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/*
* Copyright (c) 2005, 2024, 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.
*/
import java.lang.constant.ClassDesc;
import java.lang.constant.MethodTypeDesc;
import java.lang.instrument.*;
import java.security.ProtectionDomain;
import java.io.*;
import asmlib.*;
import static java.lang.constant.ConstantDescs.CD_int;
import static java.lang.constant.ConstantDescs.CD_void;
class RetransformAgent {
static ClassFileTransformer t1, t2, t3, t4;
static Instrumentation inst;
static boolean succeeded = true;
static int markCount = 0;
static int[] markGolden = {30, 40, 20, 30, 40, 20, 30, 40, 20, 30, 40, 20,
11, 40, 20, 11, 40, 20, 11, 40, 20, 11, 40, 20};
static class Tr implements ClassFileTransformer {
private static final ClassDesc CD_RetransformAgent = RetransformAgent.class.describeConstable().orElseThrow();
private static final MethodTypeDesc MTD_void_int = MethodTypeDesc.of(CD_void, CD_int);
final String trname;
final boolean onLoad;
final int loadIndex;
final boolean onRedef;
final int redefIndex;
final String cname;
final String nname;
Tr(String trname, boolean onLoad, int loadIndex, boolean onRedef, int redefIndex,
String cname, String nname) {
this.trname = trname;
this.onLoad = onLoad;
this.loadIndex = loadIndex;
this.onRedef = onRedef;
this.redefIndex = redefIndex;
this.cname = cname;
this.nname = nname;
}
public byte[] transform(Module module,
ClassLoader loader,
String className,
Class<?> classBeingRedefined,
ProtectionDomain protectionDomain,
byte[] classfileBuffer) {
boolean redef = classBeingRedefined != null;
// System.err.println("hook " + trname + ": " + className +
// (redef? " REDEF" : " LOAD"));
if ((redef? onRedef : onLoad) && className != null && className.equals(cname)) {
int fixedIndex = redef ? redefIndex : loadIndex;
try {
byte[] newcf = Instrumentor.instrFor(classfileBuffer)
.addMethodEntryInjection(
nname,
cb -> {
cb.loadConstant(fixedIndex);
cb.invokestatic(
CD_RetransformAgent,
"callTracker", MTD_void_int);
})
.apply();
/*** debugging ...
if (newcf != null) {
String fname = trname + (redef?"_redef" : "") + "/" + className;
System.err.println("dumping to: " + fname);
write_buffer(fname + "_before.class", classfileBuffer);
write_buffer(fname + "_instr.class", newcf);
}
***/
System.err.println(trname + ": " + className + " index: " + fixedIndex +
(redef? " REDEF" : " LOAD") +
" len before: " + classfileBuffer.length +
" after: " + newcf.length);
return newcf;
} catch (Throwable ex) {
System.err.println("Injection failure: " + ex);
ex.printStackTrace();
}
}
return null;
}
}
static void write_buffer(String fname, byte[]buffer) {
try {
File f = new File(fname);
if (!f.getParentFile().exists()) {
f.getParentFile().mkdirs();
}
try (FileOutputStream outStream = new FileOutputStream(f)) {
outStream.write(buffer, 0, buffer.length);
}
} catch (IOException ex) {
System.err.println("EXCEPTION in write_buffer: " + ex);
}
}
public static void premain (String agentArgs, Instrumentation instArg) {
inst = instArg;
System.err.println("Premain");
t1 = new Tr("TR1", false, 10, true, 11, "RetransformApp", "foo");
inst.addTransformer(t1, true);
t2 = new Tr("TN2", true, 20, true, 21, "RetransformApp", "foo");
inst.addTransformer(t2, false);
t3 = new Tr("TR3", true, 30, true, 31, "RetransformApp", "foo");
inst.addTransformer(t3, true);
t4 = new Tr("TN4", true, 40, true, 41, "RetransformApp", "foo");
inst.addTransformer(t4, false);
}
public static void undo() {
inst.removeTransformer(t3);
try {
System.err.println("RETRANSFORM");
inst.retransformClasses(new RetransformApp().getClass());
} catch (Exception ex) {
System.err.println("EXCEPTION on undo: " + ex);
}
}
public static boolean succeeded() {
return succeeded && markCount == markGolden.length;
}
public static void callTracker(int mark) {
System.err.println("got mark " + mark);
if (markCount >= markGolden.length || mark != markGolden[markCount++]) {
succeeded = false;
}
}
}
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