1 /*
2 * Copyright (c) 2007, 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 <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <jni.h>
27 #include <jvmti.h>
28 #include <aod.h>
29 #include <jvmti_aod.h>
30
31 extern "C" {
32
33 /*
34 * Expected agent work scenario:
35 * - receive ClassLoad event for class FirstLoadedClass, from handler for this event
36 * disable ClassLoad events for all threads except thread loading FirstLoadedClass
37 * (after these ClassLoad events should come only from this thread)
38 * - receive ClassLoad event for class LastLoadedClass and finish work
39 */
40
41 static Options* options = NULL;
42 static const char* agentName;
43
44 #define FIRST_LOADED_CLASS "Lnsk/jvmti/AttachOnDemand/attach009/FirstLoadedClass;"
45 #define LAST_LOADED_CLASS "Lnsk/jvmti/AttachOnDemand/attach009/LastLoadedClass;"
46
47 static int disabledForOthers = 0;
48
49 static volatile int success = 1;
50
51 void JNICALL
52 classLoadHandler(jvmtiEnv *jvmti,
53 JNIEnv* jni,
54 jthread thread,
55 jclass klass) {
56 static char mainThreadName[MAX_STRING_LENGTH];
57 char loadedClassName[MAX_STRING_LENGTH];
58 char threadName[MAX_STRING_LENGTH];
59
60 if (!nsk_jvmti_aod_getThreadName(jvmti, thread, threadName)) {
61 nsk_jvmti_aod_disableEventAndFinish(agentName, JVMTI_EVENT_CLASS_LOAD, 0, jvmti, jni);
62 return;
63 }
64
65 if (!nsk_jvmti_aod_getClassName(jvmti, klass, loadedClassName)) {
66 nsk_jvmti_aod_disableEventAndFinish(agentName, JVMTI_EVENT_CLASS_LOAD, 0, jvmti, jni);
67 return;
68 }
69
70 NSK_DISPLAY2("Class '%s' was loaded by thread '%s'\n", loadedClassName, threadName);
71
72 /*
73 * When class FIRST_LOADED_CLASS was loaded try to disable events for all threads
74 * except main target application thread
75 */
76 if (strcmp(loadedClassName, FIRST_LOADED_CLASS) == 0) {
77 strcpy(mainThreadName, threadName);
78
79 if (!nsk_jvmti_aod_disableEvent(jvmti, JVMTI_EVENT_CLASS_LOAD)) {
80 NSK_COMPLAIN0("Failed to disable events\n");
81 nsk_aod_agentFinished(jni, agentName, 0);
82 return;
83 }
84
85 if (!NSK_JVMTI_VERIFY( NSK_CPP_STUB4(
86 SetEventNotificationMode, jvmti, JVMTI_ENABLE, JVMTI_EVENT_CLASS_LOAD, thread) ) ) {
87 NSK_COMPLAIN1("Failed to enable events for thread '%s'\n", mainThreadName);
88 nsk_aod_agentFinished(jni, agentName, 0);
89 return;
90 }
91
92 NSK_DISPLAY1("ClassLoad events are enabled only for thread '%s'", mainThreadName);
93
94 disabledForOthers = 1;
95
96 return;
97 }
98
99 if (disabledForOthers) {
100 if (strcmp(threadName, mainThreadName) != 0) {
101 success = 0;
102 NSK_COMPLAIN1("ClassLoad event was erroneously generated for thread '%s'\n", threadName);
103 }
104 }
105
106 /*
107 * Stop agent when LAST_LOADED_CLASS was loaded
108 */
109 if (strcmp(loadedClassName, LAST_LOADED_CLASS) == 0) {
110 nsk_jvmti_aod_disableEventAndFinish(agentName, JVMTI_EVENT_CLASS_LOAD, success, jvmti, jni);
111 }
112 }
113
114
115 #ifdef STATIC_BUILD
116 JNIEXPORT jint JNI_OnLoad_attach009Agent00(JavaVM *jvm, char *options, void *reserved) {
117 return JNI_VERSION_1_8;
118 }
119 #endif
120
121 JNIEXPORT jint JNICALL
122 #ifdef STATIC_BUILD
123 Agent_OnAttach_attach009Agent00(JavaVM *vm, char *optionsString, void *reserved)
124 #else
125 Agent_OnAttach(JavaVM *vm, char *optionsString, void *reserved)
126 #endif
127 {
128 jvmtiEnv* jvmti;
129 jvmtiEventCallbacks eventCallbacks;
130 JNIEnv* jni;
131
132 if (!NSK_VERIFY((options = (Options*) nsk_aod_createOptions(optionsString)) != NULL))
133 return JNI_ERR;
134
135 agentName = nsk_aod_getOptionValue(options, NSK_AOD_AGENT_NAME_OPTION);
136
137 if ((jni = (JNIEnv*) nsk_aod_createJNIEnv(vm)) == NULL)
138 return NSK_FALSE;
139
140 if (!NSK_VERIFY((jvmti = nsk_jvmti_createJVMTIEnv(vm, reserved)) != NULL))
141 return JNI_ERR;
142
143 memset(&eventCallbacks,0, sizeof(eventCallbacks));
144 eventCallbacks.ClassLoad = classLoadHandler;
145 if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB3(SetEventCallbacks, jvmti, &eventCallbacks, sizeof(eventCallbacks))) ) {
146 return JNI_ERR;
147 }
148
149 if (!(nsk_jvmti_aod_enableEvent(jvmti, JVMTI_EVENT_CLASS_LOAD))) {
150 return JNI_ERR;
151 }
152
153 NSK_DISPLAY1("%s: initialization was done\n", agentName);
154
155 if (!NSK_VERIFY(nsk_aod_agentLoaded(jni, agentName)))
156 return JNI_ERR;
157
158 return JNI_OK;
159 }
160
161 }