--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/SharedArchiveFile/serviceability/ReplaceCriticalClasses.java Wed Oct 17 15:57:10 2018 -0700
@@ -0,0 +1,222 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ * 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.
+ *
+ */
+
+/*
+ * @test
+ * @summary Tests how CDS works when critical library classes are replaced with JVMTI ClassFileLoadHook
+ * @library /test/lib
+ * @requires vm.cds
+ * @build sun.hotspot.WhiteBox
+ * @run driver ClassFileInstaller -jar whitebox.jar sun.hotspot.WhiteBox
+ * @run main/othervm/native ReplaceCriticalClasses
+ */
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import jdk.test.lib.cds.CDSTestUtils;
+import jdk.test.lib.cds.CDSOptions;
+import jdk.test.lib.process.OutputAnalyzer;
+import sun.hotspot.WhiteBox;
+
+public class ReplaceCriticalClasses {
+ public static void main(String args[]) throws Throwable {
+ if (args.length == 0) {
+ launchChildProcesses();
+ } else if (args.length == 3 && args[0].equals("child")) {
+ Class klass = Class.forName(args[2].replace("/", "."));
+ if (args[1].equals("-shared")) {
+ testInChild(true, klass);
+ } else if (args[1].equals("-notshared")) {
+ testInChild(false, klass);
+ } else {
+ throw new RuntimeException("Unknown child exec option " + args[1]);
+ }
+ return;
+ } else {
+ throw new RuntimeException("Usage: @run main/othervm/native ReplaceCriticalClasses");
+ }
+ }
+
+ static void launchChildProcesses() throws Throwable {
+ String tests[] = {
+ // CDS should be disabled -- these critical classes will be replaced
+ // because JvmtiExport::early_class_hook_env() is true.
+ "-early -notshared java/lang/Object",
+ "-early -notshared java/lang/String",
+ "-early -notshared java/lang/Cloneable",
+ "-early -notshared java/io/Serializable",
+
+ // CDS should not be disabled -- these critical classes cannot be replaced because
+ // JvmtiExport::early_class_hook_env() is false.
+ "java/lang/Object",
+ "java/lang/String",
+ "java/lang/Cloneable",
+ "java/io/Serializable",
+
+ // Try to replace classes that are used by the archived subgraph graphs.
+ "-subgraph java/util/ArrayList",
+ "-subgraph java/lang/module/ResolvedModule",
+
+ // Replace classes that are loaded after JVMTI_PHASE_PRIMORDIAL. It's OK to replace such
+ // classes even when CDS is enabled. Nothing bad should happen.
+ "-notshared jdk/internal/vm/PostVMInitHook",
+ "-notshared java/util/Locale",
+ "-notshared sun/util/locale/BaseLocale",
+ "-notshared java/lang/Readable",
+ };
+
+ int n = 0;
+ for (String s : tests) {
+ System.out.println("Test case[" + (n++) + "] = \"" + s + "\"");
+ String args[] = s.split("\\s+"); // split by space character
+ launchChild(args);
+ }
+ }
+
+ static void launchChild(String args[]) throws Throwable {
+ if (args.length < 1) {
+ throw new RuntimeException("Invalid test case. Should be <-early> <-subgraph> <-notshared> klassName");
+ }
+ String klassName = null;
+ String early = "";
+ boolean subgraph = false;
+ String shared = "-shared";
+
+ for (int i=0; i<args.length-1; i++) {
+ String opt = args[i];
+ if (opt.equals("-early")) {
+ early = "-early,";
+ } else if (opt.equals("-subgraph")) {
+ subgraph = true;
+ } else if (opt.equals("-notshared")) {
+ shared = opt;
+ } else {
+ throw new RuntimeException("Unknown option: " + opt);
+ }
+ }
+ klassName = args[args.length-1];
+ Class.forName(klassName.replace("/", ".")); // make sure it's a valid class
+
+ // We will pass an option like "-agentlib:SimpleClassFileLoadHook=java/util/Locale,XXX,XXX".
+ // The SimpleClassFileLoadHook agent would attempt to hook the java/util/Locale class
+ // but leave the class file bytes unchanged (it replaces all bytes "XXX" with "XXX", i.e.,
+ // a no-op). JVMTI doesn't check the class file bytes returned by the agent, so as long
+ // as the agent returns a buffer, it will not load the class from CDS, and will instead
+ // load the class by parsing the buffer.
