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view src/share/vm/gc_implementation/g1/g1BiasedArray.hpp @ 17546:46fa2940e686 jdk8u5-b07
Merge
author | asaha |
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date | Sun, 02 Feb 2014 22:45:03 -0800 |
parents | a19bea467577 |
children | e9fc29d2e8ae 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. * */ #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP #include "utilities/debug.hpp" #include "memory/allocation.inline.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) { assert(length > 0, "just checking"); assert(elem_size > 0, "just checking"); return NEW_C_HEAP_ARRAY(u_char, length * elem_size, mtGC); } // 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, err_msg("Shifting by %zd, 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), err_msg("mapping granularity must be power of 2, is %zd", mapping_granularity_in_bytes)); assert((uintptr_t)bottom % mapping_granularity_in_bytes == 0, err_msg("bottom mapping area address must be a multiple of mapping granularity %zd, is "PTR_FORMAT, mapping_granularity_in_bytes, bottom)); assert((uintptr_t)end % mapping_granularity_in_bytes == 0, err_msg("end mapping area address must be a multiple of mapping granularity %zd, is "PTR_FORMAT, mapping_granularity_in_bytes, end)); size_t num_target_elems = (end - bottom) / (mapping_granularity_in_bytes / HeapWordSize); 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 T> 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]; } // 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; } 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_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP