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/*
* Copyright (c) 2014, 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.
*/
#include <jni.h>
#include <stdio.h>
#include <string.h>
#include <jvmti.h>
#define STATUS_FAILED 2
#define STATUS_PASSED 0
#define REFERENCES_ARRAY_SIZE 10000000
#ifndef _Included_gc_g1_unloading_unloading_classloaders_JNIClassloader
#define _Included_gc_g1_unloading_unloading_classloaders_JNIClassloader
extern "C" {
/*
* Class: gc_g1_unloading_unloading_classloaders_JNIClassloader
* Method: loadThroughJNI0
* Signature: (Ljava/lang/String;Ljava/lang/ClassLoader;[B)Ljava/lang/Class;
*/
JNIEXPORT jclass JNICALL Java_gc_g1_unloading_classloaders_JNIClassloader_loadThroughJNI0 (JNIEnv * env,
jclass clazz, jstring className, jobject classLoader, jbyteArray bytecode) {
const char * classNameChar = env->GetStringUTFChars(className, nullptr);
jbyte * arrayContent = env->GetByteArrayElements(bytecode, nullptr);
jsize bytecodeLength = env->GetArrayLength(bytecode);
jclass returnValue = env->DefineClass(classNameChar, classLoader, arrayContent, bytecodeLength);
env->ReleaseByteArrayElements(bytecode, arrayContent, JNI_ABORT);
env->ReleaseStringUTFChars(className, classNameChar);
if (!returnValue) {
printf("ERROR: DefineClass call returned null by some reason. Classloading failed.\n");
}
return returnValue;
}
/*
* Class: gc_g1_unloading_unloading_loading_ClassLoadingHelper
* Method: makeRedefinition0
* Signature: (ILjava/lang/Class;[B)I
*/
JNIEXPORT jint JNICALL Java_gc_g1_unloading_loading_ClassLoadingHelper_makeRedefinition0(JNIEnv *env,
jclass clazz, jint fl, jclass redefCls, jbyteArray classBytes) {
JavaVM * jvm;
jvmtiEnv * jvmti;
jvmtiError err;
jvmtiCapabilities caps;
jvmtiClassDefinition classDef;
jint jint_err = env->GetJavaVM(&jvm);
if (jint_err) {
printf("GetJavaVM returned nonzero: %d", jint_err);
return STATUS_FAILED;
}
jint_err = jvm->GetEnv((void **) &jvmti, JVMTI_VERSION_1_0);
if (jint_err) {
printf("GetEnv returned nonzero: %d", jint_err);
return STATUS_FAILED;
}
err = jvmti->GetPotentialCapabilities(&caps);
if (err != JVMTI_ERROR_NONE) {
printf("(GetPotentialCapabilities) unexpected error: %d\n",err);
return JNI_ERR;
}
err = jvmti->AddCapabilities(&caps);
if (err != JVMTI_ERROR_NONE) {
printf("(AddCapabilities) unexpected error: %d\n", err);
return JNI_ERR;
}
if (!caps.can_redefine_classes) {
printf("ERROR: Can't redefine classes. jvmtiCapabilities.can_redefine_classes isn't set up.");
return STATUS_FAILED;
}
classDef.klass = redefCls;
classDef.class_byte_count =
env->GetArrayLength(classBytes);
jbyte * class_bytes = env->GetByteArrayElements(classBytes, nullptr);
classDef.class_bytes = (unsigned char *)class_bytes;
if (fl == 2) {
printf(">>>>>>>> Invoke RedefineClasses():\n");
printf("\tnew class byte count=%d\n", classDef.class_byte_count);
}
err = jvmti->RedefineClasses(1, &classDef);
env->ReleaseByteArrayElements(classBytes, class_bytes, JNI_ABORT);
if (err != JVMTI_ERROR_NONE) {
printf("%s: Failed to call RedefineClasses():\n", __FILE__);
printf("\tthe function returned error %d\n", err);
printf("\tFor more info about this error see the JVMTI spec.\n");
return STATUS_FAILED;
}
if (fl == 2)
printf("<<<<<<<< RedefineClasses() is successfully done\n");
return STATUS_PASSED;
}
jobject referencesArray[REFERENCES_ARRAY_SIZE];
int firstFreeIndex = 0;
/*
* Class: gc_g1_unloading_unloading_keepref_JNIGlobalRefHolder
* Method: keepGlobalJNIReference
* Signature: (Ljava/lang/Object;)I
*/
JNIEXPORT jint JNICALL Java_gc_g1_unloading_keepref_JNIGlobalRefHolder_keepGlobalJNIReference
(JNIEnv * env, jclass clazz, jobject obj) {
int returnValue;
referencesArray[firstFreeIndex] = env->NewGlobalRef(obj);
printf("checkpoint1 %d \n", firstFreeIndex);
returnValue = firstFreeIndex;
firstFreeIndex++;
return returnValue;
}
/*
* Class: gc_g1_unloading_unloading_keepref_JNIGlobalRefHolder
* Method: deleteGlobalJNIReference
* Signature: (I)V
*/
JNIEXPORT void JNICALL Java_gc_g1_unloading_keepref_JNIGlobalRefHolder_deleteGlobalJNIReference
(JNIEnv * env, jclass clazz, jint index) {
env->DeleteGlobalRef(referencesArray[index]);
}
/*
* Class: gc_g1_unloading_unloading_keepref_JNILocalRefHolder
* Method: holdWithJNILocalReference
* Signature: (Ljava/lang/Object;)V
*/
JNIEXPORT void JNICALL Java_gc_g1_unloading_keepref_JNILocalRefHolder_holdWithJNILocalReference
(JNIEnv * env, jobject thisObject, jobject syncObject) {
jclass clazz, objectClazz;
jfieldID objectToKeepField;
jobject objectToKeep, localRef;
jmethodID waitMethod;
clazz = env->GetObjectClass(thisObject);
objectToKeepField = env->GetFieldID(clazz, "objectToKeep", "Ljava/lang/Object;");
objectToKeep = env->GetObjectField(thisObject, objectToKeepField);
localRef = env->NewLocalRef(objectToKeep);
env->SetObjectField(thisObject, objectToKeepField, nullptr);
objectClazz = env->FindClass("Ljava/lang/Object;");
waitMethod = env->GetMethodID(objectClazz, "wait", "()V");
env->CallVoidMethod(syncObject, waitMethod);
printf("checkpoint2 \n");
}
}
#endif
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