1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/g1/g1BiasedArray.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,177 @@
1.4 +/*
1.5 + * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP
1.30 +
1.31 +#include "memory/allocation.hpp"
1.32 +#include "utilities/debug.hpp"
1.33 +
1.34 +// Implements the common base functionality for arrays that contain provisions
1.35 +// for accessing its elements using a biased index.
1.36 +// The element type is defined by the instantiating the template.
1.37 +class G1BiasedMappedArrayBase VALUE_OBJ_CLASS_SPEC {
1.38 + friend class VMStructs;
1.39 +public:
1.40 + typedef size_t idx_t;
1.41 +protected:
1.42 + address _base; // the real base address
1.43 + size_t _length; // the length of the array
1.44 + address _biased_base; // base address biased by "bias" elements
1.45 + size_t _bias; // the bias, i.e. the offset biased_base is located to the right in elements
1.46 + uint _shift_by; // the amount of bits to shift right when mapping to an index of the array.
1.47 +
1.48 +protected:
1.49 +
1.50 + G1BiasedMappedArrayBase() : _base(NULL), _length(0), _biased_base(NULL),
1.51 + _bias(0), _shift_by(0) { }
1.52 +
1.53 + // Allocate a new array, generic version.
1.54 + static address create_new_base_array(size_t length, size_t elem_size);
1.55 +
1.56 + // Initialize the members of this class. The biased start address of this array
1.57 + // is the bias (in elements) multiplied by the element size.
1.58 + void initialize_base(address base, size_t length, size_t bias, size_t elem_size, uint shift_by) {
1.59 + assert(base != NULL, "just checking");
1.60 + assert(length > 0, "just checking");
1.61 + assert(shift_by < sizeof(uintptr_t) * 8, err_msg("Shifting by " SSIZE_FORMAT ", larger than word size?", (size_t) shift_by));
1.62 + _base = base;
1.63 + _length = length;
1.64 + _biased_base = base - (bias * elem_size);
1.65 + _bias = bias;
1.66 + _shift_by = shift_by;
1.67 + }
1.68 +
1.69 + // Allocate and initialize this array to cover the heap addresses in the range
1.70 + // of [bottom, end).
1.71 + void initialize(HeapWord* bottom, HeapWord* end, size_t target_elem_size_in_bytes, size_t mapping_granularity_in_bytes) {
1.72 + assert(mapping_granularity_in_bytes > 0, "just checking");
1.73 + assert(is_power_of_2(mapping_granularity_in_bytes),
1.74 + err_msg("mapping granularity must be power of 2, is %zd", mapping_granularity_in_bytes));
1.75 + assert((uintptr_t)bottom % mapping_granularity_in_bytes == 0,
1.76 + err_msg("bottom mapping area address must be a multiple of mapping granularity %zd, is " PTR_FORMAT,
1.77 + mapping_granularity_in_bytes, p2i(bottom)));
1.78 + assert((uintptr_t)end % mapping_granularity_in_bytes == 0,
1.79 + err_msg("end mapping area address must be a multiple of mapping granularity %zd, is " PTR_FORMAT,
1.80 + mapping_granularity_in_bytes, p2i(end)));
1.81 + size_t num_target_elems = (end - bottom) / (mapping_granularity_in_bytes / HeapWordSize);
1.82 + idx_t bias = (uintptr_t)bottom / mapping_granularity_in_bytes;
1.83 + address base = create_new_base_array(num_target_elems, target_elem_size_in_bytes);
1.84 + initialize_base(base, num_target_elems, bias, target_elem_size_in_bytes, log2_intptr(mapping_granularity_in_bytes));
1.85 + }
1.86 +
1.87 + size_t bias() const { return _bias; }
1.88 + uint shift_by() const { return _shift_by; }
1.89 +
1.90 + void verify_index(idx_t index) const PRODUCT_RETURN;
1.91 + void verify_biased_index(idx_t biased_index) const PRODUCT_RETURN;
1.92 + void verify_biased_index_inclusive_end(idx_t biased_index) const PRODUCT_RETURN;
1.93 +
1.94 +public:
1.95 + // Return the length of the array in elements.
