ui/gfx/x/x11_error_tracker.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/gfx/x/x11_error_tracker.h"
   6
   7 #include "base/logging.h"
   8 #include "ui/gfx/x/x11_types.h"
   9
  10 namespace {
  11
  12 unsigned char g_x11_error_code = 0;
  13 static gfx::X11ErrorTracker* g_handler = NULL;
  14
  15 int X11ErrorHandler(Display* display, XErrorEvent* error) {
  16   g_x11_error_code = error->error_code;
  17   return 0;
  18 }
  19
  20 }  // namespace
  21
  22 namespace gfx {
  23
  24 X11ErrorTracker::X11ErrorTracker() {
  25   // This is a poor-man's check for incorrect usage. It disallows nested
  26   // X11ErrorTracker instances on the same thread.
  27   DCHECK(g_handler == NULL);
  28   g_handler = this;
  29   XSync(GetXDisplay(), False);
  30   old_handler_ = XSetErrorHandler(X11ErrorHandler);
  31   g_x11_error_code = 0;
  32 }
  33
  34 X11ErrorTracker::~X11ErrorTracker() {
  35   g_handler = NULL;
  36   XSetErrorHandler(old_handler_);
  37 }
  38
  39 bool X11ErrorTracker::FoundNewError() {
  40   XSync(GetXDisplay(), False);
  41   unsigned char error = g_x11_error_code;
  42   g_x11_error_code = 0;
  43   return error != 0;
  44 }
  45
  46 }  // namespace gfx