/*

 * Copyright (c) 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/g1CollectedHeap.inline.hpp"

#include "gc/g1/g1IHOPControl.hpp"

#include "gc/g1/g1Predictions.hpp"

#include "unittest.hpp"

static void test_update(G1IHOPControl* ctrl, double alloc_time,

                        size_t alloc_amount, size_t young_size,

                        double mark_time) {

  for (int i = 0; i < 100; i++) {

    ctrl->update_allocation_info(alloc_time, alloc_amount, young_size);

    ctrl->update_marking_length(mark_time);

  }

}

// @requires UseG1GC

TEST_VM(G1StaticIHOPControl, simple) {

  // Test requires G1

  if (!UseG1GC) {

    return;

  }

  const size_t initial_ihop = 45;

  G1StaticIHOPControl ctrl(initial_ihop);

  ctrl.update_target_occupancy(100);

  size_t threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(initial_ihop, threshold);

  ctrl.update_allocation_info(100.0, 100, 100);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(initial_ihop, threshold);

  ctrl.update_marking_length(1000.0);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(initial_ihop, threshold);

  // Whatever we pass, the IHOP value must stay the same.

  test_update(&ctrl, 2, 10, 10, 3);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(initial_ihop, threshold);

  test_update(&ctrl, 12, 10, 10, 3);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(initial_ihop, threshold);

}

// @requires UseG1GC

TEST_VM(G1AdaptiveIHOPControl, simple) {

  // Test requires G1

  if (!UseG1GC) {

    return;

  }

  const size_t initial_threshold = 45;

  const size_t young_size = 10;

  const size_t target_size = 100;

  // The final IHOP value is always

  // target_size - (young_size + alloc_amount/alloc_time * marking_time)

  G1Predictions pred(0.95);

  G1AdaptiveIHOPControl ctrl(initial_threshold, &pred, 0, 0);

  ctrl.update_target_occupancy(target_size);

  // First "load".

  const size_t alloc_time1 = 2;

  const size_t alloc_amount1 = 10;

  const size_t marking_time1 = 2;

  const size_t settled_ihop1 = target_size

          - (young_size + alloc_amount1 / alloc_time1 * marking_time1);

  size_t threshold;

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(initial_threshold, threshold);

  for (size_t i = 0; i < G1AdaptiveIHOPNumInitialSamples - 1; i++) {

    ctrl.update_allocation_info(alloc_time1, alloc_amount1, young_size);

    ctrl.update_marking_length(marking_time1);

    // Not enough data yet.

    threshold = ctrl.get_conc_mark_start_threshold();

    ASSERT_EQ(initial_threshold, threshold) << "on step " << i;

  }

  test_update(&ctrl, alloc_time1, alloc_amount1, young_size, marking_time1);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(settled_ihop1, threshold);

  // Second "load". A bit higher allocation rate.

  const size_t alloc_time2 = 2;

  const size_t alloc_amount2 = 30;

  const size_t marking_time2 = 2;

  const size_t settled_ihop2 = target_size

          - (young_size + alloc_amount2 / alloc_time2 * marking_time2);

  test_update(&ctrl, alloc_time2, alloc_amount2, young_size, marking_time2);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_LT(threshold, settled_ihop1);

  // Third "load". Very high (impossible) allocation rate.

  const size_t alloc_time3 = 1;

  const size_t alloc_amount3 = 50;

  const size_t marking_time3 = 2;

  const size_t settled_ihop3 = 0;

  test_update(&ctrl, alloc_time3, alloc_amount3, young_size, marking_time3);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_EQ(settled_ihop3, threshold);

  // And back to some arbitrary value.

  test_update(&ctrl, alloc_time2, alloc_amount2, young_size, marking_time2);

  threshold = ctrl.get_conc_mark_start_threshold();

  EXPECT_GT(threshold, settled_ihop3);

}