1.96 + size_t length() const { return _length; }
1.97 +};
1.98 +
1.99 +// Array that provides biased access and mapping from (valid) addresses in the
1.100 +// heap into this array.
1.101 +template<class T>
1.102 +class G1BiasedMappedArray : public G1BiasedMappedArrayBase {
1.103 +public:
1.104 + typedef G1BiasedMappedArrayBase::idx_t idx_t;
1.105 +
1.106 + T* base() const { return (T*)G1BiasedMappedArrayBase::_base; }
1.107 + // Return the element of the given array at the given index. Assume
1.108 + // the index is valid. This is a convenience method that does sanity
1.109 + // checking on the index.
1.110 + T get_by_index(idx_t index) const {
1.111 + verify_index(index);
1.112 + return this->base()[index];
1.113 + }
1.114 +
1.115 + // Set the element of the given array at the given index to the
1.116 + // given value. Assume the index is valid. This is a convenience
1.117 + // method that does sanity checking on the index.
1.118 + void set_by_index(idx_t index, T value) {
1.119 + verify_index(index);
1.120 + this->base()[index] = value;
1.121 + }
1.122 +
1.123 + // The raw biased base pointer.
1.124 + T* biased_base() const { return (T*)G1BiasedMappedArrayBase::_biased_base; }
1.125 +
1.126 + // Return the element of the given array that covers the given word in the
1.127 + // heap. Assumes the index is valid.
1.128 + T get_by_address(HeapWord* value) const {
1.129 + idx_t biased_index = ((uintptr_t)value) >> this->shift_by();
1.130 + this->verify_biased_index(biased_index);
1.131 + return biased_base()[biased_index];
1.132 + }
1.133 +
1.134 + // Set the value of the array entry that corresponds to the given array.
1.135 + void set_by_address(HeapWord * address, T value) {
1.136 + idx_t biased_index = ((uintptr_t)address) >> this->shift_by();
1.137 + this->verify_biased_index(biased_index);
1.138 + biased_base()[biased_index] = value;
1.139 + }
1.140 +
1.141 +protected:
1.142 + // Returns the address of the element the given address maps to
1.143 + T* address_mapped_to(HeapWord* address) {
1.144 + idx_t biased_index = ((uintptr_t)address) >> this->shift_by();
1.145 + this->verify_biased_index_inclusive_end(biased_index);
1.146 + return biased_base() + biased_index;
1.147 + }
1.148 +
1.149 +public:
1.150 + // Return the smallest address (inclusive) in the heap that this array covers.
1.151 + HeapWord* bottom_address_mapped() const {
1.152 + return (HeapWord*) ((uintptr_t)this->bias() << this->shift_by());
1.153 + }
1.154 +
1.155 + // Return the highest address (exclusive) in the heap that this array covers.
1.156 + HeapWord* end_address_mapped() const {
1.157 + return (HeapWord*) ((uintptr_t)(this->bias() + this->length()) << this->shift_by());
1.158 + }
1.159 +
1.160 +protected:
1.161 + virtual T default_value() const = 0;
1.162 + // Set all elements of the given array to the given value.
1.163 + void clear() {
1.164 + T value = default_value();
1.165 + for (idx_t i = 0; i < length(); i++) {
1.166 + set_by_index(i, value);
1.167 + }
1.168 + }
1.169 +public:
1.170 + G1BiasedMappedArray() {}
1.171 +
1.172 + // Allocate and initialize this array to cover the heap addresses in the range
1.173 + // of [bottom, end).
1.174 + void initialize(HeapWord* bottom, HeapWord* end, size_t mapping_granularity) {
1.175 + G1BiasedMappedArrayBase::initialize(bottom, end, sizeof(T), mapping_granularity);
1.176 + this->clear();
1.177 + }
1.178 +};
1.179 +
1.180 +#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP
