mdw@git.distorted.org.uk Git - adns/blob - src/poll.c

   1 /*
   2  * poll.c
   3  * - wrappers for poll(2)
   4  */
   5 /*
   6  *  This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2, or (at your option)
  11  *  any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software Foundation,
  20  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include <limits.h>
  24 #include <string.h>
  25
  26 #include "internal.h"
  27
  28 #ifdef HAVE_POLL
  29
  30 int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeout_io,
  31                     const struct timeval *now) {
  32   struct timeval tv_nowbuf, tv_tobuf, *tv_to;
  33   int space, found, timeout_ms, r;
  34   struct pollfd fds_tmp[MAX_POLLFDS];
  35
  36   adns__consistency(ads,0,cc_entex);
  37
  38   if (timeout_io) {
  39     adns__must_gettimeofday(ads,&now,&tv_nowbuf);
  40     if (!now) { *nfds_io= 0; r= 0; goto xit; }
  41
  42     timeout_ms= *timeout_io;
  43     if (timeout_ms == -1) {
  44       tv_to= 0;
  45     } else {
  46       tv_tobuf.tv_sec= timeout_ms / 1000;
  47       tv_tobuf.tv_usec= (timeout_ms % 1000)*1000;
  48       tv_to= &tv_tobuf;
  49     }
  50
  51     adns__timeouts(ads, 0, &tv_to,&tv_tobuf, *now);
  52
  53     if (tv_to) {
  54       assert(tv_to == &tv_tobuf);
  55       timeout_ms= (tv_tobuf.tv_usec+999)/1000;
  56       assert(tv_tobuf.tv_sec < (INT_MAX-timeout_ms)/1000);
  57       timeout_ms += tv_tobuf.tv_sec*1000;
  58     } else {
  59       timeout_ms= -1;
  60     }
  61     *timeout_io= timeout_ms;
  62   }
  63
  64   space= *nfds_io;
  65   if (space >= MAX_POLLFDS) {
  66     found= adns__pollfds(ads,fds);
  67     *nfds_io= found;
  68   } else {
  69     found= adns__pollfds(ads,fds_tmp);
  70     *nfds_io= found;
  71     if (space < found) { r= ERANGE; goto xit; }
  72     memcpy(fds,fds_tmp,sizeof(struct pollfd)*found);
  73   }
  74   r= 0;
  75 xit:
  76   adns__consistency(ads,0,cc_entex);
  77   return r;
  78 }
  79
  80 void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds,
  81                     const struct timeval *now) {
  82   struct timeval tv_buf;
  83
  84   adns__consistency(ads,0,cc_entex);
  85   adns__must_gettimeofday(ads,&now,&tv_buf);
  86   if (now) {
  87     adns__timeouts(ads, 1, 0,0, *now);
  88     adns__fdevents(ads, fds,nfds, 0,0,0,0, *now,0);
  89   }
  90   adns__consistency(ads,0,cc_entex);
  91 }
  92
  93 int adns_wait_poll(adns_state ads,
  94                    adns_query *query_io,
  95                    adns_answer **answer_r,
  96                    void **context_r) {
  97   int r, nfds, to;
  98   struct pollfd fds[MAX_POLLFDS];
  99
 100   adns__consistency(ads,0,cc_entex);
 101
 102   for (;;) {
 103     r= adns__internal_check(ads,query_io,answer_r,context_r);
 104     if (r != EWOULDBLOCK) goto xit;
 105     nfds= MAX_POLLFDS; to= -1;
 106     adns_beforepoll(ads,fds,&nfds,&to,0);
 107     r= poll(fds,nfds,to);
 108     if (r == -1) {
 109       if (errno == EINTR) {
 110         if (ads->iflags & adns_if_eintr) { r= EINTR; goto xit; }
 111       } else {
 112         adns__diag(ads,-1,0,"poll failed in wait: %s",strerror(errno));
 113         adns_globalsystemfailure(ads);
 114       }
 115     } else {
 116       assert(r >= 0);
 117       adns_afterpoll(ads,fds,nfds,0);
 118     }
 119   }
 120
 121  xit:
 122   adns__consistency(ads,0,cc_entex);
 123   return r;
 124 }
 125
 126 #endif