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Edit File: pool.h
/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, you can obtain one at https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ #ifndef ISC_OBJPOOL_H #define ISC_OBJPOOL_H 1 /***** ***** Module Info *****/ /*! \file isc/pool.h * \brief An object pool is a mechanism for sharing a small pool of * fungible objects among a large number of objects that depend on them. * * This is useful, for example, when it causes performance problems for * large number of zones to share a single memory context or task object, * but it would create a different set of problems for them each to have an * independent task or memory context. */ /*** *** Imports. ***/ #include <isc/lang.h> #include <isc/mem.h> #include <isc/types.h> ISC_LANG_BEGINDECLS /***** ***** Types. *****/ typedef void (*isc_pooldeallocator_t)(void **object); typedef isc_result_t (*isc_poolinitializer_t)(void **target, void *arg); typedef struct isc_pool isc_pool_t; /***** ***** Functions. *****/ isc_result_t isc_pool_create(isc_mem_t *mctx, unsigned int count, isc_pooldeallocator_t free, isc_poolinitializer_t init, void *initarg, isc_pool_t **poolp); /*%< * Create a pool of "count" object pointers. If 'free' is not NULL, * it points to a function that will detach the objects. 'init' * points to a function that will initialize the arguments, and * 'arg' to an argument to be passed into that function (for example, * a relevant manager or context object). * * Requires: * *\li 'mctx' is a valid memory context. * *\li init != NULL * *\li poolp != NULL && *poolp == NULL * * Ensures: * *\li On success, '*poolp' points to the new object pool. * * Returns: * *\li #ISC_R_SUCCESS *\li #ISC_R_NOMEMORY *\li #ISC_R_UNEXPECTED */ void * isc_pool_get(isc_pool_t *pool); /*%< * Returns a pointer to an object from the pool. Currently the object * is chosen from the pool at random. (This may be changed in the future * to something that guaratees balance.) */ int isc_pool_count(isc_pool_t *pool); /*%< * Returns the number of objcts in the pool 'pool'. */ isc_result_t isc_pool_expand(isc_pool_t **sourcep, unsigned int count, isc_pool_t **targetp); /*%< * If 'size' is larger than the number of objects in the pool pointed to by * 'sourcep', then a new pool of size 'count' is allocated, the existing * objects are copied into it, additional ones created to bring the * total number up to 'count', and the resulting pool is attached to * 'targetp'. * * If 'count' is less than or equal to the number of objects in 'source', then * 'sourcep' is attached to 'targetp' without any other action being taken. * * In either case, 'sourcep' is detached. * * Requires: * * \li 'sourcep' is not NULL and '*source' is not NULL * \li 'targetp' is not NULL and '*source' is NULL * * Ensures: * * \li On success, '*targetp' points to a valid task pool. * \li On success, '*sourcep' points to NULL. * * Returns: * * \li #ISC_R_SUCCESS * \li #ISC_R_NOMEMORY */ void isc_pool_destroy(isc_pool_t **poolp); /*%< * Destroy a task pool. The tasks in the pool are detached but not * shut down. * * Requires: * \li '*poolp' is a valid task pool. */ ISC_LANG_ENDDECLS #endif /* ISC_OBJPOOL_H */