| 1 | /** @file
|
|---|
| 2 | * IPRT - Memory Object Allocation Cache.
|
|---|
| 3 | */
|
|---|
| 4 |
|
|---|
| 5 | /*
|
|---|
| 6 | * Copyright (C) 2006-2023 Oracle and/or its affiliates.
|
|---|
| 7 | *
|
|---|
| 8 | * This file is part of VirtualBox base platform packages, as
|
|---|
| 9 | * available from https://www.virtualbox.org.
|
|---|
| 10 | *
|
|---|
| 11 | * This program is free software; you can redistribute it and/or
|
|---|
| 12 | * modify it under the terms of the GNU General Public License
|
|---|
| 13 | * as published by the Free Software Foundation, in version 3 of the
|
|---|
| 14 | * License.
|
|---|
| 15 | *
|
|---|
| 16 | * This program is distributed in the hope that it will be useful, but
|
|---|
| 17 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 19 | * General Public License for more details.
|
|---|
| 20 | *
|
|---|
| 21 | * You should have received a copy of the GNU General Public License
|
|---|
| 22 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 23 | *
|
|---|
| 24 | * The contents of this file may alternatively be used under the terms
|
|---|
| 25 | * of the Common Development and Distribution License Version 1.0
|
|---|
| 26 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
|---|
| 27 | * in the VirtualBox distribution, in which case the provisions of the
|
|---|
| 28 | * CDDL are applicable instead of those of the GPL.
|
|---|
| 29 | *
|
|---|
| 30 | * You may elect to license modified versions of this file under the
|
|---|
| 31 | * terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 32 | *
|
|---|
| 33 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
|---|
| 34 | */
|
|---|
| 35 |
|
|---|
| 36 | #ifndef IPRT_INCLUDED_memcache_h
|
|---|
| 37 | #define IPRT_INCLUDED_memcache_h
|
|---|
| 38 | #ifndef RT_WITHOUT_PRAGMA_ONCE
|
|---|
| 39 | # pragma once
|
|---|
| 40 | #endif
|
|---|
| 41 |
|
|---|
| 42 |
|
|---|
| 43 | #include <iprt/cdefs.h>
|
|---|
| 44 | #include <iprt/types.h>
|
|---|
| 45 |
|
|---|
| 46 | RT_C_DECLS_BEGIN
|
|---|
| 47 |
|
|---|
| 48 |
|
|---|
| 49 | /** @defgroup grp_rt_memcache RTMemCache - Memory Object Allocation Cache
|
|---|
| 50 | * @ingroup grp_rt
|
|---|
| 51 | *
|
|---|
| 52 | * Optimized allocation, initialization, freeing and destruction of memory
|
|---|
| 53 | * objects of the same kind and size. Objects are constructed once, then
|
|---|
| 54 | * allocated and freed one or more times, until finally destructed together with
|
|---|
| 55 | * the cache (RTMemCacheDestroy). It's expected behavior, even when pfnCtor is
|
|---|
| 56 | * NULL, that the user will be store information that should be persistent
|
|---|
| 57 | * across RTMemCacheFree calls.
|
|---|
| 58 | *
|
|---|
| 59 | * The objects are zeroed prior to calling pfnCtor. For obvious reasons, the
|
|---|
| 60 | * objects are not touched by the cache after that, so that RTMemCacheAlloc will
|
|---|
| 61 | * return the object in the same state as when it as handed to RTMemCacheFree.
|
|---|
| 62 | *
|
|---|
| 63 | * @todo A callback for the reuse (at alloc time) might be of interest.
|
|---|
| 64 | *
|
|---|
| 65 | * @{
|
|---|
| 66 | */
|
|---|
| 67 |
|
|---|
| 68 | /** A memory cache handle. */
|
|---|
| 69 | typedef R3R0PTRTYPE(struct RTMEMCACHEINT *) RTMEMCACHE;
|
|---|
| 70 | /** Pointer to a memory cache handle. */
|
|---|
| 71 | typedef RTMEMCACHE *PRTMEMCACHE;
|
|---|
| 72 | /** Nil memory cache handle. */
|
|---|
| 73 | #define NIL_RTMEMCACHE ((RTMEMCACHE)0)
|
|---|
| 74 |
|
|---|
| 75 |
|
|---|
| 76 | /**
|
|---|
| 77 | * Object constructor.
|
|---|
| 78 | *
|
|---|
| 79 | * This is called for when an element is allocated for the first time.
|
|---|
| 80 | *
|
|---|
| 81 | * @returns IPRT status code.
|
|---|
| 82 | * @param hMemCache The cache handle.
|
|---|
| 83 | * @param pvObj The memory object that should be initialized.
|
|---|
| 84 | * @param pvUser The user argument.
|
|---|
| 85 | *
|
|---|
| 86 | * @remarks No serialization is performed.
|
|---|
| 87 | */
|
|---|
| 88 | typedef DECLCALLBACKTYPE(int, FNMEMCACHECTOR,(RTMEMCACHE hMemCache, void *pvObj, void *pvUser));
|
|---|
| 89 | /** Pointer to an object constructor for the memory cache. */
|
|---|
| 90 | typedef FNMEMCACHECTOR *PFNMEMCACHECTOR;
|
|---|
| 91 |
|
|---|
| 92 | /**
|
|---|
| 93 | * Object destructor.
