* xgselect.c (xg_select): Use auto storage for the GPollFD buffer

as that's faster and simpler than static storage.  Don't bother
with the g_main_context_query overhead if g_main_context_pending
says no events are pending.
(gfds, gfds_size): Remove these static vars.
(xgselect_initialize): Remove; no longer needed.
All uses and decls removed.

4 files changed, 27 insertions, 37 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index eacb82d9814..5654a191ec0 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,13 @@
 2012-08-25  Paul Eggert  <eggert@cs.ucla.edu>
 
+        * xgselect.c (xg_select): Use auto storage for the GPollFD buffer
+        as that's faster and simpler than static storage.  Don't bother
+        with the g_main_context_query overhead if g_main_context_pending
+        says no events are pending.
+        (gfds, gfds_size): Remove these static vars.
+        (xgselect_initialize): Remove; no longer needed.
+        All uses and decls removed.
+
         * emacs.c (fatal_error_signal_hook): Remove.
         All uses removed.  This leftover from old code was always 0.
 
diff --git a/src/xgselect.c b/src/xgselect.c
index 04ca00274e8..0c00d815820 100644
--- a/src/xgselect.c
+++ b/src/xgselect.c
@@ -29,9 +29,6 @@ along with GNU Emacs.  If not, see <http§://www.gnu.org/licenses/>.  */
 #include <setjmp.h>
 #include "xterm.h"
 
-static GPollFD *gfds;
-static ptrdiff_t gfds_size;
-
 int
 xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
            EMACS_TIME *timeout, sigset_t *sigmask)
@@ -41,35 +38,31 @@ xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
 
   GMainContext *context;
   int have_wfds = wfds != NULL;
-  int n_gfds = 0, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
+  GPollFD gfds_buf[128];
+  GPollFD *gfds = gfds_buf;
+  int gfds_size = sizeof gfds_buf / sizeof *gfds_buf;
+  int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
   int i, nfds, tmo_in_millisec;
+  USE_SAFE_ALLOCA;
 
-  if (!x_in_use)
-    return pselect (fds_lim, rfds, wfds, efds, tmop, sigmask);
+  if (! (x_in_use
+         && g_main_context_pending (context = g_main_context_default ())))
+    return pselect (fds_lim, rfds, wfds, efds, timeout, sigmask);
 
   if (rfds) memcpy (&all_rfds, rfds, sizeof (all_rfds));
   else FD_ZERO (&all_rfds);
   if (wfds) memcpy (&all_wfds, wfds, sizeof (all_rfds));
   else FD_ZERO (&all_wfds);
 
-  /* Update event sources in GLib. */
-  context = g_main_context_default ();
-  g_main_context_pending (context);
-
-  do {
-    if (n_gfds > gfds_size)
-      {
-        xfree (gfds);
-        gfds = xpalloc (0, &gfds_size, n_gfds - gfds_size, INT_MAX,
-                        sizeof *gfds);
-      }
-
-    n_gfds = g_main_context_query (context,
-                                   G_PRIORITY_LOW,
-                                   &tmo_in_millisec,
-                                   gfds,
-                                   gfds_size);
-  } while (n_gfds > gfds_size);
+  n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
+                                 gfds, gfds_size);
+  if (gfds_size < n_gfds)
+    {
+      SAFE_NALLOCA (gfds, sizeof *gfds, n_gfds);
+      gfds_size = n_gfds;
+      n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec,
+                                     gfds, gfds_size);
+    }
 
   for (i = 0; i < n_gfds; ++i)
     {
@@ -86,6 +79,8 @@ xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
         }
     }
 
+  SAFE_FREE ();
+
   if (tmo_in_millisec >= 0)
     {
       tmo = make_emacs_time (tmo_in_millisec / 1000,
@@ -147,12 +142,3 @@ xg_select (int fds_lim, SELECT_TYPE *rfds, SELECT_TYPE *wfds, SELECT_TYPE *efds,
   return retval;
 }
 #endif /* USE_GTK || HAVE_GCONF || HAVE_GSETTINGS */
-
-void
-xgselect_initialize (void)
-{
-#if defined (USE_GTK) || defined (HAVE_GCONF) || defined (HAVE_GSETTINGS)
-  gfds_size = 128;
-  gfds = xmalloc (gfds_size * sizeof *gfds);
-#endif
-}
diff --git a/src/xgselect.h b/src/xgselect.h
index 8e5614ea972..5509e23c5c0 100644
--- a/src/xgselect.h
+++ b/src/xgselect.h
@@ -31,6 +31,4 @@ extern int xg_select (int max_fds,
                       EMACS_TIME *timeout,
                       sigset_t *sigmask);
 
-extern void xgselect_initialize (void);
-
 #endif /* XGSELECT_H */
diff --git a/src/xterm.c b/src/xterm.c
index 118c8767c23..7e61cc4d8ea 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10815,8 +10815,6 @@ x_initialize (void)
   XSetIOErrorHandler (x_io_error_quitter);
 
   signal (SIGPIPE, x_connection_signal);
-
-  xgselect_initialize ();
 }