moving from https://github.com/perberos/mate-desktop-environment

1 files changed, 288 insertions, 0 deletions

diff --git a/src/core/errors.c b/src/core/errors.c
new file mode 100644
index 00000000..3b2a6334
--- /dev/null
+++ b/src/core/errors.c
@@ -0,0 +1,288 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/* Marco X error handling */
+
+/* 
+ * Copyright (C) 2001 Havoc Pennington, error trapping inspired by GDK
+ * code copyrighted by the GTK team.
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <config.h>
+#include "errors.h"
+#include "display-private.h"
+#include <errno.h>
+#include <stdlib.h>
+#include <gdk/gdk.h>
+
+static int x_error_handler    (Display     *display,
+                               XErrorEvent *error);
+static int x_io_error_handler (Display     *display);
+
+void
+meta_errors_init (void)
+{
+  XSetErrorHandler (x_error_handler);
+  XSetIOErrorHandler (x_io_error_handler);
+}
+
+typedef struct ForeignDisplay ForeignDisplay;
+
+struct ForeignDisplay
+{
+    Display *dpy;
+    ErrorHandler handler;
+    gpointer data;
+    ForeignDisplay *next;
+};
+
+static ForeignDisplay *foreign_displays;
+
+void
+meta_errors_register_foreign_display (Display      *foreign_dpy,
+				      ErrorHandler  handler,
+				      gpointer      data)
+{
+    ForeignDisplay *info = g_new0 (ForeignDisplay, 1);
+    info->dpy = foreign_dpy;
+    info->handler = handler;
+    info->data = data;
+    info->next = foreign_displays;
+    foreign_displays = info;
+}
+
+static void
+meta_error_trap_push_internal (MetaDisplay *display,
+                               gboolean     need_sync)
+{
+  /* GDK resets the error handler on each push */
+  int (* old_error_handler) (Display     *,
+                             XErrorEvent *);
+
+  if (need_sync)
+    {
+      XSync (display->xdisplay, False);
+    }
+  
+  gdk_error_trap_push ();
+
+  /* old_error_handler will just be equal to x_error_handler
+   * for nested traps
+   */
+  old_error_handler = XSetErrorHandler (x_error_handler);
+  
+  /* Replace GDK handler, but save it so we can chain up */
+  if (display->error_trap_handler == NULL)
+    {
+      g_assert (display->error_traps == 0);
+      display->error_trap_handler = old_error_handler;
+      g_assert (display->error_trap_handler != x_error_handler);
+    }
+
+  display->error_traps += 1;
+
+  meta_topic (META_DEBUG_ERRORS, "%d traps remain\n", display->error_traps);
+}
+
+static int
+meta_error_trap_pop_internal  (MetaDisplay *display,
+                               gboolean     need_sync)
+{
+  int result;
+
+  g_assert (display->error_traps > 0);
+
+  if (need_sync)
+    {
+      XSync (display->xdisplay, False);
+    }
+
+  result = gdk_error_trap_pop ();
+
+  display->error_traps -= 1;
+  
+  if (display->error_traps == 0)
+    {
+      /* check that GDK put our handler back; this
+       * assumes that there are no pending GDK traps from GDK itself
+       */
+      
+      int (* restored_error_handler) (Display     *,
+                                      XErrorEvent *);
+
+      restored_error_handler = XSetErrorHandler (x_error_handler);
+
+      /* remove this */
+      display->error_trap_handler = NULL;
+    }
+
+  meta_topic (META_DEBUG_ERRORS, "%d traps\n", display->error_traps);
+  
+  return result;
+}
+
+void
+meta_error_trap_push (MetaDisplay *display)
+{
+  meta_error_trap_push_internal (display, FALSE);
+}
+
+void
+meta_error_trap_pop (MetaDisplay *display,
+                     gboolean     last_request_was_roundtrip)
+{
+  gboolean need_sync;
+
+  /* we only have to sync when popping the outermost trap */
+  need_sync = (display->error_traps == 1 && !last_request_was_roundtrip);
+
+  if (need_sync)
+    meta_topic (META_DEBUG_SYNC, "Syncing on error_trap_pop, traps = %d, roundtrip = %d\n",
+                display->error_traps, last_request_was_roundtrip);
+
+  display->error_trap_synced_at_last_pop = need_sync || last_request_was_roundtrip;
+  
+  meta_error_trap_pop_internal (display, need_sync);
+}
+
+void
+meta_error_trap_push_with_return (MetaDisplay *display)
+{
+  gboolean need_sync;
+
+  /* We don't sync on push_with_return if there are no traps
+   * currently, because we assume that any errors were either covered
+   * by a previous pop, or were fatal.
