1 /*
2 * Copyright (c) 2017, 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 #include "jni.h"
28
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32
33 #ifndef JNI_ENV_ARG
34
35 #ifdef __cplusplus
36 #define JNI_ENV_ARG(x, y) y
37 #define JNI_ENV_PTR(x) x
38 #else
39 #define JNI_ENV_ARG(x,y) x, y
40 #define JNI_ENV_PTR(x) (*x)
41 #endif
42
43 #endif
44
45 #define TranslateError(err) "JVMTI error"
46
47 #define PASSED 0
48 #define FAILED 2
49
50 static volatile jboolean event_has_posted = JNI_FALSE;
51 static volatile jint status = PASSED;
52
53 static jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved);
54
55 JNIEXPORT void JNICALL
56 MonitorContendedEnter(jvmtiEnv *jvmti, JNIEnv *env, jthread thread, jobject monitor) {
57 jvmtiError err;
58 jvmtiThreadInfo threadInfo;
59 jint monitorCount;
60 jobject *ownedMonitors;
61
62 err = (*jvmti)->GetThreadInfo(jvmti, thread, &threadInfo);
63 if (err != JVMTI_ERROR_NONE) {
64 fprintf(stderr, "MonitorContendedEnter: error in JVMTI GetThreadInfo: %d\n", err);
65 status = FAILED;
66 event_has_posted = JNI_TRUE;
67 return;
68 }
69 err = (*jvmti)->GetOwnedMonitorInfo(jvmti, thread, &monitorCount, &ownedMonitors);
70 if (err != JVMTI_ERROR_NONE) {
71 fprintf(stderr, "MonitorContendedEnter: error in JVMTI GetOwnedMonitorInfo: %d\n", err);
72 status = FAILED;
73 event_has_posted = JNI_TRUE;
74 return;
75 }
76
77 printf("MonitorContendedEnter: %s owns %d monitor(s)\n",
78 threadInfo.name, monitorCount);
79
80 (*jvmti)->Deallocate(jvmti, (unsigned char *)ownedMonitors);
81 (*jvmti)->Deallocate(jvmti, (unsigned char *)threadInfo.name);
82
83 if (monitorCount != 0) {
84 fprintf(stderr, "MonitorContendedEnter: FAIL: monitorCount should be zero.\n");
85 status = FAILED;
86 }
87
88 event_has_posted = JNI_TRUE;
89 }
90
91 JNIEXPORT void JNICALL
92 MonitorContendedEntered(jvmtiEnv *jvmti, JNIEnv *env, jthread thread, jobject monitor) {
93 jvmtiError err;
94 jvmtiThreadInfo threadInfo;
95 jint monitorCount;
96 jobject *ownedMonitors;
97
98 err = (*jvmti)->GetThreadInfo(jvmti, thread, &threadInfo);
99 if (err != JVMTI_ERROR_NONE) {
100 fprintf(stderr, "MonitorContendedEntered: error in JVMTI GetThreadInfo: %d\n", err);
101 status = FAILED;
102 return;
103 }
104 err = (*jvmti)->GetOwnedMonitorInfo(jvmti, thread, &monitorCount, &ownedMonitors);
105 if (err != JVMTI_ERROR_NONE) {
106 fprintf(stderr, "MonitorContendedEntered: error in JVMTI GetOwnedMonitorInfo: %d\n", err);
107 status = FAILED;
108 return;
109 }
110
111 printf("MonitorContendedEntered: %s owns %d monitor(s)\n",
112 threadInfo.name, monitorCount);
113
114 (*jvmti)->Deallocate(jvmti, (unsigned char *)ownedMonitors);
115 (*jvmti)->Deallocate(jvmti, (unsigned char *)threadInfo.name);
116
117 if (monitorCount != 1) {
118 fprintf(stderr, "MonitorContendedEnter: FAIL: monitorCount should be one.\n");
119 status = FAILED;
120 }
121 }
122
123 JNIEXPORT jint JNICALL
124 Agent_OnLoad(JavaVM *jvm, char *options, void *reserved) {
