/*

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * 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.

 *

 */

#include <stdlib.h>

#include "jvm.h"

#include "jni.h"

#include "jni_util.h"

#include "jvm_symbols.h"

#include "sun_tracing_dtrace_JVM.h"

#ifdef __cplusplus

extern "C" {

#endif

static JvmSymbols* jvm_symbols = NULL;

static void initialize() {

    static int initialized = 0;

    if (initialized == 0) {

        jvm_symbols = lookupJvmSymbols();

        initialized = 1;

    }

}

/*

 * Class:     sun_tracing_dtrace_JVM

 * Method:    isSupported0

 * Signature: ()I

 */

JNIEXPORT jboolean JNICALL Java_sun_tracing_dtrace_JVM_isSupported0(

        JNIEnv* env, jclass cls) {

    initialize();

    if (jvm_symbols != NULL) {

        return jvm_symbols->IsSupported(env) ? JNI_TRUE : JNI_FALSE;

    } else {

        return JNI_FALSE;

    }

}

// Macros that cause an immediate return if we detect an exception

#define CHECK if ((*env)->ExceptionOccurred(env)) { return; }

#define CHECK_(x) if ((*env)->ExceptionOccurred(env)) { return x; }

static void readProbeData (

        JNIEnv* env, jobject probe, JVM_DTraceProbe* jvm_probe) {

    jclass clazz;

    jmethodID mid;

    jobject method;

    if (jvm_probe == NULL) {

        return; // just in case

    }

    clazz = (*env)->GetObjectClass(env, probe); CHECK

    mid = (*env)->GetMethodID(

        env, clazz, "getFunctionName", "()Ljava/lang/String;"); CHECK

    jvm_probe->function = (jstring)(*env)->CallObjectMethod(

        env, probe, mid); CHECK

    mid = (*env)->GetMethodID(

        env, clazz, "getProbeName", "()Ljava/lang/String;"); CHECK

    jvm_probe->name = (jstring)(*env)->CallObjectMethod(env, probe, mid); CHECK

    mid = (*env)->GetMethodID(

        env, clazz, "getMethod", "()Ljava/lang/reflect/Method;"); CHECK

    method = (*env)->CallObjectMethod(env, probe, mid); CHECK

    jvm_probe->method = (*env)->FromReflectedMethod(env, method); CHECK

}

static void readFieldInterfaceAttributes(

        char* annotationName, JNIEnv* env, jobject provider,

        JVM_DTraceInterfaceAttributes* attrs) {

    jobject result;

    jobject result_clazz;

    jclass provider_clazz;

    jclass annotation_clazz;

    jmethodID get;

    jmethodID enc;

    provider_clazz = (*env)->GetObjectClass(env, provider); CHECK

    annotation_clazz = (*env)->FindClass(env, annotationName); CHECK

    get = (*env)->GetMethodID(env, provider_clazz, "getNameStabilityFor",

        "(Ljava/lang/Class;)Lcom/sun/tracing/dtrace/StabilityLevel;"); CHECK

    result = (*env)->CallObjectMethod(

        env, provider, get, annotation_clazz); CHECK

    result_clazz = (*env)->GetObjectClass(env, result); CHECK

    enc = (*env)->GetMethodID(env, result_clazz, "getEncoding", "()I"); CHECK

    attrs->nameStability = (*env)->CallIntMethod(env, result, enc); CHECK

    get = (*env)->GetMethodID(env, provider_clazz, "getDataStabilityFor",

        "(Ljava/lang/Class;)Lcom/sun/tracing/dtrace/StabilityLevel;"); CHECK

    result = (*env)->CallObjectMethod(

        env, provider, get, annotation_clazz); CHECK

    result_clazz = (*env)->GetObjectClass(env, result); CHECK

    enc = (*env)->GetMethodID(env, result_clazz, "getEncoding", "()I"); CHECK

    attrs->dataStability = (*env)->CallIntMethod(env, result, enc); CHECK

    get = (*env)->GetMethodID(env, provider_clazz, "getDependencyClassFor",

        "(Ljava/lang/Class;)Lcom/sun/tracing/dtrace/DependencyClass;"); CHECK

    result = (*env)->CallObjectMethod(

        env, provider, get, annotation_clazz); CHECK

    result_clazz = (*env)->GetObjectClass(env, result); CHECK

    enc = (*env)->GetMethodID(env, result_clazz, "getEncoding", "()I"); CHECK

    attrs->dependencyClass = (*env)->CallIntMethod(env, result, enc); CHECK

}

static void readInterfaceAttributes(

        JNIEnv* env, jobject provider, JVM_DTraceProvider* jvm_provider) {

    readFieldInterfaceAttributes("com/sun/tracing/dtrace/ProviderAttributes",

        env, provider, &(jvm_provider->providerAttributes));

    readFieldInterfaceAttributes("com/sun/tracing/dtrace/ModuleAttributes",

        env, provider, &(jvm_provider->moduleAttributes));

    readFieldInterfaceAttributes("com/sun/tracing/dtrace/FunctionAttributes",

        env, provider, &(jvm_provider->functionAttributes));

    readFieldInterfaceAttributes("com/sun/tracing/dtrace/NameAttributes",

        env, provider, &(jvm_provider->nameAttributes));

    readFieldInterfaceAttributes("com/sun/tracing/dtrace/ArgsAttributes",

        env, provider, &(jvm_provider->argsAttributes));

