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 * @brief Fixed length block allocator.
39 Pools are built from clib vectors and bitmaps. Use pools when
40 repeatedly allocating and freeing fixed-size data. Pools are
41 fast, and avoid memory fragmentation.
44 #ifndef included_pool_h
45 #define included_pool_h
47 #include <vppinfra/bitmap.h>
48 #include <vppinfra/error.h>
49 #include <vppinfra/mheap.h>
54 /** Bitmap of indices of free objects. */
57 /** Vector of free indices. One element for each set bit in bitmap. */
60 /* The following fields are set for fixed-size, preallocated pools */
62 /** Maximum size of the pool, in elements */
65 /** mmap segment info: base + length */
71 /** Align pool header so that pointers are naturally aligned. */
72 #define pool_aligned_header_bytes \
73 vec_aligned_header_bytes (sizeof (pool_header_t), sizeof (void *))
75 /** Get pool header from user pool pointer */
76 always_inline pool_header_t *
79 return vec_aligned_header (v, sizeof (pool_header_t), sizeof (void *));
82 extern void _pool_init_fixed (void **, u32, u32);
83 extern void fpool_free (void *);
85 /** initialize a fixed-size, preallocated pool */
86 #define pool_init_fixed(pool,max_elts) \
88 _pool_init_fixed((void **)&(pool),sizeof(pool[0]),max_elts); \
91 /** Validate a pool */
93 pool_validate (void *v)
95 pool_header_t *p = pool_header (v);
96 uword i, n_free_bitmap;
101 n_free_bitmap = clib_bitmap_count_set_bits (p->free_bitmap);
102 ASSERT (n_free_bitmap == vec_len (p->free_indices));
103 for (i = 0; i < vec_len (p->free_indices); i++)
104 ASSERT (clib_bitmap_get (p->free_bitmap, p->free_indices[i]) == 1);
108 pool_header_validate_index (void *v, uword index)
110 pool_header_t *p = pool_header (v);
113 vec_validate (p->free_bitmap, index / BITS (uword));
116 #define pool_validate_index(v,i) \
118 uword __pool_validate_index = (i); \
119 vec_validate_ha ((v), __pool_validate_index, \
120 pool_aligned_header_bytes, /* align */ 0); \
121 pool_header_validate_index ((v), __pool_validate_index); \
124 /** Number of active elements in a pool.
125 * @return Number of active elements in a pool
130 uword ret = vec_len (v);
132 ret -= vec_len (pool_header (v)->free_indices);
136 /** Number of elements in pool vector.
138 @note You probably want to call pool_elts() instead.
140 #define pool_len(p) vec_len(p)
142 /** Number of elements in pool vector (usable as an lvalue)
144 @note You probably don't want to use this macro.
146 #define _pool_len(p) _vec_len(p)
148 /** Memory usage of pool header. */
150 pool_header_bytes (void *v)
152 pool_header_t *p = pool_header (v);
157 return vec_bytes (p->free_bitmap) + vec_bytes (p->free_indices);
160 /** Memory usage of pool. */
161 #define pool_bytes(P) (vec_bytes (P) + pool_header_bytes (P))
163 /** Local variable naming macro. */
164 #define _pool_var(v) _pool_##v
166 /** Queries whether pool has at least N_FREE free elements. */
168 pool_free_elts (void *v)
170 pool_header_t *p = pool_header (v);
175 n_free += vec_len (p->free_indices);
177 /* Space left at end of vector? */
178 n_free += vec_capacity (v, sizeof (p[0])) - vec_len (v);
184 /** Allocate an object E from a pool P (general version).
