/*

 * Copyright (c) 2011, 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 "precompiled.hpp"

#include "classfile/classLoaderData.inline.hpp"

#include "classfile/symbolTable.hpp"

#include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp"

#include "jfr/utilities/jfrTypes.hpp"

#include "oops/arrayKlass.inline.hpp"

#include "oops/klass.inline.hpp"

#include "oops/instanceKlass.inline.hpp"

#include "oops/method.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/atomic.hpp"

#include "runtime/vm_version.hpp"

#include "runtime/jniHandles.inline.hpp"

#include "runtime/thread.inline.hpp"

#include "utilities/debug.hpp"

 // returns updated value

static traceid atomic_inc(traceid volatile* const dest) {

  assert(VM_Version::supports_cx8(), "invariant");

  traceid compare_value;

  traceid exchange_value;

  do {

    exchange_value = compare_value + 1;

  } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);

  return exchange_value;

}

static traceid next_class_id() {

  static volatile traceid class_id_counter = MaxJfrEventId + 100;

  return atomic_inc(&class_id_counter) << TRACE_ID_SHIFT;

}

static traceid next_thread_id() {

  static volatile traceid thread_id_counter = 0;

  return atomic_inc(&thread_id_counter);

}

static traceid next_module_id() {

  static volatile traceid module_id_counter = 1;

  return atomic_inc(&module_id_counter) << TRACE_ID_SHIFT;

}

static traceid next_package_id() {

  static volatile traceid package_id_counter = 1;

  return atomic_inc(&package_id_counter) << TRACE_ID_SHIFT;

}

static traceid next_class_loader_data_id() {

  static volatile traceid cld_id_counter = 1;

  return atomic_inc(&cld_id_counter) << TRACE_ID_SHIFT;

}

static bool found_jdk_internal_event_klass = false;

static bool found_jdk_jfr_event_klass = false;

static void check_klass(const Klass* klass) {

  assert(klass != NULL, "invariant");

  if (found_jdk_internal_event_klass && found_jdk_jfr_event_klass) {

    return;

  }

  static const Symbol* jdk_internal_event_sym = NULL;

  if (jdk_internal_event_sym == NULL) {

    // setup when loading the first TypeArrayKlass (Universe::genesis) hence single threaded invariant

    jdk_internal_event_sym = SymbolTable::new_permanent_symbol("jdk/internal/event/Event");

  }

  assert(jdk_internal_event_sym != NULL, "invariant");

  static const Symbol* jdk_jfr_event_sym = NULL;

  if (jdk_jfr_event_sym == NULL) {

    // setup when loading the first TypeArrayKlass (Universe::genesis) hence single threaded invariant

    jdk_jfr_event_sym = SymbolTable::new_permanent_symbol("jdk/jfr/Event");

  }

  assert(jdk_jfr_event_sym != NULL, "invariant");

  const Symbol* const klass_name = klass->name();

  if (!found_jdk_internal_event_klass) {

    if (jdk_internal_event_sym == klass_name && klass->class_loader() == NULL) {

      found_jdk_internal_event_klass = true;

      JfrTraceId::tag_as_jdk_jfr_event(klass);

      return;

    }

  }

  if (!found_jdk_jfr_event_klass) {

    if (jdk_jfr_event_sym == klass_name && klass->class_loader() == NULL) {

      found_jdk_jfr_event_klass = true;

      JfrTraceId::tag_as_jdk_jfr_event(klass);

      return;

    }

  }

}

void JfrTraceId::assign(const Klass* klass) {

  assert(klass != NULL, "invariant");

  klass->set_trace_id(next_class_id());

  check_klass(klass);

  const Klass* const super = klass->super();

  if (super == NULL) {

    return;

  }

  if (IS_EVENT_KLASS(super)) {

    tag_as_jdk_jfr_event_sub(klass);

  }

}

void JfrTraceId::assign(const ModuleEntry* module) {

  assert(module != NULL, "invariant");

  module->set_trace_id(next_module_id());

}

void JfrTraceId::assign(const PackageEntry* package) {

  assert(package != NULL, "invariant");

  package->set_trace_id(next_package_id());

}

void JfrTraceId::assign(const ClassLoaderData* cld) {

  assert(cld != NULL, "invariant");

  if (cld->is_unsafe_anonymous()) {

    cld->set_trace_id(0);

    return;

  }

  cld->set_trace_id(next_class_loader_data_id());

}

traceid JfrTraceId::assign_thread_id() {

  return next_thread_id();

}

// used by CDS / APPCDS as part of "remove_unshareable_info"

void JfrTraceId::remove(const Klass* k) {

  assert(k != NULL, "invariant");

  // Mask off and store the event flags.

  // This mechanism will retain the event specific flags

  // in the archive, allowing for event flag restoration

  // when renewing the traceid on klass revival.

  k->set_trace_id(EVENT_KLASS_MASK(k));

}

// used by CDS / APPCDS as part of "restore_unshareable_info"

void JfrTraceId::restore(const Klass* k) {

  assert(k != NULL, "invariant");

  if (IS_JDK_JFR_EVENT_KLASS(k)) {

    found_jdk_jfr_event_klass = true;

  }

  const traceid event_flags = k->trace_id();

  // get a fresh traceid and restore the original event flags

  k->set_trace_id(next_class_id() | event_flags);

}

traceid JfrTraceId::get(jclass jc) {

  assert(jc != NULL, "invariant");

  assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");

  const oop my_oop = JNIHandles::resolve(jc);

  assert(my_oop != NULL, "invariant");

  return get(java_lang_Class::as_Klass(my_oop));

}

traceid JfrTraceId::use(jclass jc) {

  assert(jc != NULL, "invariant");

  assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");

  const oop my_oop = JNIHandles::resolve(jc);

  assert(my_oop != NULL, "invariant");

  return use(java_lang_Class::as_Klass(my_oop));

}

bool JfrTraceId::in_visible_set(const jclass jc) {

  assert(jc != NULL, "invariant");

  assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  return in_visible_set(java_lang_Class::as_Klass(mirror));

}

bool JfrTraceId::in_jdk_jfr_event_hierarchy(const jclass jc) {

  assert(jc != NULL, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  return in_jdk_jfr_event_hierarchy(java_lang_Class::as_Klass(mirror));

}

bool JfrTraceId::is_jdk_jfr_event_sub(const jclass jc) {

  assert(jc != NULL, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  return is_jdk_jfr_event_sub(java_lang_Class::as_Klass(mirror));

}

bool JfrTraceId::is_jdk_jfr_event(const jclass jc) {

  assert(jc != NULL, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  return is_jdk_jfr_event(java_lang_Class::as_Klass(mirror));

}

bool JfrTraceId::is_event_host(const jclass jc) {

  assert(jc != NULL, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  return is_event_host(java_lang_Class::as_Klass(mirror));

}

void JfrTraceId::tag_as_jdk_jfr_event_sub(const jclass jc) {

  assert(jc != NULL, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  const Klass* const k = java_lang_Class::as_Klass(mirror);

  tag_as_jdk_jfr_event_sub(k);

  assert(IS_JDK_JFR_EVENT_SUBKLASS(k), "invariant");

}

void JfrTraceId::tag_as_event_host(const jclass jc) {

  assert(jc != NULL, "invariant");

  const oop mirror = JNIHandles::resolve(jc);

  assert(mirror != NULL, "invariant");

  const Klass* const k = java_lang_Class::as_Klass(mirror);

  tag_as_event_host(k);

  assert(IS_EVENT_HOST_KLASS(k), "invariant");

}