/*

 * Copyright (c) 2004, 2018, 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 <string.h>

#include "jvmti.h"

#include "agent_common.h"

#include "jni_tools.h"

#include "jvmti_tools.h"

extern "C" {

/* scaffold objects */

static jvmtiEnv *jvmti = NULL;

static jlong timeout = 0;

#define TESTED_CLASS_NAME   "nsk/jvmti/scenarios/bcinstr/BI01/bi01t001a"

static jint newClassSize;

static unsigned char* newClassBytes;

static jvmtiClassDefinition oldClassDef;

/* ============================================================================= */

/*

 * Class:     nsk_jvmti_scenarios_bcinstr_BI01_bi01t001

 * Method:    setNewByteCode

 * Signature: ([B)Z

 */

JNIEXPORT jboolean JNICALL

Java_nsk_jvmti_scenarios_bcinstr_BI01_bi01t001_setNewByteCode(JNIEnv *jni_env,

                        jobject o, jbyteArray byteCode) {

    jbyte* elements;

    jboolean isCopy;

    if (!NSK_JNI_VERIFY(jni_env, (newClassSize =

            NSK_CPP_STUB2(GetArrayLength, jni_env, byteCode)) > 0)) {

        nsk_jvmti_setFailStatus();

        return NSK_FALSE;

    }

    NSK_DISPLAY1("\t... got array size: %d\n", newClassSize);

    if (!NSK_JNI_VERIFY(jni_env, (elements =

            NSK_CPP_STUB3(GetByteArrayElements, jni_env, byteCode,

                                                        &isCopy)) != NULL)) {

        nsk_jvmti_setFailStatus();

        return NSK_FALSE;

    }

    NSK_DISPLAY1("\t... got elements list: 0x%p\n", (void*)elements);

    if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB3(Allocate, jvmti,

                                newClassSize, &newClassBytes))) {

        nsk_jvmti_setFailStatus();

        return NSK_FALSE;

    }

    NSK_DISPLAY1("\t... created bytes array: 0x%p\n", (void*)newClassBytes);

    {

        int j;

        for (j = 0; j < newClassSize; j++)

            newClassBytes[j] = (unsigned char)elements[j];

    }

    NSK_DISPLAY1("\t... copied bytecode: %d bytes\n", (int)newClassSize);

    NSK_DISPLAY1("\t... release elements list: 0x%p\n", (void*)elements);

    NSK_TRACE(NSK_CPP_STUB4(ReleaseByteArrayElements, jni_env, byteCode, elements, JNI_ABORT));

    NSK_DISPLAY0("\t... released\n");

    return NSK_TRUE;

}

/* ============================================================================= */

/*

 * Class:     nsk_jvmti_scenarios_bcinstr_BI01_bi01t001

 * Method:    setClass

 * Signature: (Ljava/lang/Class;)V

 */

JNIEXPORT void JNICALL

Java_nsk_jvmti_scenarios_bcinstr_BI01_bi01t001_setClass(JNIEnv *jni_env,

                        jobject o, jclass cls) {

    if (!NSK_JNI_VERIFY(jni_env, (oldClassDef.klass = (jclass)

             NSK_CPP_STUB2(NewGlobalRef, jni_env, cls)) != NULL)) {

        nsk_jvmti_setFailStatus();

    }

}

/* ============================================================================= */

/** Callback function for ClassFileLoadHook event. */

JNIEXPORT void JNICALL

cbClassFileLoadHook(jvmtiEnv *jvmti_env, JNIEnv* jni_env,

            jclass class_being_redefined, jobject loader, const char* name,

            jobject protection_domain, jint class_data_len,

            const unsigned char* class_data, jint* new_class_data_len,

            unsigned char** new_class_data) {

    if ( name == NULL || strcmp(name, TESTED_CLASS_NAME) ) {

        return;

    }

    NSK_DISPLAY3("CLASS_FILE_LOAD_HOOK event: %s\n\treceived bytecode: 0x%p:%d\n",

                        name, (void *)class_data, class_data_len);

    if (nsk_getVerboseMode()) {

        nsk_printHexBytes("   ", 16, class_data_len, class_data);

    }

    {

        /*store original byte code, it will be used to do final redefinition*/

        int j;

        unsigned char *arr;

        oldClassDef.class_byte_count = class_data_len;

        if (!NSK_JVMTI_VERIFY(

                NSK_CPP_STUB3(Allocate, jvmti_env, class_data_len,

                                &arr))) {

            nsk_jvmti_setFailStatus();

            return;

        }

        for (j = 0; j < class_data_len; j++) {

            arr[j] = class_data[j];

        }

        oldClassDef.class_bytes = arr;

    }

    *new_class_data_len = newClassSize;

    *new_class_data = newClassBytes;

    NSK_DISPLAY2("Replace with new bytecode: 0x%p:%d\n",

                                (void*)newClassBytes,

                                (int)newClassSize);

    if (nsk_getVerboseMode()) {

        nsk_printHexBytes("   ", 16, newClassSize,

                                newClassBytes);

    }

}

/* ============================================================================= */

