/*

 * Copyright (c) 2001, 2016, 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 "gc/g1/concurrentG1Refine.hpp"

#include "gc/g1/concurrentG1RefineThread.hpp"

#include "gc/g1/g1YoungRemSetSamplingThread.hpp"

#include "logging/log.hpp"

#include "runtime/java.hpp"

#include "runtime/thread.hpp"

#include "utilities/debug.hpp"

#include "utilities/globalDefinitions.hpp"

#include "utilities/pair.hpp"

#include <math.h>

// Arbitrary but large limits, to simplify some of the zone calculations.

// The general idea is to allow expressions like

//   MIN2(x OP y, max_XXX_zone)

// without needing to check for overflow in "x OP y", because the

// ranges for x and y have been restricted.

STATIC_ASSERT(sizeof(LP64_ONLY(jint) NOT_LP64(jshort)) <= (sizeof(size_t)/2));

const size_t max_yellow_zone = LP64_ONLY(max_jint) NOT_LP64(max_jshort);

const size_t max_green_zone = max_yellow_zone / 2;

const size_t max_red_zone = INT_MAX; // For dcqs.set_max_completed_queue.

STATIC_ASSERT(max_yellow_zone <= max_red_zone);

// Range check assertions for green zone values.

#define assert_zone_constraints_g(green)                        \

  do {                                                          \

    size_t azc_g_green = (green);                               \

    assert(azc_g_green <= max_green_zone,                       \

           "green exceeds max: " SIZE_FORMAT, azc_g_green);     \

  } while (0)

// Range check assertions for green and yellow zone values.

#define assert_zone_constraints_gy(green, yellow)                       \

  do {                                                                  \

    size_t azc_gy_green = (green);                                      \

    size_t azc_gy_yellow = (yellow);                                    \

    assert_zone_constraints_g(azc_gy_green);                            \

    assert(azc_gy_yellow <= max_yellow_zone,                            \

           "yellow exceeds max: " SIZE_FORMAT, azc_gy_yellow);          \

    assert(azc_gy_green <= azc_gy_yellow,                               \

           "green (" SIZE_FORMAT ") exceeds yellow (" SIZE_FORMAT ")",  \

           azc_gy_green, azc_gy_yellow);                                \

  } while (0)

// Range check assertions for green, yellow, and red zone values.

#define assert_zone_constraints_gyr(green, yellow, red)                 \

  do {                                                                  \

    size_t azc_gyr_green = (green);                                     \

    size_t azc_gyr_yellow = (yellow);                                   \

    size_t azc_gyr_red = (red);                                         \

    assert_zone_constraints_gy(azc_gyr_green, azc_gyr_yellow);          \

    assert(azc_gyr_red <= max_red_zone,                                 \

           "red exceeds max: " SIZE_FORMAT, azc_gyr_red);               \

    assert(azc_gyr_yellow <= azc_gyr_red,                               \

           "yellow (" SIZE_FORMAT ") exceeds red (" SIZE_FORMAT ")",    \

           azc_gyr_yellow, azc_gyr_red);                                \

  } while (0)

// Logging tag sequence for refinement control updates.

#define CTRL_TAGS gc, ergo, refine

// For logging zone values, ensuring consistency of level and tags.

#define LOG_ZONES(...) log_debug( CTRL_TAGS )(__VA_ARGS__)

// Package for pair of refinement thread activation and deactivation

// thresholds.  The activation and deactivation levels are resp. the first

// and second values of the pair.

typedef Pair<size_t, size_t> Thresholds;

inline size_t activation_level(const Thresholds& t) { return t.first; }

inline size_t deactivation_level(const Thresholds& t) { return t.second; }

static Thresholds calc_thresholds(size_t green_zone,

                                  size_t yellow_zone,

                                  uint worker_i) {

  double yellow_size = yellow_zone - green_zone;

  double step = yellow_size / ConcurrentG1Refine::thread_num();

  if (worker_i == 0) {

    // Potentially activate worker 0 more aggressively, to keep

    // available buffers near green_zone value.  When yellow_size is

    // large we don't want to allow a full step to accumulate before

    // doing any processing, as that might lead to significantly more

    // than green_zone buffers to be processed by update_rs.

    step = MIN2(step, ParallelGCThreads / 2.0);

  }

  size_t activate_offset = static_cast<size_t>(ceil(step * (worker_i + 1)));

  size_t deactivate_offset = static_cast<size_t>(floor(step * worker_i));

  return Thresholds(green_zone + activate_offset,

                    green_zone + deactivate_offset);

