ARES_PROCESS

Section: C Library Functions (3) Updated: 25 July 1998 Local index Up

NAME

ares_process - Process events for name resolution

SYNOPSIS

#include <ares.h>

void ares_process(ares_channel channel, fd_set *read_fds,

void ares_process_fd(ares_channel channel, ares_socket_t read_fd,

DESCRIPTION

The ares_process(3) function handles input/output events and timeouts associated with queries pending on the name service channel identified by channel. The file descriptor sets pointed to by read_fds and write_fds should have file descriptors set in them according to whether the file descriptors specified by ares_fds(3) are ready for reading and writing. (The easiest way to determine this information is to invoke select with a timeout no greater than the timeout given by ares_timeout(3) ).

The ares_process function will invoke callbacks for pending queries if they complete successfully or fail.

ares_process_fd(3) works the same way but acts and operates only on the specific file descriptors (sockets) you pass in to the function. Use ARES_SOCKET_BAD for "no action". This function is of course provided to allow users of c-ares to void select() in their applications and within c-ares.

EXAMPLE

The following code fragment waits for all pending queries on a channel to complete:

int nfds, count;
fd_set readers, writers;
struct timeval tv, *tvp;

while (1)
  {
    FD_ZERO(&readers);
    FD_ZERO(&writers);
    nfds = ares_fds(channel, &readers, &writers);
    if (nfds == 0)
      break;
    tvp = ares_timeout(channel, NULL, &tv);
    count = select(nfds, &readers, &writers, NULL, tvp);
    ares_process(channel, &readers, &writers);
  }

AUTHOR

Greg Hudson, MIT Information Systems
Copyright 1998 by the Massachusetts Institute of Technology.

Index

NAME

SYNOPSIS

DESCRIPTION

EXAMPLE

SEE ALSO

AUTHOR

This document was created by man2html, using the manual pages.
Time: 21:41:55 GMT, April 16, 2011