1 /* 2 * Copyright (c) 2016, 2017, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 /* 26 * @test 27 * @summary Tests how CDS works when critical library classes are replaced with JVMTI ClassFileLoadHook 28 * @library /test/lib 29 * @requires vm.cds 30 * 31 * @comment CDS should not be disabled -- these critical classes will be replaced because JvmtiExport::early_class_hook_env() is true. 32 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=+early,java/lang/Object,XXX,XXX -showversion ReplaceCriticalClasses 33 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=+early,java/lang/String,XXX,XXX -showversion ReplaceCriticalClasses 34 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=+early,java/lang/Cloneable,XXX,XXX -showversion ReplaceCriticalClasses 35 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=+early,java/io/Serializable,XXX,XXX -showversion ReplaceCriticalClasses 36 * 37 * @comment CDS should not be disabled -- these critical classes cannot be replaced because JvmtiExport::early_class_hook_env() is false. 38 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/lang/Object,XXX,XXX -showversion ReplaceCriticalClasses 39 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/lang/String,XXX,XXX -showversion ReplaceCriticalClasses 40 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/lang/Cloneable,XXX,XXX -showversion ReplaceCriticalClasses 41 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/io/Serializable,XXX,XXX -showversion ReplaceCriticalClasses 42 * 43 * @comment Try to replace classes that are used by the archived subgraph graphs. As of 2018/10/21 the classes won't be replaced because 44 * all archived subgraphs were loaded in JVMTI_PHASE_PRIMORDIAL. 45 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/util/ArrayList,XXX,XXX -verbose -showversion -Xlog:cds+heap=debug ReplaceCriticalClasses 46 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/lang/module/ResolvedModule,XXX,XXX -verbose -showversion -Xlog:cds+heap=debug ReplaceCriticalClasses 47 * 48 * @comment Replace classes that are loaded after JVMTI_PHASE_PRIMORDIAL. It's OK to replace such classes even when CDS is enabled. 49 * Nothing bad should happen. 50 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=jdk/internal/vm/PostVMInitHook,XXX,XXX -showversion ReplaceCriticalClasses 51 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/util/Locale,XXX,XXX -showversion ReplaceCriticalClasses 52 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=sun/util/locale/BaseLocale,XXX,XXX -showversion ReplaceCriticalClasses 53 * @run main/othervm/native -Xshare:auto -agentlib:SimpleClassFileLoadHook=java/lang/Readable,XXX,XXX -showversion ReplaceCriticalClasses 54 */ 55 56 public class ReplaceCriticalClasses { 57 public static void main(String args[]) { 58 String strings[] = { 59 // interned strings from j.l.Object 60 "@", 61 "nanosecond timeout value out of range", 62 "timeoutMillis value is negative", 63 64 // interned strings from j.l.Integer 65 "0", 66 "0X", 67 "0x", 68 "int" 69 }; 70 71 // Make sure the interned string table is same 72 for (String s : strings) { 73 String i = s.intern(); 74 if (s != i) { 75 throw new RuntimeException("Interned string mismatch: \"" + s + "\" @ " + System.identityHashCode(s) + 76 " vs \"" + i + "\" @ " + System.identityHashCode(i)); 77 } 78 } 79 // We have tried to use ClassFileLoadHook to replace critical library classes (which may 80 // may not have succeeded, depending on whether the agent has requested 81 // can_generate_all_class_hook_events/can_generate_early_class_hook_events capabilities). 82 // 83 // In any case, the JVM should have started properly (perhaps with CDS disabled) and 84 // the above operations should succeed. 85 System.out.println("If I can come to here without crashing, things should be OK"); 86 } 87 }