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_internal(P,E,A,Z) \
190 pool_header_t * _pool_var (p) = pool_header (P); \
191 uword _pool_var (l); \
193 STATIC_ASSERT(A==0 || ((A % sizeof(P[0]))==0) || ((sizeof(P[0]) % A) == 0), \
194 "Pool aligned alloc of incorrectly sized object"); \
197 _pool_var (l) = vec_len (_pool_var (p)->free_indices); \
199 if (_pool_var (l) > 0) \
201 /* Return free element from free list. */ \
202 uword _pool_var (i) = _pool_var (p)->free_indices[_pool_var (l) - 1]; \
203 (E) = (P) + _pool_var (i); \
204 _pool_var (p)->free_bitmap = \
205 clib_bitmap_andnoti_notrim (_pool_var (p)->free_bitmap, \
207 _vec_len (_pool_var (p)->free_indices) = _pool_var (l) - 1; \
211 /* fixed-size, preallocated pools cannot expand */ \
212 if ((P) && _pool_var(p)->max_elts) \
214 clib_warning ("can't expand fixed-size pool"); \
215 os_out_of_memory(); \
217 /* Nothing on free list, make a new element and return it. */ \
218 P = _vec_resize (P, \
219 /* length_increment */ 1, \
220 /* new size */ (vec_len (P) + 1) * sizeof (P[0]), \
221 pool_aligned_header_bytes, \
223 E = vec_end (P) - 1; \
226 memset(E, 0, sizeof(*E)); \
229 /** Allocate an object E from a pool P with alignment A */
230 #define pool_get_aligned(P,E,A) _pool_get_aligned_internal(P,E,A,0)
232 /** Allocate an object E from a pool P with alignment A and zero it */
233 #define pool_get_aligned_zero(P,E,A) _pool_get_aligned_internal(P,E,A,1)
235 /** Allocate an object E from a pool P (unspecified alignment). */
236 #define pool_get(P,E) pool_get_aligned(P,E,0)
238 /** Allocate an object E from a pool P and zero it */
239 #define pool_get_zero(P,E) pool_get_aligned_zero(P,E,0)
241 /** See if pool_get will expand the pool or not */
242 #define pool_get_aligned_will_expand(P,YESNO,A) \
244 pool_header_t * _pool_var (p) = pool_header (P); \
245 uword _pool_var (l); \
250 if (_pool_var (p)->max_elts) \
251 _pool_var (l) = _pool_var (p)->max_elts; \
253 _pool_var (l) = vec_len (_pool_var (p)->free_indices); \
256 /* Free elements, certainly won't expand */ \
257 if (_pool_var (l) > 0) \
261 /* Nothing on free list, make a new element and return it. */ \
262 YESNO = _vec_resize_will_expand \
264 /* length_increment */ 1, \
265 /* new size */ (vec_len (P) + 1) * sizeof (P[0]), \
266 pool_aligned_header_bytes, \
271 /** Tell the caller if pool get will expand the pool */
272 #define pool_get_will_expand(P,YESNO) pool_get_aligned_will_expand(P,YESNO,0)
274 /** Use free bitmap to query whether given element is free. */
275 #define pool_is_free(P,E) \
277 pool_header_t * _pool_var (p) = pool_header (P); \
278 uword _pool_var (i) = (E) - (P); \
279 (_pool_var (i) < vec_len (P)) ? clib_bitmap_get (_pool_var (p)->free_bitmap, _pool_i) : 1; \
282 /** Use free bitmap to query whether given index is free */
283 #define pool_is_free_index(P,I) pool_is_free((P),(P)+(I))
285 /** Free an object E in pool P. */
286 #define pool_put(P,E) \
288 pool_header_t * _pool_var (p) = pool_header (P); \
289 uword _pool_var (l) = (E) - (P); \
290 ASSERT (vec_is_member (P, E)); \
291 ASSERT (! pool_is_free (P, E)); \
293 /* Add element to free bitmap and to free list. */ \
294 _pool_var (p)->free_bitmap = \
295 clib_bitmap_ori_notrim (_pool_var (p)->free_bitmap, \
298 /* Preallocated pool? */ \
299 if (_pool_var (p)->max_elts) \
301 ASSERT(_pool_var(l) < _pool_var (p)->max_elts); \
302 _pool_var(p)->free_indices[_vec_len(_pool_var(p)->free_indices)] = \
304 _vec_len(_pool_var(p)->free_indices) += 1; \
307 vec_add1 (_pool_var (p)->free_indices, _pool_var (l)); \
