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.event; 27 28 import com.sun.jdi.*; 29 30 /** 31 * Manager of incoming debugger events for a target VM. 32 * Events are always grouped in {@link EventSet}s. 33 * EventSets generated by the debugger back end can be read 34 * here. There is one instance of EventQueue assigned to a particular 35 * {@link com.sun.jdi.VirtualMachine VirtualMachine}. 36 * <P> 37 * Some events cause the suspension of the target VM - event requests 38 * ({@link com.sun.jdi.request}) with a 39 * {@link com.sun.jdi.request.EventRequest#suspendPolicy() suspend policy} 40 * of {@link com.sun.jdi.request.EventRequest#SUSPEND_ALL SUSPEND_ALL} 41 * or {@link com.sun.jdi.request.EventRequest#SUSPEND_EVENT_THREAD 42 * SUSPEND_EVENT_THREAD} and sometimes 43 * {@link VMStartEvent}. 44 * If these suspensions are not resumed the target VM will hang. 45 * Thus, it is always good policy to 46 * {@link #remove() remove()} every EventSet from the 47 * event queue until an EventSet containing a 48 * {@link VMDisconnectEvent} is read. 49 * Unless {@link com.sun.jdi.VirtualMachine#resume() resume} is 50 * being handled in another way, each EventSet should invoke 51 * {@link EventSet#resume()}. 52 * 53 * @see EventSet 54 * @see VirtualMachine 55 * 56 * @author Robert Field 57 * @since 1.3 58 */ 59 60 @jdk.Exported 61 public interface EventQueue extends Mirror { 62 63 /** 64 * Waits forever for the next available event. 65 * 66 * @return the next {@link EventSet}. 67 * @throws InterruptedException if any thread has interrupted 68 * this thread. 69 * @throws com.sun.jdi.VMDisconnectedException if the connection 70 * to the target VM is no longer available. Note this will always 71 * be preceded by a {@link com.sun.jdi.event.VMDisconnectEvent}. 72 */ remove()73 EventSet remove() throws InterruptedException; 74 75 /** 76 * Waits a specified time for the next available event. 77 * 78 * @param timeout Time in milliseconds to wait for the next event 79 * @return the next {@link EventSet}, or null if there is a timeout. 80 * @throws InterruptedException if any thread has interrupted 81 * this thread. 82 * @throws com.sun.jdi.VMDisconnectedException if the connection 83 * to the target VM is no longer available. Note this will always 84 * be preceded by a {@link com.sun.jdi.event.VMDisconnectEvent}. 85 * @throws IllegalArgumentException if the timeout argument 86 * contains an illegal value. 87 */ remove(long timeout)88 EventSet remove(long timeout) throws InterruptedException; 89 } 90