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pooled_alloc.c
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1 /*
2 Copyright (c) 2009 Genome Research Ltd.
3 Author: Rob Davies <rmd@sanger.ac.uk>
4 
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
7 
8  1. Redistributions of source code must retain the above copyright notice,
9 this list of conditions and the following disclaimer.
10 
11  2. Redistributions in binary form must reproduce the above copyright notice,
12 this list of conditions and the following disclaimer in the documentation
13 and/or other materials provided with the distribution.
14 
15  3. Neither the names Genome Research Ltd and Wellcome Trust Sanger
16 Institute nor the names of its contributors may be used to endorse or promote
17 products derived from this software without specific prior written permission.
18 
19 THIS SOFTWARE IS PROVIDED BY GENOME RESEARCH LTD AND CONTRIBUTORS "AS IS" AND
20 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 DISCLAIMED. IN NO EVENT SHALL GENOME RESEARCH LTD OR CONTRIBUTORS BE LIABLE
23 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
26 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30 
31 #ifdef HAVE_CONFIG_H
32 #include "io_lib_config.h"
33 #endif
34 
35 #include <stdlib.h>
36 #include <stdio.h>
37 #include <stdint.h>
38 
39 #include "cram/pooled_alloc.h"
40 
41 //#define TEST_MAIN
42 
43 #define PSIZE 1024*1024
44 
45 pool_alloc_t *pool_create(size_t dsize) {
46  pool_alloc_t *p;
47 
48  if (NULL == (p = (pool_alloc_t *)malloc(sizeof(*p))))
49  return NULL;
50 
51  /* Minimum size is a pointer, for free list */
52  dsize = (dsize + sizeof(void *) - 1) & ~(sizeof(void *)-1);
53  if (dsize < sizeof(void *))
54  dsize = sizeof(void *);
55  p->dsize = dsize;
56 
57  p->npools = 0;
58  p->pools = NULL;
59  p->free = NULL;
60 
61  return p;
62 }
63 
64 static pool_t *new_pool(pool_alloc_t *p) {
65  size_t n = PSIZE / p->dsize;
66  pool_t *pool;
67 
68  pool = realloc(p->pools, (p->npools + 1) * sizeof(*p->pools));
69  if (NULL == pool) return NULL;
70  p->pools = pool;
71  pool = &p->pools[p->npools];
72 
73  pool->pool = malloc(n * p->dsize);
74  if (NULL == pool->pool) return NULL;
75 
76  pool->used = 0;
77 
78  p->npools++;
79 
80  return pool;
81 }
82 
84  size_t i;
85 
86  for (i = 0; i < p->npools; i++) {
87  free(p->pools[i].pool);
88  }
89  free(p->pools);
90  free(p);
91 }
92 
94  pool_t *pool;
95  void *ret;
96 
97  /* Look on free list */
98  if (NULL != p->free) {
99  ret = p->free;
100  p->free = *((void **)p->free);
101  return ret;
102  }
103 
104  /* Look for space in the last pool */
105  if (p->npools) {
106  pool = &p->pools[p->npools - 1];
107  if (pool->used + p->dsize < PSIZE) {
108  ret = ((char *) pool->pool) + pool->used;
109  pool->used += p->dsize;
110  return ret;
111  }
112  }
113 
114  /* Need a new pool */
115  pool = new_pool(p);
116  if (NULL == pool) return NULL;
117 
118  pool->used = p->dsize;
119  return pool->pool;
120 }
121 
122 void pool_free(pool_alloc_t *p, void *ptr) {
123  *(void **)ptr = p->free;
124  p->free = ptr;
125 }
126 
127 #ifdef TEST_MAIN
128 typedef struct {
129  int x, y, z;
130 } xyz;
131 
132 #define NP 10000
133 int main(void) {
134  int i;
135  xyz *item;
136  xyz **items;
137  pool_alloc_t *p = pool_create(sizeof(xyz));
138 
139  items = (xyz **)malloc(NP * sizeof(*items));
140 
141  for (i = 0; i < NP; i++) {
142  item = pool_alloc(p);
143  item->x = i;
144  item->y = i+1;
145  item->z = i+2;
146  items[i] = item;
147  }
148 
149  for (i = 0; i < NP; i++) {
150  item = items[i];
151  if (i % 3)
152  pool_free(p, item);
153  }
154 
155  for (i = 0; i < NP; i++) {
156  item = pool_alloc(p);
157  item->x = 1000000+i;
158  item->y = 1000000+i+1;
159  item->z = 1000000+i+2;
160  }
161 
162  for (i = 0; i < NP; i++) {
163  item = items[i];
164  printf("%d\t%d\t%d\t%d\n", i, item->x, item->y, item->z);
165  pool_free(p, item);
166  }
167 
168  return 0;
169 }
170 #endif