|
|---|
| 94 | *
|
|---|
| 95 | * This is called when we're shrinking or destroying the cache.
|
|---|
| 96 | *
|
|---|
| 97 | * @param hMemCache The cache handle.
|
|---|
| 98 | * @param pvObj The memory object that should be initialized.
|
|---|
| 99 | * @param pvUser The user argument.
|
|---|
| 100 | *
|
|---|
| 101 | * @remarks No serialization is performed.
|
|---|
| 102 | */
|
|---|
| 103 | typedef DECLCALLBACKTYPE(void, FNMEMCACHEDTOR,(RTMEMCACHE hMemCache, void *pvObj, void *pvUser));
|
|---|
| 104 | /** Pointer to an object destructor for the memory cache. */
|
|---|
| 105 | typedef FNMEMCACHEDTOR *PFNMEMCACHEDTOR;
|
|---|
| 106 |
|
|---|
| 107 |
|
|---|
| 108 | /**
|
|---|
| 109 | * Create an allocation cache for fixed size memory objects.
|
|---|
| 110 | *
|
|---|
| 111 | * @returns IPRT status code.
|
|---|
| 112 | * @param phMemCache Where to return the cache handle.
|
|---|
| 113 | * @param cbObject The size of one memory object.
|
|---|
| 114 | * @param cbAlignment The object alignment. This must be a power of
|
|---|
| 115 | * two. The higest alignment is 64. If set to 0,
|
|---|
| 116 | * a sensible alignment value will be derived from
|
|---|
| 117 | * the object size.
|
|---|
| 118 | * @param cMaxObjects The maximum cache size. Pass UINT32_MAX if unsure.
|
|---|
| 119 | * @param pfnCtor Object constructor callback. Optional.
|
|---|
| 120 | * @param pfnDtor Object destructor callback. Optional.
|
|---|
| 121 | * @param pvUser User argument for the two callbacks.
|
|---|
| 122 | * @param fFlags Flags reserved for future use. Must be zero.
|
|---|
| 123 | */
|
|---|
| 124 | RTDECL(int) RTMemCacheCreate(PRTMEMCACHE phMemCache, size_t cbObject, size_t cbAlignment, uint32_t cMaxObjects,
|
|---|
| 125 | PFNMEMCACHECTOR pfnCtor, PFNMEMCACHEDTOR pfnDtor, void *pvUser, uint32_t fFlags);
|
|---|
| 126 |
|
|---|
| 127 | /**
|
|---|
| 128 | * Destroy a cache destroying and freeing allocated memory.
|
|---|
| 129 | *
|
|---|
| 130 | * @returns IPRT status code.
|
|---|
| 131 | * @param hMemCache The cache handle. NIL is quietly (VINF_SUCCESS)
|
|---|
| 132 | * ignored.
|
|---|
| 133 | */
|
|---|
| 134 | RTDECL(int) RTMemCacheDestroy(RTMEMCACHE hMemCache);
|
|---|
| 135 |
|
|---|
| 136 | /**
|
|---|
| 137 | * Allocate an object.
|
|---|
| 138 | *
|
|---|
| 139 | * @returns Pointer to the allocated cache object.
|
|---|
| 140 | * @param hMemCache The cache handle.
|
|---|
| 141 | */
|
|---|
| 142 | RTDECL(void *) RTMemCacheAlloc(RTMEMCACHE hMemCache);
|
|---|
| 143 |
|
|---|
| 144 | /**
|
|---|
| 145 | * Allocate an object and return a proper status code.
|
|---|
| 146 | *
|
|---|
| 147 | * @returns IPRT status code.
|
|---|
| 148 | * @retval VERR_MEM_CACHE_MAX_SIZE if we've reached maximum size (see
|
|---|
| 149 | * RTMemCacheCreate).
|
|---|
| 150 | * @retval VERR_NO_MEMORY if we failed to allocate more memory for the cache.
|
|---|
| 151 | *
|
|---|
| 152 | * @param hMemCache The cache handle.
|
|---|
| 153 | * @param ppvObj Where to return the object.
|
|---|
| 154 | */
|
|---|
| 155 | RTDECL(int) RTMemCacheAllocEx(RTMEMCACHE hMemCache, void **ppvObj);
|
|---|
| 156 |
|
|---|
| 157 | /**
|
|---|
| 158 | * Free an object previously returned by RTMemCacheAlloc or RTMemCacheAllocEx.
|
|---|
| 159 | *
|
|---|
| 160 | * @param hMemCache The cache handle.
|
|---|
| 161 | * @param pvObj The object to free. NULL is fine.
|
|---|
| 162 | */
|
|---|
| 163 | RTDECL(void) RTMemCacheFree(RTMEMCACHE hMemCache, void *pvObj);
|
|---|
| 164 |
|
|---|
| 165 | /** @} */
|
|---|
| 166 |
|
|---|
| 167 | RT_C_DECLS_END
|
|---|
| 168 |
|
|---|
| 169 | #endif /* !IPRT_INCLUDED_memcache_h */
|
|---|
| 170 |
|
|---|
