Mercurial > hg > truffle
comparison src/share/vm/gc_implementation/g1/g1BiasedArray.hpp @ 12305:a19bea467577
7163191: G1: introduce a "heap spanning table" abstraction
Summary: Add G1BiasedArray<T> that is an array where each element represents a fixed-sized subdivision of the heap. Use this abstraction to refactor the HeapRegionSeq class.
Reviewed-by: brutisso
author | tschatzl |
---|---|
date | Wed, 25 Sep 2013 13:25:24 +0200 |
parents | |
children | e9fc29d2e8ae 5479cb006184 |
comparison
equal
deleted
inserted
replaced
12304:10cc3b624f8f | 12305:a19bea467577 |
---|---|
1 /* | |
2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. | |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
20 * or visit www.oracle.com if you need additional information or have any | |
21 * questions. | |
22 * | |
23 */ | |
24 | |
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP | |
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP | |
27 | |
28 #include "utilities/debug.hpp" | |
29 #include "memory/allocation.inline.hpp" | |
30 | |
31 // Implements the common base functionality for arrays that contain provisions | |
32 // for accessing its elements using a biased index. | |
33 // The element type is defined by the instantiating the template. | |
34 class G1BiasedMappedArrayBase VALUE_OBJ_CLASS_SPEC { | |
35 friend class VMStructs; | |
36 public: | |
37 typedef size_t idx_t; | |
38 protected: | |
39 address _base; // the real base address | |
40 size_t _length; // the length of the array | |
41 address _biased_base; // base address biased by "bias" elements | |
42 size_t _bias; // the bias, i.e. the offset biased_base is located to the right in elements | |
43 uint _shift_by; // the amount of bits to shift right when mapping to an index of the array. | |
44 | |
45 protected: | |
46 | |
47 G1BiasedMappedArrayBase() : _base(NULL), _length(0), _biased_base(NULL), | |
48 _bias(0), _shift_by(0) { } | |
49 | |
50 // Allocate a new array, generic version. | |
51 static address create_new_base_array(size_t length, size_t elem_size) { | |
52 assert(length > 0, "just checking"); | |
53 assert(elem_size > 0, "just checking"); | |
54 return NEW_C_HEAP_ARRAY(u_char, length * elem_size, mtGC); | |
55 } | |
56 | |
57 // Initialize the members of this class. The biased start address of this array | |
58 // is the bias (in elements) multiplied by the element size. | |
59 void initialize_base(address base, size_t length, size_t bias, size_t elem_size, uint shift_by) { | |
60 assert(base != NULL, "just checking"); | |
61 assert(length > 0, "just checking"); | |
62 assert(shift_by < sizeof(uintptr_t) * 8, err_msg("Shifting by %zd, larger than word size?", shift_by)); | |
63 _base = base; | |
64 _length = length; | |
65 _biased_base = base - (bias * elem_size); | |
66 _bias = bias; | |
67 _shift_by = shift_by; | |
68 } | |
69 | |
70 // Allocate and initialize this array to cover the heap addresses in the range | |
71 // of [bottom, end). | |
72 void initialize(HeapWord* bottom, HeapWord* end, size_t target_elem_size_in_bytes, size_t mapping_granularity_in_bytes) { | |
73 assert(mapping_granularity_in_bytes > 0, "just checking"); | |
74 assert(is_power_of_2(mapping_granularity_in_bytes), | |
75 err_msg("mapping granularity must be power of 2, is %zd", mapping_granularity_in_bytes)); | |
76 assert((uintptr_t)bottom % mapping_granularity_in_bytes == 0, | |
77 err_msg("bottom mapping area address must be a multiple of mapping granularity %zd, is "PTR_FORMAT, | |
78 mapping_granularity_in_bytes, bottom)); | |
79 assert((uintptr_t)end % mapping_granularity_in_bytes == 0, | |
80 err_msg("end mapping area address must be a multiple of mapping granularity %zd, is "PTR_FORMAT, | |
81 mapping_granularity_in_bytes, end)); | |
82 size_t num_target_elems = (end - bottom) / (mapping_granularity_in_bytes / HeapWordSize); | |
83 idx_t bias = (uintptr_t)bottom / mapping_granularity_in_bytes; | |
84 address base = create_new_base_array(num_target_elems, target_elem_size_in_bytes); | |
