1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/ucx/mempool.h Tue Oct 17 16:15:41 2017 +0200
1.3 @@ -0,0 +1,200 @@
1.4 +/*
1.5 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 + *
1.7 + * Copyright 2017 Olaf Wintermann. All rights reserved.
1.8 + *
1.9 + * Redistribution and use in source and binary forms, with or without
1.10 + * modification, are permitted provided that the following conditions are met:
1.11 + *
1.12 + * 1. Redistributions of source code must retain the above copyright
1.13 + * notice, this list of conditions and the following disclaimer.
1.14 + *
1.15 + * 2. Redistributions in binary form must reproduce the above copyright
1.16 + * notice, this list of conditions and the following disclaimer in the
1.17 + * documentation and/or other materials provided with the distribution.
1.18 + *
1.19 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.20 + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.21 + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.22 + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
1.23 + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.24 + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.25 + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.26 + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.27 + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.28 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.29 + * POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +
1.32 +/**
1.33 + * @file mempool.h
1.34 + *
1.35 + * Memory pool implementation.
1.36 + *
1.37 + * @author Mike Becker
1.38 + * @author Olaf Wintermann
1.39 + */
1.40 +
1.41 +#ifndef UCX_MEMPOOL_H
1.42 +#define UCX_MEMPOOL_H
1.43 +
1.44 +#include <ucx/ucx.h>
1.45 +#include <ucx/allocator.h>
1.46 +#include <stddef.h>
1.47 +
1.48 +#ifdef __cplusplus
1.49 +extern "C" {
1.50 +#endif
1.51 +
1.52 +/**
1.53 + * UCX mempool structure.
1.54 + */
1.55 +typedef struct {
1.56 + /** UcxAllocator based on this pool */
1.57 + UcxAllocator *allocator;
1.58 +
1.59 + /** List of pointers to pooled memory. */
1.60 + void **data;
1.61 +
1.62 + /** Count of pooled memory items. */
1.63 + size_t ndata;
1.64 +
1.65 + /** Memory pool size. */
1.66 + size_t size;
1.67 +} UcxMempool;
1.68 +
1.69 +/** Shorthand for a new default memory pool with a capacity of 16 elements. */
1.70 +#define ucx_mempool_new_default() ucx_mempool_new(16)
1.71 +
1.72 +
1.73 +/**
1.74 + * Creates a memory pool with the specified initial size.
1.75 + *
1.76 + * As the created memory pool automatically grows in size by factor two when
1.77 + * trying to allocate memory on a full pool, it is recommended that you use
1.78 + * a power of two for the initial size.
1.79 + *
1.80 + * @param n initial pool size (should be a power of two, e.g. 16)
1.81 + * @return a pointer to the new memory pool
1.82 + * @see ucx_mempool_new_default()
1.83 + */
1.84 +UcxMempool *ucx_mempool_new(size_t n);
1.85 +
1.86 +/**
1.87 + * Resizes a memory pool.
1.88 + *
1.89 + * This function will fail if the new capacity is not sufficient for the
1.90 + * present data.
1.91 + *
1.92 + * @param pool the pool to resize
1.93 + * @param newcap the new capacity
1.94 + * @return zero on success or non-zero on failure
1.95 + */
1.96 +int ucx_mempool_chcap(UcxMempool *pool, size_t newcap);
1.97 +
1.98 +/**
1.99 + * Allocates pooled memory.
1.100 + *
1.101 + * @param pool the memory pool
1.102 + * @param n amount of memory to allocate
1.103 + * @return a pointer to the allocated memory
1.104 + * @see ucx_allocator_malloc()
1.105 + */
1.106 +void *ucx_mempool_malloc(UcxMempool *pool, size_t n);
1.107 +/**
1.108 + * Allocates a pooled memory array.
1.109 + *
1.110 + * The content of the allocated memory is set to zero.
