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_set_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_inc_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, void *heap, 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, heap);
324 _vec_set_len (pp[0], len, elt_sz);
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_dec_len (ph->free_indices, n_elts);
330 clib_bitmap_vec_validate (ph->free_bitmap, len + n_elts - 1);
333 #define pool_alloc_aligned_heap(P, N, A, H) \
334 _pool_alloc ((void **) &(P), N, _vec_align (P, A), H, _vec_elt_sz (P))
336 #define pool_alloc_heap(P, N, H) pool_alloc_aligned_heap (P, N, 0, H)
337 #define pool_alloc_aligned(P, N, A) pool_alloc_aligned_heap (P, N, A, 0)
338 #define pool_alloc(P, N) pool_alloc_aligned_heap (P, N, 0, 0)
340 static_always_inline void *
341 _pool_dup (void *p, uword align, uword elt_sz)
343 pool_header_t *nph, *ph = pool_header (p);
344 uword len = vec_len (p);
347 if (ph && ph->max_elts)
349 clib_warning ("Can't expand fixed-size pool");
353 n = _vec_realloc_inline (0, len, elt_sz, sizeof (pool_header_t), align, 0);
354 nph = pool_header (n);
355 clib_memset_u8 (nph, 0, sizeof (vec_header_t));
360 vec_foreach (fi, ph->free_indices)
361 CLIB_MEM_UNPOISON (p + elt_sz * fi[0], elt_sz);
363 clib_memcpy_fast (n, p, len * elt_sz);
365 nph->free_bitmap = clib_bitmap_dup (ph->free_bitmap);
366 nph->free_indices = vec_dup (ph->free_indices);
368 vec_foreach (fi, ph->free_indices)
370 uword offset = elt_sz * fi[0];
371 CLIB_MEM_POISON (p + offset, elt_sz);
372 CLIB_MEM_POISON (n + offset, elt_sz);
380 * Return copy of pool with alignment
382 * @param P pool to copy
383 * @param A alignment (may be zero)
384 * @return copy of pool
387 #define pool_dup_aligned(P, A) \
388 _pool_dup (P, _vec_align (P, A), _vec_elt_sz (P))
391 * Return copy of pool without alignment
393 * @param P pool to copy
394 * @return copy of pool
396 #define pool_dup(P) pool_dup_aligned(P,0)
398 /** Low-level free pool operator (do not call directly). */
400 _pool_free (void **v)
402 pool_header_t *p = pool_header (v[0]);
406 clib_bitmap_free (p->free_bitmap);
408 vec_free (p->free_indices);
411 #define pool_free(p) _pool_free ((void **) &(p))
413 static_always_inline uword
414 pool_get_first_index (void *pool)
416 pool_header_t *h = pool_header (pool);
417 return clib_bitmap_first_clear (h->free_bitmap);
420 static_always_inline uword
421 pool_get_next_index (void *pool, uword last)
423 pool_header_t *h = pool_header (pool);
424 return clib_bitmap_next_clear (h->free_bitmap, last + 1);
427 /** Optimized iteration through pool.
429 @param LO pointer to first element in chunk
430 @param HI pointer to last element in chunk
431 @param POOL pool to iterate across
432 @param BODY operation to perform
434 Optimized version which assumes that BODY is smart enough to
435 process multiple (LOW,HI) chunks. See also pool_foreach().
