summaryrefslogtreecommitdiffstats
path: root/src/vppinfra/mheap.c
blob: b5566bd6389a894091472bf3cf9606cba8e55c95 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

/* Heaps of objects of type T (e.g. int, struct foo, ...).

   Usage.  To declare a null heap:

     T * heap = 0;

   To allocate:

     offset = heap_alloc (heap, size, handle);

   New object is heap[offset] ... heap[offset + size]
   Handle is used to free/query object.

   To free object:

     heap_dealloc (heap, handle);

   To query the size of an object:

     heap_size (heap, handle)

*/

#ifndef included_heap_h
#define included_heap_h

#include <vppinfra/clib.h>
#include <vppinfra/cache.h>
#include <vppinfra/hash.h>
#include <vppinfra/format.h>
#include <vppinfra/bitmap.h>

/* Doubly linked list of elements. */
typedef struct
{
  /* Offset of this element (plus free bit).
     If element is free, data at offset contains pointer to free list. */
  u32 offset;

  /* Index of next and previous elements relative to current element. */
  i32 next, prev;
} heap_elt_t;

/* Use high bit of offset as free bit. */
#define HEAP_ELT_FREE_BIT	(1 << 31)

always_inline uword
heap_is_free (heap_elt_t * e)
{
  return (e->offset & HEAP_ELT_FREE_BIT) != 0;
}

always_inline uword
heap_offset (heap_elt_t * e)
{
  return e->offset & ~HEAP_ELT_FREE_BIT;
}

always_inline heap_elt_t *
heap_next (heap_elt_t * e)
{
  return e + e->next;
}

always_inline heap_elt_t *
heap_prev (heap_elt_t * e)
{
  return e + e->prev;
}

always_inline uword
heap_elt_size (void *v, heap_elt_t * e)
{
  heap_elt_t *n = heap_next (e);
  uword next_offset = n != e ? heap_offset (n) : vec_len (v);
  return next_offset - heap_offset (e);
}

/* Sizes are binned.  Sizes 1 to 2^log2_small_bins have their
   own free lists.  Larger sizes are grouped in powers of two. */
#define HEAP_LOG2_SMALL_BINS	(5)
#define HEAP_SMALL_BINS		(1 << HEAP_LOG2_SMALL_BINS)
#define HEAP_N_BINS		(2 * HEAP_SMALL_BINS)

/* Header for heaps. */
typedef struct
{
  /* Vector of used and free elements. */
  heap_elt_t *elts;

  /* For elt_bytes < sizeof (u32) we need some extra space
     per elt to store free list index. */
  u32 *small_free_elt_free_index;

  /* Vector of free indices of elts array. */
  u32 *free_elts;

  /* Indices of free elts indexed by size bin. */
  u32 **free_lists;

  format_function_t *format_elt;

  /* Used for validation/debugging. */
  uword *used_elt_bitmap;

  /* First and last element of doubly linked chain of elements. */
  u32 head, tail;

  u32 used_count, max_len;

  /* Number of bytes in a help element. */
  u32 elt_bytes;

  u32 flags;
  /* Static heaps are made from external memory given to
     us by user and are not re-sizable vectors. */
#define HEAP_IS_STATIC (1)
} heap_header_t;

/* Start of heap elements is always cache aligned. */
#define HEAP_DATA_ALIGN (CLIB_CACHE_LINE_BYTES)

always_inline heap_header_t *
heap_header (void *v)
{
  return vec_header (v, sizeof (heap_header_t));
}

always_inline uword
heap_header_bytes ()
{
  return vec_header_bytes (sizeof (heap_header_t));
}

always_inline void
heap_dup_header (heap_header_t * old, heap_header_t * new)
{
  uword i;

  new[0] = old[0];
  new->elts = vec_dup (new->elts);
  new->free_elts = vec_dup (new->free_elts);
  new->free_lists = vec_dup (new->free_lists);
  for (i = 0; i < vec_len (new->free_lists); i++)
    new->free_lists[i] = vec_dup (new->free_lists[i]);
  new->used_elt_bitmap = clib_bitmap_dup (new->used_elt_bitmap);
  new->small_free_elt_free_index = vec_dup (new->small_free_elt_free_index);
}

/* Make a duplicate copy of a heap. */
#define heap_dup(v) _heap_dup(v, vec_len (v) * sizeof (v[0]))

always_inline void *
_heap_dup (void *v_old, uword v_bytes)
{
  heap_header_t *h_old, *h_new;
  void *v_new;

  h_old = heap_header (v_old);

  if (!v_old)
    return v_old;

  v_new = 0;
  v_new =
    _vec_resize (v_new, _vec_len (v_old), v_bytes, sizeof (heap_header_t),
		 HEAP_DATA_ALIGN);
  h_new = heap_header (v_new);
  heap_dup_header (h_old, h_new);
  clib_memcpy_fast (v_new, v_old, v_bytes);
  return v_new;
}

always_inline uword
heap_elts (void *v)
{
  heap_header_t *h = heap_header (v);
  return h->used_count;
}

uword heap_bytes (void *v);

always_inline void *
_heap_new (u32 len, u32 n_elt_bytes)
{
  void *v = _vec_resize ((void *) 0, len, (uword) len * n_elt_bytes,
			 sizeof (heap_header_t),
			 HEAP_DATA_ALIGN);
  heap_header (v)->elt_bytes = n_elt_bytes;
  return v;
}

#define heap_new(v) (v) = _heap_new (0, sizeof ((v)[0]))

always_inline void
heap_set_format (void *v, format_function_t * format_elt)
{
  ASSERT (v);
  heap_header (v)->format_elt = format_elt;
}

always_inline void
heap_set_max_len (void *v, uword max_len)
{
  ASSERT (v);
  heap_header (v)->max_len = max_len;
}

always_inline uword
heap_get_max_len (void *v)
{
  return v ? heap_header (v)->max_len : 0;
}

/* Create fixed size heap with given block of memory. */
always_inline void *
heap_create_from_memory (void *memory, uword max_len, uword elt_bytes)
{
  heap_header_t *h;
  void *v;

  if (max_len * elt_bytes < sizeof (h[0]))
    return 0;

  h = memory;
  clib_memset (h, 0, sizeof (h[0]));
  h->max_len = max_len;
  h->elt_bytes = elt_bytes;
  h->flags = HEAP_IS_STATIC;

  v = (void *) (memory + heap_header_bytes ());
  _vec_len (v) = 0;
  return v;
}

/* Execute BODY for each allocated heap element. */
#define heap_foreach(var,len,heap,body)			\
do {							\
  if (vec_len (heap) > 0)				\
    {							\
      heap_header_t * _h = heap_header (heap);		\
      heap_elt_t * _e   = _h->elts + _h->head;		\
      heap_elt_t * _end = _h->elts + _h->tail;		\
      while (1)						\
	{						\
	  if (! heap_is_free (_e))			\
	    {						\
	      (var) = (heap) + heap_offset (_e);	\
	      (len) = heap_elt_size ((heap), _e);	\
	      do { body; } while (0);			\
	    }						\
	  if (_e == _end)				\
	    break;					\
	  _e = heap_next (_e);				\
	}						\
    }							\
} while (0)

#define heap_elt_at_index(v,index) vec_elt_at_index(v,index)

always_inline heap_elt_t *
heap_get_elt (void *v, uword handle)
{
  heap_header_t *h = heap_header (v);
  heap_elt_t *e = vec_elt_at_index (h->elts, handle);
  ASSERT (!heap_is_free (e));
  return e;
}

