1 /*
2 * Copyright (c) 2014, 2018, 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 #include <jni.h>
24 #include <stdio.h>
25
26 #include <string.h>
27 #include <jvmti.h>
28
29 #define STATUS_FAILED 2
30 #define STATUS_PASSED 0
31
32 #define REFERENCES_ARRAY_SIZE 10000000
33
34 #ifndef JNI_ENV_ARG
35
36 #ifdef __cplusplus
37 #define JNI_ENV_ARG(x, y) x
38 #define JNI_ENV_PTR(x) x
39 #else
40 #define JNI_ENV_ARG(x, y) x , y
41 #define JNI_ENV_PTR(x) (*x)
42 #endif
43
44 #endif
45
46 #ifndef _Included_gc_g1_unloading_unloading_classloaders_JNIClassloader
47 #define _Included_gc_g1_unloading_unloading_classloaders_JNIClassloader
48
49 #ifdef __cplusplus
50 extern "C" {
51 #endif
52
53 /*
54 * Class: gc_g1_unloading_unloading_classloaders_JNIClassloader
55 * Method: loadThroughJNI0
56 * Signature: (Ljava/lang/String;Ljava/lang/ClassLoader;[B)Ljava/lang/Class;
57 */
58 JNIEXPORT jclass JNICALL Java_gc_g1_unloading_classloaders_JNIClassloader_loadThroughJNI0 (JNIEnv * env,
59 jclass clazz, jstring className, jobject classLoader, jbyteArray bytecode) {
60
61 const char * classNameChar = JNI_ENV_PTR(env)->GetStringUTFChars(JNI_ENV_ARG(env, className), NULL);
62 jbyte * arrayContent = JNI_ENV_PTR(env)->GetByteArrayElements(JNI_ENV_ARG(env, bytecode), NULL);
63 jsize bytecodeLength = JNI_ENV_PTR(env)->GetArrayLength(JNI_ENV_ARG(env, bytecode));
64 jclass returnValue = JNI_ENV_PTR(env)->DefineClass(JNI_ENV_ARG(env, classNameChar), classLoader, arrayContent, bytecodeLength);
65 if (!returnValue) {
66 printf("ERROR: DefineClass call returned NULL by some reason. Classloading failed.\n");
67 }
68
69 return returnValue;
70 }
71
72 /*
73 * Class: gc_g1_unloading_unloading_loading_ClassLoadingThread
74 * Method: makeRedefinition0
75 * Signature: (ILjava/lang/Class;[B)I
76 */
77 JNIEXPORT jint JNICALL Java_gc_g1_unloading_loading_ClassLoadingThread_makeRedefinition0(JNIEnv *env,
78 jclass cls, jint fl, jclass redefCls, jbyteArray classBytes) {
79 JavaVM * jvm;
80 jvmtiEnv * jvmti;
81 jvmtiError err;
82 jvmtiCapabilities caps;
83 jvmtiClassDefinition classDef;
84 jint jint_err = JNI_ENV_PTR(env)->GetJavaVM(JNI_ENV_ARG(env, &jvm));
85 if (jint_err) {
86 printf("GetJavaVM returned nonzero: %d", jint_err);
87 return STATUS_FAILED;
88 }
89
90 jint_err = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **)&jvmti), JVMTI_VERSION_1_0);
91 if (jint_err) {
92 printf("GetEnv returned nonzero: %d", jint_err);
93 return STATUS_FAILED;
94 }
95
96 err = JNI_ENV_PTR(jvmti)->GetPotentialCapabilities(JNI_ENV_ARG(jvmti, &caps));
97 if (err != JVMTI_ERROR_NONE) {
98 printf("(GetPotentialCapabilities) unexpected error: %d\n",err);
99 return JNI_ERR;
100 }
101
102 err = JNI_ENV_PTR(jvmti)->AddCapabilities(JNI_ENV_ARG(jvmti, &caps));
103 if (err != JVMTI_ERROR_NONE) {
104 printf("(AddCapabilities) unexpected error: %d\n", err);
105 return JNI_ERR;
106 }
107
108 if (!caps.can_redefine_classes) {
109 printf("ERROR: Can't redefine classes. jvmtiCapabilities.can_redefine_classes isn't set up.");