437 #define pool_foreach_region(LO,HI,POOL,BODY) \
439 uword _pool_var (i), _pool_var (lo), _pool_var (hi), _pool_var (len); \
440 uword _pool_var (bl), * _pool_var (b); \
441 pool_header_t * _pool_var (p); \
443 _pool_var (p) = pool_header (POOL); \
444 _pool_var (b) = (POOL) ? _pool_var (p)->free_bitmap : 0; \
445 _pool_var (bl) = vec_len (_pool_var (b)); \
446 _pool_var (len) = vec_len (POOL); \
447 _pool_var (lo) = 0; \
449 for (_pool_var (i) = 0; \
450 _pool_var (i) <= _pool_var (bl); \
453 uword _pool_var (m), _pool_var (f); \
454 _pool_var (m) = (_pool_var (i) < _pool_var (bl) \
455 ? _pool_var (b) [_pool_var (i)] \
457 while (_pool_var (m) != 0) \
459 _pool_var (f) = first_set (_pool_var (m)); \
460 _pool_var (hi) = (_pool_var (i) * BITS (_pool_var (b)[0]) \
461 + min_log2 (_pool_var (f))); \
462 _pool_var (hi) = (_pool_var (i) < _pool_var (bl) \
463 ? _pool_var (hi) : _pool_var (len)); \
464 _pool_var (m) ^= _pool_var (f); \
465 if (_pool_var (hi) > _pool_var (lo)) \
467 (LO) = _pool_var (lo); \
468 (HI) = _pool_var (hi); \
469 do { BODY; } while (0); \
471 _pool_var (lo) = _pool_var (hi) + 1; \
476 /** Iterate through pool.
478 @param VAR A variable of same type as pool vector to be used as an
480 @param POOL The pool to iterate across.
481 @param BODY The operation to perform, typically a code block. See
484 This macro will call @c BODY with each active pool element.
486 It is a bad idea to allocate or free pool element from within
487 @c pool_foreach. Build a vector of indices and dispose of them later.
493 proc_t *procs; // a pool of processes.
494 proc_t *proc; // pointer to one process; used as the iterator.
496 pool_foreach (proc, procs, ({
497 if (proc->state != PROC_STATE_RUNNING)
500 // check a running proc in some way
505 @warning Because @c pool_foreach is a macro, syntax errors can be
506 difficult to find inside @c BODY, let alone actual code bugs. One
507 can temporarily split a complex @c pool_foreach into a trivial
508 @c pool_foreach which builds a vector of active indices, and a
509 vec_foreach() (or plain for-loop) to walk the active index vector.
512 #define pool_foreach(VAR,POOL) \
514 for (VAR = POOL + pool_get_first_index (POOL); \
515 VAR < vec_end (POOL); \
516 VAR = POOL + pool_get_next_index (POOL, VAR - POOL))
518 /** Returns pointer to element at given index.
520 ASSERTs that the supplied index is valid.
521 Even though one can write correct code of the form
523 p = pool_base + index;
525 use of @c pool_elt_at_index is strongly suggested.
527 #define pool_elt_at_index(p,i) \
529 typeof (p) _e = (p) + (i); \
530 ASSERT (! pool_is_free (p, _e)); \
534 /** Return next occupied pool index after @c i, useful for safe iteration. */
535 #define pool_next_index(P,I) \
537 pool_header_t * _pool_var (p) = pool_header (P); \
538 uword _pool_var (rv) = (I) + 1; \
541 (_pool_var (rv) < vec_len (P) ? \
542 clib_bitmap_next_clear (_pool_var (p)->free_bitmap, _pool_var(rv)) \
545 (_pool_var (rv) < vec_len (P) ? \
546 _pool_var (rv) : ~0); \
550 #define pool_foreach_index(i,v) \
552 for (i = pool_get_first_index (v); \
554 i = pool_get_next_index (v, i)) \
557 * @brief Remove all elements from a pool in a safe way
559 * @param VAR each element in the pool
560 * @param POOL The pool to flush
561 * @param BODY The actions to perform on each element before it is returned to
562 * the pool. i.e. before it is 'freed'
564 #define pool_flush(VAR, POOL, BODY) \
566 uword *_pool_var(ii), *_pool_var(dv) = NULL; \
568 pool_foreach((VAR), (POOL)) \
570 vec_add1(_pool_var(dv), (VAR) - (POOL)); \
572 vec_foreach(_pool_var(ii), _pool_var(dv)) \
574 (VAR) = pool_elt_at_index((POOL), *_pool_var(ii)); \
575 do { BODY; } while (0); \
576 pool_put((POOL), (VAR)); \
578 vec_free(_pool_var(dv)); \
581 #endif /* included_pool_h */
584 * fd.io coding-style-patch-verification: ON
587 * eval: (c-set-style "gnu")