/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This source code is provided to illustrate the usage of a given feature
* or technique and has been deliberately simplified. Additional steps
* required for a production-quality application, such as security checks,
* input validation and proper error handling, might not be present in
* this sample code.
*/
/* Example of using JVMTI events:
* JVMTI_EVENT_VM_INIT
* JVMTI_EVENT_VM_DEATH
* JVMTI_EVENT_THREAD_START
* JVMTI_EVENT_THREAD_END
* JVMTI_EVENT_MONITOR_CONTENDED_ENTER
* JVMTI_EVENT_MONITOR_WAIT
* JVMTI_EVENT_MONITOR_WAITED
* JVMTI_EVENT_OBJECT_FREE
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "jni.h"
#include "jvmti.h"
#include "agent_util.h"
#include "Monitor.hpp"
#include "Thread.hpp"
#include "Agent.hpp"
static jrawMonitorID vm_death_lock;
static jboolean vm_death_active;
/* Given a jvmtiEnv*, return the C++ Agent class instance */
static Agent *
get_agent(jvmtiEnv *jvmti)
{
jvmtiError err;
Agent *agent;
agent = NULL;
err = jvmti->GetEnvironmentLocalStorage((void**)&agent);
check_jvmti_error(jvmti, err, "get env local storage");
if ( agent == NULL ) {
/* This should never happen, but we should check */
fatal_error("ERROR: GetEnvironmentLocalStorage() returned NULL");
}
return agent;
}
/* Enter raw monitor */
static void
menter(jvmtiEnv *jvmti, jrawMonitorID rmon)
{
jvmtiError err;
err = jvmti->RawMonitorEnter(rmon);
check_jvmti_error(jvmti, err, "raw monitor enter");
}
/* Exit raw monitor */
static void
mexit(jvmtiEnv *jvmti, jrawMonitorID rmon)
{
jvmtiError err;
err = jvmti->RawMonitorExit(rmon);
check_jvmti_error(jvmti, err, "raw monitor exit");
}
/* All callbacks need to be extern "C" */
extern "C" {
static void JNICALL
vm_init(jvmtiEnv *jvmti, JNIEnv *env, jthread thread)
{
jvmtiError err;
Agent *agent;
/* Create raw monitor to protect against threads running after death */
err = jvmti->CreateRawMonitor("Waiters vm_death lock", &vm_death_lock);
check_jvmti_error(jvmti, err, "create raw monitor");
vm_death_active = JNI_FALSE;
/* Create an Agent instance, set JVMTI Local Storage */
agent = new Agent(jvmti, env, thread);
err = jvmti->SetEnvironmentLocalStorage((const void*)agent);
check_jvmti_error(jvmti, err, "set env local storage");
/* Enable all other events we want */
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_VM_DEATH, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_THREAD_START, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_THREAD_END, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_MONITOR_CONTENDED_ENTER, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_MONITOR_WAIT, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_MONITOR_WAITED, NULL);
check_jvmti_error(jvmti, err, "set event notify");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_OBJECT_FREE, NULL);
check_jvmti_error(jvmti, err, "set event notify");
}
static void JNICALL
vm_death(jvmtiEnv *jvmti, JNIEnv *env)
{
jvmtiError err;
Agent *agent;
/* Block all callbacks */
menter(jvmti, vm_death_lock); {
/* Set flag for other callbacks */
vm_death_active = JNI_TRUE;
/* Inform Agent instance of VM_DEATH */
agent = get_agent(jvmti);
agent->vm_death(jvmti, env);
/* Reclaim space of Agent */
err = jvmti->SetEnvironmentLocalStorage((const void*)NULL);
check_jvmti_error(jvmti, err, "set env local storage");
delete agent;
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
thread_start(jvmtiEnv *jvmti, JNIEnv *env, jthread thread)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->thread_start(jvmti, env, thread);
}
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
thread_end(jvmtiEnv *jvmti, JNIEnv *env, jthread thread)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->thread_end(jvmti, env, thread);
}
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
monitor_contended_enter(jvmtiEnv* jvmti, JNIEnv *env,
jthread thread, jobject object)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->monitor_contended_enter(jvmti, env,
thread, object);
}
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
monitor_contended_entered(jvmtiEnv* jvmti, JNIEnv *env,
jthread thread, jobject object)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->monitor_contended_entered(jvmti, env,
thread, object);
}
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
monitor_wait(jvmtiEnv* jvmti, JNIEnv *env,
jthread thread, jobject object, jlong timeout)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->monitor_wait(jvmti, env, thread,
object, timeout);
}
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
monitor_waited(jvmtiEnv* jvmti, JNIEnv *env,
jthread thread, jobject object, jboolean timed_out)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->monitor_waited(jvmti, env, thread,
object, timed_out);
}
} mexit(jvmti, vm_death_lock);
}
static void JNICALL
object_free(jvmtiEnv* jvmti, jlong tag)
{
menter(jvmti, vm_death_lock); {
if ( !vm_death_active ) {
get_agent(jvmti)->object_free(jvmti, tag);
}
} mexit(jvmti, vm_death_lock);
}
/* Agent_OnLoad() is called first, we prepare for a VM_INIT event here. */
JNIEXPORT jint JNICALL
Agent_OnLoad(JavaVM *vm, char *options, void *reserved)
{
jvmtiEnv *jvmti;
jint rc;
jvmtiError err;
jvmtiCapabilities capabilities;
jvmtiEventCallbacks callbacks;
/* Get JVMTI environment */
rc = vm->GetEnv((void **)&jvmti, JVMTI_VERSION);
if (rc != JNI_OK) {
fatal_error("ERROR: Unable to create jvmtiEnv, GetEnv failed, error=%d\n", rc);
return -1;
}
/* Get/Add JVMTI capabilities */
(void)memset(&capabilities, 0, sizeof(capabilities));
capabilities.can_generate_monitor_events = 1;
capabilities.can_get_monitor_info = 1;
capabilities.can_tag_objects = 1;
capabilities.can_generate_object_free_events = 1;
err = jvmti->AddCapabilities(&capabilities);
check_jvmti_error(jvmti, err, "add capabilities");
/* Set all callbacks and enable VM_INIT event notification */
memset(&callbacks, 0, sizeof(callbacks));
callbacks.VMInit = &vm_init;
callbacks.VMDeath = &vm_death;
callbacks.ThreadStart = &thread_start;
callbacks.ThreadEnd = &thread_end;
callbacks.MonitorContendedEnter = &monitor_contended_enter;
callbacks.MonitorContendedEntered = &monitor_contended_entered;
callbacks.MonitorWait = &monitor_wait;
callbacks.MonitorWaited = &monitor_waited;
callbacks.ObjectFree = &object_free;
err = jvmti->SetEventCallbacks(&callbacks, (jint)sizeof(callbacks));
check_jvmti_error(jvmti, err, "set event callbacks");
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_VM_INIT, NULL);
check_jvmti_error(jvmti, err, "set event notify");
return 0;
}
/* Agent_OnUnload() is called last */
JNIEXPORT void JNICALL
Agent_OnUnload(JavaVM *vm)
{
}
} /* of extern "C" */