1 /* 2 * Copyright (c) 1998, 2013, 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 */ 25 26 package com.sun.jdi.request; 27 28 import com.sun.jdi.*; 29 30 /** 31 * Represents a request for notification of an event. Examples include 32 * {@link BreakpointRequest} and {@link ExceptionRequest}. 33 * When an event occurs for which an enabled request is present, 34 * an {@link com.sun.jdi.event.EventSet EventSet} will 35 * be placed on the {@link com.sun.jdi.event.EventQueue EventQueue}. 36 * The collection of existing event requests is 37 * managed by the {@link EventRequestManager}. 38 * <p> 39 * The number of events generated for an event request can be controlled 40 * through filters. Filters provide additional constraints that an event 41 * must satisfy before it is placed on the event queue. Multiple filters can 42 * be used by making multiple calls to filter addition methods such as 43 * {@link ExceptionRequest#addClassFilter(java.lang.String classPattern)}. 44 * Filters are added to an event one at a time only while the event is 45 * disabled. Multiple filters are applied with CUT-OFF AND, in the order 46 * it was added to the request. Only events that satisfy all filters are 47 * placed in the event queue. 48 * <p> 49 * The set of available filters is dependent on the event request, 50 * some examples of filters are: 51 * <ul> 52 * <li>Thread filters allow control over the thread for which events are 53 * generated. 54 * <li>Class filters allow control over the class in which the event 55 * occurs. 56 * <li>Instance filters allow control over the instance in which 57 * the event occurs. 58 * <li>Count filters allow control over the number of times an event 59 * is reported. 60 * </ul> 61 * Filters can dramatically improve debugger performance by reducing the 62 * amount of event traffic sent from the target VM to the debugger VM. 63 * <p> 64 * Any method on <code>EventRequest</code> which 65 * takes <code>EventRequest</code> as an parameter may throw 66 * {@link com.sun.jdi.VMDisconnectedException} if the target VM is 67 * disconnected and the {@link com.sun.jdi.event.VMDisconnectEvent} has been or is 68 * available to be read from the {@link com.sun.jdi.event.EventQueue}. 69 * <p> 70 * Any method on <code>EventRequest</code> which 71 * takes <code>EventRequest</code> as an parameter may throw 72 * {@link com.sun.jdi.VMOutOfMemoryException} if the target VM has run out of memory. 73 * 74 * @see com.sun.jdi.event.BreakpointEvent 75 * @see com.sun.jdi.event.EventQueue 76 * @see EventRequestManager 77 * 78 * @author Robert Field 79 * @since 1.3 80 */ 81 @jdk.Exported 82 public interface EventRequest extends Mirror { 83 84 /** 85 * Determines if this event request is currently enabled. 86 * 87 * @return <code>true</code> if enabled; 88 * <code>false</code> otherwise. 89 */ 90 boolean isEnabled(); 91 92 /** 93 * Enables or disables this event request. While this event request is 94 * disabled, the event request will be ignored and the target VM 95 * will not be stopped if any of its threads reaches the 96 * event request. Disabled event requests still exist, 97 * and are included in event request lists such as 98 * {@link EventRequestManager#breakpointRequests()}. 99 * 100 * @param val <code>true</code> if the event request is to be enabled; 101 * <code>false</code> otherwise. 102 * @throws InvalidRequestStateException if this request 103 * has been deleted. 104 * @throws IllegalThreadStateException if this is a StepRequest, 105 * <code>val</code> is <code>true</code>, and the 106 * thread named in the request has died. 107 */ 108 void setEnabled(boolean val); 109 110 /** 111 * Same as {@link #setEnabled <CODE>setEnabled(true)</CODE>}. 112 * @throws InvalidRequestStateException if this request 113 * has been deleted. 114 * @throws IllegalThreadStateException if this is a StepRequest 115 * and the thread named in the request has died. 116 */ 117 void enable(); 118 119 /** 120 * Same as {@link #setEnabled <CODE>setEnabled(false)</CODE>}. 121 * @throws InvalidRequestStateException if this request 122 * has been deleted. 123 */ 124 void disable(); 125 126 /** 127 * Limit the requested event to be reported at most once after a 128 * given number of occurrences. The event is not reported 129 * the first <code>count - 1</code> times this filter is reached. 130 * To request a one-off event, call this method with a count of 1. 131 * <p> 132 * Once the count reaches 0, any subsequent filters in this request 133 * are applied. If none of those filters cause the event to be 134 * suppressed, the event is reported. Otherwise, the event is not 135 * reported. In either case subsequent events are never reported for 136 * this request. 137 * 138 * @param count the number of ocurrences before generating an event. 139 * @throws InvalidRequestStateException if this request is currently 140 * enabled or has been deleted. 141 * Filters may be added only to disabled requests. 142 * @throws IllegalArgumentException if <CODE>count</CODE> 143 * is less than one. 144 */ 145 void addCountFilter(int count); 146 147 /** Suspend no threads when the event occurs */ 148 int SUSPEND_NONE = 0; 149 /** Suspend only the thread which generated the event when the event occurs */ 150 int SUSPEND_EVENT_THREAD = 1; 151 /** Suspend all threads when the event occurs */ 152 int SUSPEND_ALL = 2; 153 154 /** 155 * Determines the threads to suspend when the requested event occurs 156 * in the target VM. Use {@link #SUSPEND_ALL} to suspend all 157 * threads in the target VM (the default). Use {@link #SUSPEND_EVENT_THREAD} 158 * to suspend only the thread which generated the event. Use 159 * {@link #SUSPEND_NONE} to suspend no threads. 160 * <p> 161 * Thread suspensions through events have the same functionality 162 * as explicitly requested suspensions. See 163 * {@link com.sun.jdi.ThreadReference#suspend} and 164 * {@link com.sun.jdi.VirtualMachine#suspend} for details. 165 * 166 * @param policy the selected suspend policy. 167 * @throws InvalidRequestStateException if this request is currently 168 * enabled or has been deleted. 169 * Suspend policy may only be set in disabled requests. 170 * @throws IllegalArgumentException if the policy argument 171 * contains an illegal value. 172 */ 173 void setSuspendPolicy(int policy); 174 175 /** 176 * Returns a value which describes the threads to suspend when the 177 * requested event occurs in the target VM. 178 * The returned value is {@link #SUSPEND_ALL}, 179 * {@link #SUSPEND_EVENT_THREAD}, or {@link #SUSPEND_NONE}. 180 * 181 * @return the current suspend mode for this request 182 */ 183 int suspendPolicy(); 184 185 /** 186 * Add an arbitrary key/value "property" to this request. 187 * The property can be used by a client of the JDI to 188 * associate application information with the request; 189 * These client-set properties are not used internally 190 * by the JDI. 191 * <p> 192 * The <code>get/putProperty</code> methods provide access to 193 * a small per-instance map. This is <b>not</b> to be confused 194 * with {@link java.util.Properties}. 195 * <p> 196 * If value is null this method will remove the property. 197 * 198 * @see #getProperty 199 */ 200 void putProperty(Object key, Object value); 201 202 /** 203 * Returns the value of the property with the specified key. Only 204 * properties added with {@link #putProperty} will return 205 * a non-null value. 206 * 207 * @return the value of this property or null 208 * @see #putProperty 209 */ 210 Object getProperty(Object key); 211 } 212
