--- /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 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];
+ }
+
+ // 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