}

ConcurrentG1Refine::ConcurrentG1Refine(size_t green_zone,

                                       size_t yellow_zone,

                                       size_t red_zone,

                                       size_t min_yellow_zone_size) :

  _threads(NULL),

  _sample_thread(NULL),

  _n_worker_threads(thread_num()),

  _green_zone(green_zone),

  _yellow_zone(yellow_zone),

  _red_zone(red_zone),

  _min_yellow_zone_size(min_yellow_zone_size)

{

  assert_zone_constraints_gyr(green_zone, yellow_zone, red_zone);

}

static size_t calc_min_yellow_zone_size() {

  size_t step = G1ConcRefinementThresholdStep;

  uint n_workers = ConcurrentG1Refine::thread_num();

  if ((max_yellow_zone / step) < n_workers) {

    return max_yellow_zone;

  } else {

    return step * n_workers;

  }

}

static size_t calc_init_green_zone() {

  size_t green = G1ConcRefinementGreenZone;

  if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) {

    green = ParallelGCThreads;

  }

  return MIN2(green, max_green_zone);

}

static size_t calc_init_yellow_zone(size_t green, size_t min_size) {

  size_t config = G1ConcRefinementYellowZone;

  size_t size = 0;

  if (FLAG_IS_DEFAULT(G1ConcRefinementYellowZone)) {

    size = green * 2;

  } else if (green < config) {

    size = config - green;

  }

  size = MAX2(size, min_size);

  size = MIN2(size, max_yellow_zone);

  return MIN2(green + size, max_yellow_zone);

}

static size_t calc_init_red_zone(size_t green, size_t yellow) {

  size_t size = yellow - green;

  if (!FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) {

    size_t config = G1ConcRefinementRedZone;

    if (yellow < config) {

      size = MAX2(size, config - yellow);

    }

  }

  return MIN2(yellow + size, max_red_zone);

}

ConcurrentG1Refine* ConcurrentG1Refine::create(jint* ecode) {

  size_t min_yellow_zone_size = calc_min_yellow_zone_size();

  size_t green_zone = calc_init_green_zone();

  size_t yellow_zone = calc_init_yellow_zone(green_zone, min_yellow_zone_size);

  size_t red_zone = calc_init_red_zone(green_zone, yellow_zone);

  LOG_ZONES("Initial Refinement Zones: "

            "green: " SIZE_FORMAT ", "

            "yellow: " SIZE_FORMAT ", "

            "red: " SIZE_FORMAT ", "

            "min yellow size: " SIZE_FORMAT,

            green_zone, yellow_zone, red_zone, min_yellow_zone_size);

  ConcurrentG1Refine* cg1r = new ConcurrentG1Refine(green_zone,

                                                    yellow_zone,

                                                    red_zone,

                                                    min_yellow_zone_size);

  if (cg1r == NULL) {

    *ecode = JNI_ENOMEM;

    vm_shutdown_during_initialization("Could not create ConcurrentG1Refine");

    return NULL;

  }

  cg1r->_threads = NEW_C_HEAP_ARRAY_RETURN_NULL(ConcurrentG1RefineThread*, cg1r->_n_worker_threads, mtGC);

  if (cg1r->_threads == NULL) {

    *ecode = JNI_ENOMEM;

    vm_shutdown_during_initialization("Could not allocate an array for ConcurrentG1RefineThread");

    return NULL;

  }

  uint worker_id_offset = DirtyCardQueueSet::num_par_ids();

  ConcurrentG1RefineThread *next = NULL;

  for (uint i = cg1r->_n_worker_threads - 1; i != UINT_MAX; i--) {

    Thresholds thresholds = calc_thresholds(green_zone, yellow_zone, i);

    ConcurrentG1RefineThread* t =

      new ConcurrentG1RefineThread(cg1r,

                                   next,

                                   worker_id_offset,

                                   i,

                                   activation_level(thresholds),

                                   deactivation_level(thresholds));

    assert(t != NULL, "Conc refine should have been created");

    if (t->osthread() == NULL) {

      *ecode = JNI_ENOMEM;

      vm_shutdown_during_initialization("Could not create ConcurrentG1RefineThread");

      return NULL;

    }

    assert(t->cg1r() == cg1r, "Conc refine thread should refer to this");

    cg1r->_threads[i] = t;

    next = t;

  }

  cg1r->_sample_thread = new G1YoungRemSetSamplingThread();

  if (cg1r->_sample_thread->osthread() == NULL) {

    *ecode = JNI_ENOMEM;

    vm_shutdown_during_initialization("Could not create G1YoungRemSetSamplingThread");

    return NULL;

  }

  *ecode = JNI_OK;

  return cg1r;

