/*
 * Copyright (c) 2014, 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
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 * questions.
 */

#include "precompiled.hpp"
#include "gc/g1/bufferingOopClosure.hpp"
#include "memory/iterator.hpp"
#include "unittest.hpp"

class BufferingOopClosureTest : public ::testing::Test {
 public:
  // Helper class to fake a set of oop*s and narrowOop*s.
  class FakeRoots {
   public:
    // Used for sanity checking of the values passed to the do_oops functions in the test.
    static const uintptr_t NarrowOopMarker = uintptr_t(1) << (BitsPerWord -1);

    int    _num_narrow;
    int    _num_full;
    void** _narrow;
    void** _full;

    FakeRoots(int num_narrow, int num_full) :
        _num_narrow(num_narrow),
        _num_full(num_full),
        _narrow((void**)::malloc(sizeof(void*) * num_narrow)),
        _full((void**)::malloc(sizeof(void*) * num_full)) {

      for (int i = 0; i < num_narrow; i++) {
        _narrow[i] = (void*)(NarrowOopMarker + (uintptr_t)i);
      }
      for (int i = 0; i < num_full; i++) {
        _full[i] = (void*)(uintptr_t)i;
      }
    }

    ~FakeRoots() {
      ::free(_narrow);
      ::free(_full);
    }

    void oops_do_narrow_then_full(OopClosure* cl) {
      for (int i = 0; i < _num_narrow; i++) {
        cl->do_oop((narrowOop*)_narrow[i]);
      }
      for (int i = 0; i < _num_full; i++) {
        cl->do_oop((oop*)_full[i]);
      }
    }

    void oops_do_full_then_narrow(OopClosure* cl) {
      for (int i = 0; i < _num_full; i++) {
        cl->do_oop((oop*)_full[i]);
      }
      for (int i = 0; i < _num_narrow; i++) {
        cl->do_oop((narrowOop*)_narrow[i]);
      }
    }

    void oops_do_mixed(OopClosure* cl) {
      int i;
      for (i = 0; i < _num_full && i < _num_narrow; i++) {
        cl->do_oop((oop*)_full[i]);
        cl->do_oop((narrowOop*)_narrow[i]);
      }
      for (int j = i; j < _num_full; j++) {
        cl->do_oop((oop*)_full[i]);
      }
      for (int j = i; j < _num_narrow; j++) {
        cl->do_oop((narrowOop*)_narrow[i]);
      }
    }

    static const int MaxOrder = 2;

    void oops_do(OopClosure* cl, int do_oop_order) {
      switch(do_oop_order) {
        case 0:
          oops_do_narrow_then_full(cl);
          break;
        case 1:
          oops_do_full_then_narrow(cl);
          break;
        case 2:
          oops_do_mixed(cl);
          break;
        default:
          oops_do_narrow_then_full(cl);
          break;
      }
    }
  };

  class CountOopClosure : public OopClosure {
    int _narrow_oop_count;
    int _full_oop_count;
   public:
    CountOopClosure() : _narrow_oop_count(0), _full_oop_count(0) {}
    void do_oop(narrowOop* p) {
      EXPECT_NE(uintptr_t(0), (uintptr_t(p) & FakeRoots::NarrowOopMarker))
              << "The narrowOop was unexpectedly not marked with the NarrowOopMarker";
      _narrow_oop_count++;
    }

    void do_oop(oop* p){
      EXPECT_EQ(uintptr_t(0), (uintptr_t(p) & FakeRoots::NarrowOopMarker))
              << "The oop was unexpectedly marked with the NarrowOopMarker";
      _full_oop_count++;
    }

    int narrow_oop_count() { return _narrow_oop_count; }
    int full_oop_count()   { return _full_oop_count; }
    int all_oop_count()    { return _narrow_oop_count + _full_oop_count; }
  };

  class DoNothingOopClosure : public OopClosure {
   public:
    void do_oop(narrowOop* p) {}
    void do_oop(oop* p)       {}
  };

  static void testCount(int num_narrow, int num_full, int do_oop_order) {
    FakeRoots fr(num_narrow, num_full);

    CountOopClosure coc;
    BufferingOopClosure boc(&coc);

    fr.oops_do(&boc, do_oop_order);

    boc.done();

    EXPECT_EQ(num_narrow, coc.narrow_oop_count()) << "when running testCount("
            << num_narrow << ", " << num_full << ", " << do_oop_order << ")";

