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Diffstat (limited to 'lib/isc/include/isc/quota.h')
| -rw-r--r-- | lib/isc/include/isc/quota.h | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/lib/isc/include/isc/quota.h b/lib/isc/include/isc/quota.h new file mode 100644 index 0000000..7b0d0d9 --- /dev/null +++ b/lib/isc/include/isc/quota.h @@ -0,0 +1,119 @@ +/* + * 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 */ |