1 /*
2 * Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * - Neither the name of Oracle nor the names of its
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * This source code is provided to illustrate the usage of a given feature
34 * or technique and has been deliberately simplified. Additional steps
35 * required for a production-quality application, such as security checks,
36 * input validation and proper error handling, might not be present in
37 * this sample code.
38 */
39
40
41 /* Example of using JVMTI events:
42 * JVMTI_EVENT_VM_INIT
43 * JVMTI_EVENT_VM_DEATH
44 * JVMTI_EVENT_THREAD_START
45 * JVMTI_EVENT_THREAD_END
46 * JVMTI_EVENT_MONITOR_CONTENDED_ENTER
47 * JVMTI_EVENT_MONITOR_WAIT
48 * JVMTI_EVENT_MONITOR_WAITED
49 * JVMTI_EVENT_OBJECT_FREE
50 */
51
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55
56 #include "jni.h"
57 #include "jvmti.h"
58
59 #include "agent_util.h"
60
61 #include "Monitor.hpp"
62 #include "Thread.hpp"
63 #include "Agent.hpp"
64
65 static jrawMonitorID vm_death_lock;
66 static jboolean vm_death_active;
67
68 /* Given a jvmtiEnv*, return the C++ Agent class instance */
69 static Agent *
70 get_agent(jvmtiEnv *jvmti)
71 {
72 jvmtiError err;
73 Agent *agent;
74
75 agent = NULL;
76 err = jvmti->GetEnvironmentLocalStorage((void**)&agent);
77 check_jvmti_error(jvmti, err, "get env local storage");
78 if ( agent == NULL ) {
79 /* This should never happen, but we should check */
80 fatal_error("ERROR: GetEnvironmentLocalStorage() returned NULL");
81 }
82 return agent;
83 }
84
85 /* Enter raw monitor */
86 static void
87 menter(jvmtiEnv *jvmti, jrawMonitorID rmon)
88 {
89 jvmtiError err;
90
91 err = jvmti->RawMonitorEnter(rmon);
92 check_jvmti_error(jvmti, err, "raw monitor enter");
93 }
94
95 /* Exit raw monitor */
96 static void
97 mexit(jvmtiEnv *jvmti, jrawMonitorID rmon)
98 {
99 jvmtiError err;
100
101 err = jvmti->RawMonitorExit(rmon);
102 check_jvmti_error(jvmti, err, "raw monitor exit");
103 }
104
105
106 /* All callbacks need to be extern "C" */
107 extern "C" {
108 static void JNICALL
109 vm_init(jvmtiEnv *jvmti, JNIEnv *env, jthread thread)
110 {
111 jvmtiError err;
112 Agent *agent;
113
114 /* Create raw monitor to protect against threads running after death */
115 err = jvmti->CreateRawMonitor("Waiters vm_death lock", &vm_death_lock);
116 check_jvmti_error(jvmti, err, "create raw monitor");
117 vm_death_active = JNI_FALSE;
118
119 /* Create an Agent instance, set JVMTI Local Storage */
120 agent = new Agent(jvmti, env, thread);
121 err = jvmti->SetEnvironmentLocalStorage((const void*)agent);
122 check_jvmti_error(jvmti, err, "set env local storage");
123
124 /* Enable all other events we want */
125 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
126 JVMTI_EVENT_VM_DEATH, NULL);
127 check_jvmti_error(jvmti, err, "set event notify");
128 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
129 JVMTI_EVENT_THREAD_START, NULL);
130 check_jvmti_error(jvmti, err, "set event notify");
131 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
132 JVMTI_EVENT_THREAD_END, NULL);
133 check_jvmti_error(jvmti, err, "set event notify");
134 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
135 JVMTI_EVENT_MONITOR_CONTENDED_ENTER, NULL);
136 check_jvmti_error(jvmti, err, "set event notify");
137 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
138 JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, NULL);
139 check_jvmti_error(jvmti, err, "set event notify");
140 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
141 JVMTI_EVENT_MONITOR_WAIT, NULL);
142 check_jvmti_error(jvmti, err, "set event notify");
143 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
144 JVMTI_EVENT_MONITOR_WAITED, NULL);
145 check_jvmti_error(jvmti, err, "set event notify");
146 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
147 JVMTI_EVENT_OBJECT_FREE, NULL);
148 check_jvmti_error(jvmti, err, "set event notify");
149 }
150 static void JNICALL
151 vm_death(jvmtiEnv *jvmti, JNIEnv *env)
152 {
153 jvmtiError err;
154 Agent *agent;
155
156 /* Block all callbacks */
157 menter(jvmti, vm_death_lock); {
158 /* Set flag for other callbacks */
159 vm_death_active = JNI_TRUE;
160
161 /* Inform Agent instance of VM_DEATH */
