/*

 * Copyright (c) 2016, 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 "jfrfiles/jfrEventClasses.hpp"

#include "jfr/jni/jfrJavaSupport.hpp"

#include "jfr/leakprofiler/leakProfiler.hpp"

#include "jfr/leakprofiler/checkpoint/objectSampleCheckpoint.hpp"

#include "jfr/leakprofiler/sampling/objectSampler.hpp"

#include "jfr/recorder/jfrRecorder.hpp"

#include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"

#include "jfr/recorder/checkpoint/jfrMetadataEvent.hpp"

#include "jfr/recorder/repository/jfrChunkRotation.hpp"

#include "jfr/recorder/repository/jfrChunkWriter.hpp"

#include "jfr/recorder/repository/jfrRepository.hpp"

#include "jfr/recorder/service/jfrPostBox.hpp"

#include "jfr/recorder/service/jfrRecorderService.hpp"

#include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"

#include "jfr/recorder/storage/jfrStorage.hpp"

#include "jfr/recorder/storage/jfrStorageControl.hpp"

#include "jfr/recorder/stringpool/jfrStringPool.hpp"

#include "jfr/utilities/jfrAllocation.hpp"

#include "jfr/utilities/jfrTime.hpp"

#include "jfr/writers/jfrJavaEventWriter.hpp"

#include "jfr/utilities/jfrTypes.hpp"

#include "logging/log.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/atomic.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/orderAccess.hpp"

#include "runtime/os.hpp"

#include "runtime/safepoint.hpp"

#include "runtime/thread.inline.hpp"

#include "runtime/vmOperations.hpp"

#include "runtime/vmThread.hpp"

// set data iff *dest == NULL

static bool try_set(void* const data, void** dest, bool clear) {

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

  const void* const current = OrderAccess::load_acquire(dest);

  if (current != NULL) {

    if (current != data) {

      // already set

      return false;

    }

    assert(current == data, "invariant");

    if (!clear) {

      // recursion disallowed

      return false;

    }

  }

  return Atomic::cmpxchg(clear ? NULL : data, dest, current) == current;

}

static void* rotation_thread = NULL;

static const int rotation_try_limit = 1000;

static const int rotation_retry_sleep_millis = 10;

// incremented on each flushpoint

static u8 flushpoint_id = 0;

class RotationLock : public StackObj {

 private:

  Thread* const _thread;

  bool _acquired;

  void log(bool recursion) {

    assert(!_acquired, "invariant");

    const char* error_msg = NULL;

    if (recursion) {

      error_msg = "Unable to issue rotation due to recursive calls.";

    }

    else {

      error_msg = "Unable to issue rotation due to wait timeout.";

    }

    log_info(jfr)( // For user, should not be "jfr, system"

      "%s", error_msg);

  }

 public:

  RotationLock(Thread* thread) : _thread(thread), _acquired(false) {

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

    if (_thread == rotation_thread) {

      // recursion not supported

      log(true);

      return;

    }

    // limited to not spin indefinitely

    for (int i = 0; i < rotation_try_limit; ++i) {

      if (try_set(_thread, &rotation_thread, false)) {

        _acquired = true;

        assert(_thread == rotation_thread, "invariant");

        return;

      }

      if (_thread->is_Java_thread()) {

        // in order to allow the system to move to a safepoint

        MutexLocker msg_lock(JfrMsg_lock);

        JfrMsg_lock->wait(rotation_retry_sleep_millis);

      }

      else {

        os::naked_short_sleep(rotation_retry_sleep_millis);

      }

    }

    log(false);

  }

  ~RotationLock() {

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

    if (_acquired) {

      assert(_thread == rotation_thread, "invariant");

      while (!try_set(_thread, &rotation_thread, true));

    }

  }

  bool not_acquired() const { return !_acquired; }

};

template <typename E, typename Instance, size_t(Instance::*func)()>

class ServiceFunctor {

 private:

  Instance& _instance;

  u4 _elements;

 public:

  typedef E EventType;

  ServiceFunctor(Instance& instance) : _instance(instance), _elements(0) {}

  bool process() {

    _elements = (u4)(_instance.*func)();

    return true;

  }

  u4 elements() const { return _elements; }

};

template <typename ContentFunctor>

class WriteSubsystem : public StackObj {

 protected:

  const JfrTicks _start_time;

  JfrTicks _end_time;

  JfrChunkWriter& _cw;

  ContentFunctor& _content_functor;

  const int64_t _start_offset;

 public:

  typedef typename ContentFunctor::EventType EventType;

  WriteSubsystem(JfrChunkWriter& cw, ContentFunctor& functor) :

    _start_time(JfrTicks::now()),

    _end_time(),

    _cw(cw),

    _content_functor(functor),

    _start_offset(_cw.current_offset()) {

    assert(_cw.is_valid(), "invariant");

  }

  bool process() {

    // invocation

    _content_functor.process();

    _end_time = JfrTicks::now();

    return 0 != _content_functor.elements();

  }

  const JfrTicks& start_time() const {

    return _start_time;

  }

  const JfrTicks& end_time() const {

    return _end_time;

  }

  int64_t start_offset() const {

    return _start_offset;

