| .\" |
| .\" Copyright 1998 by Daniel Stenberg |
| .\" SPDX-License-Identifier: MIT |
| .\" |
| .TH ARES_GETSOCK 3 "11 March 2010" |
| .SH NAME |
| ares_getsock \- get socket descriptors to wait on (deprecated) |
| .SH SYNOPSIS |
| .nf |
| #include <ares.h> |
| |
| int ares_getsock(const ares_channel_t *\fIchannel\fP, ares_socket_t *\fIsocks\fP, |
| int \fInumsocks\fP); |
| .fi |
| .SH DESCRIPTION |
| The |
| .B ares_getsock |
| function retrieves the set of socket descriptors which the calling |
| application should wait on for reading and/or writing for the |
| processing of name service queries pending on the name service channel |
| identified by |
| .IR channel . |
| Socket descriptors will be set in the socket descriptor array pointed to by |
| \fIsocks\fP. |
| \fInumsocks\fP is the size of the given array in number of ints. |
| |
| This function can only return information up to 16 sockets. If more are |
| in use, they are simply not reported back. |
| .SH RETURN VALUES |
| \fBares_getsock\fP returns a bitmask for what actions to wait for on the |
| different sockets. The ares.h header file provides these convenience macros to |
| extract the information appropriately: |
| |
| .nf |
| #define ARES_GETSOCK_MAXNUM 16 /* ares_getsock() can return info about |
| this many sockets */ |
| #define ARES_GETSOCK_READABLE(bits,num) (bits & (1<< (num))) |
| #define ARES_GETSOCK_WRITABLE(bits,num) (bits & (1 << ((num) + \ |
| ARES_GETSOCK_MAXNUM))) |
| .fi |
| .SH NOTES |
| This function was added in c-ares 1.3.1 and deprecated in c-ares 1.20.0 due to |
| the implementation of \fBARES_OPT_MAX_UDP_QUERIES\fP which makes it likely to |
| exceed 16 open file descriptors. |
| |
| It is recommended to use \fBARES_OPT_EVENT_THREAD\fP passed to |
| \fIares_init_options(3)\fP or to use socket state callbacks |
| (\fBARES_OPT_SOCK_STATE_CB\fP) registered via \fBares_init_options(3)\fP. |
| .SH SEE ALSO |
| .BR ares_init_options (3), |
| .BR ares_timeout (3), |
| .BR ares_fds (3), |
| .BR ares_process (3) |