310 /** Free pool element with given index. */
311 #define pool_put_index(p,i) \
313 typeof (p) _e = (p) + (i); \
317 /** Allocate N more free elements to pool (general version). */
318 #define pool_alloc_aligned(P,N,A) \
320 pool_header_t * _p; \
324 _p = pool_header (P); \
327 clib_warning ("Can't expand fixed-size pool"); \
328 os_out_of_memory(); \
332 (P) = _vec_resize ((P), 0, (vec_len (P) + (N)) * sizeof (P[0]), \
333 pool_aligned_header_bytes, \
335 _p = pool_header (P); \
336 vec_resize (_p->free_indices, (N)); \
337 _vec_len (_p->free_indices) -= (N); \
340 /** Allocate N more free elements to pool (unspecified alignment). */
341 #define pool_alloc(P,N) pool_alloc_aligned(P,N,0)
344 * Return copy of pool with alignment
346 * @param P pool to copy
347 * @param A alignment (may be zero)
348 * @return copy of pool
350 #define pool_dup_aligned(P,A) \
352 typeof (P) _pool_var (new) = 0; \
353 pool_header_t * _pool_var (ph), * _pool_var (new_ph); \
354 u32 _pool_var (n) = pool_len (P); \
357 _pool_var (new) = _vec_resize (_pool_var (new), _pool_var (n), \
358 _pool_var (n) * sizeof ((P)[0]), \
359 pool_aligned_header_bytes, (A)); \
360 clib_memcpy_fast (_pool_var (new), (P), \
361 _pool_var (n) * sizeof ((P)[0])); \
362 _pool_var (ph) = pool_header (P); \
363 _pool_var (new_ph) = pool_header (_pool_var (new)); \
364 _pool_var (new_ph)->free_bitmap = \
365 clib_bitmap_dup (_pool_var (ph)->free_bitmap); \
366 _pool_var (new_ph)->free_indices = \
367 vec_dup (_pool_var (ph)->free_indices); \
368 _pool_var (new_ph)->max_elts = _pool_var (ph)->max_elts; \
374 * Return copy of pool without alignment
376 * @param P pool to copy
377 * @return copy of pool
379 #define pool_dup(P) pool_dup_aligned(P,0)
381 /** Low-level free pool operator (do not call directly). */
385 pool_header_t *p = pool_header (v);
388 clib_bitmap_free (p->free_bitmap);
394 rv = munmap (p->mmap_base, p->mmap_size);
396 clib_unix_warning ("munmap");
400 vec_free (p->free_indices);
401 vec_free_h (v, pool_aligned_header_bytes);
407 #define pool_free(p) (p) = _pool_free(p)
409 /** Optimized iteration through pool.
411 @param LO pointer to first element in chunk
412 @param HI pointer to last element in chunk
413 @param POOL pool to iterate across
414 @param BODY operation to perform
416 Optimized version which assumes that BODY is smart enough to
417 process multiple (LOW,HI) chunks. See also pool_foreach().
419 #define pool_foreach_region(LO,HI,POOL,BODY) \
421 uword _pool_var (i), _pool_var (lo), _pool_var (hi), _pool_var (len); \
422 uword _pool_var (bl), * _pool_var (b); \
423 pool_header_t * _pool_var (p); \
425 _pool_var (p) = pool_header (POOL); \
426 _pool_var (b) = (POOL) ? _pool_var (p)->free_bitmap : 0; \
427 _pool_var (bl) = vec_len (_pool_var (b)); \
428 _pool_var (len) = vec_len (POOL); \
429 _pool_var (lo) = 0; \
431 for (_pool_var (i) = 0; \
432 _pool_var (i) <= _pool_var (bl); \
435 uword _pool_var (m), _pool_var (f); \
436 _pool_var (m) = (_pool_var (i) < _pool_var (bl) \
437 ? _pool_var (b) [_pool_var (i)] \
439 while (_pool_var (m) != 0) \
441 _pool_var (f) = first_set (_pool_var (m)); \
442 _pool_var (hi) = (_pool_var (i) * BITS (_pool_var (b)[0]) \
443 + min_log2 (_pool_var (f))); \
444 _pool_var (hi) = (_pool_var (i) < _pool_var (bl) \
445 ? _pool_var (hi) : _pool_var (len)); \
446 _pool_var (m) ^= _pool_var (f); \
447 if (_pool_var (hi) > _pool_var (lo)) \
449 (LO) = _pool_var (lo); \
450 (HI) = _pool_var (hi); \
451 do { BODY; } while (0); \
453 _pool_var (lo) = _pool_var (hi) + 1; \
458 /** Iterate through pool.
