ares_getsock(3) Library Functions Manual ares_getsock(3)
NAME
ares_getsock - get socket descriptors to wait on (deprecated)
SYNOPSIS
#include <ares.h>
int ares_getsock(const ares_channel_t *channel, ares_socket_t *socks,
int numsocks);
DESCRIPTION
The 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 channel. Socket descriptors will be set in the
socket descriptor array pointed to by socks. numsocks 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.
RETURN VALUES
ares_getsock 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:
#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)))
NOTES
This function was added in c-ares 1.3.1 and deprecated in c-ares 1.20.0
due to the implementation of ARES_OPT_MAX_UDP_QUERIES which makes it
likely to exceed 16 open file descriptors.
It is recommended to use ARES_OPT_EVENT_THREAD passed to
ares_init_options(3) or to use socket state callbacks
(ARES_OPT_SOCK_STATE_CB) registered via ares_init_options(3).
SEE ALSO
ares_init_options(3), ares_timeout(3), ares_fds(3), ares_process(3)
11 March 2010 ares_getsock(3)
c-ares 1.30.0 - Generated Thu Jun 13 11:47:11 CDT 2024