#define heap_elt_with_handle(v,handle)			\
({							\
  heap_elt_t * _e = heap_get_elt ((v), (handle));	\
  (v) + heap_offset (_e);				\
})

always_inline uword
heap_is_free_handle (void *v, uword heap_handle)
{
  heap_header_t *h = heap_header (v);
  heap_elt_t *e = vec_elt_at_index (h->elts, heap_handle);
  return heap_is_free (e);
}

extern uword heap_len (void *v, word handle);

/* Low level allocation call. */
extern void *_heap_alloc (void *v, uword size, uword alignment,
			  uword elt_bytes, uword * offset, uword * handle);

#define heap_alloc_aligned(v,size,align,handle)			\
({								\
  uword _o, _h;							\
  uword _a = (align);						\
  uword _s = (size);						\
  (v) = _heap_alloc ((v), _s, _a, sizeof ((v)[0]), &_o, &_h);	\
  (handle) = _h;						\
  _o;								\
})

#define heap_alloc(v,size,handle) heap_alloc_aligned((v),(size),0,(handle))

extern void heap_dealloc (void *v, uword handle);
extern void heap_validate (void *v);

/* Format heap internal data structures as string. */
extern u8 *format_heap (u8 * s, va_list * va);

void *_heap_free (void *v);

#define heap_free(v) (v)=_heap_free(v)

#endif /* included_heap_h */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
ref='#n1525'>1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include <vppinfra/bitops.h>
#include <vppinfra/hash.h>
#include <vppinfra/format.h>
#include <vppinfra/mheap.h>
#include <vppinfra/os.h>
#include <vppinfra/time.h>
#include <vppinfra/lock.h>

#ifdef CLIB_UNIX
#include <vppinfra/elf_clib.h>
#endif

static void mheap_get_trace (void *v, uword offset, uword size);
static void mheap_put_trace (void *v, uword offset, uword size);
static int mheap_trace_sort (const void *t1, const void *t2);

always_inline void
mheap_maybe_lock (void *v)
{
  mheap_t *h = mheap_header (v);
  if (v && (h->flags & MHEAP_FLAG_THREAD_SAFE))
    {
      u32 my_cpu = os_get_thread_index ();
      if (h->owner_cpu == my_cpu)
	{
	  h->recursion_count++;
	  return;
	}

      while (clib_atomic_test_and_set (&h->lock))
	CLIB_PAUSE ();

      h->owner_cpu = my_cpu;
      h->recursion_count = 1;
    }
}

always_inline void
mheap_maybe_unlock (void *v)
{
  mheap_t *h = mheap_header (v);
  if (v && h->flags & MHEAP_FLAG_THREAD_SAFE)
    {
      ASSERT (os_get_thread_index () == h->owner_cpu);
      if (--h->recursion_count == 0)
	{
	  h->owner_cpu = ~0;
	  clib_atomic_release (&h->lock);
	}
    }
}

/* Find bin for objects with size at least n_user_data_bytes. */
always_inline uword
user_data_size_to_bin_index (uword n_user_data_bytes)
{
  uword n_user_data_words;
  word small_bin, large_bin;

  /* User size must be at least big enough to hold free elt. */
  n_user_data_bytes = clib_max (n_user_data_bytes, MHEAP_MIN_USER_DATA_BYTES);

  /* Round to words. */
  n_user_data_words =
    (round_pow2 (n_user_data_bytes, MHEAP_USER_DATA_WORD_BYTES) /
     MHEAP_USER_DATA_WORD_BYTES);

  ASSERT (n_user_data_words > 0);
  small_bin =
    n_user_data_words -
    (MHEAP_MIN_USER_DATA_BYTES / MHEAP_USER_DATA_WORD_BYTES);
  ASSERT (small_bin >= 0);

  large_bin =
    MHEAP_N_SMALL_OBJECT_BINS + max_log2 (n_user_data_bytes) -
    MHEAP_LOG2_N_SMALL_OBJECT_BINS;

  return small_bin < MHEAP_N_SMALL_OBJECT_BINS ? small_bin : large_bin;
}

always_inline uword
mheap_elt_size_to_user_n_bytes (uword n_bytes)
{
  ASSERT (n_bytes >= sizeof (mheap_elt_t));
  return (n_bytes - STRUCT_OFFSET_OF (mheap_elt_t, user_data));
}

always_inline uword __attribute__ ((unused))
mheap_elt_size_to_user_n_words (uword n_bytes)
{
  ASSERT (n_bytes % MHEAP_USER_DATA_WORD_BYTES == 0);
  return mheap_elt_size_to_user_n_bytes (n_bytes) /
    MHEAP_USER_DATA_WORD_BYTES;
}

always_inline void
mheap_elt_set_size (void *v,
		    uword uoffset, uword n_user_data_bytes, uword is_free)
{
  mheap_elt_t *e, *n;

  e = mheap_elt_at_uoffset (v, uoffset);

  ASSERT (n_user_data_bytes % MHEAP_USER_DATA_WORD_BYTES == 0);

  e->n_user_data = n_user_data_bytes / MHEAP_USER_DATA_WORD_BYTES;
  e->is_free = is_free;
  ASSERT (e->prev_n_user_data * sizeof (e->user_data[0]) >=
	  MHEAP_MIN_USER_DATA_BYTES);

  n = mheap_next_elt (e);
  n->prev_n_user_data = e->n_user_data;
  n->prev_is_free = is_free;
}

always_inline void
set_first_free_elt_offset (mheap_t * h, uword bin, uword uoffset)
{
  uword i0, i1;

  h->first_free_elt_uoffset_by_bin[bin] = uoffset;

  i0 = bin / BITS (h->non_empty_free_elt_heads[0]);
  i1 = (uword) 1 << (uword) (bin % BITS (h->non_empty_free_elt_heads[0]));

  ASSERT (i0 < ARRAY_LEN (h->non_empty_free_elt_heads));
  if (h->first_free_elt_uoffset_by_bin[bin] == MHEAP_GROUNDED)
    h->non_empty_free_elt_heads[i0] &= ~i1;
  else
    h->non_empty_free_elt_heads[i0] |= i1;
}

always_inline void
set_free_elt (void *v, uword uoffset, uword n_user_data_bytes)
{
  mheap_t *h = mheap_header (v);
  mheap_elt_t *e = mheap_elt_at_uoffset (v, uoffset);
  mheap_elt_t *n = mheap_next_elt (e);
  uword bin = user_data_size_to_bin_index (n_user_data_bytes);

  ASSERT (n->prev_is_free);
  ASSERT (e->is_free);

  e->free_elt.prev_uoffset = MHEAP_GROUNDED;
  e->free_elt.next_uoffset = h->first_free_elt_uoffset_by_bin[bin];

  /* Fill in next free elt's previous pointer. */
  if (e->free_elt.next_uoffset != MHEAP_GROUNDED)
    {
      mheap_elt_t *nf = mheap_elt_at_uoffset (v, e->free_elt.next_uoffset);
      ASSERT (nf->is_free);
      nf->free_elt.prev_uoffset = uoffset;
    }

  set_first_free_elt_offset (h, bin, uoffset);
}

always_inline void
new_free_elt (void *v, uword uoffset, uword n_user_data_bytes)
{
  mheap_elt_set_size (v, uoffset, n_user_data_bytes, /* is_free */ 1);
  set_free_elt (v, uoffset, n_user_data_bytes);
}

always_inline void
remove_free_elt (void *v, mheap_elt_t * e, uword bin)
{
  mheap_t *h = mheap_header (v);
  mheap_elt_t *p, *n;
#if CLIB_VEC64 > 0
  u64 no, po;
#else
  u32 no, po;
#endif

  no = e->free_elt.next_uoffset;

  n = no != MHEAP_GROUNDED ? mheap_elt_at_uoffset (v, no) : 0;
  po = e->free_elt.prev_uoffset;
  p = po != MHEAP_GROUNDED ? mheap_elt_at_uoffset (v, po) : 0;

  if (!p)
    set_first_free_elt_offset (h, bin, no);
  else
    p->free_elt.next_uoffset = no;

  if (n)
    n->free_elt.prev_uoffset = po;
}

always_inline void
remove_free_elt2 (void *v, mheap_elt_t * e)
{
  uword bin;
  bin = user_data_size_to_bin_index (mheap_elt_data_bytes (e));
  remove_free_elt (v, e, bin);
}

