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)
175 vec_attr_t va = { .hdr_sz = sizeof (pool_header_t),
181 pool_header_t *ph = pool_header (p);
182 uword n_free = vec_len (ph->free_indices);
186 uword index = ph->free_indices[n_free - 1];
187 e = p + index * elt_sz;
189 clib_bitmap_andnoti_notrim (ph->free_bitmap, index);
190 vec_set_len (ph->free_indices, n_free - 1);
191 clib_mem_unpoison (e, elt_sz);
197 clib_warning ("can't expand fixed-size pool");
204 /* Nothing on free list, make a new element and return it. */
205 p = _vec_realloc_internal (p, len + 1, &va);
206 e = p + len * elt_sz;
208 _vec_update_pointer (pp, p);
213 clib_memset_u8 (e, 0, elt_sz);
216 #define _pool_get_aligned_internal(P, E, A, Z) \
217 _pool_get ((void **) &(P), (void **) &(E), _vec_align (P, A), Z, \
220 /** Allocate an object E from a pool P with alignment A */
221 #define pool_get_aligned(P,E,A) _pool_get_aligned_internal(P,E,A,0)
223 /** Allocate an object E from a pool P with alignment A and zero it */
224 #define pool_get_aligned_zero(P,E,A) _pool_get_aligned_internal(P,E,A,1)
226 /** Allocate an object E from a pool P (unspecified alignment). */
227 #define pool_get(P,E) pool_get_aligned(P,E,0)
229 /** Allocate an object E from a pool P and zero it */
230 #define pool_get_zero(P,E) pool_get_aligned_zero(P,E,0)
233 _pool_get_will_expand (void *p, uword elt_sz)
241 ph = pool_header (p);
246 len = vec_len (ph->free_indices);
248 /* Free elements, certainly won't expand */
252 return _vec_resize_will_expand (p, 1, elt_sz);
255 #define pool_get_will_expand(P) _pool_get_will_expand (P, sizeof ((P)[0]))
258 _pool_put_will_expand (void *p, uword index, uword elt_sz)
260 pool_header_t *ph = pool_header (p);
262 if (clib_bitmap_will_expand (ph->free_bitmap, index))
265 if (vec_resize_will_expand (ph->free_indices, 1))
271 #define pool_put_will_expand(P, E) _pool_put_will_expand (P, (E) - (P), sizeof ((P)[0])
273 /** Use free bitmap to query whether given element is free. */
274 static_always_inline int
275 pool_is_free_index (void *p, uword index)
277 pool_header_t *ph = pool_header (p);
278 return index < vec_len (p) ? clib_bitmap_get (ph->free_bitmap, index) : 1;
281 #define pool_is_free(P, E) pool_is_free_index ((void *) (P), (E) - (P))
283 /** Free an object E in pool P. */
284 static_always_inline void
285 _pool_put_index (void *p, uword index, uword elt_sz)
287 pool_header_t *ph = pool_header (p);
289 ASSERT (index < ph->max_elts ? ph->max_elts : vec_len (p));
290 ASSERT (!pool_is_free_index (p, index));
292 /* Add element to free bitmap and to free list. */
293 ph->free_bitmap = clib_bitmap_ori_notrim (ph->free_bitmap, index);
295 /* Preallocated pool? */
298 u32 len = _vec_len (ph->free_indices);
299 vec_set_len (ph->free_indices, len + 1);
300 ph->free_indices[len] = index;
303 vec_add1 (ph->free_indices, index);
305 clib_mem_poison (p + index * elt_sz, elt_sz);
308 #define pool_put_index(P, I) _pool_put_index ((void *) (P), I, _vec_elt_sz (P))
309 #define pool_put(P, E) pool_put_index (P, (E) - (P))
311 /** Allocate N more free elements to pool (general version). */
313 static_always_inline void
