Thu, 21 Aug 2014 16:44:41 +0200
8055098: WB API should be extended to provide information about size and age of object.
Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: Leonid Mesnik <leonid.mesnik@oracle.com>
1 /*
2 * Copyright (c) 2013, 2014, 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
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7 * published by the Free Software Foundation.
8 *
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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).
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1BiasedArray.hpp"
27 #include "memory/padded.inline.hpp"
29 // Allocate a new array, generic version.
30 address G1BiasedMappedArrayBase::create_new_base_array(size_t length, size_t elem_size) {
31 assert(length > 0, "just checking");
32 assert(elem_size > 0, "just checking");
33 return PaddedPrimitiveArray<u_char, mtGC>::create_unfreeable(length * elem_size);
34 }
36 #ifndef PRODUCT
37 void G1BiasedMappedArrayBase::verify_index(idx_t index) const {
38 guarantee(_base != NULL, "Array not initialized");
39 guarantee(index < length(), err_msg("Index out of bounds index: "SIZE_FORMAT" length: "SIZE_FORMAT, index, length()));
40 }
42 void G1BiasedMappedArrayBase::verify_biased_index(idx_t biased_index) const {
43 guarantee(_biased_base != NULL, "Array not initialized");
44 guarantee(biased_index >= bias() && biased_index < (bias() + length()),
45 err_msg("Biased index out of bounds, index: "SIZE_FORMAT" bias: "SIZE_FORMAT" length: "SIZE_FORMAT, biased_index, bias(), length()));
46 }
48 void G1BiasedMappedArrayBase::verify_biased_index_inclusive_end(idx_t biased_index) const {
49 guarantee(_biased_base != NULL, "Array not initialized");
50 guarantee(biased_index >= bias() && biased_index <= (bias() + length()),
51 err_msg("Biased index out of inclusive bounds, index: "SIZE_FORMAT" bias: "SIZE_FORMAT" length: "SIZE_FORMAT, biased_index, bias(), length()));
52 }
54 class TestMappedArray : public G1BiasedMappedArray<int> {
55 protected:
56 virtual int default_value() const { return 0xBAADBABE; }
57 public:
58 static void test_biasedarray() {
59 const size_t REGION_SIZE_IN_WORDS = 512;
60 const size_t NUM_REGIONS = 20;
61 HeapWord* fake_heap = (HeapWord*)LP64_ONLY(0xBAAA00000) NOT_LP64(0xBA000000); // Any value that is non-zero
63 TestMappedArray array;
64 array.initialize(fake_heap, fake_heap + REGION_SIZE_IN_WORDS * NUM_REGIONS,
65 REGION_SIZE_IN_WORDS * HeapWordSize);
66 // Check address calculation (bounds)
67 assert(array.bottom_address_mapped() == fake_heap,
68 err_msg("bottom mapped address should be " PTR_FORMAT ", but is " PTR_FORMAT, p2i(fake_heap), p2i(array.bottom_address_mapped())));
69 assert(array.end_address_mapped() == (fake_heap + REGION_SIZE_IN_WORDS * NUM_REGIONS), "must be");
71 int* bottom = array.address_mapped_to(fake_heap);
72 assert((void*)bottom == (void*) array.base(), "must be");
73 int* end = array.address_mapped_to(fake_heap + REGION_SIZE_IN_WORDS * NUM_REGIONS);
74 assert((void*)end == (void*)(array.base() + array.length()), "must be");
75 // The entire array should contain default value elements
76 for (int* current = bottom; current < end; current++) {
77 assert(*current == array.default_value(), "must be");
78 }
80 // Test setting values in the table
82 HeapWord* region_start_address = fake_heap + REGION_SIZE_IN_WORDS * (NUM_REGIONS / 2);
83 HeapWord* region_end_address = fake_heap + (REGION_SIZE_IN_WORDS * (NUM_REGIONS / 2) + REGION_SIZE_IN_WORDS - 1);
85 // Set/get by address tests: invert some value; first retrieve one
86 int actual_value = array.get_by_index(NUM_REGIONS / 2);
87 array.set_by_index(NUM_REGIONS / 2, ~actual_value);
88 // Get the same value by address, should correspond to the start of the "region"
89 int value = array.get_by_address(region_start_address);
90 assert(value == ~actual_value, "must be");
91 // Get the same value by address, at one HeapWord before the start
92 value = array.get_by_address(region_start_address - 1);
93 assert(value == array.default_value(), "must be");
94 // Get the same value by address, at the end of the "region"
95 value = array.get_by_address(region_end_address);
96 assert(value == ~actual_value, "must be");
97 // Make sure the next value maps to another index
98 value = array.get_by_address(region_end_address + 1);
99 assert(value == array.default_value(), "must be");
101 // Reset the value in the array
102 array.set_by_address(region_start_address + (region_end_address - region_start_address) / 2, actual_value);
104 // The entire array should have the default value again
105 for (int* current = bottom; current < end; current++) {
106 assert(*current == array.default_value(), "must be");
107 }
109 // Set/get by index tests: invert some value
110 idx_t index = NUM_REGIONS / 2;
111 actual_value = array.get_by_index(index);
112 array.set_by_index(index, ~actual_value);
114 value = array.get_by_index(index);
115 assert(value == ~actual_value, "must be");
117 value = array.get_by_index(index - 1);
118 assert(value == array.default_value(), "must be");
120 value = array.get_by_index(index + 1);
121 assert(value == array.default_value(), "must be");
123 array.set_by_index(0, 0);
124 value = array.get_by_index(0);
125 assert(value == 0, "must be");
127 array.set_by_index(array.length() - 1, 0);
128 value = array.get_by_index(array.length() - 1);
129 assert(value == 0, "must be");
131 array.set_by_index(index, 0);
133 // The array should have three zeros, and default values otherwise
134 size_t num_zeros = 0;
135 for (int* current = bottom; current < end; current++) {
136 assert(*current == array.default_value() || *current == 0, "must be");
137 if (*current == 0) {
138 num_zeros++;
139 }
140 }
141 assert(num_zeros == 3, "must be");
142 }
143 };
145 void TestG1BiasedArray_test() {
146 TestMappedArray::test_biasedarray();
147 }
149 #endif