diff -r 62f1a55535e7 -r 0b33b9396851 ucx/ucx/mempool.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ucx/ucx/mempool.h Mon Feb 04 17:49:50 2019 +0100 @@ -0,0 +1,209 @@ +/* + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. + * + * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * @file mempool.h + * + * Memory pool implementation. + * + * @author Mike Becker + * @author Olaf Wintermann + */ + +#ifndef UCX_MEMPOOL_H +#define UCX_MEMPOOL_H + +#include "ucx.h" +#include "allocator.h" +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * UCX mempool structure. + */ +typedef struct { + /** UcxAllocator based on this pool */ + UcxAllocator *allocator; + + /** List of pointers to pooled memory. */ + void **data; + + /** Count of pooled memory items. */ + size_t ndata; + + /** Memory pool size. */ + size_t size; +} UcxMempool; + +/** Shorthand for a new default memory pool with a capacity of 16 elements. */ +#define ucx_mempool_new_default() ucx_mempool_new(16) + + +/** + * Creates a memory pool with the specified initial size. + * + * As the created memory pool automatically grows in size by factor two when + * trying to allocate memory on a full pool, it is recommended that you use + * a power of two for the initial size. + * + * @param n initial pool size (should be a power of two, e.g. 16) + * @return a pointer to the new memory pool + * @see ucx_mempool_new_default() + */ +UcxMempool *ucx_mempool_new(size_t n); + +/** + * Resizes a memory pool. + * + * This function will fail if the new capacity is not sufficient for the + * present data. + * + * @param pool the pool to resize + * @param newcap the new capacity + * @return zero on success or non-zero on failure + */ +int ucx_mempool_chcap(UcxMempool *pool, size_t newcap); + +/** + * Allocates pooled memory. + * + * @param pool the memory pool + * @param n amount of memory to allocate + * @return a pointer to the allocated memory + * @see ucx_allocator_malloc() + */ +void *ucx_mempool_malloc(UcxMempool *pool, size_t n); +/** + * Allocates a pooled memory array. + * + * The content of the allocated memory is set to zero. + * + * @param pool the memory pool + * @param nelem amount of elements to allocate + * @param elsize amount of memory per element + * @return a pointer to the allocated memory + * @see ucx_allocator_calloc() + */ +void *ucx_mempool_calloc(UcxMempool *pool, size_t nelem, size_t elsize); + +/** + * Reallocates pooled memory. + * + * If the memory to be reallocated is not contained by the specified pool, the + * behavior is undefined. + * + * @param pool the memory pool + * @param ptr a pointer to the memory that shall be reallocated + * @param n the new size of the memory + * @return a pointer to the new location of the memory + * @see ucx_allocator_realloc() + */ +void *ucx_mempool_realloc(UcxMempool *pool, void *ptr, size_t n); + +/** + * Frees pooled memory. + * + * Before freeing the memory, the specified destructor function (if any) + * is called. + * + * If you specify memory, that is not pooled by the specified memory pool, the + * program will terminate with a call to abort(). + * + * @param pool the memory pool + * @param ptr a pointer to the memory that shall be freed + * @see ucx_mempool_set_destr() + */ +void ucx_mempool_free(UcxMempool *pool, void *ptr); + +/** + * Destroys a memory pool. + * + * For each element the destructor function (if any) is called and the element + * is freed. + * + * Each of the registered destructor function that has no corresponding element + * within the pool (namely those registered by ucx_mempool_reg_destr) is + * called interleaving with the element destruction, but with guarantee to the + * order in which they were registered (FIFO order). + * + * + * @param pool the mempool to destroy + */ +void ucx_mempool_destroy(UcxMempool *pool); + +/** + * Sets a destructor function for the specified memory. + * + * The destructor is automatically called when the memory is freed or the + * pool is destroyed. + * A destructor for pooled memory MUST NOT free the memory itself, + * as this is done by the pool. Use a destructor to free any resources + * managed by the pooled object. + * + * The only requirement for the specified memory is, that it MUST be + * pooled memory by a UcxMempool or an element-compatible mempool. The pointer + * to the destructor function is saved in a reserved area before the actual + * memory. + * + * @param ptr pooled memory + * @param func a pointer to the destructor function + * @see ucx_mempool_free() + * @see ucx_mempool_destroy() + */ +void ucx_mempool_set_destr(void *ptr, ucx_destructor func); + +/** + * Registers a destructor function for the specified (non-pooled) memory. + * + * This is useful, if you have memory that has not been allocated by a mempool, + * but shall be managed by a mempool. + * + * This function creates an entry in the specified mempool and the memory will + * therefore (logically) convert to pooled memory. + * However, this does not cause the memory to be freed automatically!. + * If you want to use this function, make the memory pool free non-pooled + * memory, the specified destructor function must call free() + * by itself. But keep in mind, that you then MUST NOT use this destructor + * function with pooled memory (e.g. in ucx_mempool_set_destr()), as it + * would cause a double-free. + * + * @param pool the memory pool + * @param ptr data the destructor is registered for + * @param destr a pointer to the destructor function + */ +void ucx_mempool_reg_destr(UcxMempool *pool, void *ptr, ucx_destructor destr); + +#ifdef __cplusplus +} +#endif + +#endif /* UCX_MEMPOOL_H */ +