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 <setjmp.h>
  23 #include "xgselect.h"
  24
  25 #if defined (USE_GTK) || defined (HAVE_GCONF) || defined (HAVE_GSETTINGS)
  26
  27 #include <glib.h>
  28 #include <errno.h>
  29 #include <setjmp.h>
  30 #include "xterm.h"
  31
  32 int
  33 xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
  34            EMACS_TIME *timeout, sigset_t *sigmask)
  35 {
  36   SELECT_TYPE all_rfds, all_wfds;
  37   EMACS_TIME tmo, *tmop = timeout;
  38
  39   GMainContext *context;
  40   int have_wfds = wfds != NULL;
  41   GPollFD gfds_buf[128];
  42   GPollFD *gfds = gfds_buf;
  43   int gfds_size = sizeof gfds_buf / sizeof *gfds_buf;
  44   int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
  45   int i, nfds, tmo_in_millisec;
  46   USE_SAFE_ALLOCA;
  47
  48   if (! (x_in_use
  49          && g_main_context_pending (context = g_main_context_default ())))
  50     return pselect (fds_lim, rfds, wfds, efds, timeout, sigmask);
  51
  52   if (rfds) memcpy (&all_rfds, rfds, sizeof (all_rfds));
  53   else FD_ZERO (&all_rfds);
  54   if (wfds) memcpy (&all_wfds, wfds, sizeof (all_rfds));
  55   else FD_ZERO (&all_wfds);
  56
  57   n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
  58                                  gfds, gfds_size);
  59   if (gfds_size < n_gfds)
  60     {
  61       SAFE_NALLOCA (gfds, sizeof *gfds, n_gfds);
  62       gfds_size = n_gfds;
  63       n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
  64                                      gfds, gfds_size);
  65     }
  66
  67   for (i = 0; i < n_gfds; ++i)
  68     {
  69       if (gfds[i].events & G_IO_IN)
  70         {
  71           FD_SET (gfds[i].fd, &all_rfds);
  72           if (gfds[i].fd > max_fds) max_fds = gfds[i].fd;
  73         }
  74       if (gfds[i].events & G_IO_OUT)
  75         {
  76           FD_SET (gfds[i].fd, &all_wfds);
  77           if (gfds[i].fd > max_fds) max_fds = gfds[i].fd;
  78           have_wfds = 1;
  79         }
  80     }
  81
  82   SAFE_FREE ();
  83
  84   if (tmo_in_millisec >= 0)
  85     {
  86       tmo = make_emacs_time (tmo_in_millisec / 1000,
  87                              1000 * 1000 * (tmo_in_millisec % 1000));
  88       if (!timeout || EMACS_TIME_LT (tmo, *timeout))
  89         tmop = &tmo;
  90     }
  91
  92   fds_lim = max_fds + 1;
  93   nfds = pselect (fds_lim, &all_rfds, have_wfds ? &all_wfds : NULL,
  94                   efds, tmop, sigmask);
  95
  96   if (nfds < 0)
  97     retval = nfds;
  98   else if (nfds > 0)
  99     {
 100       for (i = 0; i < fds_lim; ++i)
 101         {
 102           if (FD_ISSET (i, &all_rfds))
 103             {
 104               if (rfds && FD_ISSET (i, rfds)) ++retval;
 105               else ++our_fds;
 106             }
 107           else if (rfds)
 108             FD_CLR (i, rfds);
 109
 110           if (have_wfds && FD_ISSET (i, &all_wfds))
 111             {
 112               if (wfds && FD_ISSET (i, wfds)) ++retval;
 113               else ++our_fds;
 114             }
 115           else if (wfds)
 116             FD_CLR (i, wfds);
 117
 118           if (efds && FD_ISSET (i, efds))
 119             ++retval;
 120         }
 121     }
 122
 123   if (our_fds > 0 || (nfds == 0 && tmop == &tmo))
 124     {
 125
 126       /* If Gtk+ is in use eventually gtk_main_iteration will be called,
 127          unless retval is zero.  */
 128 #ifdef USE_GTK
 129       if (retval == 0)
 130 #endif
 131         while (g_main_context_pending (context))
 132           g_main_context_dispatch (context);
 133
 134       /* To not have to recalculate timeout, return like this.  */
 135       if (retval == 0)
 136         {
 137           retval = -1;
 138           errno = EINTR;
 139         }
 140     }
 141
 142   return retval;
 143 }
 144 #endif /* USE_GTK || HAVE_GCONF || HAVE_GSETTINGS */