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 */
28
29 #include "cx/mempool.h"
30 #include "cx/utils.h"
31 #include <string.h>
32
33 struct cx_mempool_memory_s {
34 /** The destructor. */
35 cx_destructor_func destructor;
36 /** The actual memory. */
37 char c[];
38 };
39
40 static void *cx_mempool_malloc(
41 void *p,
42 size_t n
43 ) {
44 struct cx_mempool_s *pool = p;
45
46 if (pool->size >= pool->capacity) {
47 size_t newcap = pool->capacity - (pool->capacity % 16) + 16;
48 struct cx_mempool_memory_s **newdata = realloc(pool->data, newcap*sizeof(struct cx_mempool_memory_s*));
49 if (newdata == NULL) {
50 return NULL;
51 }
52 pool->data = newdata;
53 pool->capacity = newcap;
54 }
55
56 struct cx_mempool_memory_s *mem = malloc(sizeof(cx_destructor_func) + n);
57 if (mem == NULL) {
58 return NULL;
59 }
60
61 mem->destructor = pool->auto_destr;
62 pool->data[pool->size] = mem;
63 pool->size++;
64
65 return mem->c;
66 }
67
68 static void *cx_mempool_calloc(
69 void *p,
70 size_t nelem,
71 size_t elsize
72 ) {
73 size_t msz;
74 if (cx_szmul(nelem, elsize, &msz)) {
75 return NULL;
76 }
77 void *ptr = cx_mempool_malloc(p, msz);
78 if (ptr == NULL) {
79 return NULL;
80 }
81 memset(ptr, 0, nelem * elsize);
82 return ptr;
83 }
84
85 static void *cx_mempool_realloc(
86 void *p,
87 void *ptr,
88 size_t n
89 ) {
90 struct cx_mempool_s *pool = p;
91
92 struct cx_mempool_memory_s *mem, *newm;
93 mem = (struct cx_mempool_memory_s*)(((char *) ptr) - sizeof(cx_destructor_func));
94 newm = realloc(mem, n + sizeof(cx_destructor_func));
95
96 if (newm == NULL) {
97 return NULL;
98 }
99 if (mem != newm) {
100 cx_for_n(i, pool->size) {
101 if (pool->data[i] == mem) {
102 pool->data[i] = newm;
103 return ((char*)newm) + sizeof(cx_destructor_func);
104 }
105 }
106 abort();
107 } else {
108 return ptr;
109 }
110 }
111
112 static void cx_mempool_free(
113 void *p,
114 void *ptr
115 ) {
116 if (!ptr) return;
117 struct cx_mempool_s *pool = p;
118
119 struct cx_mempool_memory_s *mem = (struct cx_mempool_memory_s *)
120 ((char *) ptr - sizeof(cx_destructor_func));
121
122 cx_for_n(i, pool->size) {
123 if (mem == pool->data[i]) {
124 if (mem->destructor) {
125 mem->destructor(mem->c);
126 }
127 free(mem);
128 size_t last_index = pool->size - 1;
129 if (i != last_index) {
130 pool->data[i] = pool->data[last_index];
131 pool->data[last_index] = NULL;
132 }
133 pool->size--;
134 return;
135 }
136 }
137 abort();
138 }
139
140 void cxMempoolDestroy(CxMempool *pool) {
141 struct cx_mempool_memory_s *mem;
142 cx_for_n(i, pool->size) {
143 mem = pool->data[i];
144 if (mem->destructor) {
145 mem->destructor(mem->c);
146 }
147 free(mem);
148 }
149 free(pool->data);
150 free((void*) pool->allocator);
151 free(pool);
152 }
153
154 void cxMempoolSetDestructor(
155 void *ptr,
156 cx_destructor_func func
157 ) {
158 *(cx_destructor_func *) ((char *) ptr - sizeof(cx_destructor_func)) = func;
159 }
160
161 struct cx_mempool_foreign_mem_s {
162 cx_destructor_func destr;
163 void* mem;
164 };
165
166 static void cx_mempool_destr_foreign_mem(void* ptr) {
167 struct cx_mempool_foreign_mem_s *fm = ptr;
168 fm->destr(fm->mem);
169 }
170
171 int cxMempoolRegister(
172 CxMempool *pool,
173 void *memory,
174 cx_destructor_func destr
175 ) {
176 struct cx_mempool_foreign_mem_s *fm = cx_mempool_malloc(
177 pool,
178 sizeof(struct cx_mempool_foreign_mem_s)
179 );
180 if (fm == NULL) return 1;
181
182 fm->mem = memory;
183 fm->destr = destr;
184 *(cx_destructor_func *) ((char *) fm - sizeof(cx_destructor_func)) = cx_mempool_destr_foreign_mem;
185
186 return 0;
187 }
188
189 static cx_allocator_class cx_mempool_allocator_class = {
190 cx_mempool_malloc,
191 cx_mempool_realloc,
192 cx_mempool_calloc,
193 cx_mempool_free
194 };
195
196 CxMempool *cxMempoolCreate(
197 size_t capacity,
198 cx_destructor_func destr
199 ) {
200 size_t poolsize;
201 if (cx_szmul(capacity, sizeof(struct cx_mempool_memory_s*), &poolsize)) {
202 return NULL;
203 }
204
205 struct cx_mempool_s *pool =
206 malloc(sizeof(struct cx_mempool_s));
207 if (pool == NULL) {
208 return NULL;
209 }
210
211 CxAllocator *provided_allocator = malloc(sizeof(CxAllocator));
212 if (provided_allocator == NULL) {
213 free(pool);
214 return NULL;
215 }
216 provided_allocator->cl = &cx_mempool_allocator_class;
217 provided_allocator->data = pool;
218
219 pool->allocator = provided_allocator;
220
221 pool->data = malloc(poolsize);
222 if (pool->data == NULL) {
223 free(provided_allocator);
224 free(pool);
225 return NULL;
226 }
227
228 pool->size = 0;
229 pool->capacity = capacity;
230 pool->auto_destr = destr;
231
232 return (CxMempool *) pool;
233 }
234