1 /*
2 * Copyright (c) 2016, 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
24 #include <stdio.h>
25 #include <string.h>
26 #include "jvmti.h"
27
28 #ifdef __cplusplus
29 extern "C" {
30 #endif
31
32 #ifndef JNI_ENV_ARG
33
34 #ifdef __cplusplus
35 #define JNI_ENV_ARG(x, y) y
36 #define JNI_ENV_PTR(x) x
37 #else
38 #define JNI_ENV_ARG(x,y) x, y
39 #define JNI_ENV_PTR(x) (*x)
40 #endif
41
42 #endif
43
44 #define TranslateError(err) "JVMTI error"
45
46 #define PASSED 0
47 #define FAILED 2
48
49 static const char *EXC_CNAME = "java/lang/Exception";
50
51 static jvmtiEnv *jvmti = NULL;
52 static jint result = PASSED;
53 static jboolean printdump = JNI_FALSE;
54
55 static int thread_start_events_vm_start = 0;
56
57 static jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved);
58
59 JNIEXPORT
60 jint JNICALL Agent_OnLoad(JavaVM *jvm, char *options, void *reserved) {
61 return Agent_Initialize(jvm, options, reserved);
62 }
63
64 JNIEXPORT
65 jint JNICALL Agent_OnAttach(JavaVM *jvm, char *options, void *reserved) {
66 return Agent_Initialize(jvm, options, reserved);
67 }
68
69 JNIEXPORT
70 jint JNICALL JNI_OnLoad(JavaVM *jvm, void *reserved) {
71 return JNI_VERSION_9;
72 }
73
74 static
75 jint throw_exc(JNIEnv *env, char *msg) {
76 jclass exc_class = JNI_ENV_PTR(env)->FindClass(JNI_ENV_ARG(env, EXC_CNAME));
77
78 if (exc_class == NULL) {
79 printf("throw_exc: Error in FindClass(env, %s)\n", EXC_CNAME);
80 return -1;
81 }
82 return JNI_ENV_PTR(env)->ThrowNew(JNI_ENV_ARG(env, exc_class), msg);
83 }
84
85
86 void JNICALL Callback_ThreadStart(jvmtiEnv *jvmti_env, JNIEnv *env, jthread thread) {
87 jvmtiError err;
88 jvmtiPhase phase;
89
90 err = (*jvmti)->GetPhase(jvmti_env,&phase);
91 if (err != JVMTI_ERROR_NONE) {
92 printf("ThreadStart event: GetPhase error: %s (%d)\n", TranslateError(err), err);
93 result = FAILED;
94 return;
95 }
96
97 if (phase == JVMTI_PHASE_START) {
98 thread_start_events_vm_start++;
99 }
100
101 if (printdump == JNI_TRUE) {
102 printf(">>> ThreadStart event: phase(%d)\n", phase);
103 }
104 }
105
106 static
107 jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {
108 jint res, size;
109 jvmtiCapabilities caps;
110 jvmtiEventCallbacks callbacks;
111 jvmtiError err;
112
113 if (options != NULL && strcmp(options, "printdump") == 0) {
114 printdump = JNI_TRUE;
115 }
116
117 res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &jvmti),
118 JVMTI_VERSION_9);
119 if (res != JNI_OK || jvmti == NULL) {
120 printf(" Error: wrong result of a valid call to GetEnv!\n");
121 return JNI_ERR;
122 }
123
124 printf("Enabling following capability: can_generate_early_vmstart\n");
125 memset(&caps, 0, sizeof(caps));
126 caps.can_generate_early_vmstart = 1;
127
128 err = (*jvmti)->AddCapabilities(jvmti, &caps);
129 if (err != JVMTI_ERROR_NONE) {
130 printf(" Error in AddCapabilites: %s (%d)\n", TranslateError(err), err);
131 return JNI_ERR;
132 }
133
134 size = (jint)sizeof(callbacks);
135
136 memset(&callbacks, 0, sizeof(callbacks));
137 callbacks.ThreadStart = Callback_ThreadStart;
138
139 err = (*jvmti)->SetEventCallbacks(jvmti, &callbacks, size);
140 if (err != JVMTI_ERROR_NONE) {
141 printf(" Error in SetEventCallbacks: %s (%d)\n", TranslateError(err), err);
142 return JNI_ERR;
143 }
144
145 err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE, JVMTI_EVENT_THREAD_START, NULL);
146 if (err != JVMTI_ERROR_NONE) {
147 printf(" Error in SetEventNotificationMode: %s (%d)\n", TranslateError(err), err);
148 return JNI_ERR;
149 }
150
151 return JNI_OK;
152 }
153
154 JNIEXPORT jint JNICALL
155 Java_MAAThreadStart_check(JNIEnv *env, jclass cls) {
156 jobject loader = NULL;
157
158 if (jvmti == NULL) {
159 throw_exc(env, "JVMTI client was not properly loaded!\n");
160 return FAILED;
161 }
162
163 /*
164 * Expecting that ThreadStart events are sent during VM Start phase when
165 * can_generate_early_vmstart capability is enabled
166 */
167 if (thread_start_events_vm_start == 0) {
168 throw_exc(env, "Didn't get ThreadStart events in start phase!\n");
169 return FAILED;
170 }
171
172 return result;
173 }
174
175 #ifdef __cplusplus
176 }
177 #endif