view src/share/vm/gc_implementation/g1/g1BiasedArray.cpp @ 17635:cb7ec2423207

8027454: Do not traverse string table during G1 remark when treating them as strong roots during initial mark Summary: Do not try to unlink string table entries unconditionally during remark. This is without side effects as the preceding initial mark always uses the string table as strong roots. Needs to be fixed with class unloading during concurrent mark. Reviewed-by: brutisso, mgerdin
author tschatzl
date Mon, 20 Jan 2014 11:47:29 +0100
parents a19bea467577
children 5479cb006184
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/*
 * Copyright (c) 2013, 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_implementation/g1/g1BiasedArray.hpp"

#ifndef PRODUCT
void G1BiasedMappedArrayBase::verify_index(idx_t index) const {
  guarantee(_base != NULL, "Array not initialized");
  guarantee(index < length(), err_msg("Index out of bounds index: "SIZE_FORMAT" length: "SIZE_FORMAT, index, length()));
}

void G1BiasedMappedArrayBase::verify_biased_index(idx_t biased_index) const {
  guarantee(_biased_base != NULL, "Array not initialized");
  guarantee(biased_index >= bias() && biased_index < (bias() + length()),
    err_msg("Biased index out of bounds, index: "SIZE_FORMAT" bias: "SIZE_FORMAT" length: "SIZE_FORMAT, biased_index, bias(), length()));
}

void G1BiasedMappedArrayBase::verify_biased_index_inclusive_end(idx_t biased_index) const {
  guarantee(_biased_base != NULL, "Array not initialized");
  guarantee(biased_index >= bias() && biased_index <= (bias() + length()),
    err_msg("Biased index out of inclusive bounds, index: "SIZE_FORMAT" bias: "SIZE_FORMAT" length: "SIZE_FORMAT, biased_index, bias(), length()));
}

class TestMappedArray : public G1BiasedMappedArray<int> {
protected:
  virtual int default_value() const { return 0xBAADBABE; }
public:
  static void test_biasedarray() {
    const size_t REGION_SIZE_IN_WORDS = 512;
    const size_t NUM_REGIONS = 20;
    HeapWord* fake_heap = (HeapWord*)LP64_ONLY(0xBAAA00000) NOT_LP64(0xBA000000); // Any value that is non-zero

    TestMappedArray array;
    array.initialize(fake_heap, fake_heap + REGION_SIZE_IN_WORDS * NUM_REGIONS,
            REGION_SIZE_IN_WORDS * HeapWordSize);
    // Check address calculation (bounds)
    assert(array.bottom_address_mapped() == fake_heap,
      err_msg("bottom mapped address should be "PTR_FORMAT", but is "PTR_FORMAT, fake_heap, array.bottom_address_mapped()));
    assert(array.end_address_mapped() == (fake_heap + REGION_SIZE_IN_WORDS * NUM_REGIONS), "must be");

    int* bottom = array.address_mapped_to(fake_heap);
    assert((void*)bottom == (void*) array.base(), "must be");
    int* end = array.address_mapped_to(fake_heap + REGION_SIZE_IN_WORDS * NUM_REGIONS);
    assert((void*)end == (void*)(array.base() + array.length()), "must be");
    // The entire array should contain default value elements
    for (int* current = bottom; current < end; current++) {
      assert(*current == array.default_value(), "must be");
    }

    // Test setting values in the table

    HeapWord* region_start_address = fake_heap + REGION_SIZE_IN_WORDS * (NUM_REGIONS / 2);
    HeapWord* region_end_address = fake_heap + (REGION_SIZE_IN_WORDS * (NUM_REGIONS / 2) + REGION_SIZE_IN_WORDS - 1);

    // Set/get by address tests: invert some value; first retrieve one
    int actual_value = array.get_by_index(NUM_REGIONS / 2);
    array.set_by_index(NUM_REGIONS / 2, ~actual_value);
    // Get the same value by address, should correspond to the start of the "region"
    int value = array.get_by_address(region_start_address);
    assert(value == ~actual_value, "must be");
    // Get the same value by address, at one HeapWord before the start
    value = array.get_by_address(region_start_address - 1);
    assert(value == array.default_value(), "must be");
    // Get the same value by address, at the end of the "region"
    value = array.get_by_address(region_end_address);
    assert(value == ~actual_value, "must be");
    // Make sure the next value maps to another index
    value = array.get_by_address(region_end_address + 1);
    assert(value == array.default_value(), "must be");

    // Reset the value in the array
    array.set_by_address(region_start_address + (region_end_address - region_start_address) / 2, actual_value);

    // The entire array should have the default value again
    for (int* current = bottom; current < end; current++) {
      assert(*current == array.default_value(), "must be");
    }

    // Set/get by index tests: invert some value
    idx_t index = NUM_REGIONS / 2;
    actual_value = array.get_by_index(index);
    array.set_by_index(index, ~actual_value);

    value = array.get_by_index(index);
    assert(value == ~actual_value, "must be");

    value = array.get_by_index(index - 1);
    assert(value == array.default_value(), "must be");

    value = array.get_by_index(index + 1);
    assert(value == array.default_value(), "must be");

    array.set_by_index(0, 0);
    value = array.get_by_index(0);
    assert(value == 0, "must be");

    array.set_by_index(array.length() - 1, 0);
    value = array.get_by_index(array.length() - 1);
    assert(value == 0, "must be");

    array.set_by_index(index, 0);

    // The array should have three zeros, and default values otherwise
    size_t num_zeros = 0;
    for (int* current = bottom; current < end; current++) {
      assert(*current == array.default_value() || *current == 0, "must be");
      if (*current == 0) {
        num_zeros++;
      }
    }
    assert(num_zeros == 3, "must be");
  }
};

void TestG1BiasedArray_test() {
  TestMappedArray::test_biasedarray();
}

#endif