125 return Agent_Initialize(jvm, options, reserved);
126 }
127
128 JNIEXPORT jint JNICALL
129 Agent_OnAttach(JavaVM *jvm, char *options, void *reserved) {
130 return Agent_Initialize(jvm, options, reserved);
131 }
132
133 JNIEXPORT jint JNICALL
134 JNI_OnLoad(JavaVM *jvm, void *reserved) {
135 return JNI_VERSION_1_8;
136 }
137
138 static
139 jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {
140 jint res;
141 jvmtiError err;
142 jvmtiEnv *jvmti;
143 jvmtiCapabilities caps;
144 jvmtiEventCallbacks callbacks;
145
146 printf("Agent_OnLoad started\n");
147
148 res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &jvmti),
149 JVMTI_VERSION_1);
150 if (res != JNI_OK || jvmti == NULL) {
151 fprintf(stderr, "Error: wrong result of a valid call to GetEnv!\n");
152 return JNI_ERR;
153 }
154
155 err = (*jvmti)->GetPotentialCapabilities(jvmti, &caps);
156 if (err != JVMTI_ERROR_NONE) {
157 fprintf(stderr, "Agent_OnLoad: error in JVMTI GetPotentialCapabilities: %d\n", err);
158 return JNI_ERR;
159 }
160
161 err = (*jvmti)->AddCapabilities(jvmti, &caps);
162 if (err != JVMTI_ERROR_NONE) {
163 fprintf(stderr, "Agent_OnLoad: error in JVMTI AddCapabilities: %d\n", err);
164 return JNI_ERR;
165 }
166
167 err = (*jvmti)->GetCapabilities(jvmti, &caps);
168 if (err != JVMTI_ERROR_NONE) {
169 fprintf(stderr, "Agent_OnLoad: error in JVMTI GetCapabilities: %d\n", err);
170 return JNI_ERR;
171 }
172
173 if (!caps.can_generate_monitor_events) {
174 fprintf(stderr, "Warning: Monitor events are not implemented\n");
175 return JNI_ERR;
176 }
177 if (!caps.can_get_owned_monitor_info) {
178 fprintf(stderr, "Warning: GetOwnedMonitorInfo is not implemented\n");
179 return JNI_ERR;
180 }
181
182 callbacks.MonitorContendedEnter = &MonitorContendedEnter;
183 callbacks.MonitorContendedEntered = &MonitorContendedEntered;
184
185 err = (*jvmti)->SetEventCallbacks(jvmti, &callbacks, sizeof(jvmtiEventCallbacks));
186 if (err != JVMTI_ERROR_NONE) {
187 fprintf(stderr, "Agent_OnLoad: error in JVMTI SetEventCallbacks: %d\n", err);
188 return JNI_ERR;
189 }
190
191 err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
192 JVMTI_EVENT_MONITOR_CONTENDED_ENTER, NULL);
193 if (err != JVMTI_ERROR_NONE) {
194 fprintf(stderr, "Agent_OnLoad: error in JVMTI SetEventNotificationMode #1: %d\n", err);
195 return JNI_ERR;
196 }
197 err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
198 JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, NULL);
199 if (err != JVMTI_ERROR_NONE) {
200 fprintf(stderr, "Agent_OnLoad: error in JVMTI SetEventNotificationMode #2: %d\n", err);
201 return JNI_ERR;
202 }
203 printf("Agent_OnLoad finished\n");
204 return JNI_OK;
205 }
206
207 JNIEXPORT jint JNICALL
208 Java_GetOwnedMonitorInfoTest_check(JNIEnv *env, jclass cls) {
209 return status;
210 }
211
212 JNIEXPORT jboolean JNICALL
213 Java_GetOwnedMonitorInfoTest_hasEventPosted(JNIEnv *env, jclass cls) {
214 return event_has_posted;
215 }
216
217 #ifdef __cplusplus
218 }
219 #endif