lib/util/select.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 3.0
   4    Samba select/poll implementation
   5    Copyright (C) Andrew Tridgell 1992-1998
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/filesys.h"
  23 #include "system/select.h"
  24 #include "lib/util/select.h"
  25
  26 int sys_poll_intr(struct pollfd *fds, int num_fds, int timeout)
  27 {
  28         int orig_timeout = timeout;
  29         struct timespec start;
  30         int ret;
  31
  32         clock_gettime_mono(&start);
  33
  34         while (true) {
  35                 struct timespec now;
  36                 int64_t elapsed;
  37
  38                 ret = poll(fds, num_fds, timeout);
  39                 if (ret != -1) {
  40                         break;
  41                 }
  42                 if (errno != EINTR) {
  43                         break;
  44                 }
  45                 /* Infinite timeout, no need to adjust. */
  46                 if (timeout < 0) {
  47                         continue;
  48                 }
  49                 clock_gettime_mono(&now);
  50                 elapsed = nsec_time_diff(&now, &start) / 1000000;
  51                 timeout = orig_timeout - elapsed;
  52                 /* Unlikely, but might happen eg. when getting traced.
  53                  * Make sure we're not hanging in this case.
  54                  */
  55                 if (timeout < 0) {
  56                         timeout = 0;
  57                 }
  58         };
  59         return ret;
  60 }