  }

  int64_t end_offset() const {

    return current_offset();

  }

  int64_t current_offset() const {

    return _cw.current_offset();

  }

  u4 elements() const {

    return (u4) _content_functor.elements();

  }

  u4 size() const {

    return (u4)(end_offset() - start_offset());

  }

  static bool is_event_enabled() {

    return EventType::is_enabled();

  }

  static u8 event_id() {

    return EventType::eventId;

  }

  void write_elements(int64_t offset) {

    _cw.write_padded_at_offset<u4>(elements(), offset);

  }

  void write_size() {

    _cw.write_padded_at_offset<u4>(size(), start_offset());

  }

  void set_last_checkpoint() {

    _cw.set_last_checkpoint_offset(start_offset());

  }

  void rewind() {

    _cw.seek(start_offset());

  }

};

static int64_t write_checkpoint_event_prologue(JfrChunkWriter& cw, u8 type_id) {

  const int64_t last_cp_offset = cw.last_checkpoint_offset();

  const int64_t last_cp_relative_offset = 0 == last_cp_offset ? 0 : last_cp_offset - cw.current_offset();

  cw.reserve(sizeof(u4));

  cw.write<u8>(EVENT_CHECKPOINT);

  cw.write(JfrTicks::now());

  cw.write<int64_t>((int64_t)0);

  cw.write(last_cp_relative_offset); // write last checkpoint offset delta

  cw.write<bool>(false); // flushpoint

  cw.write<u4>((u4)1); // nof types in this checkpoint

  cw.write<u8>(type_id);

  const int64_t number_of_elements_offset = cw.current_offset();

  cw.reserve(sizeof(u4));

  return number_of_elements_offset;

}

template <typename ContentFunctor>

class WriteSubsystemCheckpointEvent : public WriteSubsystem<ContentFunctor> {

 private:

  const u8 _type_id;

 public:

  WriteSubsystemCheckpointEvent(JfrChunkWriter& cw, ContentFunctor& functor, u8 type_id) :

    WriteSubsystem<ContentFunctor>(cw, functor), _type_id(type_id) {}

  bool process() {

    const int64_t num_elements_offset = write_checkpoint_event_prologue(this->_cw, _type_id);

    if (!WriteSubsystem<ContentFunctor>::process()) {

      // nothing to do, rewind writer to start

      this->rewind();

      assert(this->current_offset() == this->start_offset(), "invariant");

      return false;

    }

    assert(this->elements() > 0, "invariant");

    assert(this->current_offset() > num_elements_offset, "invariant");

    this->write_elements(num_elements_offset);

    this->write_size();

    this->set_last_checkpoint();

    return true;

  }

};

template <typename Functor>

static void write_flush_event(Functor& f) {

  if (Functor::is_event_enabled()) {

    typename Functor::EventType e(UNTIMED);

    e.set_starttime(f.start_time());

    e.set_endtime(f.end_time());

    e.set_flushId(flushpoint_id);

    e.set_elements(f.elements());

    e.set_size(f.size());

    e.commit();

  }

}

template <typename Functor>

static u4 invoke(Functor& f) {

  f.process();

  return f.elements();

}

template <typename Functor>

static u4 invoke_with_flush_event(Functor& f) {

  const u4 elements = invoke(f);

  return elements;

}

template <typename Instance, void(Instance::*func)()>

class JfrVMOperation : public VM_Operation {

 private:

  Instance& _instance;

 public:

  JfrVMOperation(Instance& instance) : _instance(instance) {}

  void doit() { (_instance.*func)(); }

  VMOp_Type type() const { return VMOp_JFRCheckpoint; }

  Mode evaluation_mode() const { return _safepoint; } // default

};

class FlushStackTraceRepository : public StackObj {

 private:

  JfrStackTraceRepository& _repo;

  JfrChunkWriter& _cw;

  size_t _elements;

  bool _clear;

 public:

  typedef EventFlushStacktrace EventType;

  FlushStackTraceRepository(JfrStackTraceRepository& repo, JfrChunkWriter& cw, bool clear) :

    _repo(repo), _cw(cw), _elements(0), _clear(clear) {}

  bool process() {

    _elements = _repo.write(_cw, _clear);

    return true;

  }

  size_t elements() const { return _elements; }

  void reset() { _elements = 0; }

};

class FlushMetadataEvent : public StackObj {

 private:

  JfrChunkWriter& _cw;

 public:

  typedef EventFlushMetadata EventType;

  FlushMetadataEvent(JfrChunkWriter& cw) : _cw(cw) {}

  bool process() {

    JfrMetadataEvent::write(_cw);

    return true;

  }

  size_t elements() const { return 1; }

};

static bool recording = false;

static void set_recording_state(bool is_recording) {

  OrderAccess::storestore();

  recording = is_recording;

}

bool JfrRecorderService::is_recording() {

  return recording;

}

JfrRecorderService::JfrRecorderService() :

