1/*
2 * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25package sun.awt.X11;
26
27import java.security.AccessController;
28import sun.awt.SunToolkit;
29import sun.security.action.GetBooleanAction;
30import sun.util.logging.PlatformLogger;
31
32/**
33 * This class contains code of the global toolkit error handler, exposes static
34 * methods which allow to set and unset synthetic error handlers.
35 */
36public final class XErrorHandlerUtil {
37    private static final PlatformLogger log = PlatformLogger.getLogger("sun.awt.X11.XErrorHandlerUtil");
38
39    /**
40     * The connection to X11 window server.
41     */
42    private static long display;
43
44    /**
45     * Error handler at the moment of {@code XErrorHandlerUtil} initialization.
46     */
47    private static long saved_error_handler;
48
49    /**
50     * XErrorEvent being handled.
51     */
52    static volatile XErrorEvent saved_error;
53
54    /**
55     * Current error handler or null if no error handler is set.
56     */
57    private static XErrorHandler current_error_handler;
58
59    /**
60     * Value of sun.awt.noisyerrorhandler system property.
61     */
62    private static boolean noisyAwtHandler = AccessController.doPrivileged(
63        new GetBooleanAction("sun.awt.noisyerrorhandler"));
64
65    /**
66     * The flag indicating that {@code init} was called already.
67     */
68    private static boolean initPassed;
69
70    /**
71     * Guarantees that no instance of this class can be created.
72     */
73    private XErrorHandlerUtil() {}
74
75    /**
76     * Sets the toolkit global error handler, stores the connection to X11 server,
77     * which will be used during an error handling process. This method is called
78     * once from {@code awt_init_Display} function defined in {@code awt_GraphicsEnv.c}
79     * file immediately after the connection to X11 window server is opened.
80     * @param display the connection to X11 server which should be stored
81     */
82    private static void init(long display) {
83        SunToolkit.awtLock();
84        try {
85            if (!initPassed) {
86                XErrorHandlerUtil.display = display;
87                saved_error_handler = XlibWrapper.SetToolkitErrorHandler();
88                initPassed = true;
89            }
90        } finally {
91            SunToolkit.awtUnlock();
92        }
93    }
94
95    /**
96     * Sets a synthetic error handler. Must be called with the acquired AWT lock.
97     * @param handler the synthetic error handler to set
98     */
99    public static void WITH_XERROR_HANDLER(XErrorHandler handler) {
100        XSync();
101        saved_error = null;
102        current_error_handler = handler;
103    }
104
105    /**
106     * Unsets a current synthetic error handler. Must be called with the acquired AWT lock.
107     */
108    public static void RESTORE_XERROR_HANDLER() {
109        // Wait until all requests are processed by the X server
110        // and only then uninstall the error handler.
111        XSync();
112        current_error_handler = null;
113    }
114
115    /**
116     * Should be called under LOCK.
117     */
118    public static int SAVED_XERROR_HANDLER(long display, XErrorEvent error) {
119        if (saved_error_handler != 0) {
120            // Default XErrorHandler may just terminate the process. Don't call it.
121            // return XlibWrapper.CallErrorHandler(saved_error_handler, display, error.pData);
122        }
123        if (log.isLoggable(PlatformLogger.Level.FINE)) {
124            log.fine("Unhandled XErrorEvent: " +
125                "id=" + error.get_resourceid() + ", " +
126                "serial=" + error.get_serial() + ", " +
127                "ec=" + error.get_error_code() + ", " +
128                "rc=" + error.get_request_code() + ", " +
129                "mc=" + error.get_minor_code());
130        }
131        return 0;
132    }
133
134    /**
135     * Called from the native code when an error occurs.
136     */
137    private static int globalErrorHandler(long display, long event_ptr) {
138        if (noisyAwtHandler) {
139            XlibWrapper.PrintXErrorEvent(display, event_ptr);
140        }
141        XErrorEvent event = new XErrorEvent(event_ptr);
142        saved_error = event;
143        try {
144            if (current_error_handler != null) {
145                return current_error_handler.handleError(display, event);
146            } else {
147                return SAVED_XERROR_HANDLER(display, event);
148            }
149        } catch (Throwable z) {
150            log.fine("Error in GlobalErrorHandler", z);
151        }
152        return 0;
153    }
154
155    private static void XSync() {
156        SunToolkit.awtLock();
157        try {
158            XlibWrapper.XSync(display, 0);
159        } finally {
160            SunToolkit.awtUnlock();
161        }
162    }
163}
164