src/xgselect.c

   1 /* Function for handling the GLib event loop.
   2
   3 Copyright (C) 2009-2012  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs 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 GNU Emacs 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 GNU Emacs.  If not, see <http§://www.gnu.org/licenses/>.  */
  19
  20 #include <config.h>
  21
  22 #include "xgselect.h"
  23
  24 #if defined (USE_GTK) || defined (HAVE_GCONF) || defined (HAVE_GSETTINGS)
  25
  26 #include <glib.h>
  27 #include <errno.h>
  28 #include "xterm.h"
  29
  30 int
  31 xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
  32            EMACS_TIME *timeout, sigset_t *sigmask)
  33 {
  34   SELECT_TYPE all_rfds, all_wfds;
  35   EMACS_TIME tmo, *tmop = timeout;
  36
  37   GMainContext *context;
  38   int have_wfds = wfds != NULL;
  39   GPollFD gfds_buf[128];
  40   GPollFD *gfds = gfds_buf;
  41   int gfds_size = sizeof gfds_buf / sizeof *gfds_buf;
  42   int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
  43   int i, nfds, tmo_in_millisec;
  44   USE_SAFE_ALLOCA;
  45
  46   if (! (x_in_use
  47          && g_main_context_pending (context = g_main_context_default ())))
  48     return pselect (fds_lim, rfds, wfds, efds, timeout, sigmask);
  49
  50   if (rfds) all_rfds = *rfds;
  51   else FD_ZERO (&all_rfds);
  52   if (wfds) all_wfds = *wfds;
  53   else FD_ZERO (&all_wfds);
  54
  55   n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
  56                                  gfds, gfds_size);
  57   if (gfds_size < n_gfds)
  58     {
  59       SAFE_NALLOCA (gfds, sizeof *gfds, n_gfds);
  60       gfds_size = n_gfds;
  61       n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
  62                                      gfds, gfds_size);
  63     }
  64
  65   for (i = 0; i < n_gfds; ++i)
  66     {
  67       if (gfds[i].events & G_IO_IN)
  68         {
  69           FD_SET (gfds[i].fd, &all_rfds);
  70           if (gfds[i].fd > max_fds) max_fds = gfds[i].fd;
  71         }
  72       if (gfds[i].events & G_IO_OUT)
  73         {
  74           FD_SET (gfds[i].fd, &all_wfds);
  75           if (gfds[i].fd > max_fds) max_fds = gfds[i].fd;
  76           have_wfds = 1;
  77         }
  78     }
  79
  80   SAFE_FREE ();
  81
  82   if (tmo_in_millisec >= 0)
  83     {
  84       tmo = make_emacs_time (tmo_in_millisec / 1000,
  85                              1000 * 1000 * (tmo_in_millisec % 1000));
  86       if (!timeout || EMACS_TIME_LT (tmo, *timeout))
  87         tmop = &tmo;
  88     }
  89
  90   fds_lim = max_fds + 1;
  91   nfds = pselect (fds_lim, &all_rfds, have_wfds ? &all_wfds : NULL,
  92                   efds, tmop, sigmask);
  93
  94   if (nfds < 0)
  95     retval = nfds;
  96   else if (nfds > 0)
  97     {
  98       for (i = 0; i < fds_lim; ++i)
  99         {
 100           if (FD_ISSET (i, &all_rfds))
 101             {
 102               if (rfds && FD_ISSET (i, rfds)) ++retval;
 103               else ++our_fds;
 104             }
 105           else if (rfds)
 106             FD_CLR (i, rfds);
 107
 108           if (have_wfds && FD_ISSET (i, &all_wfds))
 109             {
 110               if (wfds && FD_ISSET (i, wfds)) ++retval;
 111               else ++our_fds;
 112             }
 113           else if (wfds)
 114             FD_CLR (i, wfds);
 115
 116           if (efds && FD_ISSET (i, efds))
 117             ++retval;
 118         }
 119     }
 120
 121   if (our_fds > 0 || (nfds == 0 && tmop == &tmo))
 122     {
 123
 124       /* If Gtk+ is in use eventually gtk_main_iteration will be called,
 125          unless retval is zero.  */
 126 #ifdef USE_GTK
 127       if (retval == 0)
 128 #endif
 129         while (g_main_context_pending (context))
 130           g_main_context_dispatch (context);
 131
 132       /* To not have to recalculate timeout, return like this.  */
 133       if (retval == 0)
 134         {
 135           retval = -1;
 136           errno = EINTR;
 137         }
 138     }
 139
 140   return retval;
 141 }
 142 #endif /* USE_GTK || HAVE_GCONF || HAVE_GSETTINGS */