Edit File: ondestroy.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_ONDESTROY_H #define ISC_ONDESTROY_H 1 #include <isc/lang.h> #include <isc/types.h> ISC_LANG_BEGINDECLS /*! \file isc/ondestroy.h * ondestroy handling. * * Any class ``X'' of objects that wants to send out notifications * on its destruction should declare a field of type isc_ondestroy_t * (call it 'ondest'). * * \code * typedef struct { * ... * isc_ondestroy_t ondest; * ... * } X; * \endcode * * When an object ``A'' of type X is created * it must initialize the field ondest with a call to * * \code * isc_ondestroy_init(&A->ondest). * \endcode * * X should also provide a registration function for third-party * objects to call to register their interest in being told about * the destruction of a particular instance of X. * * \code * isc_result_t * X_ondestroy(X *instance, isc_task_t *task, * isc_event_t **eventp) { * return(isc_ondestroy_register(&instance->ondest, task,eventp)); * } * \endcode * * Note: locking of the ondestory structure embedded inside of X, is * X's responsibility. * * When an instance of X is destroyed, a call to isc_ondestroy_notify() * sends the notifications: * * \code * X *instance; * isc_ondestroy_t ondest = instance->ondest; * * ... completely cleanup 'instance' here... * * isc_ondestroy_notify(&ondest, instance); * \endcode * * * see lib/dns/zone.c for an ifdef'd-out example. */ struct isc_ondestroy { unsigned int magic; isc_eventlist_t events; }; void isc_ondestroy_init(isc_ondestroy_t *ondest); /*%< * Initialize the on ondest structure. *must* be called before first call * to isc_ondestroy_register(). */ isc_result_t isc_ondestroy_register(isc_ondestroy_t *ondest, isc_task_t *task, isc_event_t **eventp); /*%< * Stores task and *eventp away inside *ondest. Ownership of **event is * taken from the caller (and *eventp is set to NULL). The task is attached * to. */ void isc_ondestroy_notify(isc_ondestroy_t *ondest, void *sender); /*%< * Dispatches the event(s) to the task(s) that were given in * isc_ondestroy_register call(s) (done via calls to * isc_task_sendanddetach()). Before dispatch, the sender value of each * event structure is set to the value of the sender parameter. The * internal structures of the ondest parameter are cleaned out, so no other * cleanup is needed. */ ISC_LANG_ENDDECLS #endif /* ISC_ONDESTROY_H */
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