#define MHEAP_VM_MAP		(1 << 0)
#define MHEAP_VM_UNMAP		(1 << 1)
#define MHEAP_VM_NOMAP		(0 << 1)
#define MHEAP_VM_ROUND		(1 << 2)
#define MHEAP_VM_ROUND_UP	MHEAP_VM_ROUND
#define MHEAP_VM_ROUND_DOWN	(0 << 2)

static uword mheap_page_size;

static_always_inline uword
mheap_page_round (uword addr)
{
  return (addr + mheap_page_size - 1) & ~(mheap_page_size - 1);
}

static_always_inline uword
mheap_page_truncate (uword addr)
{
  return addr & ~(mheap_page_size - 1);
}

static_always_inline uword
mheap_vm (void *v, uword flags, clib_address_t start_addr, uword size)
{
  mheap_t *h = mheap_header (v);
  clib_address_t start_page, end_page, end_addr;
  uword mapped_bytes;

  ASSERT (!(h->flags & MHEAP_FLAG_DISABLE_VM));

  end_addr = start_addr + size;

  /* Round start/end address up to page boundary. */
  start_page = mheap_page_round (start_addr);

  if ((flags & MHEAP_VM_ROUND) == MHEAP_VM_ROUND_UP)
    end_page = mheap_page_round (end_addr);
  else
    end_page = mheap_page_truncate (end_addr);

  mapped_bytes = 0;
  if (end_page > start_page)
    {
      mapped_bytes = end_page - start_page;
      if (flags & MHEAP_VM_MAP)
	clib_mem_vm_map ((void *) start_page, end_page - start_page);
      else if (flags & MHEAP_VM_UNMAP)
	clib_mem_vm_unmap ((void *) start_page, end_page - start_page);
    }

  return mapped_bytes;
}

static_always_inline uword
mheap_vm_elt (void *v, uword flags, uword offset)
{
  mheap_elt_t *e;
  clib_address_t start_addr, end_addr;

  e = mheap_elt_at_uoffset (v, offset);
  start_addr = (clib_address_t) ((void *) e->user_data);
  end_addr = (clib_address_t) mheap_next_elt (e);
  return mheap_vm (v, flags, start_addr, end_addr - start_addr);
}

always_inline uword
mheap_small_object_cache_mask (mheap_small_object_cache_t * c, uword bin)
{
  uword mask;

/* $$$$ ELIOT FIXME: add Altivec version of this routine */
#if !defined (CLIB_HAVE_VEC128) || defined (__ALTIVEC__) || defined (__i386__)
  mask = 0;
#else
  u8x16 b = u8x16_splat (bin);

  ASSERT (bin < 256);

#define _(i) ((uword) u8x16_compare_byte_mask ((b == c->bins.as_u8x16[i])) << (uword) ((i)*16))
  mask = _(0) | _(1);
  if (BITS (uword) > 32)
    mask |= _(2) | _(3);
#undef _

#endif
  return mask;
}

always_inline uword
mheap_get_small_object (mheap_t * h, uword bin)
{
  mheap_small_object_cache_t *c = &h->small_object_cache;
  uword mask = mheap_small_object_cache_mask (c, bin + 1);
  uword offset = MHEAP_GROUNDED;

  if (mask)
    {
      uword i = min_log2 (mask);
      uword o = c->offsets[i];
      ASSERT (o != MHEAP_GROUNDED);
      c->bins.as_u8[i] = 0;
      offset = o;
    }

  return offset;
}

always_inline uword
mheap_put_small_object (mheap_t * h, uword bin, uword offset)
{
  mheap_small_object_cache_t *c = &h->small_object_cache;
  uword free_mask = mheap_small_object_cache_mask (c, 0);
  uword b = bin + 1;
  uword i;

  if (free_mask != 0)
    {
      i = min_log2 (free_mask);
      c->bins.as_u8[i] = b;
      c->offsets[i] = offset;
      return 0;
    }
  else
    /* Nothing free with right size: cyclic replacement. */
    {
      uword old_offset;

      i = c->replacement_index++;
      i %= BITS (uword);
      c->bins.as_u8[i] = b;
      old_offset = c->offsets[i];
      c->offsets[i] = offset;

      /* Return old offset so it can be freed. */
      return old_offset;
    }
}

static uword
mheap_get_search_free_bin (void *v,
			   uword bin,
			   uword * n_user_data_bytes_arg,
			   uword align, uword align_offset)
{
  mheap_t *h = mheap_header (v);
  mheap_elt_t *e;

  /* Free object is at offset f0 ... f1;
     Allocatted object is at offset o0 ... o1. */
  word o0, o1, f0, f1, search_n_user_data_bytes;
  word lo_free_usize, hi_free_usize;

  ASSERT (h->first_free_elt_uoffset_by_bin[bin] != MHEAP_GROUNDED);
  e = mheap_elt_at_uoffset (v, h->first_free_elt_uoffset_by_bin[bin]);

  search_n_user_data_bytes = *n_user_data_bytes_arg;

  /* Silence compiler warning. */
  o0 = o1 = f0 = f1 = 0;

  h->stats.free_list.n_search_attempts += 1;

  /* Find an object that is large enough with correct alignment at given alignment offset. */
  while (1)
    {
      uword this_object_n_user_data_bytes = mheap_elt_data_bytes (e);

      ASSERT (e->is_free);
      if (bin < MHEAP_N_SMALL_OBJECT_BINS)
	ASSERT (this_object_n_user_data_bytes >= search_n_user_data_bytes);

      h->stats.free_list.n_objects_searched += 1;

      if (this_object_n_user_data_bytes < search_n_user_data_bytes)
	goto next;

      /* Bounds of free object: from f0 to f1. */
      f0 = ((void *) e->user_data - v);
      f1 = f0 + this_object_n_user_data_bytes;

      /* Place candidate object at end of free block and align as requested. */
      o0 = ((f1 - search_n_user_data_bytes) & ~(align - 1)) - align_offset;
      while (o0 < f0)
	o0 += align;

      /* Make sure that first free fragment is either empty or
         large enough to be valid. */
      while (1)
	{
	  lo_free_usize = o0 != f0 ? o0 - f0 - MHEAP_ELT_OVERHEAD_BYTES : 0;
	  if (o0 <= f0 || lo_free_usize >= (word) MHEAP_MIN_USER_DATA_BYTES)
	    break;
	  o0 -= align;
	}

      o1 = o0 + search_n_user_data_bytes;

      /* Does it fit? */
      if (o0 >= f0 && o1 <= f1)
	goto found;

    next:
      /* Reached end of free list without finding large enough object. */
      if (e->free_elt.next_uoffset == MHEAP_GROUNDED)
	return MHEAP_GROUNDED;

      /* Otherwise keep searching for large enough object. */
      e = mheap_elt_at_uoffset (v, e->free_elt.next_uoffset);
    }

found:
  /* Free fragment at end. */
  hi_free_usize = f1 != o1 ? f1 - o1 - MHEAP_ELT_OVERHEAD_BYTES : 0;