/** Agent algorithm. */

static void JNICALL

agentProc(jvmtiEnv* jvmti, JNIEnv* agentJNI, void* arg) {

    /*Wait for debuggee to read new byte codes nsk_jvmti_waitForSync#1*/

    NSK_DISPLAY0("Wait for debuggee to read new byte codes nsk_jvmti_waitForSync#1\n");

    if (!nsk_jvmti_waitForSync(timeout))

        return;

    if (!nsk_jvmti_resumeSync())

        return;

    NSK_DISPLAY0("Wait for debuggee to load tested class by classLoader\n");

    /*Wait for debuggee to load next class nsk_jvmti_waitForSync#2*/

    if (!nsk_jvmti_waitForSync(timeout))

        return;

    if (!nsk_jvmti_resumeSync())

        return;

    /*Wait for debuggee to check instrumentation code works nsk_jvmti_waitForSync#3*/

    NSK_DISPLAY0("Wait for debuggee to check instrumentation code works nsk_jvmti_waitForSync#3\n");

    if (!nsk_jvmti_waitForSync(timeout))

        return;

    NSK_DISPLAY0("Notification disabled for CLASS_FILE_LOAD_HOOK event\n");

    if (!NSK_JVMTI_VERIFY(

            NSK_CPP_STUB4(SetEventNotificationMode, jvmti, JVMTI_DISABLE,

                                JVMTI_EVENT_CLASS_FILE_LOAD_HOOK, NULL))) {

        nsk_jvmti_setFailStatus();

        return;

    }

    if (!nsk_jvmti_resumeSync())

        return;

    /*Wait for debuggee to set classes to be redefined nsk_jvmti_waitForSync#4*/

    NSK_DISPLAY0("Wait for debuggee to set classes to be redefined nsk_jvmti_waitForSync#4\n");

    if (!nsk_jvmti_waitForSync(timeout))

        return;

    NSK_DISPLAY0("Redfine class with old byte code\n");

    NSK_DISPLAY3("class definition:\n\t0x%p, 0x%p:%d\n",

                    oldClassDef.klass,

                    oldClassDef.class_bytes,

                    oldClassDef.class_byte_count);

    if (nsk_getVerboseMode()) {

        nsk_printHexBytes("   ", 16, oldClassDef.class_byte_count,

                                oldClassDef.class_bytes);

    }

    if (!NSK_JVMTI_VERIFY(

            NSK_CPP_STUB3(RedefineClasses, jvmti, 1, &oldClassDef))) {

        nsk_jvmti_setFailStatus();

        return;

    }

    if (!nsk_jvmti_resumeSync())

        return;

    /*Wait for debuggee to check old byte code works nsk_jvmti_waitForSync#5*/

    NSK_DISPLAY0("Wait for debuggee to check old byte code works nsk_jvmti_waitForSync#5\n");

    if (!nsk_jvmti_waitForSync(timeout))

        return;

    NSK_CPP_STUB2(DeleteGlobalRef, agentJNI, oldClassDef.klass);

    NSK_DISPLAY0("Let debuggee to finish\n");

    if (!nsk_jvmti_resumeSync())

        return;

}

/* ============================================================================= */

/** Agent library initialization. */

#ifdef STATIC_BUILD

JNIEXPORT jint JNICALL Agent_OnLoad_bi01t001(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNICALL Agent_OnAttach_bi01t001(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNI_OnLoad_bi01t001(JavaVM *jvm, char *options, void *reserved) {

    return JNI_VERSION_1_8;

}

#endif

jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {

    if (!NSK_VERIFY(nsk_jvmti_parseOptions(options)))

        return JNI_ERR;

    timeout = nsk_jvmti_getWaitTime() * 60 * 1000;

    if (!NSK_VERIFY((jvmti = nsk_jvmti_createJVMTIEnv(jvm, reserved)) != NULL))

        return JNI_ERR;

    {

        jvmtiCapabilities caps;

        memset(&caps, 0, sizeof(caps));

        caps.can_redefine_classes = 1;

        if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(AddCapabilities, jvmti, &caps)))

            return JNI_ERR;

    }

    NSK_DISPLAY0("Set callback for CLASS_FILE_LOAD_HOOK event\n");

    {

        jvmtiEventCallbacks callbacks;

        jint size = (jint)sizeof(callbacks);

        memset(&callbacks, 0, size);

        callbacks.ClassFileLoadHook = cbClassFileLoadHook;

        if (!NSK_JVMTI_VERIFY(

                NSK_CPP_STUB3(SetEventCallbacks, jvmti, &callbacks, size))) {

            return JNI_ERR;

        }

    }

    NSK_DISPLAY0("Set notification enabled for CLASS_FILE_LOAD_HOOK event\n");

    if (!NSK_JVMTI_VERIFY(

            NSK_CPP_STUB4(SetEventNotificationMode, jvmti, JVMTI_ENABLE,

                                JVMTI_EVENT_CLASS_FILE_LOAD_HOOK, NULL))) {

        nsk_jvmti_setFailStatus();

        return NSK_FALSE;

    }

    if (!NSK_VERIFY(nsk_jvmti_setAgentProc(agentProc, NULL)))

        return JNI_ERR;

    return JNI_OK;

}

/* ============================================================================= */

}