packet/wait_cygwin.c

   1 /*
   2     mtr  --  a network diagnostic tool
   3     Copyright (C) 2016  Matt Kimball
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License version 2 as
   7     published by the Free Software Foundation.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License along
  15     with this program; if not, write to the Free Software Foundation, Inc.,
  16     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17 */
  18
  19 #include "wait.h"
  20
  21 #include <error.h>
  22 #include <errno.h>
  23 #include <sys/select.h>
  24
  25 #include "command.h"
  26
  27 /*
  28     Wait for either a request from the command stream or
  29     for the probe results to be passed from the ICMP service
  30     thread.
  31 */
  32 void wait_for_activity(
  33     struct command_buffer_t *command_buffer,
  34     struct net_state_t *net_state)
  35 {
  36     int nfds;
  37     fd_set read_set;
  38     int ready_count;
  39
  40     FD_ZERO(&read_set);
  41
  42     FD_SET(command_buffer->command_stream, &read_set);
  43     nfds = command_buffer->command_stream + 1;
  44
  45     FD_SET(net_state->platform.thread_out_pipe_read, &read_set);
  46     if (net_state->platform.thread_out_pipe_read >= nfds) {
  47         nfds = net_state->platform.thread_out_pipe_read + 1;
  48     }
  49
  50     while (true) {
  51         ready_count =
  52             select(nfds, &read_set, NULL, NULL, NULL);
  53
  54         if (ready_count != -1) {
  55             return;
  56         }
  57
  58         /*
  59             EINTR and EAGAIN simply mean that the select should
  60             be retried.
  61         */
  62         if (errno != EINTR && errno != EAGAIN) {
  63             error(EXIT_FAILURE, errno, "unexpected select error");
  64         }
  65     }
  66 }