}

void ConcurrentG1Refine::stop() {

  for (uint i = 0; i < _n_worker_threads; i++) {

    _threads[i]->stop();

  }

  _sample_thread->stop();

}

void ConcurrentG1Refine::update_thread_thresholds() {

  for (uint i = 0; i < _n_worker_threads; i++) {

    Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, i);

    _threads[i]->update_thresholds(activation_level(thresholds),

                                   deactivation_level(thresholds));

  }

}

ConcurrentG1Refine::~ConcurrentG1Refine() {

  for (uint i = 0; i < _n_worker_threads; i++) {

    delete _threads[i];

  }

  FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads);

  delete _sample_thread;

}

void ConcurrentG1Refine::threads_do(ThreadClosure *tc) {

  worker_threads_do(tc);

  tc->do_thread(_sample_thread);

}

void ConcurrentG1Refine::worker_threads_do(ThreadClosure * tc) {

  for (uint i = 0; i < _n_worker_threads; i++) {

    tc->do_thread(_threads[i]);

  }

}

uint ConcurrentG1Refine::thread_num() {

  return G1ConcRefinementThreads;

}

void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {

  for (uint i = 0; i < _n_worker_threads; ++i) {

    _threads[i]->print_on(st);

    st->cr();

  }

  _sample_thread->print_on(st);

  st->cr();

}

static size_t calc_new_green_zone(size_t green,

                                  double update_rs_time,

                                  size_t update_rs_processed_buffers,

                                  double goal_ms) {

  // Adjust green zone based on whether we're meeting the time goal.

  // Limit to max_green_zone.

  const double inc_k = 1.1, dec_k = 0.9;

  if (update_rs_time > goal_ms) {

    if (green > 0) {

      green = static_cast<size_t>(green * dec_k);

    }

  } else if (update_rs_time < goal_ms &&

             update_rs_processed_buffers > green) {

    green = static_cast<size_t>(MAX2(green * inc_k, green + 1.0));

    green = MIN2(green, max_green_zone);

  }

  return green;

}

static size_t calc_new_yellow_zone(size_t green, size_t min_yellow_size) {

  size_t size = green * 2;

  size = MAX2(size, min_yellow_size);

  return MIN2(green + size, max_yellow_zone);

}

static size_t calc_new_red_zone(size_t green, size_t yellow) {

  return MIN2(yellow + (yellow - green), max_red_zone);

}

void ConcurrentG1Refine::update_zones(double update_rs_time,

                                      size_t update_rs_processed_buffers,

                                      double goal_ms) {

  log_trace( CTRL_TAGS )("Updating Refinement Zones: "

                         "update_rs time: %.3fms, "

                         "update_rs buffers: " SIZE_FORMAT ", "

                         "update_rs goal time: %.3fms",

                         update_rs_time,

                         update_rs_processed_buffers,

                         goal_ms);

  _green_zone = calc_new_green_zone(_green_zone,

                                    update_rs_time,

                                    update_rs_processed_buffers,

                                    goal_ms);

  _yellow_zone = calc_new_yellow_zone(_green_zone, _min_yellow_zone_size);

  _red_zone = calc_new_red_zone(_green_zone, _yellow_zone);

  assert_zone_constraints_gyr(_green_zone, _yellow_zone, _red_zone);

  LOG_ZONES("Updated Refinement Zones: "

            "green: " SIZE_FORMAT ", "

            "yellow: " SIZE_FORMAT ", "

            "red: " SIZE_FORMAT,

            _green_zone, _yellow_zone, _red_zone);

}

void ConcurrentG1Refine::adjust(double update_rs_time,

                                size_t update_rs_processed_buffers,

                                double goal_ms) {

  DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();

  if (G1UseAdaptiveConcRefinement) {

    update_zones(update_rs_time, update_rs_processed_buffers, goal_ms);

    update_thread_thresholds();

    // Change the barrier params

    if (_n_worker_threads == 0) {

      // Disable dcqs notification when there are no threads to notify.

      dcqs.set_process_completed_threshold(INT_MAX);

    } else {

      // Worker 0 is the primary; wakeup is via dcqs notification.

      STATIC_ASSERT(max_yellow_zone <= INT_MAX);

      size_t activate = _threads[0]->activation_threshold();

      dcqs.set_process_completed_threshold((int)activate);

    }

    dcqs.set_max_completed_queue((int)red_zone());

  }

  size_t curr_queue_size = dcqs.completed_buffers_num();

  if (curr_queue_size >= yellow_zone()) {

    dcqs.set_completed_queue_padding(curr_queue_size);

  } else {

    dcqs.set_completed_queue_padding(0);

  }

  dcqs.notify_if_necessary();

}