ucx: ucx/mempool.h@a0aa1c15f46b

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2013 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  * A function pointer to a destructor function.

    51  * @see ucx_mempool_setdestr()

    52  * @see ucx_mempool_regdestr()

    53  */

    54 typedef void(*ucx_destructor)(void*);

    56 /**

    57  * UCX mempool structure.

    58  */

    59 typedef struct {

    60     /** List of pointers to pooled memory. */

    61     void   **data;

    62     /** Count of pooled memory items. */

    63     size_t ndata;

    64     /** Memory pool size. */

    65     size_t size;

    66 } UcxMempool;

    68 /** Shorthand for a new default memory pool with a capacity of 16 elements. */

    69 #define ucx_mempool_new_default() ucx_mempool_new(16)

    72 /**

    73  * Creates a memory pool with the specified initial size.

    74  *

    75  * As the created memory pool automatically grows in size by 16 elements, when

    76  * trying to allocate memory on a full pool, it is recommended that you use

    77  * a multiple of 16 for the initial size.

    78  *

    79  * @param n initial pool size (should be a multiple of 16)

    80  * @return a pointer to the new memory pool

    81  */

    82 UcxMempool *ucx_mempool_new(size_t n);

    84 /**

    85  * Resizes a memory pool.

    86  *

    87  * @param pool the pool to resize

    88  * @param newcap the new capacity

    89  * @return <code>EXIT_SUCCESS</code> on success or

    90  * <code>EXIT_FAILURE</code> on failure

    91  */

    92 int ucx_mempool_chcap(UcxMempool *pool, size_t newcap);

    94 /**

    95  * Allocates pooled memory.

    96  *

    97  * @param pool the memory pool

    98  * @param n amount of memory to allocate

    99  * @return a pointer to the allocated memory

   100  * @see ucx_allocator_malloc()

   101  */

   102 void *ucx_mempool_malloc(UcxMempool *pool, size_t n);

   103 /**

   104  * Allocates a pooled memory array.

   105  *

   106  * The contents of the allocated memory is set to zero.

   107  *

   108  * @param pool the memory pool

   109  * @param nelem amount of elements to allocate

   110  * @param elsize amount of memory per element

   111  * @return a pointer to the allocated memory

   112  * @see ucx_allocator_calloc()

   113  */

   114 void *ucx_mempool_calloc(UcxMempool *pool, size_t nelem, size_t elsize);

   115 /**

   116  * Reallocates pooled memory.

   117  *

   118  * @param pool the memory pool

   119  * @param ptr a pointer to the memory that shall be reallocated

   120  * @param n the new size of the memory

   121  * @return a pointer to the the location of the memory

   122  * @see ucx_allocator_realloc()

   123  */

   124 void *ucx_mempool_realloc(UcxMempool *pool, void *ptr, size_t n);

   125 /**

   126  * Frees pooled memory.

   127  *

   128  * Before freeing the memory, the specified destructor function (if any)

   129  * is called.

   130  *

   131  * If you specify memory, that is not pooled by the specified memory pool, this

   132  * is considered as a severe error and an error message is written to

   133  * <code>stderr</code> and the application is shut down with code

   134  * <code>EXIT_FAILURE</code>.

   135  *

   136  * @param pool the memory pool

   137  * @param ptr a pointer to the memory that shall be freed

   138  * @see ucx_mempool_set_destr()

   139  */

   140 void ucx_mempool_free(UcxMempool *pool, void *ptr);

   142 /**

   143  * Destroys a memory pool.

   144  *

   145  * For each element the destructor function (if any) is called and the element

   146  * is freed.

   147  *

   148  * Each of the registered destructor function that has no corresponding element

   149  * within the pool (namely those registered by ucx_mempool_reg_destr) is

   150  * called interleaving with the element destruction, but with guarantee to the

   151  * order in which they were registered (FIFO order).

   152  *

   153  *

   154  * @param pool the mempool to destroy

   155  */

   156 void ucx_mempool_destroy(UcxMempool *pool);

   158 /**

   159  * Sets a destructor function for the specified memory.

   160  *

   161  * The destructor is automatically called when the memory is freed or the

   162  * pool is destroyed.

   163  *

   164  * The only requirement for the specified memory is, that it <b>MUST</b> be

   165  * pooled memory by an UcxMempool or an element-compatible mempool. The pointer

   166  * to the destructor function is saved in a reserved area before the actual

   167  * memory.

   168  *

   169  * @param ptr pooled memory

   170  * @param func a pointer to the destructor function

   171  * @see ucx_mempool_free()

   172  * @see ucx_mempool_destroy()

   173  */

   174 void ucx_mempool_set_destr(void *ptr, ucx_destructor func);

   176 /**

   177  * Registers a destructor function for the specified (non-pooled) memory.

   178  *

   179  * This is useful, if you have memory that has not been allocated by a mempool,

   180  * but shall be managed by a mempool.

   181  *

   182  * This function creates an entry in the specified mempool and the memory will

   183  * therefore (logically) convert to pooled memory.

   184  *

   185  * @param pool the memory pool

   186  * @param ptr data the destructor is registered for

   187  * @param destr a pointer to the destructor function

   188  */

   189 void ucx_mempool_reg_destr(UcxMempool *pool, void *ptr, ucx_destructor destr);

   191 /**

   192  * Creates an UcxAllocator based on an UcxMempool.

   193  *

   194  * @param pool the mempool to create the UcxAllocator for

   195  * @return a new UcxAllocator based on the specified pool

   196  */

   197 UcxAllocator* ucx_mempool_allocator(UcxMempool *pool);

   199 #ifdef	__cplusplus

   200 }

   201 #endif

   203 #endif	/* UCX_MEMPOOL_H */

Mercurial > hg > ucx / file revision