+   *
+   * More generally, we don't sync if we were synchronized last time
+   * we popped. This is known to be the case if there are no traps,
+   * but we also keep a flag so we know whether it's the case otherwise.
+   */
+
+  if (!display->error_trap_synced_at_last_pop)
+    need_sync = TRUE;
+  else
+    need_sync = FALSE;
+
+  if (need_sync)
+    meta_topic (META_DEBUG_SYNC, "Syncing on error_trap_push_with_return, traps = %d\n",
+                display->error_traps);
+  
+  meta_error_trap_push_internal (display, FALSE);
+}
+
+int
+meta_error_trap_pop_with_return  (MetaDisplay *display,
+                                  gboolean     last_request_was_roundtrip)
+{
+  if (!last_request_was_roundtrip)
+    meta_topic (META_DEBUG_SYNC, "Syncing on error_trap_pop_with_return, traps = %d, roundtrip = %d\n",
+                display->error_traps, last_request_was_roundtrip);
+
+  display->error_trap_synced_at_last_pop = TRUE;
+  
+  return meta_error_trap_pop_internal (display,
+                                       !last_request_was_roundtrip);
+}
+
+static int
+x_error_handler (Display     *xdisplay,
+                 XErrorEvent *error)
+{
+  int retval;
+  gchar buf[64];
+  MetaDisplay *display;
+  ForeignDisplay *foreign;
+
+  for (foreign = foreign_displays; foreign != NULL; foreign = foreign->next)
+  {
+      if (foreign->dpy == xdisplay)
+      {
+	  foreign->handler (xdisplay, error, foreign->data);
+
+	  return 0;
+      }
+  }
+  
+  XGetErrorText (xdisplay, error->error_code, buf, 63);  
+
+  display = meta_display_for_x_display (xdisplay);
+
+  /* Display can be NULL here because the compositing manager
+   * has its own Display, but Xlib only has one global error handler
+   */
+  if (display->error_traps > 0)
+    {
+      /* we're in an error trap, chain to the trap handler
+       * saved from GDK
+       */
+      meta_verbose ("X error: %s serial %ld error_code %d request_code %d minor_code %d)\n",
+                    buf,
+                    error->serial, 
+                    error->error_code, 
+                    error->request_code,
+                    error->minor_code);
+
+      g_assert (display->error_trap_handler != NULL);
+      g_assert (display->error_trap_handler != x_error_handler);
+      
+      retval = (* display->error_trap_handler) (xdisplay, error);
+    }
+  else
+    {
+      meta_bug ("Unexpected X error: %s serial %ld error_code %d request_code %d minor_code %d)\n",
+                buf,
+                error->serial, 
+                error->error_code, 
+                error->request_code,
+                error->minor_code);
+
+      retval = 1; /* compiler warning */
+    }
+
+  return retval;
+}
+
+static int
+x_io_error_handler (Display *xdisplay)
+{
+  MetaDisplay *display;
+
+  display = meta_display_for_x_display (xdisplay);
+
+  if (display == NULL)
+    meta_bug ("IO error received for unknown display?\n");
+  
+  if (errno == EPIPE)
+    {
+      meta_warning (_("Lost connection to the display '%s';\n"
+                      "most likely the X server was shut down or you killed/destroyed\n"
+                      "the window manager.\n"),
+                    display->name);
+    }
+  else
+    {
+      meta_warning (_("Fatal IO error %d (%s) on display '%s'.\n"),
+                    errno, g_strerror (errno),
+                    display->name);
+    }
+
+  /* Xlib would force an exit anyhow */
+  exit (1);
+  
+  return 0;
+}