/* Function for handling the GLib event loop.
-Copyright (C) 2009-2013 Free Software Foundation, Inc.
+Copyright (C) 2009-2014 Free Software Foundation, Inc.
This file is part of GNU Emacs.
#include <glib.h>
#include <errno.h>
+#include <stdbool.h>
#include <timespec.h>
#include "frame.h"
+#include "blockinput.h"
+
+/* `xg_select' is a `pselect' replacement. Why do we need a separate function?
+ 1. Timeouts. Glib and Gtk rely on timer events. If we did pselect
+ with a greater timeout then the one scheduled by Glib, we would
+ not allow Glib to process its timer events. We want Glib to
+ work smoothly, so we need to reduce our timeout to match Glib.
+ 2. Descriptors. Glib may listen to more file descriptors than we do.
+ So we add Glib descriptors to our pselect pool, but we don't change
+ the value returned by the function. The return value matches only
+ the descriptors passed as arguments, making it compatible with
+ plain pselect. */
int
xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds,
int have_wfds = wfds != NULL;
GPollFD gfds_buf[128];
GPollFD *gfds = gfds_buf;
- int gfds_size = sizeof gfds_buf / sizeof *gfds_buf;
+ int gfds_size = ARRAYELTS (gfds_buf);
int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1;
int i, nfds, tmo_in_millisec;
+ bool need_to_dispatch;
USE_SAFE_ALLOCA;
- /* Do not try to optimize with an initial check with g_main_context_pending
- and a call to pselect if it returns false. If Gdk has a timeout for 0.01
- second, and Emacs has a timeout for 1 second, g_main_context_pending will
- return false, but the timeout will be 1 second, thus missing the gdk
- timeout with a lot. */
-
context = g_main_context_default ();
if (rfds) all_rfds = *rfds;
}
}
- if (our_fds > 0 || (nfds == 0 && tmop == &tmo))
- {
-
- /* If Gtk+ is in use eventually gtk_main_iteration will be called,
- unless retval is zero. */
+ /* If Gtk+ is in use eventually gtk_main_iteration will be called,
+ unless retval is zero. */
#ifdef USE_GTK
- if (retval == 0)
+ need_to_dispatch = retval == 0;
+#else
+ need_to_dispatch = true;
#endif
- while (g_main_context_pending (context))
- g_main_context_dispatch (context);
+ if (need_to_dispatch)
+ {
+ int pselect_errno = errno;
+ /* Prevent g_main_dispatch recursion, that would occur without
+ block_input wrapper, because event handlers call
+ unblock_input. Event loop recursion was causing Bug#15801. */
+ block_input ();
+ while (g_main_context_pending (context))
+ g_main_context_dispatch (context);
+ unblock_input ();
+ errno = pselect_errno;
+ }
- /* To not have to recalculate timeout, return like this. */
- if (retval == 0)
- {
- retval = -1;
- errno = EINTR;
- }
+ /* To not have to recalculate timeout, return like this. */
+ if ((our_fds > 0 || (nfds == 0 && tmop == &tmo)) && (retval == 0))
+ {
+ retval = -1;
+ errno = EINTR;
}
return retval;