1 /* 2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "modules/desktop_capture/linux/x11/x_error_trap.h" 12 13 #include <atomic> 14 15 #include <stddef.h> 16 17 #include "rtc_base/checks.h" 18 19 namespace webrtc { 20 21 namespace { 22 23 static int g_last_xserver_error_code = 0; 24 static std::atomic<Display*> g_display_for_error_handler = nullptr; 25 AcquireMutex()26Mutex* AcquireMutex() { 27 static Mutex* mutex = new Mutex(); 28 return mutex; 29 } 30 XServerErrorHandler(Display * display,XErrorEvent * error_event)31int XServerErrorHandler(Display* display, XErrorEvent* error_event) { 32 RTC_DCHECK_EQ(display, g_display_for_error_handler.load()); 33 g_last_xserver_error_code = error_event->error_code; 34 return 0; 35 } 36 37 } // namespace 38 XErrorTrap(Display * display)39XErrorTrap::XErrorTrap(Display* display) : mutex_lock_(AcquireMutex()) { 40 // We don't expect this class to be used in a nested fashion so therefore 41 // g_display_for_error_handler should never be valid here. 42 RTC_DCHECK(!g_display_for_error_handler.load()); 43 RTC_DCHECK(display); 44 g_display_for_error_handler.store(display); 45 g_last_xserver_error_code = 0; 46 original_error_handler_ = XSetErrorHandler(&XServerErrorHandler); 47 } 48 GetLastErrorAndDisable()49int XErrorTrap::GetLastErrorAndDisable() { 50 g_display_for_error_handler.store(nullptr); 51 XSetErrorHandler(original_error_handler_); 52 return g_last_xserver_error_code; 53 } 54 ~XErrorTrap()55XErrorTrap::~XErrorTrap() { 56 if (g_display_for_error_handler.load() != nullptr) 57 GetLastErrorAndDisable(); 58 } 59 60 } // namespace webrtc 61