  /* If fragment at end is too small to be a new object,
     give user's object a bit more space than requested. */
  if (hi_free_usize < (word) MHEAP_MIN_USER_DATA_BYTES)
    {
      search_n_user_data_bytes += f1 - o1;
      o1 = f1;
      hi_free_usize = 0;
    }

  /* Need to make sure that relevant memory areas are mapped. */
  if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
    {
      mheap_elt_t *f0_elt = mheap_elt_at_uoffset (v, f0);
      mheap_elt_t *f1_elt = mheap_elt_at_uoffset (v, f1);
      mheap_elt_t *o0_elt = mheap_elt_at_uoffset (v, o0);
      mheap_elt_t *o1_elt = mheap_elt_at_uoffset (v, o1);

      uword f0_page_start, f0_page_end;
      uword o0_page_start, o0_page_end;

      /* Free elt is mapped.  Addresses after that may not be mapped. */
      f0_page_start = mheap_page_round (pointer_to_uword (f0_elt->user_data));
      f0_page_end = mheap_page_truncate (pointer_to_uword (f1_elt));

      o0_page_start = mheap_page_truncate (pointer_to_uword (o0_elt));
      o0_page_end = mheap_page_round (pointer_to_uword (o1_elt->user_data));

      if (o0_page_start < f0_page_start)
	o0_page_start = f0_page_start;
      if (o0_page_end > f0_page_end)
	o0_page_end = f0_page_end;

      if (o0_page_end > o0_page_start)
	clib_mem_vm_map (uword_to_pointer (o0_page_start, void *),
			 o0_page_end - o0_page_start);
    }

  /* Remove free object from free list. */
  remove_free_elt (v, e, bin);

  /* Free fragment at begining. */
  if (lo_free_usize > 0)
    {
      ASSERT (lo_free_usize >= (word) MHEAP_MIN_USER_DATA_BYTES);
      mheap_elt_set_size (v, f0, lo_free_usize, /* is_free */ 1);
      new_free_elt (v, f0, lo_free_usize);
    }

  mheap_elt_set_size (v, o0, search_n_user_data_bytes, /* is_free */ 0);

  if (hi_free_usize > 0)
    {
      uword uo = o1 + MHEAP_ELT_OVERHEAD_BYTES;
      mheap_elt_set_size (v, uo, hi_free_usize, /* is_free */ 1);
      new_free_elt (v, uo, hi_free_usize);
    }

  /* Return actual size of block. */
  *n_user_data_bytes_arg = search_n_user_data_bytes;

  h->stats.free_list.n_objects_found += 1;

  return o0;
}

/* Search free lists for object with given size and alignment. */
static uword
mheap_get_search_free_list (void *v,
			    uword * n_user_bytes_arg,
			    uword align, uword align_offset)
{
  mheap_t *h = mheap_header (v);
  uword bin, n_user_bytes, i, bi;

  n_user_bytes = *n_user_bytes_arg;
  bin = user_data_size_to_bin_index (n_user_bytes);

  if (MHEAP_HAVE_SMALL_OBJECT_CACHE
      && (h->flags & MHEAP_FLAG_SMALL_OBJECT_CACHE)
      && bin < 255
      && align == STRUCT_SIZE_OF (mheap_elt_t, user_data[0])
      && align_offset == 0)
    {
      uword r = mheap_get_small_object (h, bin);
      h->stats.n_small_object_cache_attempts += 1;
      if (r != MHEAP_GROUNDED)
	{
	  h->stats.n_small_object_cache_hits += 1;
	  return r;
	}
    }

  for (i = bin / BITS (uword); i < ARRAY_LEN (h->non_empty_free_elt_heads);
       i++)
    {
      uword non_empty_bin_mask = h->non_empty_free_elt_heads[i];

      /* No need to search smaller bins. */
      if (i == bin / BITS (uword))
	non_empty_bin_mask &= ~pow2_mask (bin % BITS (uword));

      /* Search each occupied free bin which is large enough. */
      /* *INDENT-OFF* */
      foreach_set_bit (bi, non_empty_bin_mask,
      ({
        uword r =
          mheap_get_search_free_bin (v, bi + i * BITS (uword),
                                     n_user_bytes_arg,
                                     align,
                                     align_offset);
        if (r != MHEAP_GROUNDED) return r;
      }));
      /* *INDENT-ON* */
    }

  return MHEAP_GROUNDED;
}

static never_inline void *
mheap_get_extend_vector (void *v,
			 uword n_user_data_bytes,
			 uword align,
			 uword align_offset, uword * offset_return)
{
  /* Bounds of free and allocated objects (as above). */
  uword f0, f1, o0, o1;
  word free_size;
  mheap_t *h = mheap_header (v);
  mheap_elt_t *e;

  if (_vec_len (v) == 0)
    {
      _vec_len (v) = MHEAP_ELT_OVERHEAD_BYTES;

      /* Create first element of heap. */
      e = mheap_elt_at_uoffset (v, _vec_len (v));
      e->prev_n_user_data = MHEAP_N_USER_DATA_INVALID;
    }

  f0 = _vec_len (v);

  o0 = round_pow2 (f0, align) - align_offset;
  while (1)
    {
      free_size = o0 - f0 - MHEAP_ELT_OVERHEAD_BYTES;
      if (o0 == f0 || free_size >= (word) sizeof (mheap_elt_t))
	break;

      o0 += align;
    }

  o1 = o0 + n_user_data_bytes;
  f1 = o1 + MHEAP_ELT_OVERHEAD_BYTES;

  ASSERT (v != 0);
  h = mheap_header (v);

  /* Make sure we have space for object plus overhead. */
  if (f1 > h->max_size)
    {
      *offset_return = MHEAP_GROUNDED;
      return v;
    }

  _vec_len (v) = f1;

  if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
    {
      mheap_elt_t *f0_elt = mheap_elt_at_uoffset (v, f0);
      mheap_elt_t *f1_elt = mheap_elt_at_uoffset (v, f1);

      uword f0_page = mheap_page_round (pointer_to_uword (f0_elt->user_data));
      uword f1_page = mheap_page_round (pointer_to_uword (f1_elt->user_data));

      if (f1_page > f0_page)
	mheap_vm (v, MHEAP_VM_MAP, f0_page, f1_page - f0_page);
    }

  if (free_size > 0)
    new_free_elt (v, f0, free_size);

  mheap_elt_set_size (v, o0, n_user_data_bytes, /* is_free */ 0);

  /* Mark last element. */
  e = mheap_elt_at_uoffset (v, f1);
  e->n_user_data = MHEAP_N_USER_DATA_INVALID;

  *offset_return = o0;

  return v;
}

void *
mheap_get_aligned (void *v,
		   uword n_user_data_bytes,
		   uword align, uword align_offset, uword * offset_return)
{
  mheap_t *h;
  uword offset;
  u64 cpu_times[2];

  cpu_times[0] = clib_cpu_time_now ();

  align = clib_max (align, STRUCT_SIZE_OF (mheap_elt_t, user_data[0]));
  align = max_pow2 (align);

  /* Correct align offset to be smaller than alignment. */
  align_offset &= (align - 1);

  /* Align offset must be multiple of minimum object size. */
  if (align_offset % STRUCT_SIZE_OF (mheap_elt_t, user_data[0]) != 0)
    {
      *offset_return = MHEAP_GROUNDED;
      return v;
    }

