1 /* 2 * Copyright (c) 2014, 2016, 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 jdk.jshell.execution; 27 28 import java.io.ObjectInput; 29 import java.io.ObjectOutput; 30 import java.util.HashMap; 31 import java.util.List; 32 import java.util.Map; 33 import java.util.stream.Stream; 34 import com.sun.jdi.ReferenceType; 35 import com.sun.jdi.VirtualMachine; 36 import jdk.jshell.spi.ExecutionControl; 37 import static java.util.stream.Collectors.toMap; 38 39 /** 40 * Abstract JDI implementation of {@link jdk.jshell.spi.ExecutionControl} 41 */ 42 public abstract class JDIExecutionControl extends StreamingExecutionControl implements ExecutionControl { 43 44 /** 45 * Mapping from class names to JDI {@link com.sun.jdi.ReferenceType}. 46 */ 47 protected Map<String, ReferenceType> toReferenceType = new HashMap<>(); 48 49 /** 50 * Create an instance. 51 * @param out the output from the remote agent 52 * @param in the input to the remote agent 53 * @param log the log 54 */ 55 protected JDIExecutionControl(ObjectOutput out, ObjectInput in, ECLogger log) { 56 super(out, in, log); 57 } 58 59 /** 60 * Returns the JDI VirtualMachine instance. 61 * 62 * @return the virtual machine 63 * @throws EngineTerminationException if the VM is dead/disconnected 64 */ 65 protected abstract VirtualMachine vm() throws EngineTerminationException; 66 67 /** 68 * Redefine the specified classes. Where 'redefine' is, as in JDI and JVMTI, 69 * an in-place replacement of the classes (preserving class identity) -- 70 * that is, existing references to the class do not need to be recompiled. 71 * This implementation uses JDI 72 * {@link com.sun.jdi.VirtualMachine#redefineClasses(java.util.Map) }. 73 * It will be unsuccessful if 74 * the signature of the class has changed (see the JDI spec). The 75 * JShell-core is designed to adapt to unsuccessful redefine. 76 */ 77 @Override 78 public void redefine(ClassBytecodes[] cbcs) 79 throws ClassInstallException, EngineTerminationException { 80 try { 81 // Convert to the JDI ReferenceType to class bytes map form needed 82 // by JDI. 83 VirtualMachine vm = vm(); 84 Map<ReferenceType, byte[]> rmp = Stream.of(cbcs) 85 .collect(toMap( 86 cbc -> toReferenceType.computeIfAbsent(cbc.name, name -> nameToRef(vm, name)), 87 cbc -> cbc.bytecodes)); 88 // Attempt redefine. Throws exceptions on failure. 89 vm().redefineClasses(rmp); 90 } catch (EngineTerminationException ex) { 91 throw ex; 92 } catch (Exception ex) { 93 throw new ClassInstallException("redefine: " + ex.getMessage(), new boolean[cbcs.length]); 94 } 95 } 96 97 private static ReferenceType nameToRef(VirtualMachine vm, String name) { 98 List<ReferenceType> rtl = vm.classesByName(name); 99 if (rtl.size() != 1) { 100 return null; 101 } 102 return rtl.get(0); 103 } 104 105 }