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