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/*
* Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "jvmti.h"
#include "agent_common.hpp"
#include "jvmti_common.hpp"
#include "JVMTITools.hpp"
extern "C" {
#define PASSED 0
#define STATUS_FAILED 2
typedef struct {
const char *klass;
const char *name;
const char *sig;
int stat;
jfieldID fid;
jfieldID thrown_fid;
} field;
static jvmtiEnv *jvmti;
static jvmtiEventCallbacks callbacks;
static jvmtiCapabilities caps;
static jint result = PASSED;
static field fields[] = {
{ "nsk/jvmti/SetFieldAccessWatch/setfldw001", "fld0", "I", 0, nullptr, nullptr },
{ "nsk/jvmti/SetFieldAccessWatch/setfldw001", "fld1", "I", 1, nullptr, nullptr },
{ "nsk/jvmti/SetFieldAccessWatch/setfldw001", "fld2",
"Lnsk/jvmti/SetFieldAccessWatch/setfldw001a;", 0, nullptr, nullptr },
{ "nsk/jvmti/SetFieldAccessWatch/setfldw001a", "fld3", "[I", 0, nullptr, nullptr },
{ "nsk/jvmti/SetFieldAccessWatch/setfldw001b", "fld4", "F", 0, nullptr, nullptr },
};
void setWatch(JNIEnv *env, jint ind) {
jvmtiError err;
jclass cls;
field fld = fields[ind];
cls = env->FindClass(fld.klass);
if (cls == nullptr) {
printf("Cannot find class \"%s\"\n", fld.klass);
result = STATUS_FAILED;
return;
}
if (fld.fid == nullptr) {
if (fld.stat) {
fields[ind].fid = env->GetStaticFieldID(cls, fld.name, fld.sig);
} else {
fields[ind].fid = env->GetFieldID(cls, fld.name, fld.sig);
}
}
err = jvmti->SetFieldAccessWatch(cls, fields[ind].fid);
if (err == JVMTI_ERROR_MUST_POSSESS_CAPABILITY &&
!caps.can_generate_field_access_events) {
/* Ok, it's expected */
} else if (err != JVMTI_ERROR_NONE) {
printf("(SetFieldAccessWatch#%d) unexpected error: %s (%d)\n",
ind, TranslateError(err), err);
result = STATUS_FAILED;
}
}
void JNICALL FieldAccess(jvmtiEnv *jvmti_env, JNIEnv *env,
jthread thr, jmethodID method,
jlocation location, jclass field_klass, jobject obj, jfieldID field) {
char *fld_name = nullptr;
jint fld_ind = 0;
size_t len = 0;
jvmtiError err = jvmti_env->GetFieldName(field_klass, field,
&fld_name, nullptr, nullptr);
if (err != JVMTI_ERROR_NONE) {
printf("Error in GetFieldName: %s (%d)\n", TranslateError(err), err);
result = STATUS_FAILED;
return;
}
if (fld_name == nullptr) {
printf("GetFieldName returned null field name\n");
result = STATUS_FAILED;
return;
}
len = strlen(fld_name);
/* All field names have the same length and end with a digit. */
if (len != strlen(fields[0].name) || !isdigit(fld_name[len - 1])) {
printf("GetFieldName returned unexpected field name: %s\n", fld_name);
result = STATUS_FAILED;
return;
}
fld_ind = (int)(fld_name[len - 1] - '0'); /* last digit is index in the array */
fields[fld_ind].thrown_fid = field;
if (field == nullptr) {
fatal(env, "null field ID in FieldModification event.");
}
LOG("Event: (Field %d) field ID expected: 0x%p, got: 0x%p\n",
fld_ind, fields[fld_ind].fid, field);
jvmti_env->Deallocate((unsigned char*) fld_name);
}
#ifdef STATIC_BUILD
JNIEXPORT jint JNICALL Agent_OnLoad_setfldw001(JavaVM *jvm, char *options, void *reserved) {
return Agent_Initialize(jvm, options, reserved);
}
JNIEXPORT jint JNICALL Agent_OnAttach_setfldw001(JavaVM *jvm, char *options, void *reserved) {
return Agent_Initialize(jvm, options, reserved);
}
JNIEXPORT jint JNI_OnLoad_setfldw001(JavaVM *jvm, char *options, void *reserved) {
return JNI_VERSION_1_8;
}
#endif
jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {
jint res;
jvmtiError err;
res = jvm->GetEnv((void **) &jvmti, JVMTI_VERSION_1_1);
if (res != JNI_OK || jvmti == nullptr) {
printf("Wrong result of a valid call to GetEnv !\n");
return JNI_ERR;
}
err = jvmti->GetPotentialCapabilities(&caps);
if (err != JVMTI_ERROR_NONE) {
printf("(GetPotentialCapabilities) unexpected error: %s (%d)\n",
TranslateError(err), err);
return JNI_ERR;
}
err = jvmti->AddCapabilities(&caps);
if (err != JVMTI_ERROR_NONE) {
printf("(AddCapabilities) unexpected error: %s (%d)\n",
TranslateError(err), err);
return JNI_ERR;
}
err = jvmti->GetCapabilities(&caps);
if (err != JVMTI_ERROR_NONE) {
printf("(GetCapabilities) unexpected error: %s (%d)\n",
TranslateError(err), err);
return JNI_ERR;
}
if (caps.can_generate_field_access_events) {
callbacks.FieldAccess = &FieldAccess;
err = jvmti->SetEventCallbacks(&callbacks, sizeof(callbacks));
if (err != JVMTI_ERROR_NONE) {
printf("(SetEventCallbacks) unexpected error: %s (%d)\n",
TranslateError(err), err);
return JNI_ERR;
}
err = jvmti->SetEventNotificationMode(JVMTI_ENABLE,
JVMTI_EVENT_FIELD_ACCESS, nullptr);
if (err != JVMTI_ERROR_NONE) {
printf("Failed to enable JVMTI_EVENT_FIELD_ACCESS: %s (%d)\n",
TranslateError(err), err);
return JNI_ERR;
}
} else {
printf("Warning: FieldAccess watch is not implemented\n");
}
return JNI_OK;
}
JNIEXPORT void JNICALL
Java_nsk_jvmti_SetFieldAccessWatch_setfldw001_setWatch(JNIEnv *env,
jclass cls, jint fld_ind) {
setWatch(env, fld_ind);
}
JNIEXPORT void JNICALL
Java_nsk_jvmti_SetFieldAccessWatch_setfldw001_touchfld0(JNIEnv *env,
jobject obj) {
jint val;
setWatch(env, (jint)0);
val = env->GetIntField(obj, fields[0].fid);
}
JNIEXPORT void JNICALL
Java_nsk_jvmti_SetFieldAccessWatch_setfldw001_check(JNIEnv *env,
jclass cls, jint fld_ind, jboolean flag) {
jfieldID thrown_fid = fields[fld_ind].thrown_fid;
if (caps.can_generate_field_access_events) {
if (flag == JNI_FALSE && thrown_fid != nullptr) {
result = STATUS_FAILED;
printf("(Field %d) FIELD_ACCESS event without access watch set\n",
fld_ind);
} else if (flag == JNI_TRUE && thrown_fid != fields[fld_ind].fid) {
result = STATUS_FAILED;
printf("(Field %d) thrown field ID expected: 0x%p, got: 0x%p\n",
fld_ind, fields[fld_ind].fid, thrown_fid);
}
}
}
JNIEXPORT jint JNICALL
Java_nsk_jvmti_SetFieldAccessWatch_setfldw001_getRes(JNIEnv *env, jclass cls) {
return result;
}
}
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