mirror of https://github.com/getdnsapi/getdns.git
98 lines
3.1 KiB
Groff
98 lines
3.1 KiB
Groff
.\" The "BSD-New" License
|
|
.\"
|
|
.\" Copyright (c) 2013, NLnet Labs, Verisign, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions are met:
|
|
.\" * Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" * Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" * Neither the names of the copyright holders nor the
|
|
.\" names of its contributors may be used to endorse or promote products
|
|
.\" derived from this software without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
.\" DISCLAIMED. IN NO EVENT SHALL Verisign, Inc. BE LIABLE FOR ANY
|
|
.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
.\" SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
|
|
.TH getdns_cancel_callback 3 "@date@" "getdns @version@" getdns
|
|
.SH NAME
|
|
.B getdns_cancel_callback
|
|
-- cancel an outstanding asyn getdns request
|
|
|
|
.SH LIBRARY
|
|
DNS Resolver library (libgetdns, \-lgetdns)
|
|
|
|
.SH SYNOPSIS
|
|
#include <getdns.h>
|
|
|
|
getdns_return_t
|
|
.br
|
|
.B getdns_cancel_callback
|
|
(getdns_context_t context,
|
|
.RS 3
|
|
.br
|
|
getdns_transaction_t *transaction_id)
|
|
.RE
|
|
|
|
.SH DESCRIPTION
|
|
|
|
.LP
|
|
To cancel an outstanding callback, use getdns_cancel_callback. This causes the
|
|
API to call the callback with a callback_type of GETDNS_CALLBACK_CANCEL if the
|
|
callback for this transaction_id has not already been called. The callback code
|
|
for cancellation should clean up any memory related to the identified call,
|
|
such as to deallocate the memory for the userarg. getdns_cancel_callback() may
|
|
return immediately, even before the callback finishes its work and returns.
|
|
|
|
.HP 3
|
|
.I context
|
|
see getdns_context (3)
|
|
|
|
.HP 3
|
|
.I transaction_id
|
|
populated by the API and used to identify the callback (for example to getdns_cancel_callback), can be NULL, set to 0 if the function fails
|
|
|
|
.HP
|
|
.SH "RETURN VALUES"
|
|
|
|
Upon successful completion the functions return
|
|
.B GETDNS_RETURN_GOOD
|
|
, otherwise the following error values are returned:
|
|
|
|
.LP
|
|
.B GETDNS_RETURN_INVALID_PARAMETER
|
|
if context == NULL
|
|
.LP
|
|
.B GETDNS_RETURN_UNKNOWN_TRANSACTION
|
|
if the transaction_id that is unknown or belongs to a callback that has already been called
|
|
|
|
.SH EXAMPLES
|
|
|
|
TBD
|
|
|
|
.SH FILES
|
|
.br
|
|
/etc/hosts
|
|
.br
|
|
/etc/resolv.conf
|
|
|
|
.SH SEE ALSO
|
|
.BR libgetdns (3),
|
|
.BR getdns_context (3),
|
|
.BR getdns_general (3),
|
|
.BR getdns_hostname (3),
|
|
.BR getdns_service (3),
|
|
|