460 @param VAR A variable of same type as pool vector to be used as an
462 @param POOL The pool to iterate across.
463 @param BODY The operation to perform, typically a code block. See
466 This macro will call @c BODY with each active pool element.
468 It is a bad idea to allocate or free pool element from within
469 @c pool_foreach. Build a vector of indices and dispose of them later.
475 proc_t *procs; // a pool of processes.
476 proc_t *proc; // pointer to one process; used as the iterator.
478 pool_foreach (proc, procs, ({
479 if (proc->state != PROC_STATE_RUNNING)
482 // check a running proc in some way
487 @warning Because @c pool_foreach is a macro, syntax errors can be
488 difficult to find inside @c BODY, let alone actual code bugs. One
489 can temporarily split a complex @c pool_foreach into a trivial
490 @c pool_foreach which builds a vector of active indices, and a
491 vec_foreach() (or plain for-loop) to walk the active index vector.
493 #define pool_foreach(VAR,POOL,BODY) \
495 uword _pool_foreach_lo, _pool_foreach_hi; \
496 pool_foreach_region (_pool_foreach_lo, _pool_foreach_hi, (POOL), \
498 for ((VAR) = (POOL) + _pool_foreach_lo; \
499 (VAR) < (POOL) + _pool_foreach_hi; \
501 do { BODY; } while (0); \
505 /** Returns pointer to element at given index.
507 ASSERTs that the supplied index is valid.
508 Even though one can write correct code of the form
510 p = pool_base + index;
512 use of @c pool_elt_at_index is strongly suggested.
514 #define pool_elt_at_index(p,i) \
516 typeof (p) _e = (p) + (i); \
517 ASSERT (! pool_is_free (p, _e)); \
521 /** Return next occupied pool index after @c i, useful for safe iteration. */
522 #define pool_next_index(P,I) \
524 pool_header_t * _pool_var (p) = pool_header (P); \
525 uword _pool_var (rv) = (I) + 1; \
528 (_pool_var (rv) < vec_len (P) ? \
529 clib_bitmap_next_clear (_pool_var (p)->free_bitmap, _pool_var(rv)) \
532 (_pool_var (rv) < vec_len (P) ? \
533 _pool_var (rv) : ~0); \
537 /** Iterate pool by index. */
538 #define pool_foreach_index(i,v,body) \
539 for ((i) = 0; (i) < vec_len (v); (i)++) \
541 if (! pool_is_free_index ((v), (i))) \
542 do { body; } while (0); \
546 * @brief Remove all elements from a pool in a safe way
548 * @param VAR each element in the pool
549 * @param POOL The pool to flush
550 * @param BODY The actions to perform on each element before it is returned to
551 * the pool. i.e. before it is 'freed'
553 #define pool_flush(VAR, POOL, BODY) \
555 uword *_pool_var(ii), *_pool_var(dv) = NULL; \
557 pool_foreach((VAR), (POOL), \
559 vec_add1(_pool_var(dv), (VAR) - (POOL)); \
561 vec_foreach(_pool_var(ii), _pool_var(dv)) \
563 (VAR) = pool_elt_at_index((POOL), *_pool_var(ii)); \
564 do { BODY; } while (0); \
565 pool_put((POOL), (VAR)); \
567 vec_free(_pool_var(dv)); \
570 #endif /* included_pool_h */
573 * fd.io coding-style-patch-verification: ON
576 * eval: (c-set-style "gnu")