  /*
   * Round requested size.
   *
   * Step 1: round up to the minimum object size.
   * Step 2: round up to a multiple of the user data size (e.g. 4)
   * Step 3: if non-trivial alignment requested, round up
   *         so that the object precisely fills a chunk
   *         as big as the alignment request.
   *
   * Step 3 prevents the code from going into "bin search hyperspace":
   * looking at a huge number of fractional remainder chunks, none of which
   * will satisfy the alignment constraint. This fixes an allocator
   * performance issue when one requests a large number of 16 byte objects
   * aligned to 64 bytes, to name one variation on the theme.
   */
  n_user_data_bytes = clib_max (n_user_data_bytes, MHEAP_MIN_USER_DATA_BYTES);
  n_user_data_bytes =
    round_pow2 (n_user_data_bytes,
		STRUCT_SIZE_OF (mheap_elt_t, user_data[0]));
  if (align > MHEAP_ELT_OVERHEAD_BYTES)
    n_user_data_bytes = clib_max (n_user_data_bytes,
				  align - MHEAP_ELT_OVERHEAD_BYTES);
  if (!v)
    v = mheap_alloc (0, 64 << 20);

  mheap_maybe_lock (v);

  h = mheap_header (v);

  if (h->flags & MHEAP_FLAG_VALIDATE)
    mheap_validate (v);

  /* First search free lists for object. */
  offset =
    mheap_get_search_free_list (v, &n_user_data_bytes, align, align_offset);

  h = mheap_header (v);

  /* If that fails allocate object at end of heap by extending vector. */
  if (offset == MHEAP_GROUNDED && _vec_len (v) < h->max_size)
    {
      v =
	mheap_get_extend_vector (v, n_user_data_bytes, align, align_offset,
				 &offset);
      h = mheap_header (v);
      h->stats.n_vector_expands += offset != MHEAP_GROUNDED;
    }

  *offset_return = offset;
  if (offset != MHEAP_GROUNDED)
    {
      h->n_elts += 1;

      if (h->flags & MHEAP_FLAG_TRACE)
	{
	  /* Recursion block for case when we are traceing main clib heap. */
	  h->flags &= ~MHEAP_FLAG_TRACE;

	  mheap_get_trace (v, offset, n_user_data_bytes);

	  h->flags |= MHEAP_FLAG_TRACE;
	}
    }

  if (h->flags & MHEAP_FLAG_VALIDATE)
    mheap_validate (v);

  mheap_maybe_unlock (v);

  cpu_times[1] = clib_cpu_time_now ();
  h->stats.n_clocks_get += cpu_times[1] - cpu_times[0];
  h->stats.n_gets += 1;

  return v;
}

static void
free_last_elt (void *v, mheap_elt_t * e)
{
  mheap_t *h = mheap_header (v);

  /* Possibly delete preceeding free element also. */
  if (e->prev_is_free)
    {
      e = mheap_prev_elt (e);
      remove_free_elt2 (v, e);
    }

  if (e->prev_n_user_data == MHEAP_N_USER_DATA_INVALID)
    {
      if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
	mheap_vm_elt (v, MHEAP_VM_UNMAP, mheap_elt_uoffset (v, e));
      _vec_len (v) = 0;
    }
  else
    {
      uword uo = mheap_elt_uoffset (v, e);
      if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
	mheap_vm_elt (v, MHEAP_VM_UNMAP, uo);
      e->n_user_data = MHEAP_N_USER_DATA_INVALID;
      _vec_len (v) = uo;
    }
}

void
mheap_put (void *v, uword uoffset)
{
  mheap_t *h;
  uword n_user_data_bytes, bin;
  mheap_elt_t *e, *n;
  uword trace_uoffset, trace_n_user_data_bytes;
  u64 cpu_times[2];

  cpu_times[0] = clib_cpu_time_now ();

  h = mheap_header (v);

  mheap_maybe_lock (v);

  if (h->flags & MHEAP_FLAG_VALIDATE)
    mheap_validate (v);

  ASSERT (h->n_elts > 0);
  h->n_elts--;
  h->stats.n_puts += 1;

  e = mheap_elt_at_uoffset (v, uoffset);
  n = mheap_next_elt (e);
  n_user_data_bytes = mheap_elt_data_bytes (e);

  trace_uoffset = uoffset;
  trace_n_user_data_bytes = n_user_data_bytes;

  bin = user_data_size_to_bin_index (n_user_data_bytes);
  if (MHEAP_HAVE_SMALL_OBJECT_CACHE
      && bin < 255 && (h->flags & MHEAP_FLAG_SMALL_OBJECT_CACHE))
    {
      uoffset = mheap_put_small_object (h, bin, uoffset);
      if (uoffset == 0)
	goto done;

      e = mheap_elt_at_uoffset (v, uoffset);
      n = mheap_next_elt (e);
      n_user_data_bytes = mheap_elt_data_bytes (e);
    }

  /* Assert that forward and back pointers are equal. */
  if (e->n_user_data != n->prev_n_user_data)
    os_panic ();

  /* Forward and backwards is_free must agree. */
  if (e->is_free != n->prev_is_free)
    os_panic ();

  /* Object was already freed. */
  if (e->is_free)
    os_panic ();

  /* Special case: delete last element in heap. */
  if (n->n_user_data == MHEAP_N_USER_DATA_INVALID)
    free_last_elt (v, e);

  else
    {
      uword f0, f1, n_combine;

      f0 = uoffset;
      f1 = f0 + n_user_data_bytes;
      n_combine = 0;

      if (e->prev_is_free)
	{
	  mheap_elt_t *p = mheap_prev_elt (e);
	  f0 = mheap_elt_uoffset (v, p);
	  remove_free_elt2 (v, p);
	  n_combine++;
	}

      if (n->is_free)
	{
	  mheap_elt_t *m = mheap_next_elt (n);
	  f1 = (void *) m - v;
	  remove_free_elt2 (v, n);
	  n_combine++;
	}

      if (n_combine)
	mheap_elt_set_size (v, f0, f1 - f0, /* is_free */ 1);
      else
	e->is_free = n->prev_is_free = 1;
      set_free_elt (v, f0, f1 - f0);

      if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
	mheap_vm_elt (v, MHEAP_VM_UNMAP, f0);
    }

done:
  h = mheap_header (v);

  if (h->flags & MHEAP_FLAG_TRACE)
    {
      /* Recursion block for case when we are traceing main clib heap. */
      h->flags &= ~MHEAP_FLAG_TRACE;

      mheap_put_trace (v, trace_uoffset, trace_n_user_data_bytes);

      h->flags |= MHEAP_FLAG_TRACE;
    }

  if (h->flags & MHEAP_FLAG_VALIDATE)
    mheap_validate (v);

  mheap_maybe_unlock (v);

  cpu_times[1] = clib_cpu_time_now ();
  h->stats.n_clocks_put += cpu_times[1] - cpu_times[0];
}

void *
mheap_alloc_with_flags (void *memory, uword memory_size, uword flags)
{
  mheap_t *h;
  void *v;
  uword size;

  if (!mheap_page_size)
    mheap_page_size = clib_mem_get_page_size ();

  if (!memory)
    {
      /* No memory given, try to VM allocate some. */
      memory = clib_mem_vm_alloc (memory_size);
      if (!memory)
	return 0;

      /* No memory region implies we have virtual memory. */
      flags &= ~MHEAP_FLAG_DISABLE_VM;
    }

