/* $Id: ares_getsock.c,v 1.8 2009-11-02 11:55:53 yangtse Exp $ */ /* Copyright (C) 2005 - 2007, Daniel Stenberg * * 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. */ #include "ares_setup.h" #ifdef HAVE_SYS_TIME_H #include <sys/time.h> #endif #include "ares.h" #include "ares_private.h" int ares_getsock(ares_channel channel, int *s, int numsocks) /* size of the 'socks' array */ { struct server_state *server; int i; int sockindex=0; int bitmap = 0; unsigned int setbits = 0xffffffff; ares_socket_t *socks = (ares_socket_t *)s; /* Are there any active queries? */ int active_queries = !ares__is_list_empty(&(channel->all_queries)); for (i = 0; (i < channel->nservers) && (sockindex < ARES_GETSOCK_MAXNUM); i++) { server = &channel->servers[i]; /* We only need to register interest in UDP sockets if we have * outstanding queries. */ if (active_queries && server->udp_socket != ARES_SOCKET_BAD) { if(sockindex >= numsocks) break; socks[sockindex] = server->udp_socket; bitmap |= ARES_GETSOCK_READABLE(setbits, sockindex); sockindex++; } /* We always register for TCP events, because we want to know * when the other side closes the connection, so we don't waste * time trying to use a broken connection. */ if (server->tcp_socket != ARES_SOCKET_BAD) { if(sockindex >= numsocks) break; socks[sockindex] = server->tcp_socket; bitmap |= ARES_GETSOCK_READABLE(setbits, sockindex); if (server->qhead && active_queries) /* then the tcp socket is also writable! */ bitmap |= ARES_GETSOCK_WRITABLE(setbits, sockindex); sockindex++; } } return bitmap; }