85 initialize_base(base, num_target_elems, bias, target_elem_size_in_bytes, log2_intptr(mapping_granularity_in_bytes)); | |
86 } | |
87 | |
88 size_t bias() const { return _bias; } | |
89 uint shift_by() const { return _shift_by; } | |
90 | |
91 void verify_index(idx_t index) const PRODUCT_RETURN; | |
92 void verify_biased_index(idx_t biased_index) const PRODUCT_RETURN; | |
93 void verify_biased_index_inclusive_end(idx_t biased_index) const PRODUCT_RETURN; | |
94 | |
95 public: | |
96 // Return the length of the array in elements. | |
97 size_t length() const { return _length; } | |
98 }; | |
99 | |
100 // Array that provides biased access and mapping from (valid) addresses in the | |
101 // heap into this array. | |
102 template<class T> | |
103 class G1BiasedMappedArray : public G1BiasedMappedArrayBase { | |
104 public: | |
105 typedef G1BiasedMappedArrayBase::idx_t idx_t; | |
106 | |
107 T* base() const { return (T*)G1BiasedMappedArrayBase::_base; } | |
108 // Return the element of the given array at the given index. Assume | |
109 // the index is valid. This is a convenience method that does sanity | |
110 // checking on the index. | |
111 T get_by_index(idx_t index) const { | |
112 verify_index(index); | |
113 return this->base()[index]; | |
114 } | |
115 | |
116 // Set the element of the given array at the given index to the | |
117 // given value. Assume the index is valid. This is a convenience | |
118 // method that does sanity checking on the index. | |
119 void set_by_index(idx_t index, T value) { | |
120 verify_index(index); | |
121 this->base()[index] = value; | |
122 } | |
123 | |
124 // The raw biased base pointer. | |
125 T* biased_base() const { return (T*)G1BiasedMappedArrayBase::_biased_base; } | |
126 | |
127 // Return the element of the given array that covers the given word in the | |
128 // heap. Assumes the index is valid. | |
129 T get_by_address(HeapWord* value) const { | |
130 idx_t biased_index = ((uintptr_t)value) >> this->shift_by(); | |
131 this->verify_biased_index(biased_index); | |
132 return biased_base()[biased_index]; | |
133 } | |
134 | |
135 // Set the value of the array entry that corresponds to the given array. | |
136 void set_by_address(HeapWord * address, T value) { | |
137 idx_t biased_index = ((uintptr_t)address) >> this->shift_by(); | |
138 this->verify_biased_index(biased_index); | |
139 biased_base()[biased_index] = value; | |
140 } | |
141 | |
142 protected: | |
143 // Returns the address of the element the given address maps to | |
144 T* address_mapped_to(HeapWord* address) { | |
145 idx_t biased_index = ((uintptr_t)address) >> this->shift_by(); | |
146 this->verify_biased_index_inclusive_end(biased_index); | |
147 return biased_base() + biased_index; | |
148 } | |
149 | |
150 public: | |
151 // Return the smallest address (inclusive) in the heap that this array covers. | |
152 HeapWord* bottom_address_mapped() const { | |
153 return (HeapWord*) ((uintptr_t)this->bias() << this->shift_by()); | |
154 } | |
155 | |
156 // Return the highest address (exclusive) in the heap that this array covers. | |
157 HeapWord* end_address_mapped() const { | |
158 return (HeapWord*) ((uintptr_t)(this->bias() + this->length()) << this->shift_by()); | |
159 } | |
160 | |
161 protected: | |
162 virtual T default_value() const = 0; | |
163 // Set all elements of the given array to the given value. | |
164 void clear() { | |
165 T value = default_value(); | |
166 for (idx_t i = 0; i < length(); i++) { | |
167 set_by_index(i, value); | |
168 } | |
169 } | |
170 public: | |
171 G1BiasedMappedArray() {} | |
172 | |
173 // Allocate and initialize this array to cover the heap addresses in the range | |
174 // of [bottom, end). | |
175 void initialize(HeapWord* bottom, HeapWord* end, size_t mapping_granularity) { | |
176 G1BiasedMappedArrayBase::initialize(bottom, end, sizeof(T), mapping_granularity); | |
177 this->clear(); | |
178 } | |
179 }; | |
180 | |
181 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BIASEDARRAY_HPP |