  /* Make sure that given memory is page aligned. */
  {
    uword am, av, ah;

    am = pointer_to_uword (memory);
    av = mheap_page_round (am);
    v = uword_to_pointer (av, void *);
    h = mheap_header (v);
    ah = pointer_to_uword (h);
    while (ah < am)
      ah += mheap_page_size;

    h = uword_to_pointer (ah, void *);
    v = mheap_vector (h);

    if (PREDICT_FALSE (memory + memory_size < v))
      {
	/*
	 * This will happen when the requested memory_size is too
	 * small to cope with the heap header and/or memory alignment.
	 */
	clib_mem_vm_free (memory, memory_size);
	return 0;
      }

    size = memory + memory_size - v;
  }

  /* VM map header so we can use memory. */
  if (!(flags & MHEAP_FLAG_DISABLE_VM))
    clib_mem_vm_map (h, sizeof (h[0]));

  /* Zero vector header: both heap header and vector length. */
  clib_memset (h, 0, sizeof (h[0]));
  _vec_len (v) = 0;

  h->vm_alloc_offset_from_header = (void *) h - memory;
  h->vm_alloc_size = memory_size;

  h->max_size = size;
  h->owner_cpu = ~0;

  /* Set flags based on those given less builtin-flags. */
  h->flags |= (flags & ~MHEAP_FLAG_TRACE);

  /* Unmap remainder of heap until we will be ready to use it. */
  if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
    mheap_vm (v, MHEAP_VM_UNMAP | MHEAP_VM_ROUND_UP,
	      (clib_address_t) v, h->max_size);

  /* Initialize free list heads to empty. */
  clib_memset (h->first_free_elt_uoffset_by_bin, 0xFF,
	       sizeof (h->first_free_elt_uoffset_by_bin));

  return v;
}

void *
mheap_alloc (void *memory, uword size)
{
  uword flags = 0;

  if (memory != 0)
    flags |= MHEAP_FLAG_DISABLE_VM;

#ifdef CLIB_HAVE_VEC128
  flags |= MHEAP_FLAG_SMALL_OBJECT_CACHE;
#endif

  return mheap_alloc_with_flags (memory, size, flags);
}

void *
mheap_alloc_with_lock (void *memory, uword size, int locked)
{
  uword flags = 0;
  void *rv;

  if (memory != 0)
    flags |= MHEAP_FLAG_DISABLE_VM;

#ifdef CLIB_HAVE_VEC128
  flags |= MHEAP_FLAG_SMALL_OBJECT_CACHE;
#endif

  rv = mheap_alloc_with_flags (memory, size, flags);

  if (rv && locked)
    {
      mheap_t *h = mheap_header (rv);
      h->flags |= MHEAP_FLAG_THREAD_SAFE;
    }
  return rv;
}

void *
_mheap_free (void *v)
{
  mheap_t *h = mheap_header (v);

  if (v)
    clib_mem_vm_free ((void *) h - h->vm_alloc_offset_from_header,
		      h->vm_alloc_size);

  return 0;
}

/* Call user's function with each object in heap. */
void
mheap_foreach (void *v,
	       uword (*func) (void *arg, void *v, void *elt_data,
			      uword elt_size), void *arg)
{
  mheap_elt_t *e;
  u8 *stack_heap, *clib_mem_mheap_save;
  u8 tmp_heap_memory[16 * 1024];

  mheap_maybe_lock (v);

  if (vec_len (v) == 0)
    goto done;

  clib_mem_mheap_save = 0;
  stack_heap = 0;

  /* Allocate a new temporary heap on the stack.
     This is so that our hash table & user's callback function can
     themselves allocate memory somewhere without getting in the way
     of the heap we are looking at. */
  if (v == clib_mem_get_heap ())
    {
      stack_heap = mheap_alloc (tmp_heap_memory, sizeof (tmp_heap_memory));
      clib_mem_mheap_save = v;
      clib_mem_set_heap (stack_heap);
    }

  for (e = v;
       e->n_user_data != MHEAP_N_USER_DATA_INVALID; e = mheap_next_elt (e))
    {
      void *p = mheap_elt_data (v, e);
      if (e->is_free)
	continue;
      if ((*func) (arg, v, p, mheap_elt_data_bytes (e)))
	break;
    }

  /* Restore main CLIB heap. */
  if (clib_mem_mheap_save)
    clib_mem_set_heap (clib_mem_mheap_save);

done:
  mheap_maybe_unlock (v);
}

/* Bytes in mheap header overhead not including data bytes. */
always_inline uword
mheap_bytes_overhead (void *v)
{
  mheap_t *h = mheap_header (v);
  return v ? sizeof (h[0]) + h->n_elts * sizeof (mheap_elt_t) : 0;
}

/* Total number of bytes including both data and overhead. */
uword
mheap_bytes (void *v)
{
  return mheap_bytes_overhead (v) + vec_bytes (v);
}

static void
mheap_usage_no_lock (void *v, clib_mem_usage_t * usage)
{
  mheap_t *h = mheap_header (v);
  uword used = 0, free = 0, free_vm_unmapped = 0;

  if (vec_len (v) > 0)
    {
      mheap_elt_t *e;

      for (e = v;
	   e->n_user_data != MHEAP_N_USER_DATA_INVALID;
	   e = mheap_next_elt (e))
	{
	  uword size = mheap_elt_data_bytes (e);
	  if (e->is_free)
	    {
	      free += size;
	      if (!(h->flags & MHEAP_FLAG_DISABLE_VM))
		free_vm_unmapped +=
		  mheap_vm_elt (v, MHEAP_VM_NOMAP, mheap_elt_uoffset (v, e));
	    }
	  else
	    used += size;
	}
    }

  usage->object_count = mheap_elts (v);
  usage->bytes_total = mheap_bytes (v);
  usage->bytes_overhead = mheap_bytes_overhead (v);
  usage->bytes_max = mheap_max_size (v);
  usage->bytes_used = used;
  usage->bytes_free = free;
  usage->bytes_free_reclaimed = free_vm_unmapped;
}

void
mheap_usage (void *v, clib_mem_usage_t * usage)
{
  mheap_maybe_lock (v);
  mheap_usage_no_lock (v, usage);
  mheap_maybe_unlock (v);
}

static u8 *
format_mheap_byte_count (u8 * s, va_list * va)
{
  uword n_bytes = va_arg (*va, uword);
  if (n_bytes < 1024)
    return format (s, "%wd", n_bytes);
  else
    return format (s, "%wdk", n_bytes / 1024);
}

/* Returns first corrupt heap element. */
static mheap_elt_t *
mheap_first_corrupt (void *v)
{
  mheap_elt_t *e, *n;

  if (vec_len (v) == 0)
    return 0;

  e = v;
  while (1)
    {
      if (e->n_user_data == MHEAP_N_USER_DATA_INVALID)
	break;

      n = mheap_next_elt (e);

      if (e->n_user_data != n->prev_n_user_data)
	return e;

      if (e->is_free != n->prev_is_free)
	return e;

      e = n;
    }

  return 0;
}

static u8 *
format_mheap_stats (u8 * s, va_list * va)
{
  mheap_t *h = va_arg (*va, mheap_t *);
  mheap_stats_t *st = &h->stats;
  u32 indent = format_get_indent (s);

  s =
    format (s,
	    "alloc. from small object cache: %Ld hits %Ld attempts (%.2f%%) replacements %d",
	    st->n_small_object_cache_hits, st->n_small_object_cache_attempts,
	    (st->n_small_object_cache_attempts !=
	     0 ? 100. * (f64) st->n_small_object_cache_hits /
	     (f64) st->n_small_object_cache_attempts : 0.),
	    h->small_object_cache.replacement_index);

