/* * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 2000, 2001 Internet Software Consortium. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ /* $Id: quota.h,v 1.16 2007/06/19 23:47:18 tbox Exp $ */ #ifndef ISC_QUOTA_H #define ISC_QUOTA_H 1 /***** ***** Module Info *****/ /*! \file isc/quota.h * * \brief The isc_quota_t object is a simple helper object for implementing * quotas on things like the number of simultaneous connections to * a server. It keeps track of the amount of quota in use, and * encapsulates the locking necessary to allow multiple tasks to * share a quota. */ /*** *** Imports. ***/ #include <isc/lang.h> #include <isc/mutex.h> #include <isc/types.h> /***** ***** Types. *****/ ISC_LANG_BEGINDECLS /*% isc_quota structure */ struct isc_quota { isc_mutex_t lock; /*%< Locked by lock. */ int max; int used; int soft; }; isc_result_t isc_quota_init(isc_quota_t *quota, int max); /*%< * Initialize a quota object. * * Returns: * ISC_R_SUCCESS * Other error Lock creation failed. */ void isc_quota_destroy(isc_quota_t *quota); /*%< * Destroy a quota object. */ void isc_quota_soft(isc_quota_t *quota, int soft); /*%< * Set a soft quota. */ void isc_quota_max(isc_quota_t *quota, int max); /*%< * Re-set a maximum quota. */ isc_result_t isc_quota_reserve(isc_quota_t *quota); /*%< * Attempt to reserve one unit of 'quota'. * * Returns: * \li #ISC_R_SUCCESS Success * \li #ISC_R_SOFTQUOTA Success soft quota reached * \li #ISC_R_QUOTA Quota is full */ void isc_quota_release(isc_quota_t *quota); /*%< * Release one unit of quota. */ isc_result_t isc_quota_attach(isc_quota_t *quota, isc_quota_t **p); /*%< * Like isc_quota_reserve, and also attaches '*p' to the * quota if successful (ISC_R_SUCCESS or ISC_R_SOFTQUOTA). */ void isc_quota_detach(isc_quota_t **p); /*%< * Like isc_quota_release, and also detaches '*p' from the * quota. */ ISC_LANG_ENDDECLS #endif /* ISC_QUOTA_H */