ucx/mempool.h@4f02199d8aae
ucx/mempool.h
Thu, 15 Oct 2015 14:59:25 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Thu, 15 Oct 2015 14:59:25 +0200
- changeset 209
- 4f02199d8aae
- parent 192
- 1e51558b9d09
- child 215
- e0853e077770
- permissions
- -rw-r--r--
moved ucx_destructor type to ucx.h and added destructor argument to ucx_map_free_content
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2015 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 /**
30 * @file mempool.h
31 *
32 * Memory pool implementation.
33 *
34 * @author Mike Becker
35 * @author Olaf Wintermann
36 */
38 #ifndef UCX_MEMPOOL_H
39 #define UCX_MEMPOOL_H
41 #include "ucx.h"
42 #include <stddef.h>
43 #include "allocator.h"
45 #ifdef __cplusplus
46 extern "C" {
47 #endif
49 /**
50 * UCX mempool structure.
51 */
52 typedef struct {
53 /** UcxAllocator based on this pool */
54 UcxAllocator *allocator;
56 /** List of pointers to pooled memory. */
57 void **data;
59 /** Count of pooled memory items. */
60 size_t ndata;
62 /** Memory pool size. */
63 size_t size;
64 } UcxMempool;
66 /** Shorthand for a new default memory pool with a capacity of 16 elements. */
67 #define ucx_mempool_new_default() ucx_mempool_new(16)
70 /**
71 * Creates a memory pool with the specified initial size.
72 *
73 * As the created memory pool automatically grows in size by 16 elements, when
74 * trying to allocate memory on a full pool, it is recommended that you use
75 * a multiple of 16 for the initial size.
76 *
77 * @param n initial pool size (should be a multiple of 16)
78 * @return a pointer to the new memory pool
79 */
80 UcxMempool *ucx_mempool_new(size_t n);
82 /**
83 * Resizes a memory pool.
84 *
85 * @param pool the pool to resize
86 * @param newcap the new capacity
87 * @return <code>EXIT_SUCCESS</code> on success or
88 * <code>EXIT_FAILURE</code> on failure
89 */
90 int ucx_mempool_chcap(UcxMempool *pool, size_t newcap);
92 /**
93 * Changes the pool size to the next smallest multiple of 16.
94 *
95 * You may use this macro, to reduce the pool size after freeing
96 * many pooled memory items.
97 *
98 * @param pool the pool to clamp
99 * @return <code>EXIT_SUCCESS</code> on success or
100 * <code>EXIT_FAILURE</code> on failure
101 */
102 #define ucx_mempool_clamp(pool) ucx_mempool_chcap(pool, \
103 (pool->ndata & ~0xF)+0x10)
105 /**
106 * Allocates pooled memory.
107 *
108 * @param pool the memory pool
109 * @param n amount of memory to allocate
110 * @return a pointer to the allocated memory
111 * @see ucx_allocator_malloc()
112 */
113 void *ucx_mempool_malloc(UcxMempool *pool, size_t n);
114 /**
115 * Allocates a pooled memory array.
116 *
117 * The content of the allocated memory is set to zero.
118 *
119 * @param pool the memory pool
120 * @param nelem amount of elements to allocate
121 * @param elsize amount of memory per element
122 * @return a pointer to the allocated memory
123 * @see ucx_allocator_calloc()
124 */
125 void *ucx_mempool_calloc(UcxMempool *pool, size_t nelem, size_t elsize);
127 /**
128 * Reallocates pooled memory.
129 *
130 * If the memory to be reallocated is not contained by the specified pool, this
131 * function will possibly fail. In case the memory had to be moved to another
132 * location, this function will print out a message to <code>stderr</code>
133 * and exit the program with error code <code>EXIT_FAILURE</code>.
134 *
135 * @param pool the memory pool
136 * @param ptr a pointer to the memory that shall be reallocated
137 * @param n the new size of the memory
138 * @return a pointer to the new location of the memory
139 * @see ucx_allocator_realloc()
140 */
141 void *ucx_mempool_realloc(UcxMempool *pool, void *ptr, size_t n);
143 /**
144 * Frees pooled memory.
145 *
146 * Before freeing the memory, the specified destructor function (if any)
147 * is called.
148 *
149 * If you specify memory, that is not pooled by the specified memory pool, this
150 * is considered as a severe error and an error message is written to
151 * <code>stderr</code> and the application is shut down with code
152 * <code>EXIT_FAILURE</code>.
153 *
154 * @param pool the memory pool
155 * @param ptr a pointer to the memory that shall be freed
156 * @see ucx_mempool_set_destr()
157 */
158 void ucx_mempool_free(UcxMempool *pool, void *ptr);
160 /**
161 * Destroys a memory pool.
162 *
163 * For each element the destructor function (if any) is called and the element
164 * is freed.
165 *
166 * Each of the registered destructor function that has no corresponding element
167 * within the pool (namely those registered by ucx_mempool_reg_destr) is
168 * called interleaving with the element destruction, but with guarantee to the
169 * order in which they were registered (FIFO order).
170 *
171 *
172 * @param pool the mempool to destroy
173 */
174 void ucx_mempool_destroy(UcxMempool *pool);
176 /**
177 * Sets a destructor function for the specified memory.
178 *
179 * The destructor is automatically called when the memory is freed or the
180 * pool is destroyed.
181 *
182 * The only requirement for the specified memory is, that it <b>MUST</b> be
183 * pooled memory by an UcxMempool or an element-compatible mempool. The pointer
184 * to the destructor function is saved in a reserved area before the actual
185 * memory.
186 *
187 * @param ptr pooled memory
188 * @param func a pointer to the destructor function
189 * @see ucx_mempool_free()
190 * @see ucx_mempool_destroy()
191 */
192 void ucx_mempool_set_destr(void *ptr, ucx_destructor func);
194 /**
195 * Registers a destructor function for the specified (non-pooled) memory.
196 *
197 * This is useful, if you have memory that has not been allocated by a mempool,
198 * but shall be managed by a mempool.
199 *
200 * This function creates an entry in the specified mempool and the memory will
201 * therefore (logically) convert to pooled memory.
202 *
203 * @param pool the memory pool
204 * @param ptr data the destructor is registered for
205 * @param destr a pointer to the destructor function
206 */
207 void ucx_mempool_reg_destr(UcxMempool *pool, void *ptr, ucx_destructor destr);
209 #ifdef __cplusplus
210 }
211 #endif
213 #endif /* UCX_MEMPOOL_H */