  s =
    format (s,
	    "\n%Ualloc. from free-list: %Ld attempts, %Ld hits (%.2f%%), %Ld considered (per-attempt %.2f)",
	    format_white_space, indent, st->free_list.n_search_attempts,
	    st->free_list.n_objects_found,
	    (st->free_list.n_search_attempts !=
	     0 ? 100. * (f64) st->free_list.n_objects_found /
	     (f64) st->free_list.n_search_attempts : 0.),
	    st->free_list.n_objects_searched,
	    (st->free_list.n_search_attempts !=
	     0 ? (f64) st->free_list.n_objects_searched /
	     (f64) st->free_list.n_search_attempts : 0.));

  s = format (s, "\n%Ualloc. from vector-expand: %Ld",
	      format_white_space, indent, st->n_vector_expands);

  s = format (s, "\n%Uallocs: %Ld %.2f clocks/call",
	      format_white_space, indent,
	      st->n_gets, (f64) st->n_clocks_get / (f64) st->n_gets);

  s = format (s, "\n%Ufrees: %Ld %.2f clocks/call",
	      format_white_space, indent,
	      st->n_puts, (f64) st->n_clocks_put / (f64) st->n_puts);

  return s;
}

u8 *
format_mheap (u8 * s, va_list * va)
{
  void *v = va_arg (*va, u8 *);
  int verbose = va_arg (*va, int);

  mheap_t *h;
  uword i, size;
  u32 indent;
  clib_mem_usage_t usage;
  mheap_elt_t *first_corrupt;

  mheap_maybe_lock (v);

  h = mheap_header (v);

  mheap_usage_no_lock (v, &usage);

  indent = format_get_indent (s);

  s =
    format (s,
	    "%d objects, %U of %U used, %U free, %U reclaimed, %U overhead",
	    usage.object_count, format_mheap_byte_count, usage.bytes_used,
	    format_mheap_byte_count, usage.bytes_total,
	    format_mheap_byte_count, usage.bytes_free,
	    format_mheap_byte_count, usage.bytes_free_reclaimed,
	    format_mheap_byte_count, usage.bytes_overhead);

  if (usage.bytes_max != ~0)
    s = format (s, ", %U capacity", format_mheap_byte_count, usage.bytes_max);

  /* Show histogram of sizes. */
  if (verbose > 1)
    {
      uword hist[MHEAP_N_BINS];
      mheap_elt_t *e;
      uword i, n_hist;

      clib_memset (hist, 0, sizeof (hist));

      n_hist = 0;
      for (e = v;
	   e->n_user_data != MHEAP_N_USER_DATA_INVALID;
	   e = mheap_next_elt (e))
	{
	  uword n_user_data_bytes = mheap_elt_data_bytes (e);
	  uword bin = user_data_size_to_bin_index (n_user_data_bytes);
	  if (!e->is_free)
	    {
	      hist[bin] += 1;
	      n_hist += 1;
	    }
	}

      s = format (s, "\n%U%=12s%=12s%=16s",
		  format_white_space, indent + 2,
		  "Size", "Count", "Fraction");

      for (i = 0; i < ARRAY_LEN (hist); i++)
	{
	  if (hist[i] == 0)
	    continue;
	  s = format (s, "\n%U%12d%12wd%16.4f",
		      format_white_space, indent + 2,
		      MHEAP_MIN_USER_DATA_BYTES +
		      i * MHEAP_USER_DATA_WORD_BYTES, hist[i],
		      (f64) hist[i] / (f64) n_hist);
	}
    }

  if (verbose)
    s = format (s, "\n%U%U",
		format_white_space, indent + 2, format_mheap_stats, h);

  if ((h->flags & MHEAP_FLAG_TRACE) && vec_len (h->trace_main.traces) > 0)
    {
      /* Make a copy of traces since we'll be sorting them. */
      mheap_trace_t *t, *traces_copy;
      u32 indent, total_objects_traced;

      traces_copy = vec_dup (h->trace_main.traces);
      qsort (traces_copy, vec_len (traces_copy), sizeof (traces_copy[0]),
	     mheap_trace_sort);

      total_objects_traced = 0;
      s = format (s, "\n");
      vec_foreach (t, traces_copy)
      {
	/* Skip over free elements. */
	if (t->n_allocations == 0)
	  continue;

	total_objects_traced += t->n_allocations;

	/* When not verbose only report allocations of more than 1k. */
	if (!verbose && t->n_bytes < 1024)
	  continue;

	if (t == traces_copy)
	  s = format (s, "%=9s%=9s %=10s Traceback\n", "Bytes", "Count",
		      "Sample");
	s = format (s, "%9d%9d %p", t->n_bytes, t->n_allocations,
		    t->offset + v);
	indent = format_get_indent (s);
	for (i = 0; i < ARRAY_LEN (t->callers) && t->callers[i]; i++)
	  {
	    if (i > 0)
	      s = format (s, "%U", format_white_space, indent);
#ifdef CLIB_UNIX
	    s =
	      format (s, " %U\n", format_clib_elf_symbol_with_address,
		      t->callers[i]);
#else
	    s = format (s, " %p\n", t->callers[i]);
#endif
	  }
      }

      s = format (s, "%d total traced objects\n", total_objects_traced);

      vec_free (traces_copy);
    }

  first_corrupt = mheap_first_corrupt (v);
  if (first_corrupt)
    {
      size = mheap_elt_data_bytes (first_corrupt);
      s = format (s, "\n  first corrupt object: %p, size %wd\n  %U",
		  first_corrupt, size, format_hex_bytes, first_corrupt, size);
    }

  /* FIXME.  This output could be wrong in the unlikely case that format
     uses the same mheap as we are currently inspecting. */
  if (verbose > 1)
    {
      mheap_elt_t *e;
      uword i, o;

      s = format (s, "\n");

      e = mheap_elt_at_uoffset (v, 0);
      i = 0;
      while (1)
	{
	  if ((i % 8) == 0)
	    s = format (s, "%8d: ", i);

	  o = mheap_elt_uoffset (v, e);

	  if (e->is_free)
	    s = format (s, "(%8d) ", o);
	  else
	    s = format (s, " %8d  ", o);

	  if ((i % 8) == 7 || (i + 1) >= h->n_elts)
	    s = format (s, "\n");
	}
    }

  mheap_maybe_unlock (v);

  return s;
}

void
dmh (void *v)
{
  fformat (stderr, "%U", format_mheap, v, 1);
}

static void
mheap_validate_breakpoint ()
{
  os_panic ();
}

void
mheap_validate (void *v)
{
  mheap_t *h = mheap_header (v);
  uword i, s;

  uword elt_count, elt_size;
  uword free_count_from_free_lists, free_size_from_free_lists;
  uword small_elt_free_count, small_elt_free_size;

#define CHECK(x) if (! (x)) { mheap_validate_breakpoint (); os_panic (); }

  if (vec_len (v) == 0)
    return;

  mheap_maybe_lock (v);

  /* Validate number of elements and size. */
  free_size_from_free_lists = free_count_from_free_lists = 0;
  for (i = 0; i < ARRAY_LEN (h->first_free_elt_uoffset_by_bin); i++)
    {
      mheap_elt_t *e, *n;
      uword is_first;

      CHECK ((h->first_free_elt_uoffset_by_bin[i] != MHEAP_GROUNDED)
	     ==
	     ((h->non_empty_free_elt_heads[i /
					   BITS (uword)] & ((uword) 1 <<
							    (uword) (i %
								     BITS
								     (uword))))
	      != 0));

      if (h->first_free_elt_uoffset_by_bin[i] == MHEAP_GROUNDED)
	continue;

      e = mheap_elt_at_uoffset (v, h->first_free_elt_uoffset_by_bin[i]);
      is_first = 1;
      while (1)
	{
	  uword s;

	  n = mheap_next_elt (e);

	  /* Object must be marked free. */
	  CHECK (e->is_free);

