/* * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.jdi.request; import com.sun.jdi.*; /** * Represents a request for notification of an event.  Examples include * {@link BreakpointRequest} and {@link ExceptionRequest}. * When an event occurs for which an enabled request is present, * an  {@link com.sun.jdi.event.EventSet EventSet} will * be placed on the {@link com.sun.jdi.event.EventQueue EventQueue}. * The collection of existing event requests is * managed by the {@link EventRequestManager}. * <p> * The number of events generated for an event request can be controlled * through filters. Filters provide additional constraints that an event * must satisfy before it is placed on the event queue. Multiple filters can * be used by making multiple calls to filter addition methods such as * {@link ExceptionRequest#addClassFilter(java.lang.String classPattern)}. * Filters are added to an event one at a time only while the event is * disabled. Multiple filters are applied with CUT-OFF AND, in the order * it was added to the request. Only events that satisfy all filters are * placed in the event queue. * <p> * The set of available filters is dependent on the event request, * some examples of filters are: * <ul> * <li>Thread filters allow control over the thread for which events are * generated. * <li>Class filters allow control over the class in which the event * occurs. * <li>Instance filters allow control over the instance in which * the event occurs. * <li>Count filters allow control over the number of times an event * is reported. * </ul> * Filters can dramatically improve debugger performance by reducing the * amount of event traffic sent from the target VM to the debugger VM. * <p> * Any method on <code>EventRequest</code> which * takes <code>EventRequest</code> as an parameter may throw * {@link com.sun.jdi.VMDisconnectedException} if the target VM is * disconnected and the {@link com.sun.jdi.event.VMDisconnectEvent} has been or is * available to be read from the {@link com.sun.jdi.event.EventQueue}. * <p> * Any method on <code>EventRequest</code> which * takes <code>EventRequest</code> as an parameter may throw * {@link com.sun.jdi.VMOutOfMemoryException} if the target VM has run out of memory. * * @see com.sun.jdi.event.BreakpointEvent * @see com.sun.jdi.event.EventQueue * @see EventRequestManager * * @author Robert Field * @since  1.3 */public interface EventRequest extends Mirror {     /**     * Determines if this event request is currently enabled.     *     * @return <code>true</code> if enabled;     * <code>false</code> otherwise.     */    boolean isEnabled();     /**     * Enables or disables this event request. While this event request is     * disabled, the event request will be ignored and the target VM     * will not be stopped if any of its threads reaches the     * event request.  Disabled event requests still exist,     * and are included in event request lists such as     * {@link EventRequestManager#breakpointRequests()}.     *     * @param val <code>true</code> if the event request is to be enabled;     * <code>false</code> otherwise.     * @throws InvalidRequestStateException if this request     * has been deleted.     * @throws IllegalThreadStateException if this is a StepRequest,     * <code>val</code> is <code>true</code>, and the     * thread named in the request has died.     */    void setEnabled(boolean val);     /**     * Same as {@link #setEnabled <CODE>setEnabled(true)</CODE>}.     * @throws InvalidRequestStateException if this request     * has been deleted.     * @throws IllegalThreadStateException if this is a StepRequest     * and the thread named in the request has died.     */    void enable();     /**     * Same as {@link #setEnabled <CODE>setEnabled(false)</CODE>}.     * @throws InvalidRequestStateException if this request     * has been deleted.     */    void disable();     /**     * Limit the requested event to be reported at most once after a     * given number of occurrences.  The event is not reported     * the first <code>count - 1</code> times this filter is reached.     * To request a one-off event, call this method with a count of 1.     * <p>     * Once the count reaches 0, any subsequent filters in this request     * are applied. If none of those filters cause the event to be     * suppressed, the event is reported. Otherwise, the event is not     * reported. In either case subsequent events are never reported for     * this request.     *     * @param count the number of ocurrences before generating an event.     * @throws InvalidRequestStateException if this request is currently     * enabled or has been deleted.     * Filters may be added only to disabled requests.     * @throws IllegalArgumentException if <CODE>count</CODE>     * is less than one.     */    void addCountFilter(int count);     /** Suspend no threads when the event occurs */    int SUSPEND_NONE = 0;    /** Suspend only the thread which generated the event when the event occurs */    int SUSPEND_EVENT_THREAD = 1;    /** Suspend all threads when the event occurs */    int SUSPEND_ALL = 2;     /**     * Determines the threads to suspend when the requested event occurs     * in the target VM. Use {@link #SUSPEND_ALL} to suspend all     * threads in the target VM (the default). Use {@link #SUSPEND_EVENT_THREAD}     * to suspend only the thread which generated the event. Use     * {@link #SUSPEND_NONE} to suspend no threads.     * <p>     * Thread suspensions through events have the same functionality     * as explicitly requested suspensions. See     * {@link com.sun.jdi.ThreadReference#suspend} and     * {@link com.sun.jdi.VirtualMachine#suspend} for details.     *     * @param policy the selected suspend policy.     * @throws InvalidRequestStateException if this request is currently     * enabled or has been deleted.     * Suspend policy may only be set in disabled requests.     * @throws IllegalArgumentException if the policy argument     * contains an illegal value.     */    void setSuspendPolicy(int policy);     /**     * Returns a value which describes the threads to suspend when the     * requested event occurs in the target VM.     * The returned value is  {@link #SUSPEND_ALL},     * {@link #SUSPEND_EVENT_THREAD}, or {@link #SUSPEND_NONE}.     *     * @return the current suspend mode for this request     */    int suspendPolicy();     /**     * Add an arbitrary key/value "property" to this request.     * The property can be used by a client of the JDI to     * associate application information with the request;     * These client-set properties are not used internally     * by the JDI.     * <p>     * The <code>get/putProperty</code> methods provide access to     * a small per-instance map. This is <b>not</b> to be confused     * with {@link java.util.Properties}.     * <p>     * If value is null this method will remove the property.     *     * @see #getProperty     */    void putProperty(Object key, Object value);     /**     * Returns the value of the property with the specified key.  Only     * properties added with {@link #putProperty} will return     * a non-null value.     *     * @return the value of this property or null     * @see #putProperty     */    Object getProperty(Object key);}