186 First search free list. If nothing is free extend vector of objects.
188 #define pool_get_aligned(P,E,A) \
190 pool_header_t * _pool_var (p) = pool_header (P); \
191 uword _pool_var (l); \
195 _pool_var (l) = vec_len (_pool_var (p)->free_indices); \
197 if (_pool_var (l) > 0) \
199 /* Return free element from free list. */ \
200 uword _pool_var (i) = _pool_var (p)->free_indices[_pool_var (l) - 1]; \
201 (E) = (P) + _pool_var (i); \
202 _pool_var (p)->free_bitmap = \
203 clib_bitmap_andnoti (_pool_var (p)->free_bitmap, _pool_var (i)); \
204 _vec_len (_pool_var (p)->free_indices) = _pool_var (l) - 1; \
208 /* fixed-size, preallocated pools cannot expand */ \
209 if ((P) && _pool_var(p)->max_elts) \
211 clib_warning ("can't expand fixed-size pool"); \
212 os_out_of_memory(); \
214 /* Nothing on free list, make a new element and return it. */ \
215 P = _vec_resize (P, \
216 /* length_increment */ 1, \
217 /* new size */ (vec_len (P) + 1) * sizeof (P[0]), \
218 pool_aligned_header_bytes, \
220 E = vec_end (P) - 1; \
224 /** Allocate an object E from a pool P (unspecified alignment). */
225 #define pool_get(P,E) pool_get_aligned(P,E,0)
227 /** See if pool_get will expand the pool or not */
228 #define pool_get_aligned_will_expand(P,YESNO,A) \
230 pool_header_t * _pool_var (p) = pool_header (P); \
231 uword _pool_var (l); \
236 if (_pool_var (p)->max_elts) \
238 _pool_var (l) = vec_len (_pool_var (p)->free_indices); \
241 /* Free elements, certainly won't expand */ \
242 if (_pool_var (l) > 0) \
246 /* Nothing on free list, make a new element and return it. */ \
247 YESNO = _vec_resize_will_expand \
249 /* length_increment */ 1, \
250 /* new size */ (vec_len (P) + 1) * sizeof (P[0]), \
251 pool_aligned_header_bytes, \
256 #define pool_get_will_expand(P,YESNO) pool_get_aligned_will_expand(P,YESNO,0)
258 /** Use free bitmap to query whether given element is free. */
259 #define pool_is_free(P,E) \
261 pool_header_t * _pool_var (p) = pool_header (P); \
262 uword _pool_var (i) = (E) - (P); \
263 (_pool_var (i) < vec_len (P)) ? clib_bitmap_get (_pool_var (p)->free_bitmap, _pool_i) : 1; \
266 /** Use free bitmap to query whether given index is free */
267 #define pool_is_free_index(P,I) pool_is_free((P),(P)+(I))
269 /** Free an object E in pool P. */
270 #define pool_put(P,E) \
272 pool_header_t * _pool_var (p) = pool_header (P); \
273 uword _pool_var (l) = (E) - (P); \
274 ASSERT (vec_is_member (P, E)); \
275 ASSERT (! pool_is_free (P, E)); \
277 /* Add element to free bitmap and to free list. */ \
278 _pool_var (p)->free_bitmap = \
279 clib_bitmap_ori (_pool_var (p)->free_bitmap, _pool_var (l)); \
280 /* Preallocated pool? */ \
281 if (_pool_var (p)->max_elts) \
283 ASSERT(_pool_var(l) < _pool_var (p)->max_elts); \
284 _pool_var(p)->free_indices[_vec_len(_pool_var(p)->free_indices)] = \
286 _vec_len(_pool_var(p)->free_indices) += 1; \
289 vec_add1 (_pool_var (p)->free_indices, _pool_var (l)); \
292 /** Free pool element with given index. */
293 #define pool_put_index(p,i) \
295 typeof (p) _e = (p) + (i); \
299 /** Allocate N more free elements to pool (general version). */
300 #define pool_alloc_aligned(P,N,A) \
302 pool_header_t * _p; \
306 _p = pool_header (P); \
309 clib_warning ("Can't expand fixed-size pool"); \
310 os_out_of_memory(); \
314 (P) = _vec_resize ((P), 0, (vec_len (P) + (N)) * sizeof (P[0]), \
315 pool_aligned_header_bytes, \
317 _p = pool_header (P); \
318 vec_resize (_p->free_indices, (N)); \
319 _vec_len (_p->free_indices) -= (N); \
322 /** Allocate N more free elements to pool (unspecified alignment). */
323 #define pool_alloc(P,N) pool_alloc_aligned(P,N,0)
325 /** Low-level free pool operator (do not call directly). */
329 pool_header_t *p = pool_header (v);
332 clib_bitmap_free (p->free_bitmap);
338 rv = munmap (p->mmap_base, p->mmap_size);
340 clib_unix_warning ("munmap");
344 vec_free (p->free_indices);
345 vec_free_h (v, pool_aligned_header_bytes);
351 #define pool_free(p) (p) = _pool_free(p)
353 /** Optimized iteration through pool.
355 @param LO pointer to first element in chunk
356 @param HI pointer to last element in chunk
357 @param POOL pool to iterate across
358 @param BODY operation to perform
360 Optimized version which assumes that BODY is smart enough to
361 process multiple (LOW,HI) chunks. See also pool_foreach().
