/*

 * Copyright (c) 2007, 2019, 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 <jni.h>

#include <jvmti.h>

#include "agent_common.h"

#include <string.h>

#include <stdarg.h>

#include "jvmti_tools.h"

#include "JVMTITools.h"

/*

hs202t002:

*/

extern "C" {

#define FILE_NAME "nsk/jvmti/scenarios/hotswap/HS202/hs202t002/MyThread"

#define CLASS_NAME "Lnsk/jvmti/scenarios/hotswap/HS202/hs202t002/MyThread;"

#define PATH_FORMAT "%s%02d/%s"

#define DIR_NAME "newclass"

#define METHOD_NAME "display"

static jint redefineNumber = 0;

static jvmtiEnv * jvmti = NULL;

static volatile bool thread_suspend_error = false;

void JNICALL callbackMethodExit(jvmtiEnv *jvmti_env,

                                JNIEnv* jni_env,

                                jthread thread,

                                jmethodID method,

                                jboolean was_popped_by_exception,

                                jvalue return_value) {

    if (was_popped_by_exception) {

        char * name;

        char * signature;

        char * generic ;

        jvmtiError err;

        err= JVMTI_ERROR_NONE;

        jvmti_env->GetMethodName(method, &name, &signature, &generic);

        if (strcmp(name,METHOD_NAME) == 0) {

            jclass cls;

            char fileName[512];

            nsk_jvmti_getFileName(redefineNumber, FILE_NAME, fileName,

                                  sizeof(fileName)/sizeof(char));

            jvmti_env->GetMethodDeclaringClass(method, &cls);

            if (nsk_jvmti_redefineClass(jvmti_env, cls,fileName)) {

                nsk_printf(" Agent:: redefine class success ..\n");

                nsk_printf("Agent::SUSPENDING>> \n");

                err=jvmti_env->SuspendThread(thread);

                if (err == JVMTI_ERROR_NONE) {

                  // we don't get here until we are resumed

                    nsk_printf("Agent:: Thread successfully suspended and was resumed\n");

                } else {

                    thread_suspend_error = true;

                    nsk_printf(" ## Error occured %s \n",TranslateError(err));

                }

            }

        }

    }

}

#ifdef STATIC_BUILD

JNIEXPORT jint JNICALL Agent_OnLoad_hs202t002(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNICALL Agent_OnAttach_hs202t002(JavaVM *jvm, char *options, void *reserved) {

    return Agent_Initialize(jvm, options, reserved);

}

JNIEXPORT jint JNI_OnLoad_hs202t002(JavaVM *jvm, char *options, void *reserved) {

    return JNI_VERSION_1_8;

}

#endif

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

    jint rc ;

    nsk_printf("Agent:: VM.. Started..\n");

    redefineNumber=0;

    rc=vm->GetEnv((void **)&jvmti, JVMTI_VERSION_1_1);

    if (rc != JNI_OK) {

        nsk_printf("Agent:: Could not load JVMTI interface \n");

        return JNI_ERR;

    } else {

        jvmtiCapabilities caps;

        jvmtiEventCallbacks eventCallbacks;

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

        if (!nsk_jvmti_parseOptions(options)) {

            nsk_printf("# error agent Failed to parse options \n");

            return JNI_ERR;

        }

        caps.can_redefine_classes = 1;

        caps.can_suspend = 1;

        caps.can_pop_frame = 1;

        caps.can_generate_method_exit_events = 1;

        jvmti->AddCapabilities(&caps);

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

        eventCallbacks.MethodExit = callbackMethodExit;

        rc=jvmti->SetEventCallbacks(&eventCallbacks, sizeof(eventCallbacks));

        if (rc != JVMTI_ERROR_NONE) {

            nsk_printf(" Agent:: Error occured while setting event callbacks \n");

            return JNI_ERR;

        }

        if (nsk_jvmti_enableNotification(jvmti,JVMTI_EVENT_METHOD_EXIT, NULL)) {

            nsk_printf(" Agent :: NOTIFICATIONS ARE ENABLED \n");

        } else {

            nsk_printf(" Agent :: Error Enabling Notifications..");

        }

    }

    return JNI_OK;

}

JNIEXPORT jboolean JNICALL

Java_nsk_jvmti_scenarios_hotswap_HS202_hs202t002_hs202t002_popThreadFrame(JNIEnv * jni,

                                                                          jclass clas,

                                                                          jthread thread) {

    jvmtiError err = JVMTI_ERROR_NONE;

    jboolean retvalue = JNI_FALSE;

    jint state;

    nsk_printf("Agent:: POPPING THE FRAME..\n");

    jvmti->GetThreadState(thread, &state);

    if (state & JVMTI_THREAD_STATE_SUSPENDED) {

        err = jvmti->PopFrame(thread);

        if (err == JVMTI_ERROR_NONE) {

            nsk_printf("Agent:: PopFrame succeeded..\n");

            return JNI_TRUE;

        } else  {

            nsk_printf(" ## Error occured %s \n",TranslateError(err));

        }

    } else {

        nsk_printf("Agent:: Thread was not suspened.. check for capabilities, and java method signature ");

    }

    return retvalue;

}

JNIEXPORT jboolean JNICALL

Java_nsk_jvmti_scenarios_hotswap_HS202_hs202t002_hs202t002_resumeThread(JNIEnv * jni,

                                                                        jclass clas,

                                                                        jthread thread) {

    jvmtiError err = JVMTI_ERROR_NONE;

    jboolean retvalue = JNI_FALSE;

    // disable notifications before resuming thread

    // to avoid recursion on PopFrame issued reinvoke

    if (nsk_jvmti_disableNotification(jvmti,JVMTI_EVENT_METHOD_EXIT, NULL)) {

        nsk_printf("Agent :: nsk_jvmti_disabled notifications..\n");

    } else {

        nsk_printf("Agent :: Failed to disable notifications..");

        return JNI_FALSE;

    }

    err = jvmti->ResumeThread(thread);

    if (err == JVMTI_ERROR_NONE) {

        retvalue = JNI_TRUE;

        nsk_printf(" Agent:: Thread Resumed.. \n");

    } else {

        nsk_printf(" Agent:: Failed.. to Resume the thread.\n");

        retvalue = JNI_FALSE;

    }

    return retvalue;

}

JNIEXPORT jboolean JNICALL

Java_nsk_jvmti_scenarios_hotswap_HS202_hs202t002_hs202t002_isThreadSuspended(JNIEnv* jni,

                                                                             jclass clas,

                                                                             jthread thread) {

    if (thread_suspend_error) {

        jclass ex_class = jni->FindClass("java/lang/IllegalThreadStateException");

        jni->ThrowNew(ex_class, "Thread has failed to self suspend");

        return JNI_FALSE;

    }

    // There is an inherent race here if the suspend fails for some reason but

    // thread_suspend_error is not yet set. But as long as we report the suspend

    // state correctly there is no problem as the Java code will simply loop and call

    // this again until we see thread_suspend_error is true.

    jint state = 0;

    // No errors possible here: thread is valid, and state is not NULL

    jvmti->GetThreadState(thread, &state);

    return (state & JVMTI_THREAD_STATE_SUSPENDED) != 0;

}

} // extern C