diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/gc/g1/g1BiasedArray.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/gc/g1/g1BiasedArray.hpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,198 @@ +/* + * Copyright (c) 2013, 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. + * + */ + +#ifndef SHARE_VM_GC_G1_G1BIASEDARRAY_HPP +#define SHARE_VM_GC_G1_G1BIASEDARRAY_HPP + +#include "memory/allocation.hpp" +#include "memory/memRegion.hpp" +#include "utilities/debug.hpp" + +// Implements the common base functionality for arrays that contain provisions +// for accessing its elements using a biased index. +// The element type is defined by the instantiating the template. +class G1BiasedMappedArrayBase VALUE_OBJ_CLASS_SPEC { + friend class VMStructs; +public: + typedef size_t idx_t; +protected: + address _base; // the real base address + size_t _length; // the length of the array + address _biased_base; // base address biased by "bias" elements + size_t _bias; // the bias, i.e. the offset biased_base is located to the right in elements + uint _shift_by; // the amount of bits to shift right when mapping to an index of the array. + +protected: + + G1BiasedMappedArrayBase() : _base(NULL), _length(0), _biased_base(NULL), + _bias(0), _shift_by(0) { } + + // Allocate a new array, generic version. + static address create_new_base_array(size_t length, size_t elem_size); + + // Initialize the members of this class. The biased start address of this array + // is the bias (in elements) multiplied by the element size. + void initialize_base(address base, size_t length, size_t bias, size_t elem_size, uint shift_by) { + assert(base != NULL, "just checking"); + assert(length > 0, "just checking"); + assert(shift_by < sizeof(uintptr_t) * 8, "Shifting by %u, larger than word size?", shift_by); + _base = base; + _length = length; + _biased_base = base - (bias * elem_size); + _bias = bias; + _shift_by = shift_by; + } + + // Allocate and initialize this array to cover the heap addresses in the range + // of [bottom, end). + void initialize(HeapWord* bottom, HeapWord* end, size_t target_elem_size_in_bytes, size_t mapping_granularity_in_bytes) { + assert(mapping_granularity_in_bytes > 0, "just checking"); + assert(is_power_of_2(mapping_granularity_in_bytes), + "mapping granularity must be power of 2, is " SIZE_FORMAT, mapping_granularity_in_bytes); + assert((uintptr_t)bottom % mapping_granularity_in_bytes == 0, + "bottom mapping area address must be a multiple of mapping granularity " SIZE_FORMAT ", is " PTR_FORMAT, + mapping_granularity_in_bytes, p2i(bottom)); + assert((uintptr_t)end % mapping_granularity_in_bytes == 0, + "end mapping area address must be a multiple of mapping granularity " SIZE_FORMAT ", is " PTR_FORMAT, + mapping_granularity_in_bytes, p2i(end)); + size_t num_target_elems = pointer_delta(end, bottom, mapping_granularity_in_bytes); + idx_t bias = (uintptr_t)bottom / mapping_granularity_in_bytes; + address base = create_new_base_array(num_target_elems, target_elem_size_in_bytes); + initialize_base(base, num_target_elems, bias, target_elem_size_in_bytes, log2_intptr(mapping_granularity_in_bytes)); + } + + size_t bias() const { return _bias; } + uint shift_by() const { return _shift_by; } + + void verify_index(idx_t index) const PRODUCT_RETURN; + void verify_biased_index(idx_t biased_index) const PRODUCT_RETURN; + void verify_biased_index_inclusive_end(idx_t biased_index) const PRODUCT_RETURN; + +public: + // Return the length of the array in elements. + size_t length() const { return _length; } +}; + +// Array that provides biased access and mapping from (valid) addresses in the +// heap into this array. +template +class G1BiasedMappedArray : public G1BiasedMappedArrayBase { +public: + typedef G1BiasedMappedArrayBase::idx_t idx_t; + + T* base() const { return (T*)G1BiasedMappedArrayBase::_base; } + // Return the element of the given array at the given index. Assume + // the index is valid. This is a convenience method that does sanity + // checking on the index. + T get_by_index(idx_t index) const { + verify_index(index); + return this->base()[index]; + } + + // Set the element of the given array at the given index to the + // given value. Assume the index is valid. This is a convenience + // method that does sanity checking on the index. + void set_by_index(idx_t index, T value) { + verify_index(index); + this->base()[index] = value; + } + + // The raw biased base pointer. + T* biased_base() const { return (T*)G1BiasedMappedArrayBase::_biased_base; } + + // Return the element of the given array that covers the given word in the + // heap. Assumes the index is valid. + T get_by_address(HeapWord* value) const { + idx_t biased_index = ((uintptr_t)value) >> this->shift_by(); + this->verify_biased_index(biased_index); + return biased_base()[biased_index]; + } + + // Return the index of the element of the given array that covers the given + // word in the heap. + idx_t get_index_by_address(HeapWord* value) const { + idx_t biased_index = ((uintptr_t)value) >> this->shift_by(); + this->verify_biased_index(biased_index); + return biased_index - _bias; + } + + // Set the value of the array entry that corresponds to the given array. + void set_by_address(HeapWord * address, T value) { + idx_t biased_index = ((uintptr_t)address) >> this->shift_by(); + this->verify_biased_index(biased_index); + biased_base()[biased_index] = value; + } + + // Set the value of all array entries that correspond to addresses + // in the specified MemRegion. + void set_by_address(MemRegion range, T value) { + idx_t biased_start = ((uintptr_t)range.start()) >> this->shift_by(); + idx_t biased_last = ((uintptr_t)range.last()) >> this->shift_by(); + this->verify_biased_index(biased_start); + this->verify_biased_index(biased_last); + for (idx_t i = biased_start; i <= biased_last; i++) { + biased_base()[i] = value; + } + } + +protected: + // Returns the address of the element the given address maps to + T* address_mapped_to(HeapWord* address) { + idx_t biased_index = ((uintptr_t)address) >> this->shift_by(); + this->verify_biased_index_inclusive_end(biased_index); + return biased_base() + biased_index; + } + +public: + // Return the smallest address (inclusive) in the heap that this array covers. + HeapWord* bottom_address_mapped() const { + return (HeapWord*) ((uintptr_t)this->bias() << this->shift_by()); + } + + // Return the highest address (exclusive) in the heap that this array covers. + HeapWord* end_address_mapped() const { + return (HeapWord*) ((uintptr_t)(this->bias() + this->length()) << this->shift_by()); + } + +protected: + virtual T default_value() const = 0; + // Set all elements of the given array to the given value. + void clear() { + T value = default_value(); + for (idx_t i = 0; i < length(); i++) { + set_by_index(i, value); + } + } +public: + G1BiasedMappedArray() {} + + // Allocate and initialize this array to cover the heap addresses in the range + // of [bottom, end). + void initialize(HeapWord* bottom, HeapWord* end, size_t mapping_granularity) { + G1BiasedMappedArrayBase::initialize(bottom, end, sizeof(T), mapping_granularity); + this->clear(); + } +}; + +#endif // SHARE_VM_GC_G1_G1BIASEDARRAY_HPP