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>
53 /** Bitmap of indices of free objects. */
56 /** Vector of free indices. One element for each set bit in bitmap. */
59 /* The following fields are set for fixed-size, preallocated pools */
61 /** Maximum size of the pool, in elements */
66 /** Get pool header from user pool pointer */
67 always_inline pool_header_t *
70 return vec_header (v);
73 void _pool_init_fixed (void **pool_ptr, uword elt_sz, uword max_elts,
76 /** initialize a fixed-size, preallocated pool */
77 #define pool_init_fixed(P, E) \
78 _pool_init_fixed ((void **) &(P), _vec_elt_sz (P), E, _vec_align (P, 0));
80 /** Validate a pool */
82 pool_validate (void *v)
84 pool_header_t *p = pool_header (v);
85 uword i, n_free_bitmap;
90 n_free_bitmap = clib_bitmap_count_set_bits (p->free_bitmap);
91 ASSERT (n_free_bitmap == vec_len (p->free_indices));
92 for (i = 0; i < vec_len (p->free_indices); i++)
93 ASSERT (clib_bitmap_get (p->free_bitmap, p->free_indices[i]) == 1);
96 /** Number of active elements in a pool.
97 * @return Number of active elements in a pool
102 uword ret = vec_len (v);
104 ret -= vec_len (pool_header (v)->free_indices);
108 /** Number of elements in pool vector.
110 @note You probably want to call pool_elts() instead.
112 #define pool_len(p) vec_len(p)
114 /** Number of elements in pool vector (usable as an lvalue)
116 @note You probably don't want to use this macro.
118 #define _pool_len(p) _vec_len(p)
120 /** Memory usage of pool header. */
122 pool_header_bytes (void *v)
124 pool_header_t *p = pool_header (v);
129 return vec_bytes (p->free_bitmap) + vec_bytes (p->free_indices);
132 /** Memory usage of pool. */
133 #define pool_bytes(P) (vec_bytes (P) + pool_header_bytes (P))
135 /** Local variable naming macro. */
136 #define _pool_var(v) _pool_##v
138 /** Number of elements that can fit into pool with current allocation */
139 #define pool_max_len(P) vec_max_len (P)
141 /** Number of free elements in pool */
142 static_always_inline uword
143 _pool_free_elts (void *p, uword elt_sz)
151 ph = pool_header (p);
153 n_free = vec_len (ph->free_indices);
155 /* Fixed-size pools have max_elts set non-zero */
156 if (ph->max_elts == 0)
157 n_free += _vec_max_len (p, elt_sz) - vec_len (p);
162 #define pool_free_elts(P) _pool_free_elts ((void *) (P), _vec_elt_sz (P))
164 /** Allocate an object E from a pool P (general version).
166 First search free list. If nothing is free extend vector of objects.
169 static_always_inline void
170 _pool_get (void **pp, void **ep, uword align, int zero, uword elt_sz)
178 pool_header_t *ph = pool_header (p);
179 uword n_free = vec_len (ph->free_indices);
183 uword index = ph->free_indices[n_free - 1];
184 e = p + index * elt_sz;
186 clib_bitmap_andnoti_notrim (ph->free_bitmap, index);
187 _vec_len (ph->free_indices) = n_free - 1;
188 CLIB_MEM_UNPOISON (e, elt_sz);
194 clib_warning ("can't expand fixed-size pool");
201 /* Nothing on free list, make a new element and return it. */
203 _vec_realloc_inline (p, len + 1, elt_sz, sizeof (pool_header_t), align, 0);
204 e = p + len * elt_sz;
206 _vec_update_pointer (pp, p);
211 clib_memset_u8 (e, 0, elt_sz);
214 #define _pool_get_aligned_internal(P, E, A, Z) \
215 _pool_get ((void **) &(P), (void **) &(E), _vec_align (P, A), Z, \
218 /** Allocate an object E from a pool P with alignment A */
219 #define pool_get_aligned(P,E,A) _pool_get_aligned_internal(P,E,A,0)
221 /** Allocate an object E from a pool P with alignment A and zero it */
222 #define pool_get_aligned_zero(P,E,A) _pool_get_aligned_internal(P,E,A,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 /** Allocate an object E from a pool P and zero it */
228 #define pool_get_zero(P,E) pool_get_aligned_zero(P,E,0)
231 _pool_get_will_expand (void *p, uword elt_sz)
239 ph = pool_header (p);
244 len = vec_len (ph->free_indices);
246 /* Free elements, certainly won't expand */
250 return _vec_resize_will_expand (p, 1, elt_sz);
253 #define pool_get_will_expand(P) _pool_get_will_expand (P, sizeof ((P)[0]))
256 _pool_put_will_expand (void *p, uword index, uword elt_sz)