+ //
+ // Note that for safety we don't change the contents of the class file bytes. If in the
+ // future JVMTI starts checking the contents of the class file bytes, this test would need
+ // to be updated. (You'd see the test case with java/util/Locale staring to fail).
+ String agent = "-agentlib:SimpleClassFileLoadHook=" + early + klassName + ",XXX,XXX";
+
+ CDSOptions opts = (new CDSOptions())
+ .setXShareMode("auto")
+ .setUseSystemArchive(true)
+ .setUseVersion(false)
+ .addSuffix("-showversion",
+ "-Xlog:cds",
+ "-XX:+UnlockDiagnosticVMOptions",
+ agent,
+ "-XX:+WhiteBoxAPI",
+ "-Xbootclasspath/a:" + ClassFileInstaller.getJarPath("whitebox.jar"));
+
+ if (subgraph) {
+ opts.addSuffix("-Xlog:cds+heap",
+ "-Xlog:class+load");
+ }
+
+ opts.addSuffix("ReplaceCriticalClasses",
+ "child",
+ shared,
+ klassName);
+
+ final boolean expectDisable = !early.equals("");
+ final boolean checkSubgraph = subgraph;
+ CDSTestUtils.run(opts).assertNormalExit(out -> {
+ if (expectDisable) {
+ out.shouldContain("UseSharedSpaces: CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
+ System.out.println("CDS disabled as expected");
+ }
+ if (checkSubgraph) {
+ // As of 2018/10/21 the classes in the archived subgraphs won't be
+ // replaced because all archived subgraphs were loaded in JVMTI_PHASE_PRIMORDIAL.
+ //
+ // This is the first class to be loaded after JVMTI has exited JVMTI_PHASE_PRIMORDIAL.
+ // Make sure no subgraphs are loaded afterwards.
+ //
+ // Can't use out.shouldNotMatch() because that doesn't match across multiple lines.
+ String firstNonPrimordialClass = "jdk.jfr.internal.EventWriter";
+ String regexp = firstNonPrimordialClass + ".*initialize_from_archived_subgraph";
+ Pattern regex = Pattern.compile(regexp, Pattern.DOTALL);
+ Matcher matcher = regex.matcher(out.getStdout());
+ if (matcher.find()) {
+ out.reportDiagnosticSummary();
+ throw new RuntimeException("'" + regexp
+ + "' found in stdout: '" + matcher.group() + "' \n");
+ }
+ }
+ });
+ }
+
+ static void testInChild(boolean shouldBeShared, Class klass) {
+ WhiteBox wb = WhiteBox.getWhiteBox();
+
+ if (shouldBeShared && !wb.isSharedClass(klass)) {
+ throw new RuntimeException(klass + " should be shared but but actually is not.");
+ }
+ if (!shouldBeShared && wb.isSharedClass(klass)) {
+ throw new RuntimeException(klass + " should not be shared but actually is.");
+ }
+ System.out.println("wb.isSharedClass(klass): " + wb.isSharedClass(klass) + " == " + shouldBeShared);
+
+ String strings[] = {
+ // interned strings from j.l.Object
+ "@",
+ "nanosecond timeout value out of range",
+ "timeoutMillis value is negative",
+
+ // interned strings from j.l.Integer
+ "0",
+ "0X",
+ "0x",
+ "int"
+ };
+
+ // Make sure the interned string table is same
+ for (String s : strings) {
+ String i = s.intern();
+ if (s != i) {
+ throw new RuntimeException("Interned string mismatch: \"" + s + "\" @ " + System.identityHashCode(s) +
+ " vs \"" + i + "\" @ " + System.identityHashCode(i));
+ }
+ }
+ // We have tried to use ClassFileLoadHook to replace critical library classes (which may
+ // may not have succeeded, depending on whether the agent has requested
+ // can_generate_all_class_hook_events/can_generate_early_class_hook_events capabilities).
+ //
+ // In any case, the JVM should have started properly (perhaps with CDS disabled) and
+ // the above operations should succeed.
+ System.out.println("If I can come to here without crashing, things should be OK");
+ }
+}