162 agent = get_agent(jvmti);
163 agent->vm_death(jvmti, env);
164
165 /* Reclaim space of Agent */
166 err = jvmti->SetEnvironmentLocalStorage((const void*)NULL);
167 check_jvmti_error(jvmti, err, "set env local storage");
168 delete agent;
169 } mexit(jvmti, vm_death_lock);
170
171 }
172 static void JNICALL
173 thread_start(jvmtiEnv *jvmti, JNIEnv *env, jthread thread)
174 {
175 menter(jvmti, vm_death_lock); {
176 if ( !vm_death_active ) {
177 get_agent(jvmti)->thread_start(jvmti, env, thread);
178 }
179 } mexit(jvmti, vm_death_lock);
180 }
181 static void JNICALL
182 thread_end(jvmtiEnv *jvmti, JNIEnv *env, jthread thread)
183 {
184 menter(jvmti, vm_death_lock); {
185 if ( !vm_death_active ) {
186 get_agent(jvmti)->thread_end(jvmti, env, thread);
187 }
188 } mexit(jvmti, vm_death_lock);
189 }
190 static void JNICALL
191 monitor_contended_enter(jvmtiEnv* jvmti, JNIEnv *env,
192 jthread thread, jobject object)
193 {
194 menter(jvmti, vm_death_lock); {
195 if ( !vm_death_active ) {
196 get_agent(jvmti)->monitor_contended_enter(jvmti, env,
197 thread, object);
198 }
199 } mexit(jvmti, vm_death_lock);
200 }
201 static void JNICALL
202 monitor_contended_entered(jvmtiEnv* jvmti, JNIEnv *env,
203 jthread thread, jobject object)
204 {
205 menter(jvmti, vm_death_lock); {
206 if ( !vm_death_active ) {
207 get_agent(jvmti)->monitor_contended_entered(jvmti, env,
208 thread, object);
209 }
210 } mexit(jvmti, vm_death_lock);
211 }
212 static void JNICALL
213 monitor_wait(jvmtiEnv* jvmti, JNIEnv *env,
214 jthread thread, jobject object, jlong timeout)
215 {
216 menter(jvmti, vm_death_lock); {
217 if ( !vm_death_active ) {
218 get_agent(jvmti)->monitor_wait(jvmti, env, thread,
219 object, timeout);
220 }
221 } mexit(jvmti, vm_death_lock);
222 }
223 static void JNICALL
224 monitor_waited(jvmtiEnv* jvmti, JNIEnv *env,
225 jthread thread, jobject object, jboolean timed_out)
226 {
227 menter(jvmti, vm_death_lock); {
228 if ( !vm_death_active ) {
229 get_agent(jvmti)->monitor_waited(jvmti, env, thread,
230 object, timed_out);
231 }
232 } mexit(jvmti, vm_death_lock);
233 }
234 static void JNICALL
235 object_free(jvmtiEnv* jvmti, jlong tag)
236 {
237 menter(jvmti, vm_death_lock); {
238 if ( !vm_death_active ) {
239 get_agent(jvmti)->object_free(jvmti, tag);
240 }
241 } mexit(jvmti, vm_death_lock);
242 }
243
244 /* Agent_OnLoad() is called first, we prepare for a VM_INIT event here. */
245 JNIEXPORT jint JNICALL
246 Agent_OnLoad(JavaVM *vm, char *options, void *reserved)
247 {
248 jvmtiEnv *jvmti;
249 jint rc;
250 jvmtiError err;
251 jvmtiCapabilities capabilities;
252 jvmtiEventCallbacks callbacks;
253
254 /* Get JVMTI environment */
255 rc = vm->GetEnv((void **)&jvmti, JVMTI_VERSION);
256 if (rc != JNI_OK) {
257 fatal_error("ERROR: Unable to create jvmtiEnv, GetEnv failed, error=%d\n", rc);
258 return -1;
259 }
260
261 /* Get/Add JVMTI capabilities */
262 (void)memset(&capabilities, 0, sizeof(capabilities));
263 capabilities.can_generate_monitor_events = 1;
264 capabilities.can_get_monitor_info = 1;
265 capabilities.can_tag_objects = 1;
266 capabilities.can_generate_object_free_events = 1;
267 err = jvmti->AddCapabilities(&capabilities);
268 check_jvmti_error(jvmti, err, "add capabilities");
269
270 /* Set all callbacks and enable VM_INIT event notification */
271 memset(&callbacks, 0, sizeof(callbacks));
272 callbacks.VMInit = &vm_init;
273 callbacks.VMDeath = &vm_death;
274 callbacks.ThreadStart = &thread_start;
275 callbacks.ThreadEnd = &thread_end;
276 callbacks.MonitorContendedEnter = &monitor_contended_enter;
277 callbacks.MonitorContendedEntered = &monitor_contended_entered;
278 callbacks.MonitorWait = &monitor_wait;
279 callbacks.MonitorWaited = &monitor_waited;
280 callbacks.ObjectFree = &object_free;
281 err = jvmti->SetEventCallbacks(&callbacks, (jint)sizeof(callbacks));
282 check_jvmti_error(jvmti, err, "set event callbacks");
283 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
284 JVMTI_EVENT_VM_INIT, NULL);
285 check_jvmti_error(jvmti, err, "set event notify");
286 return 0;
287 }
288
289 /* Agent_OnUnload() is called last */
290 JNIEXPORT void JNICALL
291 Agent_OnUnload(JavaVM *vm)
292 {
293 }
294
295 } /* of extern "C" */