258 pool_header_t *ph = pool_header (p);
260 if (clib_bitmap_will_expand (ph->free_bitmap, index))
263 if (vec_resize_will_expand (ph->free_indices, 1))
269 #define pool_put_will_expand(P, E) _pool_put_will_expand (P, (E) - (P), sizeof ((P)[0])
271 /** Use free bitmap to query whether given element is free. */
272 static_always_inline int
273 pool_is_free_index (void *p, uword index)
275 pool_header_t *ph = pool_header (p);
276 return index < vec_len (p) ? clib_bitmap_get (ph->free_bitmap, index) : 1;
279 #define pool_is_free(P, E) pool_is_free_index ((void *) (P), (E) - (P))
281 /** Free an object E in pool P. */
282 static_always_inline void
283 _pool_put_index (void *p, uword index, uword elt_sz)
285 pool_header_t *ph = pool_header (p);
287 ASSERT (index < ph->max_elts ? ph->max_elts : vec_len (p));
288 ASSERT (!pool_is_free_index (p, index));
290 /* Add element to free bitmap and to free list. */
291 ph->free_bitmap = clib_bitmap_ori_notrim (ph->free_bitmap, index);
293 /* Preallocated pool? */
296 ph->free_indices[_vec_len (ph->free_indices)] = index;
297 _vec_len (ph->free_indices) += 1;
300 vec_add1 (ph->free_indices, index);
302 CLIB_MEM_POISON (p + index * elt_sz, elt_sz);
305 #define pool_put_index(P, I) _pool_put_index ((void *) (P), I, _vec_elt_sz (P))
306 #define pool_put(P, E) pool_put_index (P, (E) - (P))
308 /** Allocate N more free elements to pool (general version). */
310 static_always_inline void
311 _pool_alloc (void **pp, uword n_elts, uword align, uword elt_sz)
313 pool_header_t *ph = pool_header (pp[0]);
314 uword len = vec_len (pp[0]);
316 if (ph && ph->max_elts)
318 clib_warning ("Can't expand fixed-size pool");
322 pp[0] = _vec_realloc_inline (pp[0], len + n_elts, elt_sz,
323 sizeof (pool_header_t), align, 0);
324 _vec_len (pp[0]) = len;
325 CLIB_MEM_POISON (pp[0] + len * elt_sz, n_elts * elt_sz);
327 ph = pool_header (pp[0]);
328 vec_resize (ph->free_indices, n_elts);
329 _vec_len (ph->free_indices) -= n_elts;
330 clib_bitmap_vec_validate (ph->free_bitmap, len + n_elts - 1);
333 #define pool_alloc_aligned(P, N, A) \
334 _pool_alloc ((void **) &(P), N, _vec_align (P, A), _vec_elt_sz (P))
336 /** Allocate N more free elements to pool (unspecified alignment). */
337 #define pool_alloc(P,N) pool_alloc_aligned(P,N,0)
339 static_always_inline void *
340 _pool_dup (void *p, uword align, uword elt_sz)
342 pool_header_t *nph, *ph = pool_header (p);
343 uword len = vec_len (p);
346 if (ph && ph->max_elts)
348 clib_warning ("Can't expand fixed-size pool");
352 n = _vec_realloc_inline (0, len, elt_sz, sizeof (pool_header_t), align, 0);
353 nph = pool_header (n);
354 clib_memset_u8 (nph, 0, sizeof (vec_header_t));
359 vec_foreach (fi, ph->free_indices)
360 CLIB_MEM_UNPOISON (p + elt_sz * fi[0], elt_sz);
362 clib_memcpy_fast (n, p, len * elt_sz);
364 nph->free_bitmap = clib_bitmap_dup (ph->free_bitmap);
365 nph->free_indices = vec_dup (ph->free_indices);
367 vec_foreach (fi, ph->free_indices)
369 uword offset = elt_sz * fi[0];
370 CLIB_MEM_POISON (p + offset, elt_sz);
371 CLIB_MEM_POISON (n + offset, elt_sz);
379 * Return copy of pool with alignment
381 * @param P pool to copy
382 * @param A alignment (may be zero)
383 * @return copy of pool
386 #define pool_dup_aligned(P, A) \
387 _pool_dup (P, _vec_align (P, A), _vec_elt_sz (P))
390 * Return copy of pool without alignment
392 * @param P pool to copy
393 * @return copy of pool
395 #define pool_dup(P) pool_dup_aligned(P,0)
397 /** Low-level free pool operator (do not call directly). */
399 _pool_free (void **v)
401 pool_header_t *p = pool_header (v[0]);
405 clib_bitmap_free (p->free_bitmap);
407 vec_free (p->free_indices);
410 #define pool_free(p) _pool_free ((void **) &(p))
412 static_always_inline uword
413 pool_get_first_index (void *pool)
415 pool_header_t *h = pool_header (pool);
416 return clib_bitmap_first_clear (h->free_bitmap);
419 static_always_inline uword
420 pool_get_next_index (void *pool, uword last)
422 pool_header_t *h = pool_header (pool);
423 return clib_bitmap_next_clear (h->free_bitmap, last + 1);
426 /** Optimized iteration through pool.