110 return STATUS_FAILED;
111 }
112
113 classDef.klass = redefCls;
114 classDef.class_byte_count =
115 JNI_ENV_PTR(env)->GetArrayLength(JNI_ENV_ARG(env, classBytes));
116 classDef.class_bytes = (unsigned char *)
117 JNI_ENV_PTR(env)->GetByteArrayElements(JNI_ENV_ARG(env, classBytes),
118 NULL);
119
120 if (fl == 2) {
121 printf(">>>>>>>> Invoke RedefineClasses():\n");
122 printf("\tnew class byte count=%d\n", classDef.class_byte_count);
123 }
124 err = JNI_ENV_PTR(jvmti)->RedefineClasses(JNI_ENV_ARG(jvmti, 1), &classDef);
125 if (err != JVMTI_ERROR_NONE) {
126 printf("%s: Failed to call RedefineClasses():\n", __FILE__);
127 printf("\tthe function returned error %d\n", err);
128 printf("\tFor more info about this error see the JVMTI spec.\n");
129 return STATUS_FAILED;
130 }
131 if (fl == 2)
132 printf("<<<<<<<< RedefineClasses() is successfully done\n");
133
134 return STATUS_PASSED;
135 }
136
137 jobject referencesArray[REFERENCES_ARRAY_SIZE];
138 int firstFreeIndex = 0;
139
140 /*
141 * Class: gc_g1_unloading_unloading_keepref_JNIGlobalRefHolder
142 * Method: keepGlobalJNIReference
143 * Signature: (Ljava/lang/Object;)I
144 */
145 JNIEXPORT jint JNICALL Java_gc_g1_unloading_keepref_JNIGlobalRefHolder_keepGlobalJNIReference
146 (JNIEnv * env, jclass clazz, jobject obj) {
147 int returnValue;
148 referencesArray[firstFreeIndex] = JNI_ENV_PTR(env)->NewGlobalRef(JNI_ENV_ARG(env, obj));
149 printf("checkpoint1 %d \n", firstFreeIndex);
150 returnValue = firstFreeIndex;
151 firstFreeIndex++;
152 return returnValue;
153 }
154
155 /*
156 * Class: gc_g1_unloading_unloading_keepref_JNIGlobalRefHolder
157 * Method: deleteGlobalJNIReference
158 * Signature: (I)V
159 */
160 JNIEXPORT void JNICALL Java_gc_g1_unloading_keepref_JNIGlobalRefHolder_deleteGlobalJNIReference
161 (JNIEnv * env, jclass clazz, jint index) {
162 JNI_ENV_PTR(env)->DeleteGlobalRef(JNI_ENV_ARG(env, referencesArray[index]));
163 }
164
165
166 /*
167 * Class: gc_g1_unloading_unloading_keepref_JNILocalRefHolder
168 * Method: holdWithJNILocalReference
169 * Signature: (Ljava/lang/Object;)V
170 */
171 JNIEXPORT void JNICALL Java_gc_g1_unloading_keepref_JNILocalRefHolder_holdWithJNILocalReference
172 (JNIEnv * env, jobject thisObject, jobject syncObject) {
173 jclass clazz, objectClazz;
174 jfieldID objectToKeepField;
175 jobject objectToKeep, localRef;
176 jmethodID waitMethod;
177
178 clazz = (*env)->GetObjectClass(env, thisObject);
179 objectToKeepField = (*env)->GetFieldID(env, clazz, "objectToKeep", "Ljava/lang/Object;");
180 objectToKeep = (*env)->GetObjectField(env, thisObject, objectToKeepField);
181 localRef = (*env)->NewLocalRef(env, objectToKeep);
182 (*env)->SetObjectField(env, thisObject, objectToKeepField, NULL);
183
184 objectClazz = (*env)->FindClass(env, "Ljava/lang/Object;");
185 waitMethod = (*env)->GetMethodID(env, objectClazz, "wait", "()V");
186 (*env)->CallVoidMethod(env, syncObject, waitMethod);
187 printf("checkpoint2 \n");
188 }
189
190
191 #ifdef __cplusplus
192 }
193 #endif
194 #endif