363 #define pool_foreach_region(LO,HI,POOL,BODY) \
365 uword _pool_var (i), _pool_var (lo), _pool_var (hi), _pool_var (len); \
366 uword _pool_var (bl), * _pool_var (b); \
367 pool_header_t * _pool_var (p); \
369 _pool_var (p) = pool_header (POOL); \
370 _pool_var (b) = (POOL) ? _pool_var (p)->free_bitmap : 0; \
371 _pool_var (bl) = vec_len (_pool_var (b)); \
372 _pool_var (len) = vec_len (POOL); \
373 _pool_var (lo) = 0; \
375 for (_pool_var (i) = 0; \
376 _pool_var (i) <= _pool_var (bl); \
379 uword _pool_var (m), _pool_var (f); \
380 _pool_var (m) = (_pool_var (i) < _pool_var (bl) \
381 ? _pool_var (b) [_pool_var (i)] \
383 while (_pool_var (m) != 0) \
385 _pool_var (f) = first_set (_pool_var (m)); \
386 _pool_var (hi) = (_pool_var (i) * BITS (_pool_var (b)[0]) \
387 + min_log2 (_pool_var (f))); \
388 _pool_var (hi) = (_pool_var (i) < _pool_var (bl) \
389 ? _pool_var (hi) : _pool_var (len)); \
390 _pool_var (m) ^= _pool_var (f); \
391 if (_pool_var (hi) > _pool_var (lo)) \
393 (LO) = _pool_var (lo); \
394 (HI) = _pool_var (hi); \
395 do { BODY; } while (0); \
397 _pool_var (lo) = _pool_var (hi) + 1; \
402 /** Iterate through pool.
404 @param VAR A variable of same type as pool vector to be used as an
406 @param POOL The pool to iterate across.
407 @param BODY The operation to perform, typically a code block. See
410 This macro will call @c BODY with each active pool element.
412 It is a bad idea to allocate or free pool element from within
413 @c pool_foreach. Build a vector of indices and dispose of them later.
419 proc_t *procs; // a pool of processes.
420 proc_t *proc; // pointer to one process; used as the iterator.
422 pool_foreach (proc, procs, ({
423 if (proc->state != PROC_STATE_RUNNING)
426 // check a running proc in some way
431 @warning Because @c pool_foreach is a macro, syntax errors can be
432 difficult to find inside @c BODY, let alone actual code bugs. One
433 can temporarily split a complex @c pool_foreach into a trivial
434 @c pool_foreach which builds a vector of active indices, and a
435 vec_foreach() (or plain for-loop) to walk the active index vector.
437 #define pool_foreach(VAR,POOL,BODY) \
439 uword _pool_foreach_lo, _pool_foreach_hi; \
440 pool_foreach_region (_pool_foreach_lo, _pool_foreach_hi, (POOL), \
442 for ((VAR) = (POOL) + _pool_foreach_lo; \
443 (VAR) < (POOL) + _pool_foreach_hi; \
445 do { BODY; } while (0); \
449 /** Returns pointer to element at given index.
451 ASSERTs that the supplied index is valid.
452 Even though one can write correct code of the form
454 p = pool_base + index;
456 use of @c pool_elt_at_index is strongly suggested.
458 #define pool_elt_at_index(p,i) \
460 typeof (p) _e = (p) + (i); \
461 ASSERT (! pool_is_free (p, _e)); \
465 /** Return next occupied pool index after @c i, useful for safe iteration. */
466 #define pool_next_index(P,I) \
468 pool_header_t * _pool_var (p) = pool_header (P); \
469 uword _pool_var (rv) = (I) + 1; \
472 (_pool_var (rv) < vec_len (P) ? \
473 clib_bitmap_next_clear (_pool_var (p)->free_bitmap, _pool_var(rv)) \
478 /** Iterate pool by index. */
479 #define pool_foreach_index(i,v,body) \
480 for ((i) = 0; (i) < vec_len (v); (i)++) \
482 if (! pool_is_free_index ((v), (i))) \
483 do { body; } while (0); \
487 * @brief Remove all elemenets from a pool in a safe way
489 * @param VAR each element in the pool
490 * @param POOL The pool to flush
491 * @param BODY The actions to perform on each element before it is returned to
492 * the pool. i.e. before it is 'freed'
494 #define pool_flush(VAR, POOL, BODY) \
496 uword *_pool_var(ii), *_pool_var(dv) = NULL; \
498 pool_foreach((VAR), (POOL), \
500 vec_add1(_pool_var(dv), (VAR) - (POOL)); \
502 vec_foreach(_pool_var(ii), _pool_var(dv)) \
504 (VAR) = pool_elt_at_index((POOL), *_pool_var(ii)); \
505 do { BODY; } while (0); \
506 pool_put((POOL), (VAR)); \
508 vec_free(_pool_var(dv)); \
511 #endif /* included_pool_h */
514 * fd.io coding-style-patch-verification: ON
517 * eval: (c-set-style "gnu")