  _checkpoint_manager(JfrCheckpointManager::instance()),

  _chunkwriter(JfrRepository::chunkwriter()),

  _repository(JfrRepository::instance()),

  _stack_trace_repository(JfrStackTraceRepository::instance()),

  _storage(JfrStorage::instance()),

  _string_pool(JfrStringPool::instance()) {}

void JfrRecorderService::start() {

  RotationLock rl(Thread::current());

  if (rl.not_acquired()) {

    return;

  }

  log_debug(jfr, system)("Request to START recording");

  assert(!is_recording(), "invariant");

  clear();

  set_recording_state(true);

  assert(is_recording(), "invariant");

  open_new_chunk();

  log_debug(jfr, system)("Recording STARTED");

}

void JfrRecorderService::clear() {

  ResourceMark rm;

  HandleMark hm;

  pre_safepoint_clear();

  invoke_safepoint_clear();

  post_safepoint_clear();

}

void JfrRecorderService::pre_safepoint_clear() {

  _stack_trace_repository.clear();

  _string_pool.clear();

  _storage.clear();

}

void JfrRecorderService::invoke_safepoint_clear() {

  JfrVMOperation<JfrRecorderService, &JfrRecorderService::safepoint_clear> safepoint_task(*this);

  VMThread::execute(&safepoint_task);

}

//

// safepoint clear sequence

//

//  clear stacktrace repository ->

//    clear string pool ->

//      clear storage ->

//        shift epoch ->

//          update time

//

void JfrRecorderService::safepoint_clear() {

  assert(SafepointSynchronize::is_at_safepoint(), "invariant");

  _stack_trace_repository.clear();

  _string_pool.clear();

  _storage.clear();

  _checkpoint_manager.shift_epoch();

  _chunkwriter.time_stamp_chunk_now();

}

void JfrRecorderService::post_safepoint_clear() {

  _checkpoint_manager.clear();

}

static void stop() {

  assert(JfrRecorderService::is_recording(), "invariant");

  log_debug(jfr, system)("Recording STOPPED");

  set_recording_state(false);

  assert(!JfrRecorderService::is_recording(), "invariant");

}

void JfrRecorderService::rotate(int msgs) {

  RotationLock rl(Thread::current());

  if (rl.not_acquired()) {

    return;

  }

  static bool vm_error = false;

  if (msgs & MSGBIT(MSG_VM_ERROR)) {

    vm_error = true;

    prepare_for_vm_error_rotation();

  }

  if (!_storage.control().to_disk()) {

    in_memory_rotation();

  } else if (vm_error) {

    vm_error_rotation();

  } else {

    chunk_rotation();

  }

  if (msgs & (MSGBIT(MSG_STOP))) {

    stop();

  }

}

void JfrRecorderService::prepare_for_vm_error_rotation() {

  if (!_chunkwriter.is_valid()) {

    open_new_chunk(true);

  }

  _checkpoint_manager.register_service_thread(Thread::current());

}

void JfrRecorderService::open_new_chunk(bool vm_error) {

  JfrChunkRotation::on_rotation();

  const bool valid_chunk = _repository.open_chunk(vm_error);

  _storage.control().set_to_disk(valid_chunk);

  if (valid_chunk) {

    _checkpoint_manager.write_constants();

  }

}

void JfrRecorderService::in_memory_rotation() {

  // currently running an in-memory recording

  assert(!_storage.control().to_disk(), "invariant");

  open_new_chunk();

  if (_chunkwriter.is_valid()) {

    // dump all in-memory buffer data to the newly created chunk

    serialize_storage_from_in_memory_recording();

  }

}

void JfrRecorderService::serialize_storage_from_in_memory_recording() {

  _storage.write();

}

void JfrRecorderService::chunk_rotation() {

  finalize_current_chunk();

  open_new_chunk();

}

void JfrRecorderService::finalize_current_chunk() {

  assert(_chunkwriter.is_valid(), "invariant");

  write();

}

void JfrRecorderService::write() {

  ResourceMark rm;

  HandleMark hm;

  pre_safepoint_write();

  invoke_safepoint_write();

  post_safepoint_write();

}

typedef ServiceFunctor<EventFlushStringPool, JfrStringPool, &JfrStringPool::write> FlushStringPoolFunctor;

typedef ServiceFunctor<EventFlushStringPool, JfrStringPool, &JfrStringPool::write_at_safepoint> FlushStringPoolSafepointFunctor;

typedef WriteSubsystemCheckpointEvent<FlushStackTraceRepository> FlushStackTraceCheckpoint;

typedef WriteSubsystemCheckpointEvent<FlushStringPoolFunctor> FlushStringPoolCheckpoint;

typedef WriteSubsystemCheckpointEvent<FlushStringPoolSafepointFunctor> FlushStringPoolCheckpointSafepoint;

static u4 flush_stacktrace(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter, bool clear) {

  FlushStackTraceRepository flush_stacktrace_repo(stack_trace_repo, chunkwriter, clear);

  FlushStackTraceCheckpoint flush_stack_trace_checkpoint(chunkwriter, flush_stacktrace_repo, TYPE_STACKTRACE);

  return invoke_with_flush_event(flush_stack_trace_checkpoint);

}

static u4 flush_stacktrace(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter) {

  return flush_stacktrace(stack_trace_repo, chunkwriter, false);

}