/*

 * 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 "jfr/jni/jfrJavaSupport.hpp"

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

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; }

};

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

  cw.reserve(sizeof(u4));

  cw.write<u8>(EVENT_CHECKPOINT);

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

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

  const int64_t number_of_elements_offset = cw.current_offset();

  cw.reserve(sizeof(u4));

  return number_of_elements_offset;

}

template <typename ContentFunctor>

 private:

 public:

  bool process() {

      // nothing to do, rewind writer to start

    }

    return true;

  }

};

  }

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

};

 private:

  JfrStackTraceRepository& _repo;

  JfrChunkWriter& _cw;

  bool _clear;

 public:

  bool process() {

    return true;

  }

};

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 (msgs & (MSGBIT(MSG_STOP))) {

    stop();

  }

    in_memory_rotation();

    return;

  }

  if (vm_error) {

    vm_error_rotation();

    return;

  }

  chunk_rotation();

}

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();

  }

}

void JfrRecorderService::in_memory_rotation() {

  // currently running an in-memory recording

  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();

}