src/basic_mempool.c@f83583a0bbac
src/basic_mempool.c
Wed, 03 Aug 2022 17:27:55 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Wed, 03 Aug 2022 17:27:55 +0200
- changeset 571
- f83583a0bbac
- child 572
- f0f99dd06d9f
- permissions
- -rw-r--r--
#201 - add mempool implementation
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
29 #include "cx/basic_mempool.h"
30 #include "cx/utils.h"
31 #include <stdint.h>
32 #include <string.h>
34 #define of_chk_(n) if (SIZE_MAX - sizeof(cx_destructor_func) < (n)) return NULL
36 /** Internal structure for denoting pooled memory. */
37 typedef struct {
38 /** The destructor. */
39 cx_destructor_func destructor;
40 /**
41 * Access to the first byte of the polled memory.
42 */
43 char c;
44 } cx_basic_mempool_memory;
46 static int cx_basic_mempool_chcap(
47 struct cx_basic_mempool_s *pool,
48 size_t newcap
49 ) {
50 if (newcap < pool->ndata) {
51 return 1;
52 }
54 size_t newcapsz;
55 if (cx_szmul(newcap, sizeof(void *), &newcapsz)) {
56 return 1;
57 }
59 void **data = realloc(pool->data, newcapsz);
60 if (data) {
61 pool->data = data;
62 pool->size = newcap;
63 return 0;
64 } else {
65 return 1;
66 }
67 }
69 void *cx_malloc_basic_mempool(
70 void *data,
71 size_t n
72 ) {
73 of_chk_(n);
74 struct cx_basic_mempool_s *pool = data;
76 if (pool->ndata >= pool->size) {
77 size_t newcap = pool->size * 2;
78 if (newcap < pool->size || cx_basic_mempool_chcap(pool, newcap)) {
79 return NULL;
80 }
81 }
83 cx_basic_mempool_memory *mem = cxMalloc(pool->allocator,
84 sizeof(cx_destructor_func) + n);
85 if (mem == NULL) {
86 return NULL;
87 }
89 mem->destructor = NULL;
90 pool->data[pool->ndata] = mem;
91 pool->ndata++;
93 return &(mem->c);
94 }
96 void *cx_calloc_basic_mempool(
97 void *data,
98 size_t nelem,
99 size_t elsize
100 ) {
101 size_t msz;
102 if (cx_szmul(nelem, elsize, &msz)) {
103 return NULL;
104 }
105 void *ptr = cx_malloc_basic_mempool(data, msz);
106 if (ptr == NULL) {
107 return NULL;
108 }
109 memset(ptr, 0, nelem * elsize);
110 return ptr;
111 }
113 void *cx_realloc_basic_mempool(
114 void *data,
115 void *ptr,
116 size_t n
117 ) {
118 of_chk_(n);
119 struct cx_basic_mempool_s *pool = data;
121 char *mem = ((char *) ptr) - sizeof(cx_destructor_func);
122 char *newm = (char *) cxRealloc(pool->allocator, mem,
123 n + sizeof(cx_destructor_func));
124 if (newm == NULL) {
125 return NULL;
126 }
127 if (mem != newm) {
128 cx_for_n(i, pool->ndata) {
129 if (pool->data[i] == mem) {
130 pool->data[i] = newm;
131 return newm + sizeof(cx_destructor_func);
132 }
133 }
134 abort();
135 } else {
136 return newm + sizeof(cx_destructor_func);
137 }
138 }
140 void cx_free_basic_mempool(
141 void *data,
142 void *ptr
143 ) {
144 struct cx_basic_mempool_s *pool = data;
146 cx_basic_mempool_memory *mem = (cx_basic_mempool_memory *)
147 ((char *) ptr - sizeof(cx_destructor_func));
148 cx_for_n(i, pool->ndata) {
149 if (mem == pool->data[i]) {
150 if (mem->destructor != NULL) {
151 mem->destructor(&(mem->c));
152 }
153 cxFree(pool->allocator, mem);
154 size_t last_index = pool->ndata - 1;
155 if (i != last_index) {
156 pool->data[i] = pool->data[last_index];
157 pool->data[last_index] = NULL;
158 }
159 pool->ndata--;
160 return;
161 }
162 }
163 abort();
164 }
166 void cx_basic_mempool_destroy(CxMempool *p) {
167 struct cx_basic_mempool_s *pool = (struct cx_basic_mempool_s *) p;
168 cx_basic_mempool_memory *mem;
169 cx_for_n(i, pool->ndata) {
170 mem = (cx_basic_mempool_memory *) pool->data[i];
171 if (mem) {
172 if (mem->destructor) {
173 mem->destructor(&(mem->c));
174 }
175 cxFree(pool->allocator, mem);
176 }
177 }
178 free(pool->data);
179 free((void *) p->allocator);
180 free(pool);
181 }
183 void cx_basic_mempool_set_destr(
184 __attribute__((__unused__)) CxMempool *pool,
185 void *ptr,
186 cx_destructor_func func
187 ) {
188 *(cx_destructor_func *) ((char *) ptr - sizeof(cx_destructor_func)) = func;
189 }
191 static cx_allocator_class cx_basic_mempool_allocator_class = {
192 cx_malloc_basic_mempool,
193 cx_realloc_basic_mempool,
194 cx_calloc_basic_mempool,
195 cx_free_basic_mempool
196 };
198 static cx_mempool_class cx_basic_mempool_class = {
199 cx_basic_mempool_destroy,
200 cx_basic_mempool_set_destr,
201 };
203 CxMempool *cxBasicMempoolCreate(
204 size_t capacity,
205 CxAllocator *allocator
206 ) {
207 size_t poolsize;
208 if (cx_szmul(capacity, sizeof(void *), &poolsize)) {
209 return NULL;
210 }
212 struct cx_basic_mempool_s *pool =
213 malloc(sizeof(struct cx_basic_mempool_s));
214 if (pool == NULL) {
215 return NULL;
216 }
219 CxAllocator *provided_allocator = malloc(sizeof(CxAllocator));
220 if (!provided_allocator) {
221 free(pool);
222 return NULL;
223 }
224 provided_allocator->cl = &cx_basic_mempool_allocator_class;
225 provided_allocator->data = pool;
227 pool->base.cl = &cx_basic_mempool_class;
228 pool->base.allocator = provided_allocator;
230 pool->data = malloc(poolsize);
231 if (pool->data == NULL) {
232 free(provided_allocator);
233 free(pool);
234 return NULL;
235 }
237 pool->ndata = 0;
238 pool->size = capacity;
239 pool->allocator = allocator;
241 return (CxMempool *) pool;
242 }