314 _pool_alloc (void **pp, uword n_elts, uword align, void *heap, uword elt_sz)
316 pool_header_t *ph = pool_header (pp[0]);
317 uword len = vec_len (pp[0]);
318 const vec_attr_t va = { .hdr_sz = sizeof (pool_header_t),
323 if (ph && ph->max_elts)
325 clib_warning ("Can't expand fixed-size pool");
329 pp[0] = _vec_resize_internal (pp[0], len + n_elts, &va);
330 _vec_set_len (pp[0], len, elt_sz);
331 clib_mem_poison (pp[0] + len * elt_sz, n_elts * elt_sz);
333 ph = pool_header (pp[0]);
334 vec_resize (ph->free_indices, n_elts);
335 vec_dec_len (ph->free_indices, n_elts);
336 clib_bitmap_validate (ph->free_bitmap, (len + n_elts) ?: 1);
339 #define pool_alloc_aligned_heap(P, N, A, H) \
340 _pool_alloc ((void **) &(P), N, _vec_align (P, A), H, _vec_elt_sz (P))
342 #define pool_alloc_heap(P, N, H) pool_alloc_aligned_heap (P, N, 0, H)
343 #define pool_alloc_aligned(P, N, A) pool_alloc_aligned_heap (P, N, A, 0)
344 #define pool_alloc(P, N) pool_alloc_aligned_heap (P, N, 0, 0)
346 static_always_inline void *
347 _pool_dup (void *p, uword align, uword elt_sz)
349 pool_header_t *nph, *ph = pool_header (p);
350 uword len = vec_len (p);
351 const vec_attr_t va = { .hdr_sz = sizeof (pool_header_t),
356 if (ph && ph->max_elts)
358 clib_warning ("Can't expand fixed-size pool");
362 n = _vec_alloc_internal (len, &va);
363 nph = pool_header (n);
364 clib_memset_u8 (nph, 0, sizeof (vec_header_t));
369 vec_foreach (fi, ph->free_indices)
370 clib_mem_unpoison (p + elt_sz * fi[0], elt_sz);
372 clib_memcpy_fast (n, p, len * elt_sz);
374 nph->free_bitmap = clib_bitmap_dup (ph->free_bitmap);
375 nph->free_indices = vec_dup (ph->free_indices);
377 vec_foreach (fi, ph->free_indices)
379 uword offset = elt_sz * fi[0];
380 clib_mem_poison (p + offset, elt_sz);
381 clib_mem_poison (n + offset, elt_sz);
389 * Return copy of pool with alignment
391 * @param P pool to copy
392 * @param A alignment (may be zero)
393 * @return copy of pool
396 #define pool_dup_aligned(P, A) \
397 _pool_dup (P, _vec_align (P, A), _vec_elt_sz (P))
400 * Return copy of pool without alignment
402 * @param P pool to copy
403 * @return copy of pool
405 #define pool_dup(P) pool_dup_aligned(P,0)
407 /** Low-level free pool operator (do not call directly). */
409 _pool_free (void **v)
411 pool_header_t *p = pool_header (v[0]);
415 clib_bitmap_free (p->free_bitmap);
417 vec_free (p->free_indices);
420 #define pool_free(p) _pool_free ((void **) &(p))
422 static_always_inline uword
423 pool_get_first_index (void *pool)
425 pool_header_t *h = pool_header (pool);
426 return clib_bitmap_first_clear (h->free_bitmap);
429 static_always_inline uword
430 pool_get_next_index (void *pool, uword last)
432 pool_header_t *h = pool_header (pool);
433 return clib_bitmap_next_clear (h->free_bitmap, last + 1);
436 /** Optimized iteration through pool.
438 @param LO pointer to first element in chunk
439 @param HI pointer to last element in chunk
440 @param POOL pool to iterate across
441 @param BODY operation to perform
443 Optimized version which assumes that BODY is smart enough to
444 process multiple (LOW,HI) chunks. See also pool_foreach().