}

static void readProviderData(

        JNIEnv* env, jobject provider, JVM_DTraceProvider* jvm_provider) {

    jmethodID mid;

    jobjectArray probes;

    jsize i;

    jclass clazz = (*env)->GetObjectClass(env, provider); CHECK

    mid = (*env)->GetMethodID(

        env, clazz, "getProbes", "()[Lsun/tracing/dtrace/DTraceProbe;"); CHECK

    probes = (jobjectArray)(*env)->CallObjectMethod(

        env, provider, mid); CHECK

    // Fill JVM structure, describing provider

    jvm_provider->probe_count = (*env)->GetArrayLength(env, probes); CHECK

    jvm_provider->probes = (JVM_DTraceProbe*)calloc(

        jvm_provider->probe_count, sizeof(*jvm_provider->probes));

    mid = (*env)->GetMethodID(

        env, clazz, "getProviderName", "()Ljava/lang/String;"); CHECK

    jvm_provider->name = (jstring)(*env)->CallObjectMethod(

        env, provider, mid); CHECK

    readInterfaceAttributes(env, provider, jvm_provider); CHECK

    for (i = 0; i < jvm_provider->probe_count; ++i) {

        jobject probe = (*env)->GetObjectArrayElement(env, probes, i); CHECK

        readProbeData(env, probe, &jvm_provider->probes[i]); CHECK

    }

}

/*

 * Class:     sun_tracing_dtrace_JVM

 * Method:    activate0

 * Signature: ()J

 */

JNIEXPORT jlong JNICALL Java_sun_tracing_dtrace_JVM_activate0(

        JNIEnv* env, jclass cls, jstring moduleName, jobjectArray providers) {

    jlong handle = 0;

    jsize num_providers;

    jsize i;

    JVM_DTraceProvider* jvm_providers;

    initialize();

    if (jvm_symbols == NULL) {

      return 0;

    }

    num_providers = (*env)->GetArrayLength(env, providers); CHECK_(0L)

    jvm_providers = (JVM_DTraceProvider*)calloc(

        num_providers, sizeof(*jvm_providers));

    for (i = 0; i < num_providers; ++i) {

        JVM_DTraceProvider* p = &(jvm_providers[i]);

        jobject provider = (*env)->GetObjectArrayElement(

            env, providers, i);

        readProviderData(env, provider, p);

    }

    handle = jvm_symbols->Activate(

        env, JVM_TRACING_DTRACE_VERSION, moduleName,

        num_providers, jvm_providers);

    for (i = 0; i < num_providers; ++i) {

        JVM_DTraceProvider* p = &(jvm_providers[i]);

        free(p->probes);

    }

    free(jvm_providers);

    return handle;

}

/*

 * Class:     sun_tracing_dtrace_JVM

 * Method:    dispose0

 * Signature: (J)V

 */

JNIEXPORT void JNICALL Java_sun_tracing_dtrace_JVM_dispose0(

        JNIEnv* env, jclass cls, jlong handle) {

    if (jvm_symbols != NULL && handle != 0) {

        jvm_symbols->Dispose(env, handle);

    }

}

/*

 * Class:     sun_tracing_dtrace_JVM

 * Method:    isEnabled0

 * Signature: (Ljava/lang/String;Ljava/lang/String;)Z

 */

JNIEXPORT jboolean JNICALL Java_sun_tracing_dtrace_JVM_isEnabled0(

        JNIEnv* env, jclass cls, jobject method) {

    jmethodID mid;

    if (jvm_symbols != NULL && method != NULL) {

        mid = (*env)->FromReflectedMethod(env, method);

        return jvm_symbols->IsProbeEnabled(env, mid);

    }

    return JNI_FALSE;

}

/*

 * Class:     sun_tracing_dtrace_JVM

 * Method:    defineClass0

 * Signature: (Ljava/lang/ClassLoader;Ljava/lang/String;[BII)Ljava/lang/Class;

 *

 * The implementation of this native static method is a copy of that of

 * the native instance method Java_java_lang_ClassLoader_defineClass0()

 * with the implicit "this" parameter becoming the "loader" parameter.

 *

 * This code was cloned and modified from java_lang_reflect_Proxy

 */

JNIEXPORT jclass JNICALL

Java_sun_tracing_dtrace_JVM_defineClass0(

        JNIEnv *env, jclass ignore, jobject loader, jstring name, jbyteArray data,

        jint offset, jint length)

{

    jbyte *body;

    char *utfName;

    jclass result = 0;

    char buf[128];

    if (data == NULL) {

        return 0;

    }

    /* Work around 4153825. malloc crashes on Solaris when passed a

     * negative size.

     */

    if (length < 0) {

        return 0;

    }

    body = (jbyte *)malloc(length);

    if (body == 0) {

        return 0;

    }

    (*env)->GetByteArrayRegion(env, data, offset, length, body);

    if ((*env)->ExceptionOccurred(env))

        goto free_body;

    if (name != NULL) {

        int i;

        int len = (*env)->GetStringUTFLength(env, name);

        int unicode_len = (*env)->GetStringLength(env, name);

        if (len >= sizeof(buf)) {

            utfName = malloc(len + 1);

            if (utfName == NULL) {

                goto free_body;

            }

        } else {

            utfName = buf;

        }

        (*env)->GetStringUTFRegion(env, name, 0, unicode_len, utfName);

        // Convert '.' to '/' in the package name

        for (i = 0; i < unicode_len; ++i) {

            if (utfName[i] == '.') {

                utfName[i] = '/';

            }

        }

    } else {

        utfName = NULL;

    }

    result = (*env)->DefineClass(env, utfName, loader, body, length);

    if (utfName && utfName != buf)

        free(utfName);

 free_body:

    free(body);

    return result;

}

#ifdef __cplusplus

}

#endif