428 @param LO pointer to first element in chunk
429 @param HI pointer to last element in chunk
430 @param POOL pool to iterate across
431 @param BODY operation to perform
433 Optimized version which assumes that BODY is smart enough to
434 process multiple (LOW,HI) chunks. See also pool_foreach().
436 #define pool_foreach_region(LO,HI,POOL,BODY) \
438 uword _pool_var (i), _pool_var (lo), _pool_var (hi), _pool_var (len); \
439 uword _pool_var (bl), * _pool_var (b); \
440 pool_header_t * _pool_var (p); \
442 _pool_var (p) = pool_header (POOL); \
443 _pool_var (b) = (POOL) ? _pool_var (p)->free_bitmap : 0; \
444 _pool_var (bl) = vec_len (_pool_var (b)); \
445 _pool_var (len) = vec_len (POOL); \
446 _pool_var (lo) = 0; \
448 for (_pool_var (i) = 0; \
449 _pool_var (i) <= _pool_var (bl); \
452 uword _pool_var (m), _pool_var (f); \
453 _pool_var (m) = (_pool_var (i) < _pool_var (bl) \
454 ? _pool_var (b) [_pool_var (i)] \
456 while (_pool_var (m) != 0) \
458 _pool_var (f) = first_set (_pool_var (m)); \
459 _pool_var (hi) = (_pool_var (i) * BITS (_pool_var (b)[0]) \
460 + min_log2 (_pool_var (f))); \
461 _pool_var (hi) = (_pool_var (i) < _pool_var (bl) \
462 ? _pool_var (hi) : _pool_var (len)); \
463 _pool_var (m) ^= _pool_var (f); \
464 if (_pool_var (hi) > _pool_var (lo)) \
466 (LO) = _pool_var (lo); \
467 (HI) = _pool_var (hi); \
468 do { BODY; } while (0); \
470 _pool_var (lo) = _pool_var (hi) + 1; \
475 /** Iterate through pool.
477 @param VAR A variable of same type as pool vector to be used as an
479 @param POOL The pool to iterate across.
480 @param BODY The operation to perform, typically a code block. See
483 This macro will call @c BODY with each active pool element.
485 It is a bad idea to allocate or free pool element from within
486 @c pool_foreach. Build a vector of indices and dispose of them later.
492 proc_t *procs; // a pool of processes.
493 proc_t *proc; // pointer to one process; used as the iterator.
495 pool_foreach (proc, procs, ({
496 if (proc->state != PROC_STATE_RUNNING)
499 // check a running proc in some way
504 @warning Because @c pool_foreach is a macro, syntax errors can be
505 difficult to find inside @c BODY, let alone actual code bugs. One
506 can temporarily split a complex @c pool_foreach into a trivial
507 @c pool_foreach which builds a vector of active indices, and a
508 vec_foreach() (or plain for-loop) to walk the active index vector.
511 #define pool_foreach(VAR,POOL) \
513 for (VAR = POOL + pool_get_first_index (POOL); \
514 VAR < vec_end (POOL); \
515 VAR = POOL + pool_get_next_index (POOL, VAR - POOL))
517 /** Returns pointer to element at given index.
519 ASSERTs that the supplied index is valid.
520 Even though one can write correct code of the form
522 p = pool_base + index;
524 use of @c pool_elt_at_index is strongly suggested.
526 #define pool_elt_at_index(p,i) \
528 typeof (p) _e = (p) + (i); \
529 ASSERT (! pool_is_free (p, _e)); \
533 /** Return next occupied pool index after @c i, useful for safe iteration. */
534 #define pool_next_index(P,I) \
536 pool_header_t * _pool_var (p) = pool_header (P); \
537 uword _pool_var (rv) = (I) + 1; \
540 (_pool_var (rv) < vec_len (P) ? \
541 clib_bitmap_next_clear (_pool_var (p)->free_bitmap, _pool_var(rv)) \
544 (_pool_var (rv) < vec_len (P) ? \
545 _pool_var (rv) : ~0); \
549 #define pool_foreach_index(i,v) \
551 for (i = pool_get_first_index (v); \
553 i = pool_get_next_index (v, i)) \
556 * @brief Remove all elements from a pool in a safe way
558 * @param VAR each element in the pool
559 * @param POOL The pool to flush
560 * @param BODY The actions to perform on each element before it is returned to
561 * the pool. i.e. before it is 'freed'
563 #define pool_flush(VAR, POOL, BODY) \
565 uword *_pool_var(ii), *_pool_var(dv) = NULL; \
567 pool_foreach((VAR), (POOL)) \
569 vec_add1(_pool_var(dv), (VAR) - (POOL)); \
571 vec_foreach(_pool_var(ii), _pool_var(dv)) \
573 (VAR) = pool_elt_at_index((POOL), *_pool_var(ii)); \
574 do { BODY; } while (0); \
575 pool_put((POOL), (VAR)); \
577 vec_free(_pool_var(dv)); \
580 #endif /* included_pool_h */
583 * fd.io coding-style-patch-verification: ON
586 * eval: (c-set-style "gnu")