	  /* Next object's previous free bit must also be set. */
	  CHECK (n->prev_is_free);

	  if (is_first)
	    CHECK (e->free_elt.prev_uoffset == MHEAP_GROUNDED);
	  is_first = 0;

	  s = mheap_elt_data_bytes (e);
	  CHECK (user_data_size_to_bin_index (s) == i);

	  free_count_from_free_lists += 1;
	  free_size_from_free_lists += s;

	  if (e->free_elt.next_uoffset == MHEAP_GROUNDED)
	    break;

	  n = mheap_elt_at_uoffset (v, e->free_elt.next_uoffset);

	  /* Check free element linkages. */
	  CHECK (n->free_elt.prev_uoffset == mheap_elt_uoffset (v, e));

	  e = n;
	}
    }

  /* Go through small object cache. */
  small_elt_free_count = small_elt_free_size = 0;
  for (i = 0; i < ARRAY_LEN (h->small_object_cache.bins.as_u8); i++)
    {
      if (h->small_object_cache.bins.as_u8[i] != 0)
	{
	  mheap_elt_t *e;
	  uword b = h->small_object_cache.bins.as_u8[i] - 1;
	  uword o = h->small_object_cache.offsets[i];
	  uword s;

	  e = mheap_elt_at_uoffset (v, o);

	  /* Object must be allocated. */
	  CHECK (!e->is_free);

	  s = mheap_elt_data_bytes (e);
	  CHECK (user_data_size_to_bin_index (s) == b);

	  small_elt_free_count += 1;
	  small_elt_free_size += s;
	}
    }

  {
    mheap_elt_t *e, *n;
    uword elt_free_size, elt_free_count;

    elt_count = elt_size = elt_free_size = elt_free_count = 0;
    for (e = v; e->n_user_data != MHEAP_N_USER_DATA_INVALID; e = n)
      {
	if (e->prev_n_user_data != MHEAP_N_USER_DATA_INVALID)
	  CHECK (e->prev_n_user_data * sizeof (e->user_data[0]) >=
		 MHEAP_MIN_USER_DATA_BYTES);

	CHECK (e->n_user_data * sizeof (e->user_data[0]) >=
	       MHEAP_MIN_USER_DATA_BYTES);

	n = mheap_next_elt (e);

	CHECK (e->is_free == n->prev_is_free);

	elt_count++;
	s = mheap_elt_data_bytes (e);
	elt_size += s;

	if (e->is_free)
	  {
	    elt_free_count++;
	    elt_free_size += s;
	  }

	/* Consecutive free objects should have been combined. */
	CHECK (!(e->prev_is_free && n->prev_is_free));
      }

    CHECK (free_count_from_free_lists == elt_free_count);
    CHECK (free_size_from_free_lists == elt_free_size);
    CHECK (elt_count == h->n_elts + elt_free_count + small_elt_free_count);
    CHECK (elt_size + (elt_count + 1) * MHEAP_ELT_OVERHEAD_BYTES ==
	   vec_len (v));
  }

  {
    mheap_elt_t *e, *n;

    for (e = v; e->n_user_data == MHEAP_N_USER_DATA_INVALID; e = n)
      {
	n = mheap_next_elt (e);
	CHECK (e->n_user_data == n->prev_n_user_data);
      }
  }

#undef CHECK

  mheap_maybe_unlock (v);

  h->validate_serial += 1;
}

static void
mheap_get_trace (void *v, uword offset, uword size)
{
  mheap_t *h;
  mheap_trace_main_t *tm;
  mheap_trace_t *t;
  uword i, n_callers, trace_index, *p;
  mheap_trace_t trace;

  /* Spurious Coverity warnings be gone. */
  clib_memset (&trace, 0, sizeof (trace));

  n_callers = clib_backtrace (trace.callers, ARRAY_LEN (trace.callers),
			      /* Skip mheap_get_aligned's frame */ 1);
  if (n_callers == 0)
    return;

  for (i = n_callers; i < ARRAY_LEN (trace.callers); i++)
    trace.callers[i] = 0;

  h = mheap_header (v);
  tm = &h->trace_main;

  if (!tm->trace_by_callers)
    tm->trace_by_callers =
      hash_create_shmem (0, sizeof (trace.callers), sizeof (uword));

  p = hash_get_mem (tm->trace_by_callers, &trace.callers);
  if (p)
    {
      trace_index = p[0];
      t = tm->traces + trace_index;
    }
  else
    {
      i = vec_len (tm->trace_free_list);
      if (i > 0)
	{
	  trace_index = tm->trace_free_list[i - 1];
	  _vec_len (tm->trace_free_list) = i - 1;
	}
      else
	{
	  mheap_trace_t *old_start = tm->traces;
	  mheap_trace_t *old_end = vec_end (tm->traces);

	  vec_add2 (tm->traces, t, 1);

	  if (tm->traces != old_start)
	    {
	      hash_pair_t *p;
	      mheap_trace_t *q;
            /* *INDENT-OFF* */
	    hash_foreach_pair (p, tm->trace_by_callers,
            ({
              q = uword_to_pointer (p->key, mheap_trace_t *);
              ASSERT (q >= old_start && q < old_end);
	      p->key = pointer_to_uword (tm->traces + (q - old_start));
	    }));
            /* *INDENT-ON* */
	    }
	  trace_index = t - tm->traces;
	}

      t = tm->traces + trace_index;
      t[0] = trace;
      t->n_allocations = 0;
      t->n_bytes = 0;
      hash_set_mem (tm->trace_by_callers, t->callers, trace_index);
    }

  t->n_allocations += 1;
  t->n_bytes += size;
  t->offset = offset;		/* keep a sample to autopsy */
  hash_set (tm->trace_index_by_offset, offset, t - tm->traces);
}

static void
mheap_put_trace (void *v, uword offset, uword size)
{
  mheap_t *h;
  mheap_trace_main_t *tm;
  mheap_trace_t *t;
  uword trace_index, *p;

  h = mheap_header (v);
  tm = &h->trace_main;
  p = hash_get (tm->trace_index_by_offset, offset);
  if (!p)
    return;

  trace_index = p[0];
  hash_unset (tm->trace_index_by_offset, offset);
  ASSERT (trace_index < vec_len (tm->traces));

  t = tm->traces + trace_index;
  ASSERT (t->n_allocations > 0);
  ASSERT (t->n_bytes >= size);
  t->n_allocations -= 1;
  t->n_bytes -= size;
  if (t->n_allocations == 0)
    {
      hash_unset_mem (tm->trace_by_callers, t->callers);
      vec_add1 (tm->trace_free_list, trace_index);
      clib_memset (t, 0, sizeof (t[0]));
    }
}

static int
mheap_trace_sort (const void *_t1, const void *_t2)
{
  const mheap_trace_t *t1 = _t1;
  const mheap_trace_t *t2 = _t2;
  word cmp;

  cmp = (word) t2->n_bytes - (word) t1->n_bytes;
  if (!cmp)
    cmp = (word) t2->n_allocations - (word) t1->n_allocations;
  return cmp;
}

always_inline void
mheap_trace_main_free (mheap_trace_main_t * tm)
{
  vec_free (tm->traces);
  vec_free (tm->trace_free_list);
  hash_free (tm->trace_by_callers);
  hash_free (tm->trace_index_by_offset);
}

void
mheap_trace (void *v, int enable)
{
  mheap_t *h;

  h = mheap_header (v);

  if (enable)
    {
      h->flags |= MHEAP_FLAG_TRACE;
    }
  else
    {
      mheap_trace_main_free (&h->trace_main);
      h->flags &= ~MHEAP_FLAG_TRACE;
    }
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */