool_foreach_hi; \
331 pool_foreach_region (_pool_foreach_lo, _pool_foreach_hi, (POOL), \
333 for ((VAR) = (POOL) + _pool_foreach_lo; \
334 (VAR) < (POOL) + _pool_foreach_hi; \
336 do { BODY; } while (0); \
340 /* Returns pointer to element at given index
342 ASSERTs that the supplied index is valid. Even though
343 one can write correct code of the form "p = pool_base + index",
344 use of pool_elt_at_index is strongly suggested.
346 #define pool_elt_at_index(p,i) \
348 typeof (p) _e = (p) + (i); \
349 ASSERT (! pool_is_free (p, _e)); \
353 /* Return next occupied pool index after i, useful for safe iteration */
354 #define pool_next_index(P,I) \
356 pool_header_t * _pool_var (p) = pool_header (P); \
357 uword _pool_var (rv) = (I) + 1; \
360 (_pool_var (rv) < vec_len (P) ? \
361 clib_bitmap_next_clear (_pool_var (p)->free_bitmap, _pool_var(rv)) \
366 #define pool_foreach_index(i,v,body) \
367 for ((i) = 0; (i) < vec_len (v); (i)++) \
369 if (! pool_is_free_index ((v), (i))) \
370 do { body; } while (0); \
373 #endif /* included_pool_h */