    EXPECT_EQ(num_full, coc.full_oop_count()) << "when running testCount("
            << num_narrow << ", " << num_full << ", " << do_oop_order << ")";

    EXPECT_EQ(num_narrow + num_full, coc.all_oop_count()) << "when running testCount("
            << num_narrow << ", " << num_full << ", " << do_oop_order << ")";
  }

  static void testIsBufferEmptyOrFull(int num_narrow, int num_full, bool expect_empty, bool expect_full) {
    FakeRoots fr(num_narrow, num_full);

    DoNothingOopClosure cl;
    BufferingOopClosure boc(&cl);

    fr.oops_do(&boc, 0);

    EXPECT_EQ(expect_empty, boc.is_buffer_empty())
            << "when running testIsBufferEmptyOrFull("
            << num_narrow << ", " << num_full << ", "
            << expect_empty << ", " << expect_full << ")";

    EXPECT_EQ(expect_full, boc.is_buffer_full())
            << "when running testIsBufferEmptyOrFull("
            << num_narrow << ", " << num_full << ", "
            << expect_empty << ", " << expect_full << ")";
  }

  static void testEmptyAfterDone(int num_narrow, int num_full) {
    FakeRoots fr(num_narrow, num_full);

    DoNothingOopClosure cl;
    BufferingOopClosure boc(&cl);

    fr.oops_do(&boc, 0);

    // Make sure all get processed.
    boc.done();

    EXPECT_TRUE(boc.is_buffer_empty()) << "Should be empty after call to done()."
            << " testEmptyAfterDone(" << num_narrow << ", " << num_full << ")";
  }

  static int get_buffer_length() {
    return BufferingOopClosure::BufferLength;
  }
};

TEST_VM_F(BufferingOopClosureTest, count_test) {
  int bl = BufferingOopClosureTest::get_buffer_length();

  for (int order = 0; order < FakeRoots::MaxOrder; order++) {
    testCount(0,      0,      order);
    testCount(10,     0,      order);
    testCount(0,      10,     order);
    testCount(10,     10,     order);
    testCount(bl,     10,     order);
    testCount(10,     bl,     order);
    testCount(bl,     bl,     order);
    testCount(bl + 1, 10,     order);
    testCount(10,     bl + 1, order);
    testCount(bl + 1, bl,     order);
    testCount(bl,     bl + 1, order);
    testCount(bl + 1, bl + 1, order);
  }
}

TEST_VM_F(BufferingOopClosureTest, buffer_empty_or_full) {
  int bl = BufferingOopClosureTest::get_buffer_length();

  testIsBufferEmptyOrFull(0,      0,      true,  false);
  testIsBufferEmptyOrFull(1,      0,      false, false);
  testIsBufferEmptyOrFull(0,      1,      false, false);
  testIsBufferEmptyOrFull(1,      1,      false, false);
  testIsBufferEmptyOrFull(10,     0,      false, false);
  testIsBufferEmptyOrFull(0,      10,     false, false);
  testIsBufferEmptyOrFull(10,     10,     false, false);
  testIsBufferEmptyOrFull(0,      bl,     false, true);
  testIsBufferEmptyOrFull(bl,     0,      false, true);
  testIsBufferEmptyOrFull(bl / 2, bl / 2, false, true);
  testIsBufferEmptyOrFull(bl - 1, 1,      false, true);
  testIsBufferEmptyOrFull(1,      bl - 1, false, true);
  // Processed
  testIsBufferEmptyOrFull(bl + 1, 0,      false, false);
  testIsBufferEmptyOrFull(bl * 2, 0,      false, true);
}

TEST_VM_F(BufferingOopClosureTest, empty_after_done) {
  int bl = BufferingOopClosureTest::get_buffer_length();

  testEmptyAfterDone(0,      0);
  testEmptyAfterDone(1,      0);
  testEmptyAfterDone(0,      1);
  testEmptyAfterDone(1,      1);
  testEmptyAfterDone(10,     0);
  testEmptyAfterDone(0,      10);
  testEmptyAfterDone(10,     10);
  testEmptyAfterDone(0,      bl);
  testEmptyAfterDone(bl,     0);
  testEmptyAfterDone(bl / 2, bl / 2);
  testEmptyAfterDone(bl - 1, 1);
  testEmptyAfterDone(1,      bl - 1);
  // Processed
  testEmptyAfterDone(bl + 1, 0);
  testEmptyAfterDone(bl * 2, 0);
}