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-rw-r--r-- | src/c-ares/ares_process.3 | 74 |
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diff --git a/src/c-ares/ares_process.3 b/src/c-ares/ares_process.3 new file mode 100644 index 00000000..62836ad2 --- /dev/null +++ b/src/c-ares/ares_process.3 @@ -0,0 +1,74 @@ +.\" +.\" Copyright 1998 by the Massachusetts Institute of Technology. +.\" +.\" Permission to use, copy, modify, and distribute this +.\" software and its documentation for any purpose and without +.\" fee is hereby granted, provided that the above copyright +.\" notice appear in all copies and that both that copyright +.\" notice and this permission notice appear in supporting +.\" documentation, and that the name of M.I.T. not be used in +.\" advertising or publicity pertaining to distribution of the +.\" software without specific, written prior permission. +.\" M.I.T. makes no representations about the suitability of +.\" this software for any purpose. It is provided "as is" +.\" without express or implied warranty. +.\" +.TH ARES_PROCESS 3 "25 July 1998" +.SH NAME +ares_process \- Process events for name resolution +.SH SYNOPSIS +.nf +#include <ares.h> + +void ares_process(ares_channel \fIchannel\fP, + fd_set *\fIread_fds\fP, + fd_set *\fIwrite_fds\fP) + +void ares_process_fd(ares_channel \fIchannel\fP, + ares_socket_t \fIread_fd\fP, + ares_socket_t \fIwrite_fd\fP) +.fi +.SH DESCRIPTION +The \fBares_process(3)\fP function handles input/output events and timeouts +associated with queries pending on the name service channel identified by +.IR channel . +The file descriptor sets pointed to by \fIread_fds\fP and \fIwrite_fds\fP +should have file descriptors set in them according to whether the file +descriptors specified by \fIares_fds(3)\fP are ready for reading and writing. +(The easiest way to determine this information is to invoke \fBselect(3)\fP +with a timeout no greater than the timeout given by \fIares_timeout(3)\fP). + +The \fBares_process(3)\fP function will invoke callbacks for pending queries +if they complete successfully or fail. + +\fBares_process_fd(3)\fP 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 provided to allow users of +c-ares to void \fIselect(3)\fP in their applications and within c-ares. +.SH EXAMPLE +The following code fragment waits for all pending queries on a channel +to complete: + +.nf +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); +} +.fi +.SH SEE ALSO +.BR ares_fds (3), +.BR ares_timeout (3) +.SH AUTHOR +Greg Hudson, MIT Information Systems +.br +Copyright 1998 by the Massachusetts Institute of Technology. |