446 #define pool_foreach_region(LO,HI,POOL,BODY) \
448 uword _pool_var (i), _pool_var (lo), _pool_var (hi), _pool_var (len); \
449 uword _pool_var (bl), * _pool_var (b); \
450 pool_header_t * _pool_var (p); \
452 _pool_var (p) = pool_header (POOL); \
453 _pool_var (b) = (POOL) ? _pool_var (p)->free_bitmap : 0; \
454 _pool_var (bl) = vec_len (_pool_var (b)); \
455 _pool_var (len) = vec_len (POOL); \
456 _pool_var (lo) = 0; \
458 for (_pool_var (i) = 0; \
459 _pool_var (i) <= _pool_var (bl); \
462 uword _pool_var (m), _pool_var (f); \
463 _pool_var (m) = (_pool_var (i) < _pool_var (bl) \
464 ? _pool_var (b) [_pool_var (i)] \
466 while (_pool_var (m) != 0) \
468 _pool_var (f) = first_set (_pool_var (m)); \
469 _pool_var (hi) = (_pool_var (i) * BITS (_pool_var (b)[0]) \
470 + min_log2 (_pool_var (f))); \
471 _pool_var (hi) = (_pool_var (i) < _pool_var (bl) \
472 ? _pool_var (hi) : _pool_var (len)); \
473 _pool_var (m) ^= _pool_var (f); \
474 if (_pool_var (hi) > _pool_var (lo)) \
476 (LO) = _pool_var (lo); \
477 (HI) = _pool_var (hi); \
478 do { BODY; } while (0); \
480 _pool_var (lo) = _pool_var (hi) + 1; \
485 /** Iterate through pool.
487 @param VAR A variable of same type as pool vector to be used as an
489 @param POOL The pool to iterate across.
490 @param BODY The operation to perform, typically a code block. See
493 This macro will call @c BODY with each active pool element.
495 It is a bad idea to allocate or free pool element from within
496 @c pool_foreach. Build a vector of indices and dispose of them later.
502 proc_t *procs; // a pool of processes.
503 proc_t *proc; // pointer to one process; used as the iterator.
505 pool_foreach (proc, procs, ({
506 if (proc->state != PROC_STATE_RUNNING)
509 // check a running proc in some way
514 @warning Because @c pool_foreach is a macro, syntax errors can be
515 difficult to find inside @c BODY, let alone actual code bugs. One
516 can temporarily split a complex @c pool_foreach into a trivial
517 @c pool_foreach which builds a vector of active indices, and a
518 vec_foreach() (or plain for-loop) to walk the active index vector.
521 #define pool_foreach(VAR,POOL) \
523 for (VAR = POOL + pool_get_first_index (POOL); \
524 VAR < vec_end (POOL); \
525 VAR = POOL + pool_get_next_index (POOL, VAR - POOL))
527 /** Returns pointer to element at given index.
529 ASSERTs that the supplied index is valid.
530 Even though one can write correct code of the form
532 p = pool_base + index;
534 use of @c pool_elt_at_index is strongly suggested.
536 #define pool_elt_at_index(p,i) \
538 typeof (p) _e = (p) + (i); \
539 ASSERT (! pool_is_free (p, _e)); \
543 /** Return next occupied pool index after @c i, useful for safe iteration. */
544 #define pool_next_index(P,I) \
546 pool_header_t * _pool_var (p) = pool_header (P); \
547 uword _pool_var (rv) = (I) + 1; \
550 (_pool_var (rv) < vec_len (P) ? \
551 clib_bitmap_next_clear (_pool_var (p)->free_bitmap, _pool_var(rv)) \
554 (_pool_var (rv) < vec_len (P) ? \
555 _pool_var (rv) : ~0); \
559 #define pool_foreach_index(i, v) \
561 for (i = pool_get_first_index (v); i < vec_len (v); \
562 i = pool_get_next_index (v, i))
564 /* Iterate pool by index from s to e */
565 #define pool_foreach_stepping_index(i, s, e, v) \
567 (pool_is_free_index ((v), (s)) ? pool_get_next_index ((v), (s)) : \
569 (i) < (e); (i) = pool_get_next_index ((v), (i)))
572 * @brief Remove all elements from a pool in a safe way
574 * @param VAR each element in the pool
575 * @param POOL The pool to flush
576 * @param BODY The actions to perform on each element before it is returned to
577 * the pool. i.e. before it is 'freed'
579 #define pool_flush(VAR, POOL, BODY) \
581 uword *_pool_var(ii), *_pool_var(dv) = NULL; \
583 pool_foreach((VAR), (POOL)) \
585 vec_add1(_pool_var(dv), (VAR) - (POOL)); \
587 vec_foreach(_pool_var(ii), _pool_var(dv)) \
589 (VAR) = pool_elt_at_index((POOL), *_pool_var(ii)); \
590 do { BODY; } while (0); \
591 pool_put((POOL), (VAR)); \
593 vec_free(_pool_var(dv)); \
596 #endif /* included_pool_h */
599 * fd.io coding-style-patch-verification: ON
602 * eval: (c-set-style "gnu")