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 * \file mempool.h
30 * \brief Interface for memory pool implementations.
31 * \author Mike Becker
32 * \author Olaf Wintermann
33 * \version 3.0
34 * \copyright 2-Clause BSD License
35 */
36
37 #ifndef UCX_MEMPOOL_H
38 #define UCX_MEMPOOL_H
39
40 #include "common.h"
41 #include "allocator.h"
42
43 #ifdef __cplusplus
44 extern "C" {
45 #endif
46
47 /** Internal structure for pooled memory. */
48 struct cx_mempool_memory_s;
49
50 /**
51 * The basic structure of a memory pool.
52 * Should be the first member of an actual memory pool implementation.
53 */
54 struct cx_mempool_s {
55 /** The provided allocator. */
56 CxAllocator const *allocator;
57
58 /**
59 * A destructor that shall be automatically registered for newly allocated memory.
60 * This destructor MUST NOT free the memory.
61 */
62 cx_destructor_func auto_destr;
63
64 /** Array of pooled memory. */
65 struct cx_mempool_memory_s **data;
66
67 /** Number of pooled memory items. */
68 size_t size;
69
70 /** Memory pool capacity. */
71 size_t capacity;
72 };
73
74 /**
75 * Common type for all memory pool implementations.
76 */
77 typedef struct cx_mempool_s CxMempool;
78
79 /**
80 * Creates an array-based memory pool with a shared destructor function.
81 *
82 * This destructor MUST NOT free the memory.
83 *
84 * @param capacity the initial capacity of the pool
85 * @param destr the destructor function to use for allocated memory
86 * @return the created memory pool or \c NULL if allocation failed
87 */
88 __attribute__((__warn_unused_result__))
89 CxMempool *cxMempoolCreate(size_t capacity, cx_destructor_func destr);
90
91 /**
92 * Creates a basic array-based memory pool.
93 *
94 * @param capacity the initial capacity of the pool
95 * @return the created memory pool or \c NULL if allocation failed
96 */
97 __attribute__((__warn_unused_result__))
98 static inline CxMempool *cxBasicMempoolCreate(size_t capacity) {
99 return cxMempoolCreate(capacity, NULL);
100 }
101
102 /**
103 * Destroys a memory pool and frees the managed memory.
104 *
105 * @param pool the memory pool to destroy
106 */
107 __attribute__((__nonnull__))
108 void cxMempoolDestroy(CxMempool *pool);
109
110 /**
111 * Sets the destructor function for a specific allocated memory object.
112 *
113 * If the memory is not managed by a UCX memory pool, the behavior is undefined.
114 * The destructor MUST NOT free the memory.
115 *
116 * @param memory the object allocated in the pool
117 * @param fnc the destructor function
118 */
119 __attribute__((__nonnull__))
120 void cxMempoolSetDestructor(
121 void *memory,
122 cx_destructor_func fnc
123 );
124
125 /**
126 * Registers foreign memory with this pool.
127 *
128 * The destructor, in contrast to memory allocated by the pool, MUST free the memory.
129 *
130 * A small portion of memory will be allocated to register the information in the pool.
131 * If that allocation fails, this function will return non-zero.
132 *
133 * @param pool the pool
134 * @param memory the object allocated in the pool
135 * @param destr the destructor function
136 * @return zero on success, non-zero on failure
137 */
138 __attribute__((__nonnull__))
139 int cxMempoolRegister(
140 CxMempool *pool,
141 void *memory,
142 cx_destructor_func destr
143 );
144
145 #ifdef __cplusplus
146 } // extern "C"
147 #endif
148
149 #endif // UCX_MEMPOOL_H
150