1.111 + *
1.112 + * @param pool the memory pool
1.113 + * @param nelem amount of elements to allocate
1.114 + * @param elsize amount of memory per element
1.115 + * @return a pointer to the allocated memory
1.116 + * @see ucx_allocator_calloc()
1.117 + */
1.118 +void *ucx_mempool_calloc(UcxMempool *pool, size_t nelem, size_t elsize);
1.119 +
1.120 +/**
1.121 + * Reallocates pooled memory.
1.122 + *
1.123 + * If the memory to be reallocated is not contained by the specified pool, the
1.124 + * behavior is undefined.
1.125 + *
1.126 + * @param pool the memory pool
1.127 + * @param ptr a pointer to the memory that shall be reallocated
1.128 + * @param n the new size of the memory
1.129 + * @return a pointer to the new location of the memory
1.130 + * @see ucx_allocator_realloc()
1.131 + */
1.132 +void *ucx_mempool_realloc(UcxMempool *pool, void *ptr, size_t n);
1.133 +
1.134 +/**
1.135 + * Frees pooled memory.
1.136 + *
1.137 + * Before freeing the memory, the specified destructor function (if any)
1.138 + * is called.
1.139 + *
1.140 + * If you specify memory, that is not pooled by the specified memory pool, the
1.141 + * program will terminate with a call to <code>abort()</code>.
1.142 + *
1.143 + * @param pool the memory pool
1.144 + * @param ptr a pointer to the memory that shall be freed
1.145 + * @see ucx_mempool_set_destr()
1.146 + */
1.147 +void ucx_mempool_free(UcxMempool *pool, void *ptr);
1.148 +
1.149 +/**
1.150 + * Destroys a memory pool.
1.151 + *
1.152 + * For each element the destructor function (if any) is called and the element
1.153 + * is freed.
1.154 + *
1.155 + * Each of the registered destructor function that has no corresponding element
1.156 + * within the pool (namely those registered by ucx_mempool_reg_destr) is
1.157 + * called interleaving with the element destruction, but with guarantee to the
1.158 + * order in which they were registered (FIFO order).
1.159 + *
1.160 + *
1.161 + * @param pool the mempool to destroy
1.162 + */
1.163 +void ucx_mempool_destroy(UcxMempool *pool);
1.164 +
1.165 +/**
1.166 + * Sets a destructor function for the specified memory.
1.167 + *
1.168 + * The destructor is automatically called when the memory is freed or the
1.169 + * pool is destroyed.
1.170 + *
1.171 + * The only requirement for the specified memory is, that it <b>MUST</b> be
1.172 + * pooled memory by a UcxMempool or an element-compatible mempool. The pointer
1.173 + * to the destructor function is saved in a reserved area before the actual
1.174 + * memory.
1.175 + *
1.176 + * @param ptr pooled memory
1.177 + * @param func a pointer to the destructor function
1.178 + * @see ucx_mempool_free()
1.179 + * @see ucx_mempool_destroy()
1.180 + */
1.181 +void ucx_mempool_set_destr(void *ptr, ucx_destructor func);
1.182 +
1.183 +/**
1.184 + * Registers a destructor function for the specified (non-pooled) memory.
1.185 + *
1.186 + * This is useful, if you have memory that has not been allocated by a mempool,
1.187 + * but shall be managed by a mempool.
1.188 + *
1.189 + * This function creates an entry in the specified mempool and the memory will
1.190 + * therefore (logically) convert to pooled memory.
1.191 + *
1.192 + * @param pool the memory pool
1.193 + * @param ptr data the destructor is registered for
1.194 + * @param destr a pointer to the destructor function
1.195 + */
1.196 +void ucx_mempool_reg_destr(UcxMempool *pool, void *ptr, ucx_destructor destr);
1.197 +
1.198 +#ifdef __cplusplus
1.199 +}
1.200 +#endif
1.201 +
1.202 +#endif /* UCX_MEMPOOL_H */
1.203 +
